CN104807152B - The constant air capacity control of PM motor direct Power Controls and its HVAC system of application - Google Patents

The present invention discloses the constant air capacity control of PM motor direct Power Controls and its HVAC system of application, includes the following steps：Step A）Start electric machine controller and receive target air volume IN CFM；Step B）Corresponding function P=f (n) is obtained according to target air volume value IN CFM；Step C）Into direct Power Control permanent wind amount control model：Motor is controlled to reach an operating point stablized along the control track of function P=f (n)（pt,nt）；Step D）The real-time input power Pi of motor is calculated according to motor operating parameter, calculate Δ P=| Pt Pi |；Step E）If Δ P is less than setting value Pset, present working point is kept；Step F）If Δ P is more than or equal to setting value Pset, whether the operating time of calculating speed ring reaches, and as speed is not reaching to, keeps present working point；Step G）As the time has reached, admission velocity control loop governing speed realizes the new operating point on track（Pi, ni), even pt=Pi, nt=ni, returns to step C.It is especially suitable for the Boiler pressure control under stable state, and algorithm is succinct, of less demanding to CPU computings, and cost is relatively low, and control accuracy is higher.

The constant air capacity control of PM motor direct Power Controls and its HVAC system of application

Technical field：

The present invention relates to the constant air capacity control of variable speed electric motors, particularly, more particularly to the permanent wind amount of PM motor direct Power Controls Control method and its HVAC system of application and other variable speed electric motors, particularly systems.

Background technology：

PM motors, the abbreviation of direct current brushless permanent magnet synchronous motor, may also be referred to as ECM motors, because of PM motor use environments Difference, its control model is also different, generally has：Constant speed control, constant moment of force control and permanent Boiler pressure control etc., permanent Boiler pressure control exists HVAC (HVAC system) is more common pattern.

In the room ventilation pipeline of domestic air conditioning, static pressure often changes as time goes by, such as because pipeline Dust stratification or plugged filter.Static pressure also because the installation of pipeline is different and often higher than the nominal system in manufacturer laboratory when Standard static pressure.Permanent Boiler pressure control can bring constant air quantity to user in these cases, so that in extensive hydrostatic pressure condition The effect of the lower comfortable ventilation of maintenance, refrigeration or heating, and system operation is reached energy-efficient.

General constant air capacity control is to be mounted directly air volume meter, not only improves cost, is also brought potential because air quantity Meter failure causes control to fail, and current air-conditioning manufacturer also constant air capacity control of the generally use without air volume meter, what is had will monitor The change of static pressure carrys out speed governing, and some calculation formula are related to Logarithmic calculation or higher order polynomial, this needs electric machine controller MCU has more powerful computing capability, further increases cost.

United States Patent (USP) US4806833 is disclosed for exterior static pressure to change motor speed, to obtain permanent wind amount.It is exterior quiet The change of pressure is that the rotation speed change of the tachometer sensing carried by motor calculates, and Wind Coverage Calculation passes through torque and the letter of rotating speed Count to control；United States Patent (USP) US5736823a also discloses that a kind of constant air capacity control, and passes through torque and the letter of rotating speed Count to control.

The control method of above permanent wind amount uses torque, and as key control variable, there are following technical problem：

1) torque is a mechanical variables, it is difficult to measures and calculates it, can influence control accuracy；

2) Torque Control is chiefly used in the application of dynamic control, but the perseverance Boiler pressure control is a typical lower state control System, therefore be simultaneously not bery applicable in；

3) Torque Control is complex in motor control, and best example is that vector controlled realizes a good torque Control, but the precision of system torque control is limited be subject to the cost of system hardware and software；

4) torque is not one and allows consumer and governability, understands the characteristic parameter of the operation of system.

In other words：Torque is a mechanical variables, is not easy directly to measure and realizes permanent wind amount control as Variable Control with torque System, causes computing complicated, and cost is higher, and torque is difficult that the energy-saving and environment-friendly management advocated with government and standard are associated, It is not directly perceived.

The content of the invention：

The object of the present invention is to provide the constant air capacity control of PM motor direct Power Controls and its HVAC systems of application System and other variable speed electric motors, particularly systems, especially suitable for the Boiler pressure control under stable state, algorithm is succinct, of less demanding to CPU computings for it, Cost is relatively low, and control accuracy is higher, is conducive to the control of energy-saving and emission-reduction.

The purpose of the present invention is what is be achieved by following technical proposals.

The constant air capacity control of PM motor direct Power Controls, the PM motors are installed in HVAC system with driving Wind wheel rotates and has stator module, permanent magnet rotor component and, electric machine controller include motor operating parameter detection circuit and Microprocessor, it is characterised in that：It includes the following steps：

Step A) start electric machine controller, reception or default target air volume value IN-CFM；

Step B) electric machine controller contains in several target air volumes each target air volume and corresponds to a function P=f (n), corresponding permanent wind amount control function P=f (n) is obtained according to target air volume value IN-CFM, wherein n is rotating speed, and P is motor Input power, if external input target air volume value IN-CFM is not equal to one of them of several above-mentioned target air volumes, meter Calculation and the corresponding function P=f (n) of any external input target air volume value IN-CFM, realize whole arbitrary target air quantity Permanent Boiler pressure control；

Step C) enter direct Power Control permanent wind amount control model：The control for controlling motor to make it along function P=f (n) Track processed reaches an operating point (Pt, nt) stablized；Pt, nt are to be located to meet on the track of permanent wind amount control function P=f (n) A pair of of input power and rotating speed；

Step D) keep direct Power Control permanent wind amount control model：It is defeated in real time that motor is calculated according to motor operating parameter Enter power P i, calculate power increment value Δ P=| Pt-Pi |；

Step E) if power increment value Δ P is less than setting value P_set, keep present working point；

Step F) if power increment value Δ P is more than or equal to setting value P_set, power/rotating speed control logic is by calculating speed ring Operating time whether reach, if the operating time of speed ring is not reaching to, keep present working point；

Step G) if the operating time of speed ring has reached, admission velocity control loop presses Δ n=| ni-nt | adjust Speed, ni are real-time rotating speeds, realize the new operating point (Pi, ni) on track, even Pt=Pi, nt=ni, return to step C.

Motor operating parameter detection circuit described above includes bus current detection circuit and busbar voltage detection circuit, Bus current detection circuit and the real-time bus current I of busbar voltage detection electric circuit inspection_busWith real-time busbar voltage V_bus, motor reality When input power Pi=I_bus×V_bus。

Motor operating parameter detection circuit described above includes phase line current detection circuit and busbar voltage detection circuit, Phase line current detection circuit, busbar voltage detection electric circuit inspection phase current and busbar voltage data are input to microprocessor, in real time Phase current and real-time busbar voltage V_busAnd the electric current I α on alpha-beta coordinate, I β, voltage V α, V β are converted into, the real-time input work of motor Rate Pi=3/2 (I α V α+I β V β).

What function P=f (n) described above was obtained by：Initial data is first gathered, for several target air volumes, Adjusted always to high static pressure from low static pressure, this static pressure will can cover the actual static pressure scope of application, in the process of regulating static In, allow motor to be in constant speed control, and it is target to keep air quantity by regulation motor rotating speed n and the real-time input power Pi of motor Air quantity, and motor steady-state speed n and the real-time input power Pi of corresponding motor at this time are recorded, in this way, being directed to several targets Air quantity, all generates one group of rotating speed n and the real-time input power Pi of motor, then produces several mesh by the method for curve matching Mark each target air volume in air quantity and correspond to a function P=f (n).

If external input target air volume value IN-CFM is not equal to one of them of several above-mentioned target air volumes, can By interpolation method, the Fitting Calculation and the corresponding function P=f (n) of any external input target air volume value IN-CFM, to realize The permanent Boiler pressure control of whole arbitrary target air quantity.

The real-time input power Pi of motor described above is handled using wave digital lowpass filter, to real-time bus current I_bus, real-time busbar voltage V_busData acquisition when, handled using wave digital lowpass filter.

Functional relation P=f (n) described above is a polynomial function：P=C₁+C₂×n+...+C_m×n^m-1, its Middle C₁,C₂,…,C_mIt is coefficient, n is motor speed value, each target air volume corresponds to one group of C₁,C₂,…,C_mCoefficient simultaneously stores Come, microprocessor obtains corresponding one group of C according to the target air volume value IN-CFM of input by look-up table or interpolation method₁, C₂,…,C_mCoefficient, so as to obtain functional relation P=f (n).

Functional relation P=f (n) described above is a second order function：P=C₁+C₂×n+C₃×n²。

A kind of HVAC system of the constant air capacity control of PM motors direct Power Control described above, including PM motors and Wind wheel, wind wheel rotates and has stator module the driving of PM motors, permanent magnet rotor component and electric machine controller, PM motors pass through straight Connect Power Control and realize permanent Boiler pressure control.

A kind of variable speed electric motors, particularly system of the constant air capacity control of PM motors direct Power Control described above, including speed change Motor and wind wheel, variable speed electric motors, particularly driving wind wheel rotates and has stator module, rotor assembly and electric machine controller, variable speed electric motors, particularly Permanent Boiler pressure control is realized by direct Power Control.

Compared with prior art, the present invention have the effect that：1) target of several inputs is obtained using laboratory facilities Airflow value CFM_setCorresponding function P=f (n), is converted into corresponding motor using function P=f (n) according to motor speed n and inputs The calculated value Pt of power, detects real-time bus current I_busOr phase current and real-time busbar voltage V_bus, converse vector alpha-beta seat Electric current I α, the I β and voltage V α, V β put on, calculates the real-time input power Pi of motor, compares the calculated value of power input to machine Pt carries out closed-loop control with the real-time input power Pi of motor, it is especially suitable for the permanent Boiler pressure control under stable state, and precision is high, cost It is low；2) permanent wind amount of the invention is to directly control power input to a machine, and power input to machine is electric variable, and measurement is easily and accurate Really, power input to machine can be obtained by the DC bus-bar voltage of precision higher, DC bus current or phase current, directly The stable state control of Power Control suitable system, and Boiler pressure control is a typical stable state control problem in itself, thus both Matching somebody with somebody makes system more accurate and stablizes.Direct Power Control is to control to realize by motor speed, accurate high, cost It is low；3) the real-time input power Pi of motor is handled using wave digital lowpass filter, computational accuracy higher, and cost is lower.

Brief description of the drawings：

Fig. 1 is the structure diagram of traditional air conditioner draught fan system；

Fig. 2 is the scheme of installation of PM motors of the present invention；

Fig. 3 is the stereogram of PM motors of the present invention；

Fig. 4 is the stereogram of the electric machine controller of PM motors of the present invention；

Fig. 5 is the sectional view of PM motors of the present invention；

Fig. 6 is a kind of implementing circuit block diagram of the electric machine controller of one PM motors of the embodiment of the present invention；

Fig. 7 is the corresponding circuit diagrams of Fig. 6；

Fig. 8 is the control flow chart of the constant air capacity control of the embodiment of the present invention one；

Fig. 9 is that the present invention measures to obtain family's permanent wind amount matched curve by experiment；

Figure 10 is the fitting experimental data curve map of the PM motor direct Power Control permanent wind amounts of 1/3HP of the present invention；

Figure 11 is that the present invention solves any input air quantity fitting experimental data curve map using interpolation method

Figure 12 is the control logic figure of the constant air capacity control of the embodiment of the present invention one；

Figure 13 is a kind of control process schematic of the constant air capacity control of the embodiment of the present invention one；

Figure 14 is another control process schematic of the constant air capacity control of the embodiment of the present invention one；

Figure 15 is the test result figure by experimental verification of the constant air capacity control of the embodiment of the present invention one；

Figure 16 is a kind of implementing circuit block diagram of the electric machine controller of the PM motors of the embodiment of the present invention two；

Figure 17 is the corresponding circuit diagrams of Figure 12；

Figure 18 is the schematic diagram of the typical PM motor vector controlleds of traditional one；

Figure 19 is each coordinate system graph of a relation of the typical PM motor vector controlleds of traditional one；

Figure 20 is the control logic figure of the constant air capacity control of the embodiment of the present invention two；

Embodiment：

Below by specific embodiment and with reference to attached drawing, the present invention is described in further detail.

The present invention is as shown in Figure 1, in a typical ventilating duct for air-conditioner, is mounted with a blower system (as fired Steam stove or air processing machine), replaced with " motor+wind wheel " in figure, also have air filter in pipeline, when electric motor starting starts to rouse Wind, since the quantity of air outlet and air intake vent is related with room number, the design of pipeline is also without unified standard, while filter May also have different pressure drops, cause to carry traditional load motor --- the blower system of PSC motors is in different pipelines In, actual air quantity can be different.As shown in Fig. 2, 1) control of product is a HVAC controller, HVAC controller control is all The peripheral circuit and agreement configuration information of product operation device and the interface for passing through a customization are sent to PM electric machine controllers.2) Electric machine controller includes that a microprocessor --- microcontroller or DSP electron plates do motor control, it have a power unit to Controller each several part circuit provides electric power, and power supply is to set a DC bus-bar voltage and electric current.Therefore, the control of motor will be into Row power transmission.Low cost and the electric machine controller generally use parallel resistive circuit of batch production are as electric current and voltage sensor Hardware, controls motor driving actuating motor to control as the feedback of system, such as vector controlled, Direct Torque Control, and its The sensor or sensorless strategy of his type.It is well known that the change of any electronic building brick runtime, these changes are to influence Accuracy of detection and persistent reason.3) there are magnet body and structure on PM rotors, there are polyphase windings in stator side or groove. When the temperature is changed, permanent magnet and winding resistance can change, this may result in motor and controls different changes.Motor system The process of making generally produces also a degree of change, the aging of motor, new motor and old motor, the standard of the factor controlling of contribution True property and persistence, can be due to temperature change from the magnetic flux of the motor of magnet in time of life etc., demagnetization etc..It is in addition, electric The possibility risk of arbor failure, the security of system, and to detect or monitor in real time.4) air blower：Air blower is installed on motor On axis, the air-flow of generation is rotated with certain speed.The position of installation may influence to operate, increase friction, low discharge, even It is the direction of rotation of mistake.5) filter：Filter should regularly replace and maintenance service.But this is probably to lose very one section long The tracking of time.This will increase frictional influence stream pressure.6) pipe control：Pipe-line system may change due to dust and pipe The reason for road ruptures, Region control and ON/OFF wind port system pressure change.If do permanent wind amount according to actual conditions above Control can produce many unstable factors.

As shown in Fig. 3, Fig. 4, Fig. 5, PM motors are usually by electric machine controller 2 and motor monomer 1, the motor monomer 1 Including stator module 12, rotor assembly 13 and case component 11, stator module 13 is installed on case component 11, motor monomer 1 The Hall sensor 14 of detection rotor-position is installed, rotor assembly 13 is sleeved on inner side or the outside group of stator module 12 Into electric machine controller 2 includes control box 22 and the control circuit board 21 installed in the inside of control box 22, and control circuit board 21 is general Including power circuit, microprocessor, bus current detection circuit, inverter circuit and rotor position measurement circuit 14, (i.e. Hall passes Sensor), power circuit is powered for each several part circuit, and rotor position measurement electric circuit inspection rotor-position signal is simultaneously input to microprocessor The bus circuit of detection is input to microprocessor by device, bus current detection circuit, and busbar voltage detection circuit is by dc bus Control source controls each phase coil winding of stator module 12 to microprocessor, microprocessor control inverter circuit, inverter circuit Power on/off.

Embodiment one：

As shown in Figure 6, Figure 7, it is assumed that PM motors are 3 phase brushless direct current permanent magnetic synchronous motors, rotor position measurement circuit 14 General to use 3 Hall sensors, 3 Hall sensors detect the rotor-position in 360 degree of electrical angle cycle respectively, every turn The energization that 120 degree of electrical angles change each phase coil winding of a stator module 12 is crossed, forms 3 phase, 6 step control model.Exchange defeated Enter (AC INPUT) after the full-wave rectifying circuit being made of diode D7, D8, D9, D10, output is straight in one end of capacitance C1 Busbar voltage Vbus is flowed, DC bus-bar voltage Vbus is related with input ac voltage, and the voltage of exchange input (AC INPUT) is true After fixed, the line voltage UP of 3 phase windings is PWM copped wave output voltages, and UP=Vbus*w, w are that microprocessor is input to inverter circuit Pwm signal duty cycle, change line voltage UP can change DC bus current Ibus, inverter circuit is by electronic switching tube Q1, Q2, Q3, Q4, Q5, Q6 are formed, and the control terminal of electronic switching tube Q1, Q2, Q3, Q4, Q5, Q6 are respectively by microprocessor output 6 road pwm signals (P1, P2, P3, P4, P5, P6) control, and inverter circuit is also connected with resistance R1 and is used to detect bus current Ibus, female Line current detection circuit is transmitted to microprocessor after the detection bus current Ibus of resistance R1 is changed.Power input to machine controls Controlled by electronic switching tube Q7,1 road pwm signal -- i.e. P0 of microprocessor output, during controlling the conducting of electronic switching tube Q7 Between, to control power input to machine.

As shown in figure 8, the constant air capacity control of the PM motor direct Power Controls in HVAC system, the PM motors Driving wind wheel simultaneously has stator module, permanent magnet rotor component and electric machine controller, and the electric machine controller includes microprocessor Device, inverter circuit, rotor position measurement circuit, bus current detection circuit, busbar voltage detection circuit and power input to machine Control circuit (is not drawn into) in figure, and rotor position measurement electric circuit inspection rotor-position signal is simultaneously input to microprocessor, microprocessor Device calculates the real-time rotating speed n of motor according to rotor-position signal, and bus current is input to micro- place by bus current detection circuit Device is managed, DC bus-bar voltage is input to microprocessor, microprocessor control inverter circuit, inversion electricity by busbar voltage detection circuit The power on/off of each phase coil winding of road control stator module, microprocessor control power input to machine control circuit, its feature It is：It includes the following steps：

Step A) start electric machine controller, reception or default target air volume value IN-CFM；

Step B) according to the corresponding function P=f (n) of target air volume value IN-CFM acquisitions, wherein n is rotating speed, and P is motor Input power；

Step C) enter direct Power Control permanent wind amount control model：Start electricity when to control motor or motor speed be zero Machine, makes it reach an operating point (Pt, nt) stablized along the control track of function P=f (n)；Pt, nt are to be located to meet permanent wind Measure a pair of of input power and rotating speed on the track of control function P=f (n)；

Step D) keep direct Power Control permanent wind amount control model：It is defeated in real time that motor is calculated according to motor operating parameter Enter power P i；Calculate Δ P=| Pt-Pi |；

Step E) if power increment value Δ P is less than setting value P_set, keep present working point；

Step F) if power increment value Δ P is more than or equal to setting value P_set；Power/rotating speed control logic is by calculating speed ring Operating time whether reach；If the operating time of speed ring is not reaching to, present working point is kept；

Step G) if the operating time of speed ring has reached, admission velocity control loop presses Δ n=| ni-nt | adjust Speed, ni are real-time rotating speeds, realize the new operating point (Pi, ni) on track, even Pt=Pi, nt=ni, return to step C.

What function P=f (n) described above described above was obtained by：Initial data is first gathered, for several Target air volume, is adjusted to high static pressure always from low static pressure, this static pressure will can cover the actual static pressure scope of application, quiet adjusting During pressure, motor is allowed to be in constant speed control, and wind is kept by regulation motor rotating speed n and the real-time input power Pi of motor Measure as target air volume, and record motor steady-state speed n and the real-time input power Pi of corresponding motor at this time, if in this way, for Dry target air volume, all generates one group of rotating speed n and the real-time input power Pi of motor, is then produced by the method for curve matching Each target air volume corresponds to a function P=f (n) in several target air volumes.

If external input target air volume value IN-CFM described above is not equal to its of several above-mentioned target air volumes In one, interpolation method, the Fitting Calculation and any corresponding function P=f of external input target air volume value IN-CFM can be passed through (n).Realize the permanent Boiler pressure control of whole arbitrary target air quantity.

Functional relation P=f (n) described above is a polynomial function：P=C₁+C₂×n+...+C_m×n^m-1, its Middle C₁,C₂,…,C_mIt is coefficient, n is motor speed value, each target air volume corresponds to one group of C₁,C₂,…,C_mCoefficient simultaneously stores Come, microprocessor obtains corresponding one group of C according to the target air volume value IN-CFM of input by look-up table or interpolation method₁, C₂,…,C_mCoefficient, so as to obtain functional relation P=f (n).

It is a second order function to state the functional relation P=f (n)：P=C₁+C₂×n+C₃×n²。

Control method (the Direct P Control for Constant of the direct Power Control permanent wind amount of the present invention Airflow Control Apparatus Method) exploitation and mathematics model foundation be such：In general, it is logical at one Wind system, the stream air that wind turbine is produced by the motor-driven drivings of PM in a stable state.One constant air quantity control System is realized by the speed under a static pressure condition, Power Control, sees following relational expression：CFM=F (P, speed, Pressure), wherein CFM is air quantity, and P is power, and speed is speed, and pressure is static pressure.When the change of static pressure, The permanent wind amount is maintained with the control of power and speed.As static pressure increases, power changes therewith with speed.Cluster permanent wind amount CFM curves can test out, as shown in Figure 9.Based on these permanent wind amount CFM curves, Controlling model is developed, when the control of product is true Air quantity requirement is determined, by controlling power and speed to provide a constant wind quantity CFM in specific static pressure.In fig.9, characteristic Curve represents the permanent wind amount physical characteristic for keeping control power and speed, in the rated operating range of all motors, to any The air-conditioning producer of the air flow system of the design of type, test result and rate curve based on power, it can be deduced that conclusion, one Typical quadratic function can perform well in exploitation modeling and be used as a kind of typical function, P=C₁+C₂×n+C₃×n², pass through Three point to be located (A, B and C) of the person of choosing on curve, the data on its corresponding coordinate are (p1, n1), (p2, n2), (p3, n3) Coefficient C1, C2, C3 are obtained, sees equation below：

Pass throughandBy solving equation, m=3.

The process of curve matching is that selection multinomial describes curve, and polynomial coefficient can be asked by least square method Go out.P=C can be used in theory₁+C₂×n+C₃×n²+...+Cm×n^m-1, actually select binomial to meet general Need.Functional relation P=f (n) is a second order function：P=C₁+C₂×n+C₃×n², wherein C₁、C₂And C₃It is coefficient, n is Motor speed value, any one target air volume corresponds to one group of C in several target air volumes of test₁、C₂And C₃Coefficient simultaneously stores Get up, microprocessor obtains corresponding one group of C according to the target air volume value IN-CFM of input by look-up table₁、C₂And C₃Coefficient, So as to obtain functional relation P=f (n), each target air volume corresponds to one group of C in certain load₁、C₂And C₃Coefficient is specifically such as Shown in table 1 below：

Table 1

Figure 10 be 1/3HP PM motors small pipeline HVAC system direct Power Control permanent wind amount experimental data Matched curve figure, for a given target airflow, some typical air quantity CFM of Systematic selection establish one as test point Database is used for founding mathematical models.These typical points include minimum and maximum airflow value, some additional intermediate points according to Product specification, typical air quantity CFM have 5 as test point, are respectively 150/300/450/600 and 750CFM.

Table 2 shows an example of test data result.The scope of the rotating speed of motor is from 200 to 1400rpm；System Static pressure is from 0.1 to 1H₂O.Default permanent wind amount CCFM outputs are kept, obtain the power input to machine mark of a corresponding diagram 10 Value, forms a database.

Table 2

Using least square method, each predetermined CFM air quantity corresponds to the quadratic function of power and rotating speed, in standard What computational methods obtained：The power that these equations define and the speed of the operating point of any system in a specific static pressure Degree.When input setting air quantity IN-CFM is preset, electric system defines a corresponding function, and the track of its operating point is abided by Follow function definition.Equation (3) to (7) can be expressed as a normal equation, and C1, C2, C3 are constants.

Obtain P=C₁+C₂×n+C₃×n², equation (3) to (7) model curve provides several permanent wind amount CFM demands The track of 5 selection operating points, Power is power, and n is rotating speed.

As shown in figure 11, if request permanent wind amount IN-CFM requirement be not model curve one of those, use one kind Interpolation method obtains the permanent wind amount IN-CFM that a new characteristic equation is fitted the request, such as the permanent wind amount IN- when request CFM=525cfm requirements are received, and two neighboring curve CFM1-600cfm and CFM2-450cfm modeling can identify.Then two A corresponding equation can be used for the new equation for calculating IN-CFM=525cfm curves.Need-based IN-CFM=525cfm, Three selected speed omegas 1, ω 2, ω 3, determine to calculate performance number in these speed, corresponding using the two model curves For double power points in selected speed, linear weighted function interpolation can be used for calculating P values first equation

It is as follows to list matrix data.

For a pair of of power points (p_1i, p_2i) a selected speed omega is corresponded to, selected speed omega 1, ω 2, ω 3 correspond to 3 To power points (p_1i, p_2i), linear weighted function interpolation can be for calculating Pi values

Pi=p_2i+w.(p_1i-p_2i)。

Weighted value W is so calculated：

Pay attention to the CFM2≤IN-CFM≤CFM1, wait 0≤W≤1.Following matrix equation is computable,

The function P=C of so corresponding IN-CFM=525cfm₁+C₂×n+C₃×n²It can be obtained.Solve this matrix Equation, can calculate C1, C2, C3 coefficient.Therefore, any demand input air quantity IN-CFM can obtain power equation.By In this process be the microprocessor inside electric machine controller --- microcontroller initialization complete, so the calculating of power is not required to Consume more real-time cpu resource.

The real-time input power Pi of motor is handled using wave digital lowpass filter：The filtering of infinite impulse response filter The application of technology, it is assumed that output and input sampling within the sampling period (PWM switching frequencies).The sequence of power input represents (P_in1... P_ini..., P_inn) and the sequence of power output represent (Pout1 ... Pouti ..., Poutn), corresponding to the same time Point, then conduct can be contemplated in low-pass filter：

Wherein T：Time constant；

After above clause, recurrence relation, discrete time are given again, and low-pass filter can be expressed as exponential weighting shifting It is dynamic average.

p_outi=ap_ini+(1-a)·p_outi-1

Wherein

According to definition, smoothing factor 0≤α≤1.If α=0.5, then time constant is equal to the sampling period.If α ＜ ＜ 0.5, then time constant is significant to be more than the sampling interval.

Electric filtering is controlled in DPC, a≤0.01.So Δ t=a T.

It is that the pervious difference exported between input is proportional to be output to next change from a wave filter, this is flat The ratio of slip exponential damping is in continuous time system.As expected, being continuously increased with the time, discrete time is put down Factor-alpha reduction, and the sequence of power output are slided to represent that (Pout1 ... Pouti ..., Poutn) reaction is slow, it is defeated in power The sequence entered represents (P_in1... P_ini..., P_inn) therefore inertia of the system with higher.

This filtering technique can also be applied to DC bus-bar voltage, and two signal processings of DC bus current calculate.

As can be seen that this direct Power Control DPC (Direct Power Control) realizes work(using rotating speed control Rate controls.The function of power/rotating speed control logic is coordinating power/rotating speed loop time constant to ensure the stability of system. Control can be by controlling the accurate of motor to control, and direct torque compares.Either in scalar or vector controlled, speed control compared with The more effective of direct torque, improves control accuracy.

DPC controls are to carry out speed control by unique power and fans load speed characteristics.Motor from zero-turn speed to High rotating speed, power are also so from zero to increase.The rotating speed of motor will rise up to reaching a pair of of operating point A (power, speed), It is static pressure force, as shown in figure 13, when static pressure increases suddenly, under speed control mode, motor provides more work( Rate (or moment of torsion of bigger) keeps speed, since higher static pressure needs very big power requirement.Power can sharp rise to Higher, when electric system has reached " B " of a new operating point with identical speed, the algorithm will be appreciated by this whether Constant CFM geometric locuses operating point, so that it is determined that a pair of of power/speed point " C ".But C points are not a stable operating points, Due to high-power requirement, " D " point is then removed, repeatedly, waits " G " for converging to a new stable operating point, is terminated.

In force, when we can reduce power swing suddenly change, controlled by using restricted power increment. It shows that delta power can be designated as Δ P in fig. 14.As long as changed power exceedes power increment Δ P, speed control It will carry out speed control.In this fashion, all operating points are under corresponding permanent wind amount CFM one positive and negative bandwidth of geometric locus Work.Distinguished and admirable control system in static pressure change transient process is stable.

As shown in figure 15, above-mentioned motor direct Power Control constant air capacity control and algorithm are in our PM motor controls Tested on device processed, all system performances, meet requirement as shown in figure 15.

Figure 12 is logic diagram of this algorithm in the control application of PM motors scalar, and input power is by DC bus-bar voltage, electricity Stream calculation obtains power and rotating speed and will be limited in maximum power P_max, and rotating speed n_maxWithin.

The real-time input power value Pi of motor is calculated by DC bus current/voltage of feedback, then according to external input Air quantity IN-CFM matched with power/speed data, obtain the calculated value Pt of power input to machine, compare power input to machine Calculated value Pt and the real-time output power Pi of motor, obtain difference power Δ P, and difference power Δ P is limited, and avoids difference power Δ P excessive, It is larger to adjust power swing.Difference power Δ P is exported by power/speed control logic, carries out speed ring control, PWM frequency converters Carry out rotating speed control

Embodiment two：The maximum difference of the present embodiment and embodiment one be on：The meter of the real-time input power Pi of motor Calculate, embodiment 1 is controlled using scalar, that is, gathers real-time bus current I_busMotor is calculated with real-time busbar voltage to input in real time Power P=I_bus×V_bus.But the PM motors of the present embodiment are using the vector controlled of no sensor, the real-time input power Pi's of motor Calculate complex.

As shown in Figure 16, Figure 17, it is assumed that PM motors are the 3 mutually brushless straight of the vector controlled based on no-rotor position sensor Permanent magnet synchronous motor is flowed, the phase current of phase current sensing electric circuit inspection stator winding is then input to microprocessor, microprocessor The flow observer of the inside calculates the rotating speed n and rotor-position of rotor according to the electric current and DC bus-bar voltage of phase.Exchange input (AC INPUT) exports direct current after the full-wave rectifying circuit being made of diode D7, D8, D9, D10, in one end of capacitance C1 Busbar voltage Vbus, DC bus-bar voltage Vbus are the side of a typical vector controlled with input ac voltage in relation to Figure 18 Block diagram.

As described in Figure 19, it is the coordinate system figure of a typical vector controlled, vector controlled is in textbook and patent text Present and be documented, so herein It is not necessary to narration.Know the rotating speed of target of control, it is possible to real using vector controlled Existing closed-loop control.There are 3 coordinate systems in figure, a fixed cartesian coordinate system (alpha-beta coordinate), one is rotor rotational coordinates (d-q axis coordinate systems), one is stator magnetic flux rotating coordinate system (ds-qs axis coordinate systems).In figure, ω represents spinner velocity, and θ is The rotation angle of d-q axis coordinate systems and alpha-beta coordinate, δ is the rotary load angle of d-q axis coordinate systems and ds-qs axis coordinate systems.Therefore The vector current and vector voltage of d-q axis coordinate systems can be converted to the electric current and voltage of alpha-beta coordinate system.

In Figure 16, Figure 17 in vector controlled, motor operating parameter detection circuit includes phase current sensing circuit and busbar Voltage detecting circuit, phase current sensing circuit, busbar voltage detection electric circuit inspection phase current and busbar voltage data are input to micro- Processor, real-time phase current and real-time busbar voltage V_busAnd electric current I α, I β, voltage V α, V β on α β coordinates are converted into, electricity The real-time input power Pi=3/2 of machine (I α × V α+I β × V β)

As shown in figure 20, in ensorless control PM electric systems, the logic diagram of DPC constant air capacity controls Input power calculates the filtered rear Power Control flux observers that are used for of this power of by vector controlled and estimates rotor speed and turn Sub- position, then matched with power/speed data according to externally input air quantity IN-CFM, be converted into using function P=f (n) The calculated value Pt of corresponding power input to machine, compares the calculated value Pt and the real-time output power Pi of motor of power input to machine, Difference power Δ P is obtained, difference power Δ P is limited, and avoids difference power Δ P excessive, and it is larger to adjust power swing.Difference power Δ P leads to Overpower/speed control logic output, carries out speed ring control, and speed ring control is achieved by vector controlled.

1. The constant air capacity control of 1.PM motor direct Power Controls, the PM motors are installed in HVAC system to drive wind Wheel rotates and has stator module, permanent magnet rotor component and electric machine controller, and the electric machine controller includes motor operation Electrical parameter detection circuit and microprocessor, it is characterised in that：It includes the following steps：

   Step A) start electric machine controller, reception or default target air volume value IN-CFM；

   Step B) electric machine controller contains in several target air volumes each target air volume and corresponds to a function P=f (n), root Corresponding permanent wind amount control function P=f (n) is obtained according to target air volume value IN-CFM, wherein n is rotating speed, and P is the input work of motor Rate, if external input target air volume value IN-CFM is not equal to one of them of several above-mentioned target air volumes, calculates and appoints What corresponding function P=f (n) of external input target air volume value IN-CFM, realizes the permanent wind amount of whole arbitrary target air quantity Control；

   Step C) enter direct Power Control permanent wind amount control model：Control motor makes it along the control rail of function P=f (n) Mark reaches an operating point (Pt, nt) stablized；Pt, nt are a pair of on the track of permanent wind amount control function P=f (n) positioned at meeting Input power and rotating speed；

   Step D) keep direct Power Control permanent wind amount control model：The real-time input work of motor is calculated according to motor operating parameter Rate Pi, calculates power increment value Δ P=| Pt-Pi |；

   Step E) if power increment value Δ P is less than setting value P_set, keep present working point；

   Step F) if power increment value Δ P is more than or equal to setting value P_set, power/rotating speed control logic is by the behaviour of calculating speed ring Make whether the time reaches, if the operating time of speed ring is not reaching to, keep present working point；

   Step G) if the operating time of speed ring has reached, admission velocity control loop presses Δ n=| ni-nt | adjust speed Degree, ni is real-time rotating speed, realizes the new operating point (Pi, ni) on track, even Pt=Pi, nt=ni, returns to step C.

2. 2. the constant air capacity control of PM motors direct Power Control according to claim 1, it is characterised in that：Motor is transported Row electrical parameter detection circuit includes bus current detection circuit and busbar voltage detection circuit, bus current detection circuit and busbar electricity Detection circuit is pressed to detect real-time bus current I_busWith real-time busbar voltage V_bus, the real-time input power Pi=I of motor_bus×V_bus。

3. 3. the constant air capacity control of PM motors direct Power Control according to claim 1, it is characterised in that：Motor is transported Row electrical parameter detection circuit includes phase line current detection circuit and busbar voltage detection circuit, phase line current detection circuit, busbar electricity Pressure detection circuit detection phase current and busbar voltage data are input to microprocessor, real-time phase current and real-time busbar voltage V_bus And the electric current I α on alpha-beta coordinate, I β, voltage V α, V β are converted into, the real-time input power Pi=3/2 of motor (I α V α+I β V β)。

4. 4. the constant air capacity control of the PM motor direct Power Controls according to claim 1 or 2 or 3, it is characterised in that： What function P=f (n) described above was obtained by：Initial data is first gathered, for several target air volumes, from low static pressure Adjust always and arrive high static pressure, this static pressure wants the actual static pressure scope that can cover application, during regulating static, allows motor Controlled in rotating speed, and it is target air volume to keep air quantity by regulation motor rotating speed n and the real-time input power Pi of motor, and record The real-time input power Pi of motor steady-state speed n and corresponding motor at this time, in this way, being directed to several target air volumes, produces The one group of rotating speed n and real-time input power Pi of motor, is then produced every in several target air volumes by the method for curve matching One target air volume corresponds to a function P=f (n).

5. 5. the constant air capacity control of PM motors direct Power Control according to claim 4, it is characterised in that：It is if outer Portion input target air volume value IN-CFM is not equal to one of them of several above-mentioned target air volumes, passes through interpolation method, fitting Calculating and the corresponding function P=f (n) of any external input target air volume value IN-CFM, realize whole arbitrary target air quantity Permanent Boiler pressure control.

6. 6. the constant air capacity control of PM motors direct Power Control according to claim 2, it is characterised in that：Motor is real When input power Pi handled using wave digital lowpass filter, to real-time bus current I_bus, real-time busbar voltage V_busNumber During according to collection, handled using wave digital lowpass filter.

7. 7. the constant air capacity control of PM motors direct Power Control according to claim 4, it is characterised in that：Above-mentioned institute The functional relation P=f (n) stated is a polynomial function：P=C₁+C₂×n+...+C_m×n^m-1, wherein C₁,C₂,…,C_mIt is Coefficient, n are motor speed values, each target air volume corresponds to one group of C₁,C₂,…,C_mCoefficient simultaneously stores, microprocessor root Corresponding one group of C is obtained by look-up table or interpolation method according to the target air volume value IN-CFM of input₁,C₂,…,C_mCoefficient, so that Obtain functional relation P=f (n).

8. 8. the constant air capacity control of PM motors direct Power Control according to claim 7, it is characterised in that：Function closes It is that formula P=f (n) is a second order function：P=C₁+C₂×n+C₃×n²。

9. It is 9. a kind of using the constant air capacity control of PM motors direct Power Control described in claim 1 to 8 any one HVAC system, including PM motors and wind wheel, PM motors driving wind wheel rotates and has stator module, permanent magnet rotor component and electricity Machine controller, PM motors realize permanent Boiler pressure control by direct Power Control.

10. A kind of 10. change using the constant air capacity control of PM motors direct Power Control described in claim 1 to 8 any one Speed motor system, including variable speed electric motors, particularly and wind wheel, variable speed electric motors, particularly driving wind wheel rotate and there is stator module, rotor assembly and Electric machine controller, variable speed electric motors, particularly realize permanent Boiler pressure control by direct Power Control.