CN103424730A - Current transformer field calibration system - Google Patents

本发明提供的电流互感器现场校验系统，属于互感器检定技术领域。主要解决现有技术中对于特殊结构类互感器现场校验时抗干扰能力不高的问题。包括由开关电源组成的供电单元、测试接口单元和人机交互单元，其特点是：还包括控制及运算单元和变频单元，所述供电单元向人机交互单元及变频单元供电；变频单元向控制及运算单元供电并接受控制及运算单元的指令；所述人机交互单元包括显示模块、键盘模块和USB接口模块；所述测试接口单元包括电流互感器一次回路接口和二次回路接口；所述控制及运算单元包括采样模块、运算模块和保护模块；所述变频单元包括变频模块和滤波模块；保护模块接受运算模块指令接通或关闭测试电流。

The on-site verification system for a current transformer provided by the invention belongs to the technical field of transformer verification. It mainly solves the problem in the prior art that the anti-interference ability is not high during on-site calibration of transformers with special structures. It includes a power supply unit composed of a switching power supply, a test interface unit and a human-computer interaction unit, and its characteristics are: it also includes a control and calculation unit and a frequency conversion unit. The power supply unit supplies power to the human-computer interaction unit and the frequency conversion unit; the frequency conversion unit supplies power to the control and the operation unit supplies power and accepts the instructions of the control and operation unit; the human-computer interaction unit includes a display module, a keyboard module and a USB interface module; the test interface unit includes a current transformer primary circuit interface and a secondary circuit interface; the The control and operation unit includes a sampling module, an operation module and a protection module; the frequency conversion unit includes a frequency conversion module and a filter module; the protection module accepts instructions from the operation module to turn on or off the test current.

电流互感器现场校验系统On-site calibration system for current transformers

技术领域technical field

本发明属于互感器检定技术领域，具体涉及电流互感器现场校验系统。The invention belongs to the technical field of transformer verification, and in particular relates to a current transformer field verification system.

背景技术Background technique

特殊结构类互感器，包括GIS式电流互感器，套管式电流互感器及发电厂出口类电流互感器，由于其特殊的结构，例如GIS电流互感器、套管式电流互感器是封闭装置，其一次侧和二次侧从根部至引出端子部位具有几十至上百米的引线，引线产生的阻抗给电流互感器的一次侧和二次侧都增加了负荷，这就要求现场升流测试电流互感器时需要较大容量，给传统的测试方法检测电流互感器带来非常大的困难，同时也需要增加现场电源容量进行匹配。升流装置容量的大幅增加导致设备笨重、安装操作难等问题，且变电站现场电源容量有限，空间也有限制；因此，这类特殊结构的互感器的现场校验甚至不能正常进行。同时由于电力行业发展的需求，发电厂出口电流互感器、套管式、GIS式电流互感器的使用越来越多，因此急需解决该类电流互感器的测试问题。Special structure transformers, including GIS type current transformers, bushing type current transformers and power plant outlet type current transformers, due to their special structures, such as GIS current transformers and bushing type current transformers are closed devices, Its primary side and secondary side have dozens to hundreds of meters of lead wires from the root to the lead-out terminal. The impedance generated by the lead wires increases the load on both the primary side and the secondary side of the current transformer, which requires on-site current testing. The transformer needs a large capacity, which brings great difficulties to the traditional test method to detect the current transformer, and also needs to increase the on-site power supply capacity for matching. The large increase in the capacity of the current-raising device has led to problems such as bulky equipment and difficult installation and operation. Moreover, the on-site power supply capacity of the substation is limited and the space is also limited; therefore, the on-site calibration of transformers with this special structure cannot even be carried out normally. At the same time, due to the needs of the development of the power industry, more and more current transformers, bushing-type and GIS-type current transformers are used at the outlet of power plants, so it is urgent to solve the testing problems of such current transformers.

此外，目前对于电流互感器的现场校验普遍采用间接测试方法，此类方法相比于传统的比较测差法，具有传统方法无可比拟的优点和便利性，因而对于电流互感器的日常检验工作非常方便。In addition, at present, the indirect test method is generally used for the on-site calibration of current transformers. Work is very convenient.

但是在现场实际测试中发现，大部分采用间接测试原理的设备，存在以下三个不足：However, in the actual field test, it is found that most of the equipment using the indirect test principle has the following three deficiencies:

现场抗干扰能力不高：由于采用间接测试原理，大部分设备的输出信号及输入信号均为小信号，当现场干扰比较大时，往往造成测试结果不准确和不稳定。On-site anti-interference ability is not high: due to the indirect test principle, the output signals and input signals of most equipment are small signals. When the on-site interference is relatively large, the test results are often inaccurate and unstable.

无法测试GIS式及套管式电流互感器：虽然很多设备能实现对大部分电磁式电流互感器的现场校验，但是对于特殊结构的如GIS及套管式电流互感器并没有很好的解决办法，现场测试效果也不理想。Unable to test GIS-type and bushing-type current transformers: Although many devices can realize on-site calibration of most electromagnetic current transformers, there is no good solution for special structures such as GIS and bushing-type current transformers method, field test results are not satisfactory.

测试变比受限，对于发电机口的大变比及一些非标准变比的CT，目前绝大部分间接测试的设备采取的内置标准法均无法实现测试。The test transformation ratio is limited. For the large transformation ratio of the generator port and some non-standard transformation ratio CTs, the built-in standard method adopted by most indirect test equipment cannot realize the test.

实现对现场大部分电磁式电流互感器，包括GIS式和套管式电流互感器进行快速准确的误差检验，同时适用于运行电站强电场干扰的现实情况，实现准确稳定的测试效果，是现场测试主要研究的方向。Realize fast and accurate error inspection for most of the electromagnetic current transformers on site, including GIS type and bushing type current transformers. It is also suitable for the actual situation of strong electric field interference in operating power stations, and achieves accurate and stable test results. It is an on-site test The main research direction.

发明内容Contents of the invention

本发明的目的为了解决现有技术的问题，提供电流互感器现场校验系统。The object of the present invention is to provide a field calibration system for current transformers in order to solve the problems in the prior art.

本发明为解决上述技术问题而采取的技术方案是：The technical scheme that the present invention takes for solving the problems of the technologies described above is:

电流互感器现场校验系统，包括由开关电源组成的供电单元、测试接口单元和人机交互单元，其特点是：还包括控制及运算单元和变频单元，所述供电单元向人机交互单元及变频单元供电；变频单元向控制及运算单元供电；所述人机交互单元包括显示模块、键盘模块和USB接口模块；所述测试接口单元包括电流互感器一次回路接口和二次回路接口；所述控制及运算单元包括采样模块、运算模块和保护模块；所述变频单元包括变频模块和滤波模块；The current transformer on-site calibration system includes a power supply unit composed of a switching power supply, a test interface unit and a human-computer interaction unit. It is characterized in that it also includes a control and calculation unit and a frequency conversion unit. The frequency conversion unit supplies power; the frequency conversion unit supplies power to the control and computing unit; the man-machine interaction unit includes a display module, a keyboard module and a USB interface module; the test interface unit includes a current transformer primary loop interface and a secondary loop interface; the The control and operation unit includes a sampling module, an operation module and a protection module; the frequency conversion unit includes a frequency conversion module and a filter module;

所述人机交互单元以串口方式与控制及运算单元通信，传输测试输入参数、发送测试命令，并接收控制及运算单元上传的测试数据，显示、存储最终结果；The human-computer interaction unit communicates with the control and calculation unit through a serial port, transmits test input parameters, sends test commands, receives test data uploaded by the control and calculation unit, and displays and stores the final results;

所述控制及运算单元接收人机交互单元的测试参数及测试命令，向变频模块发出输出测试信号的指令；其中：采样模块采集滤波模块滤波后的信号，并传输给运算模块，运算模块对采集数据进行运算，得到测试参数及测试结果；保护模块接受运算模块指令接通或关闭测试电流。The control and operation unit receives the test parameters and test commands of the human-computer interaction unit, and sends an instruction to output the test signal to the frequency conversion module; wherein: the sampling module collects the signal filtered by the filter module and transmits it to the operation module, and the operation module performs the collection The data is calculated to obtain test parameters and test results; the protection module accepts the command of the calculation module to turn on or off the test current.

本发明与现有技术相比，具有以下有益效果：Compared with the prior art, the present invention has the following beneficial effects:

本发明中采用了变频单元，采取异频的方法，可以有效避免外界工频的干扰，特别是在一些不停电站点内，此种方式的抗干扰效果极为明显。In the present invention, the frequency conversion unit is adopted, and the method of different frequency can effectively avoid the interference of external power frequency, especially in some uninterrupted stations, the anti-interference effect of this method is very obvious.

附图说明Description of drawings

图1为本发明的结构原理示意图。Fig. 1 is a schematic diagram of the structure principle of the present invention.

图中：1—供电单元；2—人机交互单元；3—测试接口单元；4—控制及运算单元；5—变频单元。In the figure: 1—power supply unit; 2—human-computer interaction unit; 3—test interface unit; 4—control and calculation unit; 5—frequency conversion unit.

具体实施方式Detailed ways

如图1所示，电流互感器现场校验系统，包括由开关电源组成的供电单元1、测试接口单元3和人机交互单元2，其特点是：还包括控制及运算单元4和变频单元5，所述供电单元1向人机交互单元2及变频单元5供电；变频单元5向控制及运算单元4供电；所述人机交互单元2包括显示模块、键盘模块和USB接口模块；所述测试接口单元3包括电流互感器一次回路接口和二次回路接口；所述控制及运算单元4包括采样模块、运算模块和保护模块；所述变频单元5包括变频模块和滤波模块；As shown in Figure 1, the current transformer on-site calibration system includes a power supply unit 1 composed of a switching power supply, a test interface unit 3 and a human-computer interaction unit 2, and its characteristics are: it also includes a control and calculation unit 4 and a frequency conversion unit 5 , the power supply unit 1 supplies power to the human-computer interaction unit 2 and the frequency conversion unit 5; the frequency conversion unit 5 supplies power to the control and computing unit 4; the human-computer interaction unit 2 includes a display module, a keyboard module and a USB interface module; the test The interface unit 3 includes a current transformer primary loop interface and a secondary loop interface; the control and computing unit 4 includes a sampling module, a computing module and a protection module; the frequency conversion unit 5 includes a frequency conversion module and a filtering module;

所述人机交互单元2以串口方式与控制及运算单元4通信，传输测试输入参数、发送测试命令，并接收控制及运算单元上传的测试数据，显示、存储最终结果；The human-computer interaction unit 2 communicates with the control and calculation unit 4 in a serial port mode, transmits test input parameters, sends test commands, and receives test data uploaded by the control and calculation unit, and displays and stores the final results;

所述控制及运算单元4接收人机交互单元2的测试参数及测试命令，向变频单元5发出输出测试信号的指令；其中：采样模块采集滤波模块滤波后的信号，并传输给运算模块，运算模块对采集数据进行运算，得到测试参数及测试结果；保护模块接受运算模块指令接通或关闭测试电流。The control and calculation unit 4 receives the test parameters and the test order of the human-computer interaction unit 2, and sends an instruction for outputting a test signal to the frequency conversion unit 5; wherein: the sampling module collects the signal filtered by the filter module, and transmits it to the calculation module, and calculates The module performs operations on the collected data to obtain test parameters and test results; the protection module receives instructions from the operation module to turn on or off the test current.