CN111490705A - H-bridge drive and closed-loop speed regulation control circuit design - Google Patents

本发明涉及嵌入式系统设计、电子电路设计和H桥电路设计以及控制方法技术领域，特别涉及一种H桥驱动和闭环调速控制电路设计，可以实现大功率的直流电机正反转换向控制、调速和保护控制功能。系统包括MCU100主控单元，光电隔离单元200，H桥短路保护逻辑单元300，H桥驱动单元400，混合电路H桥500单元，电压采集保护单元600。本发明的有益效果为：解决了现有技术中H桥控制逻辑容易出错，单片机复位期间引脚状态不确定，会造成同臂导通，形成短路的问题；而且解决了大功率H桥的桥臂构成问题以及大功率的在线电流检测困难的问题。

The invention relates to the technical field of embedded system design, electronic circuit design, H-bridge circuit design and control method, in particular to the design of an H-bridge drive and closed-loop speed regulation control circuit, which can realize forward and reverse conversion control of high-power DC motors, Speed regulation and protection control functions. The system includes MCU100 main control unit, optoelectronic isolation unit 200, H-bridge short-circuit protection logic unit 300, H-bridge drive unit 400, hybrid circuit H-bridge unit 500, and voltage acquisition protection unit 600. The beneficial effects of the invention are as follows: in the prior art, the control logic of the H-bridge is prone to errors, and the pin state is uncertain during the reset of the single-chip microcomputer, which will lead to the conduction of the same arm and form a short circuit; and the bridge of the high-power H-bridge is solved. The problem of arm configuration and the difficulty of high-power online current detection.

一种H桥驱动和闭环调速控制电路设计Design of an H-bridge drive and closed-loop speed control circuit

技术领域technical field

本发明涉及嵌入式系统设计、电子电路设计和H桥电路设计以及控制方法技术领域，特别涉及一种H桥驱动和闭环调速控制电路设计。The invention relates to the technical field of embedded system design, electronic circuit design, H bridge circuit design and control method, in particular to an H bridge drive and closed-loop speed regulation control circuit design.

背景技术Background technique

H桥常应用于逆变电流和直流电机控制电路，本发明的直流电机驱动和控制调速电路可以被广泛应用于大功率直流电机的驱动和控制应用系统中。H桥首先要解决同臂导通问题，如附图1 H桥电路原理图所示，H桥有四个桥臂构成，每个桥臂均由开关器件和控制回路组成，左桥上臂开关K1和控制端CTR1，右桥上臂开关K2和控制端CTR2，右桥下臂开关K3和控制端CTR3，左桥下臂开关K4和控制端CTR4。K1和K3闭合，同时 K2和K4断开，形成正向回路。K1和K3断开，同时 K2和K4闭合，形成反向回路。控制逻辑出现问题，或者单片机复位期间引脚状态不确定的问题，会造成同臂导通，形成短路。H bridges are often used in inverter current and DC motor control circuits, and the DC motor drive and control speed regulation circuit of the present invention can be widely used in high-power DC motor drive and control application systems. The H-bridge must first solve the same-arm conduction problem. As shown in the schematic diagram of the H-bridge circuit in Figure 1, the H-bridge consists of four bridge arms, each of which is composed of a switching device and a control loop. The upper arm of the left bridge switches K1 And control terminal CTR1, right bridge upper arm switch K2 and control terminal CTR2, right bridge lower arm switch K3 and control terminal CTR3, left bridge lower arm switch K4 and control terminal CTR4. K1 and K3 are closed, while K2 and K4 are open, forming a forward loop. K1 and K3 are disconnected, while K2 and K4 are closed, forming a reverse loop. There is a problem with the control logic, or the pin state is uncertain during the reset of the microcontroller, which will cause the same arm to be turned on and form a short circuit.

其次大功率H桥要解决桥臂的构成问题，桥臂常用的开关器件有继电器，三极管，MOS管，IGBT等。继电器属机械器件，开关次数有限，开关速度比较慢。MOS 管属于电压驱动型器件，对于NMOS来说，只要栅极电压高于源极电压即可实现NMOS的饱和导通，MOS管开启与关断的能量损失仅是对栅极和源极之间的寄生电容的充放电，对MOS管驱动端要求不高。同时MOS端可以做到很大的电流输出，因此可以用于需要大电流的场所。Secondly, the high-power H-bridge should solve the problem of the composition of the bridge arm. The commonly used switching devices of the bridge arm are relays, triodes, MOS tubes, IGBTs, etc. Relays are mechanical devices with limited switching times and relatively slow switching speeds. The MOS tube is a voltage-driven device. For NMOS, as long as the gate voltage is higher than the source voltage, the saturated conduction of the NMOS can be achieved. The charging and discharging of the parasitic capacitance of the MOS tube is not high on the driving end of the MOS tube. At the same time, the MOS terminal can achieve a large current output, so it can be used in places that require a large current.

由NMOS管构成的H桥中，要打开由NMOS构成的 H 桥的上管，必须处理好A点(也就是上管的S极)“悬浮”的问题。由于NMOS的S 极一般接地，被称为“浮地”。要使上管NMOS打开，必须使上管的G 极相对于浮地有10-15V的电压差，这就需要采用升压电路。In the H-bridge composed of NMOS tubes, to open the upper tube of the H-bridge composed of NMOS tubes, the problem of "floating" point A (that is, the S pole of the upper tube) must be handled well. Since the S pole of NMOS is generally grounded, it is called "floating ground". To turn on the NMOS of the upper tube, the G pole of the upper tube must have a voltage difference of 10-15V relative to the floating ground, which requires a boost circuit.

发明专利CN110112966A1提出一种H桥控制电路，其特点是左桥上臂和右桥上臂由1个智能功率开关组成，左桥下臂和右桥下臂由1个NMOS管组成。该发明充分利用了智能功率开关提供各种检测功能。但是没有同臂导通解决方法，H桥输出的电流由1个NMOS管决定，电机正反转电流检测需要对智能功率开关2个点分别进行检测，占用资源多。Invention patent CN110112966A1 proposes an H bridge control circuit, which is characterized in that the upper arm of the left bridge and the upper arm of the right bridge are composed of an intelligent power switch, and the lower arm of the left bridge and the lower arm of the right bridge are composed of an NMOS tube. The invention makes full use of the intelligent power switch to provide various detection functions. However, there is no solution for the same arm conduction. The output current of the H bridge is determined by one NMOS tube. The detection of the forward and reverse current of the motor needs to detect two points of the intelligent power switch respectively, which occupies a lot of resources.

发明专利CN103872956B提出H桥四个桥臂均由多个半桥并联组成，实际为2个半桥并联。该专利每个并联的半桥由独立的引脚控制，占用控制引脚多。同时该发明左桥上臂和右桥上臂采用N沟道MOS管，均需要升压电路控制，发明中没有提及，而只是描述计算单元“113”和“123”为用于控制半桥的晶体管。Invention patent CN103872956B proposes that the four bridge arms of the H-bridge are composed of multiple half-bridges in parallel, and actually two half-bridges are connected in parallel. In this patent, each parallel half-bridge is controlled by an independent pin, which occupies a lot of control pins. At the same time, the upper arm of the left bridge and the upper arm of the right bridge of the invention use N-channel MOS transistors, both of which need booster circuit control, which is not mentioned in the invention, but only describes the calculation units "113" and "123" as transistors used to control the half-bridge .

大功率的在线电流检测也是当前大功率H桥驱动的一个难题。发明专利CN110112966A1的电流检测是智能功率开关提供的，检测电流小，电机正反转电流检测需要对智能功率开关2个点分别进行检测，占用资源多。High-power online current detection is also a difficult problem in the current high-power H-bridge drive. The current detection of the invention patent CN110112966A1 is provided by the intelligent power switch, and the detection current is small. The detection of the forward and reverse current of the motor needs to detect two points of the intelligent power switch respectively, which occupies a lot of resources.

对此，需要设计一种新的H桥驱动和闭环调速控制电路，以解决上述问题。In this regard, it is necessary to design a new H-bridge drive and closed-loop speed control circuit to solve the above problems.

发明内容SUMMARY OF THE INVENTION

本发明为了弥补现有技术中的不足，同时充分利用成熟的先进技术，提供了一种H桥驱动和闭环调速控制电路设计。In order to make up for the deficiencies in the prior art and at the same time make full use of mature advanced technologies, the present invention provides an H-bridge drive and closed-loop speed regulation control circuit design.

本发明是通过如下技术方案实现的：The present invention is achieved through the following technical solutions:

一种H桥驱动和闭环调速控制电路设计，系统包括MCU100主控单元，光电隔离单元200，H桥短路保护逻辑单元300，H桥驱动单元400，混合电路H桥500单元，电压采集保护单元600，构成一套完成的H桥驱动和闭环控制调速系统。An H-bridge drive and closed-loop speed control circuit design, the system includes a MCU100 main control unit, an optoelectronic isolation unit 200, an H-bridge short-circuit protection logic unit 300, an H-bridge drive unit 400, a hybrid circuit H-bridge unit 500, and a voltage acquisition protection unit 600, constitute a complete set of H-bridge drive and closed-loop control speed regulation system.

进一步地，为了更好的实现本发明，所述MCU100主控单元是系统控制核心，包括4类模块，采用程序和算法实现系统的闭环控制。第一类模块是PWM脉宽调制输出模块PWM101和PWM102，主要作用是通过后级电路实现混合电路H桥500单元左下臂和右下臂的驱动和调速控制。第二类模块是GPIO通用IO口输出模块REL103，其主要（1）实现混合电路H桥500单元的上桥臂，即并联继电器组的控制；（2）与PWM101和PWM102一起通过H桥短路保护逻辑单元300产生混合电路H桥500单元的驱动信号，实现H桥的短路保护。第三类模块是ADC数模变换输入模块，作用是将来经过电压采集保护单元600处理后的，来自混合电路H桥500单元的3个特征点VDD，M+和M-处的电压信号进行采样，从而得到电路H桥500单元的正向回路时的左桥上臂或者反向回路时的右桥上臂压差，根据上臂的闭合电阻，计算出实时正向电流或者反向电流。与串联电阻方法相比，输出的电流大。与电流互感方法相比，结构简单、成本低。第四类模块是COM107数字通信模块，该类模块与其他智能控制系统进行通信，即可以接收控制命令，又可以将整个系统的状态信息传输给其他智能控制系统。Further, in order to better realize the present invention, the main control unit of the MCU100 is the system control core, including four types of modules, and the closed-loop control of the system is realized by using programs and algorithms. The first type of modules is the PWM pulse width modulation output module PWM101 and PWM102, the main function is to realize the drive and speed control of the lower left arm and the lower right arm of the hybrid circuit H-bridge 500 unit through the post-stage circuit. The second type of module is the GPIO general IO port output module REL103, which mainly (1) realizes the upper bridge arm of the hybrid circuit H-bridge 500 unit, that is, the control of the parallel relay group; (2) together with PWM101 and PWM102, through the H-bridge short circuit protection The logic unit 300 generates a drive signal for the unit of the H-bridge 500 of the hybrid circuit, so as to realize the short-circuit protection of the H-bridge. The third type of module is the ADC digital-to-analog conversion input module. Its function is to sample the voltage signals at the three characteristic points VDD, M+ and M- of the hybrid circuit H-bridge 500 unit after being processed by the voltage acquisition protection unit 600 in the future. Thereby, the voltage difference between the upper arm of the left bridge and the upper arm of the right bridge during the forward loop of the circuit H-bridge 500 unit or the upper arm of the right bridge during the reverse loop is obtained, and the real-time forward current or reverse current is calculated according to the closed resistance of the upper arm. Compared with the series resistance method, the output current is large. Compared with the current mutual inductance method, the structure is simple and the cost is low. The fourth type of module is the COM107 digital communication module, which communicates with other intelligent control systems, that is, it can receive control commands and transmit the status information of the entire system to other intelligent control systems.

进一步地，为了更好的实现本发明，所述光电隔离单元由三组独立的光电隔离电路201、202和203组成，接收来自MCU100主控单元的PWM101、PWM102和REL103的输入，经过光电隔离后，输出OPT201、OPT202和REL203给后级单元H桥短路保护逻辑单元300。MCU100主控单元是系统控制核心，其控制程序和采样检测运行容易受到外部干扰而“跑飞”。光电隔离单元通过将MCU100主控单元与后级电路的隔离，实现对主控单元的光电隔离保护，提高主控单元工作的稳定性和可靠性。Further, in order to better realize the present invention, the optoelectronic isolation unit is composed of three groups of independent optoelectronic isolation circuits 201, 202 and 203, and receives the input of PWM101, PWM102 and REL103 from the main control unit of MCU100, and after optoelectronic isolation , and output OPT201, OPT202 and REL203 to the H-bridge short-circuit protection logic unit 300 of the subsequent unit. The main control unit of MCU100 is the core of the system control, and its control program and sampling detection operation are prone to "runaway" due to external interference. The photoelectric isolation unit realizes the photoelectric isolation protection of the main control unit by isolating the MCU100 main control unit from the subsequent circuit, and improves the stability and reliability of the main control unit.

进一步地，为了更好的实现本发明，所述H桥短路保护逻辑单元300由7个逻辑门电路组成，分别是非门301、二输入与非门302、二输入与门306和307、三输入或门303、三输入与非门304和三输入与门305构成。H桥短路保护逻辑单元300的作用是将独立的控制信号PWM101、 PWM102和REL103，通过逻辑门电路，产生具有互锁功能的输出RRO301和RRO302，从电路硬件方面避免混合电路H桥500单元同臂导通电源短路的故障的发生。Further, in order to better realize the present invention, the H-bridge short-circuit protection logic unit 300 is composed of 7 logic gate circuits, which are respectively a NOT gate 301, a two-input NAND gate 302, two-input AND gates 306 and 307, and a three-input AND gate. An OR gate 303 , a three-input NAND gate 304 and a three-input AND gate 305 are formed. The function of the H-bridge short-circuit protection logic unit 300 is to use the independent control signals PWM101, PWM102 and REL103 to generate outputs RRO301 and RRO302 with interlocking function through the logic gate circuit, so as to avoid the hybrid circuit H-bridge 500 unit from the same arm from the circuit hardware aspect Occurrence of a fault that turns on the power supply short-circuit.

进一步地，为了更好的实现本发明，所述H桥驱动单元400有三路独立的驱动电路401、402和403构成。每个驱动电路基本结构相同都是由三极管和PMOS管构成，电路参数根据不用的驱动要求而不同。其作用是将H桥短路保护逻辑单元300的输出PRO301、PRO302和REL203转换为混合电路H桥500单元的左桥下臂控制信号C1、右桥下臂控制信号C2和上桥臂控制信号RELC，实现H桥驱动和调速控制。Further, in order to better realize the present invention, the H-bridge driving unit 400 is composed of three independent driving circuits 401 , 402 and 403 . The basic structure of each driving circuit is the same, which is composed of triode and PMOS tube, and the circuit parameters are different according to different driving requirements. Its function is to convert the outputs PRO301, PRO302 and REL203 of the H bridge short circuit protection logic unit 300 into the left bridge lower arm control signal C1, the right bridge lower arm control signal C2 and the upper bridge arm control signal RELC of the hybrid circuit H bridge 500 unit. Realize H-bridge drive and speed control.

进一步地，为了更好的实现本发明，所述混合电路H桥500单元的左桥上臂和右桥上臂由单刀双掷并联继电器组501构成，左桥下臂和右桥下臂由并联结构NMOS管组502和503构成。500由这种配置能够充分发挥继电器和NMOS管的优点，上桥臂由继电器解决了上桥使用电子开关时的“浮地问题”。控制信号可以直接使用开关量，避免使用升压电路和自举电容，脉宽可以达到100%，简化了上桥臂控制信号的输出。下桥臂NMOS管组成，相比PMOS，NMOS控制简单，又可以实现PWM调速控制，并联结构的桥臂极大提高了H桥的输出电流。Further, in order to better realize the present invention, the upper arm of the left bridge and the upper arm of the right bridge of the hybrid circuit H-bridge 500 unit are composed of a single-pole double-throw parallel relay group 501, and the lower arm of the left bridge and the lower arm of the right bridge are composed of parallel structure NMOS. Tube groups 502 and 503 are formed. With this configuration, the 500 can give full play to the advantages of relays and NMOS tubes, and the upper bridge arm is made of relays to solve the "floating ground problem" when using electronic switches on the upper bridge. The control signal can directly use the switch value, avoid using the boost circuit and the bootstrap capacitor, and the pulse width can reach 100%, which simplifies the output of the upper bridge arm control signal. The lower bridge arm is composed of NMOS transistors. Compared with PMOS, NMOS control is simple, and PWM speed control can be realized. The bridge arm of the parallel structure greatly improves the output current of the H bridge.

进一步地，为了更好的实现本发明，所述电压采集保护单元600由三路结构相同而又独立的调理电路601、602和603组成，根据采样电压的不同，电路参数有所不同。H桥输出电流采用间接法获得，即电压采集保护单元600将混合电路H桥500单元三处特征点VDD，M+和M-处的电压，调理成MCU100主控单元ADC模块的输入信号，经主控单元采样并处理后，计算出H桥上臂的压差，根据上臂的闭合电阻，计算出实时正向电流或者反向电流。与串联电阻方法相比，输出的电流大。与电流互感方法相比，结构简单、成本低。Further, in order to better realize the present invention, the voltage acquisition protection unit 600 is composed of three independent conditioning circuits 601 , 602 and 603 with the same structure, and the circuit parameters are different according to different sampling voltages. The output current of the H-bridge is obtained by an indirect method, that is, the voltage acquisition and protection unit 600 adjusts the voltages at the three characteristic points VDD, M+ and M- of the H-bridge 500 unit of the hybrid circuit into the input signal of the ADC module of the main control unit of the MCU100. After sampling and processing by the control unit, the voltage difference of the upper arm of the H bridge is calculated, and the real-time forward current or reverse current is calculated according to the closed resistance of the upper arm. Compared with the series resistance method, the output current is large. Compared with the current mutual inductance method, the structure is simple and the cost is low.

本发明的有益效果是：The beneficial effects of the present invention are:

本发明可以被广泛应用于大功率直流电机的驱动和控制应用系统中，本发明中的MCU100主控单元的通信接口可以跟其他外部智能设备通信，接收外部控制命令，输入H桥的工作状态参数信息；光电隔离单元200将MCU100主控单元与后级单元隔离，提高MCU工作的可靠性，MCU复位期间IO口处于浮空输入状态，将MCU复位期间转换成确定的低电平，MCU正常工作时，光电耦合电路的输入和输出是同相的；H桥短路保护逻辑单元300的设计可以避免H桥同臂导通引起短路现象；H桥驱动单元400可以实现直流电机控制和调速功能；混合电路H桥500单元的配置能够充分发挥继电器和NMOS管的优点，上桥臂和下桥臂控制简单，既避免了H桥上臂的升压电路，又可以实现PWM调速控制，并联结构的桥臂极大提高了H桥的输出电流；电压采集保护单元600使H桥输出电流采用间接法获得，与串联电阻测流方法相比，克服了检测电路对串联电阻精度要求高，测量大直流电流时消耗功率大的难题，与电流互感方法相比，结构简单、成本低。The present invention can be widely used in driving and control application systems of high-power DC motors. The communication interface of the MCU100 main control unit in the present invention can communicate with other external intelligent devices, receive external control commands, and input the working state parameters of the H bridge. Information; the photoelectric isolation unit 200 isolates the main control unit of the MCU100 from the subsequent unit to improve the reliability of the MCU operation. During the MCU reset, the IO port is in the floating input state, and the MCU reset period is converted to a certain low level, and the MCU works normally. When the input and output of the photoelectric coupling circuit are in phase; the design of the H-bridge short-circuit protection logic unit 300 can avoid the short-circuit phenomenon caused by the conduction of the same arm of the H-bridge; the H-bridge drive unit 400 can realize the functions of DC motor control and speed regulation; hybrid The configuration of the circuit H-bridge 500 units can give full play to the advantages of relays and NMOS tubes, and the control of the upper and lower arms of the bridge is simple, which not only avoids the boost circuit of the upper arm of the H-bridge, but also realizes PWM speed control. The arm greatly improves the output current of the H-bridge; the voltage acquisition and protection unit 600 makes the H-bridge output current obtained by an indirect method. Compared with the series resistance current measurement method, it overcomes the detection circuit's high requirement for series resistance accuracy and measures large DC currents. Compared with the current mutual inductance method, the structure is simple and the cost is low.

本发明解决了现有技术中H桥控制逻辑容易出错，单片机复位期间引脚状态不确定，会造成同臂导通，形成短路的问题；而且解决了大功率H桥的桥臂构成问题以及大功率的在线电流检测困难的问题。The invention solves the problem that the control logic of the H-bridge in the prior art is prone to errors, and the pin state is uncertain during the reset of the single-chip microcomputer, which will lead to the conduction of the same arm and form a short circuit; and solves the problem of the structure of the bridge arm of the high-power H-bridge and the large The problem of online current detection of power is difficult.

附图说明Description of drawings

图1为本发明H桥驱动和闭环调速控制电路设计的整体结构图；Fig. 1 is the overall structure diagram of H-bridge drive and closed-loop speed control circuit design of the present invention;

图2为本发明H桥驱动和闭环调速控制电路设计的光电隔离单元原理图；Fig. 2 is the schematic diagram of the photoelectric isolation unit designed by the H-bridge drive and closed-loop speed control circuit of the present invention;

图3为本发明H桥驱动和闭环调速控制电路设计的H桥短路保护逻辑单元原理图；3 is a schematic diagram of the H-bridge short-circuit protection logic unit designed by the H-bridge drive and closed-loop speed regulation control circuit of the present invention;

图4为本发明H桥驱动和闭环调速控制电路设计的H桥驱动单元原理图；4 is a schematic diagram of the H-bridge drive unit designed by the H-bridge drive and closed-loop speed control circuit of the present invention;

图5为本发明H桥驱动和闭环调速控制电路设计的混合电路H桥单元原理图；5 is a schematic diagram of the hybrid circuit H-bridge unit designed by the H-bridge drive and closed-loop speed control circuit of the present invention;

图6为本发明H桥驱动和闭环调速控制电路设计的电压采集保护单元原理图。FIG. 6 is a schematic diagram of the voltage acquisition protection unit designed by the H-bridge drive and closed-loop speed regulation control circuit of the present invention.

具体实施方式Detailed ways

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述。显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例。通常在此处附图中描述和示出的本发明实施例的组件可以以各种不同的配置来布置和设计。The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

因此，以下对在附图中提供的本发明的实施例的详细描述并非旨在限制要求保护的本发明的范围，而是仅仅表示本发明的选定实施例。基于本发明的实施例，本领域技术人员在没有做出创造性劳动的前提下所获得的所有其他实施例，都属于本发明保护的范围。Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present invention.

图1-图6为本发明的一种具体实施例，该实施例为一种H桥驱动和闭环调速控制电路设计。FIG. 1 to FIG. 6 are a specific embodiment of the present invention, which is a design of an H-bridge drive and closed-loop speed regulation control circuit.

如图1所示，混合电路H桥500单元的左桥上臂和右桥上臂由单刀双掷并联继电器组501分时构成，左桥下臂和右桥下臂分别由并联结构NMOS管组502和503构成。每个继电器的线圈Coil两端分别接PIN5和PIN5，PIN1和PIN2是公共端COM。PIN3是常闭触点NC，电路原理图网络标号是M+。PIN4是常开触点NO，电路原理图网络标号是M-。上桥臂的端共同点COM连接于H桥供电电源的正极VDD，下桥臂NMOS管组的公共端S连接于地。继电器的常闭触点NC和常开触点NO由继电器的线圈Coil控制，Coil的控制电源为RELC，每个继电器线圈并联1个二极管，作用是释放线圈断电时的残余能量。当线圈Coil失电时，常闭触点NC闭合常开触点NO断开，此时代表H桥左桥上臂闭合，右桥上臂断开。当线圈得电时，常闭触点NC断开常开触点NO闭合，此时代表H桥左桥上臂断开，右桥上臂闭合。即继电器的常闭触点NC代表左桥上臂，继电器的常开触点NO代表右桥上臂，任意时刻的状态必定为其中一个闭合，另外一个断开。As shown in Figure 1, the upper left and right upper arms of the hybrid circuit H-bridge 500 are composed of SPDT parallel relay groups 501, and the lower left and right bridges are composed of parallel NMOS transistors 502 and 501, respectively. 503 composition. Both ends of the coil Coil of each relay are connected to PIN5 and PIN5 respectively, and PIN1 and PIN2 are the common terminal COM. PIN3 is a normally closed contact NC, and the network label of the circuit schematic diagram is M+. PIN4 is the normally open contact NO, and the network label of the circuit schematic diagram is M-. The terminal common point COM of the upper bridge arm is connected to the positive pole VDD of the H-bridge power supply, and the common terminal S of the NMOS transistor group of the lower bridge arm is connected to the ground. The normally closed contact NC and normally open contact NO of the relay are controlled by the coil Coil of the relay. The control power supply of the Coil is RELC. Each relay coil is connected in parallel with a diode to release the residual energy when the coil is powered off. When the coil Coil loses power, the normally closed contact NC is closed and the normally open contact NO is disconnected, which means that the upper arm of the left bridge of the H bridge is closed and the upper arm of the right bridge is disconnected. When the coil is energized, the normally closed contact NC is disconnected and the normally open contact NO is closed, which means that the upper arm of the left bridge of the H bridge is disconnected and the upper arm of the right bridge is closed. That is, the normally closed contact NC of the relay represents the upper arm of the left bridge, and the normally open contact NO of the relay represents the upper arm of the right bridge. The state at any time must be that one of them is closed and the other is open.

采用单刀双掷并联继电器组501分时构成H桥左桥上臂和右桥上臂的优势比较突出：1. 结构简单、成本低、占用PCB板面积小，大大节约了成本和PCB板的体积。2. 继电器控制简单。H桥左桥上臂和右桥上臂原理上可以采用MOS管来实现。PMOS管实现高端驱动较为方便，但是其导通电阻大，工作电流小，成本高，可选种类少。因此，在高端驱动中，通常还是使用NMOS管。NMOS管的导需要栅极电压大于源极电压10-15V，由于 NMOS的 S 极一般接地，被称为“浮地”。 要使H 桥的上桥臂NMOS 打开，必须使上管的 G 极相对于浮地有 10-15V的电压差，这就需要采用升压电路，控制电路较为复杂。采用继电器作为上桥臂避免了上述情况的发生。The advantages of using SPDT parallel relay group 501 to form the upper arm of the left bridge and the upper arm of the right bridge of the H bridge are more prominent: 1. The structure is simple, the cost is low, and the PCB board area is small, which greatly saves the cost and the volume of the PCB board. 2. The relay control is simple. In principle, the upper arm of the left bridge and the upper arm of the right bridge of the H bridge can be realized by using MOS tubes. It is more convenient to realize high-end driving of PMOS tube, but its on-resistance is large, the working current is small, the cost is high, and there are few options. Therefore, in the high-end drive, NMOS transistors are usually used. The conduction of the NMOS tube requires the gate voltage to be greater than the source voltage by 10-15V. Since the S pole of the NMOS is generally grounded, it is called "floating ground". To turn on the NMOS of the upper bridge arm of the H bridge, the G pole of the upper tube must have a voltage difference of 10-15V relative to the floating ground, which requires a boost circuit, and the control circuit is more complicated. The above situation is avoided by using the relay as the upper bridge arm.

并联结构NMOS管组502和503的控制电源为分别为C1和C2，C1和C2的大小相等。H桥供电电源VDD、继电器组工作电源RELC和NMOS管驱动C1相互独立，大小可以相同，也可以不同，提高了H桥供电的灵活性。The control power supplies of the NMOS transistor groups 502 and 503 in the parallel structure are respectively C1 and C2, and the sizes of C1 and C2 are equal. The H-bridge power supply VDD, the relay group working power supply RELC and the NMOS transistor drive C1 are independent of each other, and the size can be the same or different, which improves the flexibility of the H-bridge power supply.

并联结构NMOS管组502和503均由任意多个NMOS管及其驱动电路并联构成，502和503除了NMOS管的数量不同，结构完全相同。实例实施以左桥下臂为例，左桥下臂由X个NMOS管及其驱动电路并联构成，图中以X=4为例。Q13~Q16是NMOS管，NMOS管的源级S级直接并联后接GND，漏级D级直接并联后接常闭触点NC，即电路原理图的网络标号M+。Parallel structure NMOS transistor groups 502 and 503 are formed by parallel connection of any number of NMOS transistors and their driving circuits. Except for the difference in the number of NMOS transistors, 502 and 503 have the same structure. The example implementation takes the lower arm of the left bridge as an example. The lower arm of the left bridge is composed of X NMOS transistors and their driving circuits in parallel. In the figure, X=4 is taken as an example. Q13~Q16 are NMOS tubes. The source S stage of the NMOS tube is directly connected in parallel and then connected to GND, and the drain stage D is directly connected in parallel and then connected to the normally closed contact NC, that is, the network label M+ of the circuit schematic diagram.

每个NMOS管的栅极G级各接一个15V的保护稳压管到GND，即电路原理图中的D24~D27，保护二极管的主要作用是保护NMOS管的栅极和防止NMOS管的误导通。下桥臂NMOS管栅极也可以采用下拉电阻，即GS电阻来保护。但是如果GS电阻太小，则NMOS管驱动电流和驱动功率变大。电阻太大，则NMOS管的关闭时间增大。在某些特殊的应用场合下，比如对待机电流有限制的电池保护板，这个电阻往往取值很大甚至没有，这样栅极的阻抗会比较高，极易感应比较高的静电损坏NMOS管的栅极和防止NMOS管的误导通。采用15V的稳压管D24~D27，则会避免上述故障现象的发生。The gate G level of each NMOS tube is connected to a 15V protection voltage regulator tube to GND, that is, D24~D27 in the circuit schematic diagram. The main function of the protection diode is to protect the gate of the NMOS tube and prevent the misdirection of the NMOS tube. . The gate of the lower arm NMOS transistor can also be protected by a pull-down resistor, that is, a GS resistor. But if the GS resistance is too small, the drive current and drive power of the NMOS transistor become larger. If the resistance is too large, the turn-off time of the NMOS transistor increases. In some special applications, such as battery protection boards with limited standby current, this resistance is often very large or not, so the impedance of the gate will be relatively high, and it is easy to induce relatively high static electricity damage to the NMOS tube. gate and prevent mis-turning of NMOS transistors. The use of 15V voltage regulator tubes D24~D27 will avoid the occurrence of the above-mentioned faults.

每个NMOS管的栅极G级驱动各有一个栅极电阻和栅极二极管并联组成，即电路原理图中的R45~R48和D8~D11。每个NMOS管都由独立的栅极电阻隔离驱动，主要是可以防止各个MOS管的寄生振荡，起到阻尼的作用。R45~R48的取值受如下条件限制：如果取值过小，就起不到防止NMOS管寄生振荡的产生；如果取值过大，开关速度会变慢。另外，由于每个NMOS管的结电容会有稍微的不同，因此取值过大还会导致各个NMOS管的导通速度相差比较大。所以R45~R48在能够防止各个NMOS管的寄生振荡的情况下，尽量小到可以满足开关速度。栅极二极管的作用加快NMOS 管的关断速度。MOS 管的关断时间要比开启时间慢(开启充电，关断放电)，在栅极电阻上反向并联一个二极管，当 NMOS 管关断时，二极管导通，将栅极电阻短路从而减少放电时间。H桥控制逻辑真值表如表1所示，当C1和C2同时为“0”时，NMOS管组502和503断开，H桥输出断开。RELC=“0”，C1=“0”，C2=“1”时，继电器处于常闭状态，常闭触点NC接COM端，502断开，503闭合，H桥形成正向回路。电流经继电器常闭触点NC，负载直流电机M540和右桥下臂503到GND。同理，RELC=“1”，C1=“1”，C2=“0”时，H桥形成反向回路。The gate G-level drive of each NMOS transistor is composed of a gate resistor and a gate diode in parallel, that is, R45~R48 and D8~D11 in the circuit schematic diagram. Each NMOS tube is isolated and driven by an independent gate resistor, mainly to prevent parasitic oscillation of each MOS tube and play a damping role. The value of R45~R48 is limited by the following conditions: if the value is too small, it will not prevent the generation of parasitic oscillation of the NMOS tube; if the value is too large, the switching speed will be slower. In addition, since the junction capacitance of each NMOS transistor will be slightly different, if the value is too large, the conduction speed of each NMOS transistor will vary greatly. Therefore, under the condition of preventing the parasitic oscillation of each NMOS tube, R45~R48 should be as small as possible to meet the switching speed. The function of the gate diode accelerates the turn-off speed of the NMOS transistor. The turn-off time of the MOS tube is slower than the turn-on time (turn-on charging, turn-off discharge), and a diode is connected in anti-parallel to the gate resistor. When the NMOS tube is turned off, the diode is turned on and the gate resistor is short-circuited to reduce discharge. time. The truth table of the H-bridge control logic is shown in Table 1. When C1 and C2 are "0" at the same time, the NMOS transistor groups 502 and 503 are disconnected, and the H-bridge output is disconnected. When RELC=“0”, C1=“0”, and C2=“1”, the relay is in a normally closed state, the normally closed contact NC is connected to the COM terminal, 502 is disconnected, 503 is closed, and the H bridge forms a forward loop. The current passes through the relay normally closed contact NC, the load DC motor M540 and the lower arm 503 of the right bridge to GND. Similarly, when RELC = "1", C1 = "1", and C2 = "0", the H bridge forms a reverse loop.

H桥正向导通时，通过C2的PWM脉冲信号来控制NMOS管组503的导通，则能够调节直流电机的正向转速，PWM脉冲信号占空比越大，直流电机转速越高；同理，H桥反向导通时，通过C1的PWM脉冲信号来控制NMOS管组502的导通，则能够调节直流电机的正向转速，PWM脉冲信号占空比越大，直流电机转速越高。When the H bridge is conducting in the forward direction, the conduction of the NMOS transistor group 503 is controlled by the PWM pulse signal of C2, so that the forward speed of the DC motor can be adjusted. The larger the duty cycle of the PWM pulse signal, the higher the speed of the DC motor; , When the H bridge is reversely conducted, the conduction of the NMOS transistor group 502 is controlled by the PWM pulse signal of C1, and the forward speed of the DC motor can be adjusted. The larger the duty cycle of the PWM pulse signal, the higher the DC motor speed.

混合电路H桥500单元电路在器件选型和数量选择上，要求组成左桥上臂的并联继电器组的常闭触点NC的总负荷电流与右桥下臂NMOS管组503的总漏级直流电流Id一致，组成右桥上臂的并联继电器组的常闭触点NO的总负荷电流与左桥下臂NMOS管组502的总漏级直流电流Id一致。The hybrid circuit H bridge 500 unit circuit requires the total load current of the normally closed contacts NC of the parallel relay group of the upper arm of the left bridge and the total leakage DC current of the NMOS tube group 503 of the lower arm of the right bridge in terms of device selection and quantity selection. Id is the same, the total load current of the normally closed contacts NO of the parallel relay group forming the upper arm of the right bridge is the same as the total drain DC current Id of the NMOS transistor group 502 of the lower arm of the left bridge.

MCU100主控单元是实现H桥PWM调速控制的核心单元。MCU100的GPIO通用IO口输出模块REL103，经过光电隔离单元200的203模块，输出为REL203。MCU100的PWM信号输出模块PWM101、PWM102，分别经过光电隔离单元200的201模块和202模块，输出为OPT201和OPT202。The MCU100 main control unit is the core unit that realizes the H-bridge PWM speed control. The output module REL103 of the GPIO general IO port of the MCU100 passes through the module 203 of the photoelectric isolation unit 200, and the output is REL203. The PWM signal output modules PWM101 and PWM102 of the MCU100 pass through the modules 201 and 202 of the optoelectronic isolation unit 200 respectively, and the outputs are OPT201 and OPT202.

光电隔离单元200的作用是将MCU100主控单元的输出与后级单元进行隔离，避免MCU100主控单元受到后级电路干扰而损坏，或者程序跑飞。光电隔离单元200的201、202和203模块相互独立，结构和工作原理完全相同，输出和输入是同相的。以201模块为例，U1是光耦模块，由发光二极管和光控晶闸管构成。R1是光耦限流电阻，R4，R7和三极管Q1组成光耦的输入电路，输入电路工作电源电压为VCC1，与MCU100输出信号PWM101相匹配。R10组成光耦的输出电路，其工作电源电压为VCC2，与H桥短路保护逻辑单元300输入要求相匹配。R4电阻左侧输入信号为“0”时，三极管Q1截止，U1发光二极管截止。因此，U1的光控晶闸管截止，R10输出为“0”。R4电阻左侧输入信号为“1”时，三极管Q1导通，U1发光二极管导通。因此，U1的光控晶闸管导通，R10输出为“1”。因此，光电隔离单元200的输出和输入是同相的。即，REL103、PWM101和PWM102分别与REL203、OPT201和OPT202是同相的。The function of the optoelectronic isolation unit 200 is to isolate the output of the main control unit of the MCU100 from the post-stage unit, so as to prevent the main control unit of the MCU100 from being damaged by the interference of the post-stage circuit, or the program running away. The modules 201 , 202 and 203 of the optoelectronic isolation unit 200 are independent of each other, have the same structure and working principle, and the output and input are in phase. Taking the 201 module as an example, U1 is an optocoupler module, which is composed of light-emitting diodes and light-controlled thyristors. R1 is an optocoupler current-limiting resistor, R4, R7 and transistor Q1 form an optocoupler input circuit. The working power supply voltage of the input circuit is VCC1, which matches the MCU100 output signal PWM101. R10 constitutes the output circuit of the optocoupler, and its working power supply voltage is VCC2, which matches the input requirements of the H-bridge short-circuit protection logic unit 300. When the input signal on the left side of the R4 resistor is "0", the transistor Q1 is turned off, and the U1 light-emitting diode is turned off. Therefore, the light-controlled thyristor of U1 is turned off, and the output of R10 is "0". When the input signal on the left side of the R4 resistor is "1", the transistor Q1 is turned on, and the U1 light-emitting diode is turned on. Therefore, the light-controlled thyristor of U1 is turned on, and the output of R10 is "1". Therefore, the output and input of the opto-isolation unit 200 are in phase. That is, REL103, PWM101 and PWM102 are in phase with REL203, OPT201 and OPT202, respectively.

REL203、OPT201和OPT202通过H桥短路保护逻辑单元300产生互锁的短路保护输出PRO301和PRO302。REL203、PRO301和PRO302 通过H桥驱动单元400，最终产生混合电路H桥500单元的左桥上臂和右桥上臂单刀双掷并联继电器组501的驱动RELC、左桥下臂驱动信号C1和右桥下臂驱动信号C2，从而实现H桥的驱动和调速控制，同时实现了H桥的短路保护。The REL203, OPT201 and OPT202 generate interlocked short-circuit protection outputs PRO301 and PRO302 through the H-bridge short-circuit protection logic unit 300. REL203, PRO301 and PRO302 pass through the H-bridge drive unit 400, and finally generate the drive RELC of the left bridge upper arm and the right bridge upper arm SPDT parallel relay group 501 of the hybrid circuit H bridge unit 500, the drive signal C1 of the left bridge lower arm and the right bridge lower arm Arm drive signal C2, so as to realize the drive and speed control of the H-bridge, and at the same time realize the short-circuit protection of the H-bridge.

H桥驱动单元400单元由3组独立的模块401、402和403组成，这3个模块相互独立，结构和工作原理完全相同，只是电路参数不同。以401模块为例，驱动模块由输入三极管Q9、输出PMOS功率管Q5及其附属电路构成。R30、R38、R26和三极管Q9组成输入电路。功率管Q5、R34和电源VCC4组成输出电路。VCC4与左桥下臂驱动信号C1相匹配。The H-bridge drive unit 400 is composed of 3 groups of independent modules 401, 402 and 403. These 3 modules are independent of each other and have the same structure and working principle, but with different circuit parameters. Taking the 401 module as an example, the driving module is composed of an input transistor Q9, an output PMOS power transistor Q5 and its auxiliary circuits. R30, R38, R26 and transistor Q9 form the input circuit. Power tube Q5, R34 and power supply VCC4 form an output circuit. VCC4 matches the drive signal C1 of the lower arm of the left bridge.

R30电阻左侧输入信号为“0”时，三极管Q1截止，功率管Q5截止。C1=“0”。R30电阻左侧输入信号为“1”时，三极管Q1导通，功率管Q5导通。C1= VCC4 =“1”因此，H桥驱动单元400单元的输出和输入是同相的。即，REL203、OPT201和OPT202分别与RELC、C1和C2是同相的。When the input signal on the left side of the R30 resistor is "0", the transistor Q1 is turned off, and the power tube Q5 is turned off. C1 = "0". When the input signal on the left side of the R30 resistor is "1", the transistor Q1 is turned on, and the power tube Q5 is turned on. C1 = VCC4 = "1" Therefore, the output and input of the H-bridge driver unit 400 are in phase. That is, REL203, OPT201 and OPT202 are in phase with RELC, C1 and C2, respectively.

H桥短路保护逻辑单元300电路原理图如图3所示。根据上述对光电隔离单元200和H桥驱动单元400单元分析，因为REL103与REL203和RELC、OPT201与PWM102、OPT202与PWM102、PRO201与C1和PRO202与C2分别是同相的。因此H桥短路保护逻辑单元300其输入/输出真值表可简化为REL103、PWM101和 PWM102作为输入， C1和C2作为输出，如表2所示。The circuit schematic diagram of the H-bridge short-circuit protection logic unit 300 is shown in FIG. 3 . According to the above analysis of the photoelectric isolation unit 200 and the H-bridge drive unit 400, because REL103 and REL203 and RELC, OPT201 and PWM102, OPT202 and PWM102, PRO201 and C1, and PRO202 and C2 are in the same phase respectively. Therefore, the input/output truth table of the H-bridge short-circuit protection logic unit 300 can be simplified as REL103, PWM101 and PWM102 as inputs, and C1 and C2 as outputs, as shown in Table 2.

表2的第一列表示H桥短路保护逻辑单元300输入的3组信号REL103、PWM101和PWM102，第二列表示H桥短路保护逻辑单元300输出的2组信号C1、C2和H桥的动作状态。第三列表示没有“H桥短路保护逻辑单元300”的情况下，即C1= PWM101和C2=PWM102时的H桥的动作状态。由表2可以看出H桥短路保护逻辑单元300有效地避免了H桥同臂导通，造成电源VDD短路的问题的发生。The first column of Table 2 indicates the three groups of signals REL103, PWM101 and PWM102 input by the H-bridge short-circuit protection logic unit 300, and the second column indicates the two groups of signals C1, C2 and the H-bridge output by the H-bridge short-circuit protection logic unit 300. . The third column shows the operating state of the H-bridge when there is no "H-bridge short-circuit protection logic unit 300", that is, when C1=PWM101 and C2=PWM102. It can be seen from Table 2 that the H-bridge short-circuit protection logic unit 300 effectively avoids the occurrence of the problem that the H-bridge is connected to the same arm and causes the short circuit of the power supply VDD.

最后说明的是，以上实施例仅用以说明本发明的技术方案而非限制，本领域普通技术人员对本发明的技术方案所做的其他修改或者等同替换，只要不脱离本发明技术方案的精神和范围，均应涵盖在本发明的权利要求范围当中。Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention, as long as they do not depart from the spirit of the technical solutions of the present invention and The scope should be included in the scope of the claims of the present invention.