技术领域Technical Field
本发明涉及电力系统继电保护技术领域，尤其涉及一种高压变频继电保 护装置的硬件测频电路。The present invention relates to the technical field of relay protection of electric power systems, and in particular to a hardware frequency measuring circuit of a high-voltage variable frequency relay protection device.
背景技术Background technique
目前，在电力系统继电保护领域都使用微机型保护产品，实现电力系统 的故障保护功能，其中系统的频率测量对微机型保护产品至关重要，不仅关 系到继电保护产品的数据采样计算，也影响到系统的稳定运行监测功能；同 时，对于目前的高压电动机一般都是采用变频启动、运行的方式，其最大的 特点为频率变化范围较宽，对频率采样要求较高。At present, microcomputer protection products are used in the field of power system relay protection to realize the fault protection function of the power system. Among them, the frequency measurement of the system is crucial to the microcomputer protection products. It is not only related to the data sampling and calculation of the relay protection products, but also affects the stable operation monitoring function of the system. At the same time, the current high-voltage motors generally adopt the variable frequency starting and operation mode. Its biggest feature is the wide frequency variation range and high frequency sampling requirements.
目前，现有的电力系统的继电保护装置采用的频率计算方法都是基于软 件算法实现的。目前，使用软件算法计算电力系统频率的方法，容易受到采 样波形上的干扰信号影响，尤其是在电力系统发生故障或高压电动机启动过 程、负载较大时，波形畸变较为严重，软件算法不能预知波形的畸变程度， 造成频率计算结果误差较大，影响到继电保护产品的功能。At present, the frequency calculation methods used by the existing power system relay protection devices are all based on software algorithms. At present, the method of using software algorithms to calculate the power system frequency is easily affected by the interference signal on the sampled waveform, especially when the power system fails or the high-voltage motor starts, and the load is large, the waveform distortion is more serious, and the software algorithm cannot predict the degree of waveform distortion, resulting in a large error in the frequency calculation result, affecting the function of the relay protection product.
发明内容Summary of the invention
为了解决电力系统继电保护产品频率采样不稳定可靠的问题，本发明提 供一种高压变频继电保护装置的硬件测频电路，使继电保护产品在系统发生 故障或运行异常时，能正确计算出系统的频率，提高继电保护产品的数据采 样精度、稳定性，进而改善产品的功能。In order to solve the problem of unstable and unreliable frequency sampling of relay protection products in power systems, the present invention provides a hardware frequency measurement circuit for a high-voltage variable-frequency relay protection device, so that the relay protection product can correctly calculate the frequency of the system when a system failure or abnormal operation occurs, thereby improving the data sampling accuracy and stability of the relay protection product and further improving the function of the product.
为达到上述目的，本发明提供了一种高压变频继电保护装置的硬件测频 电路，包括单相测频模块，单相测频模块接收对应电压互感器采集的二次电 压信号，进行频率测量；To achieve the above object, the present invention provides a hardware frequency measurement circuit for a high-voltage variable frequency relay protection device, including a single-phase frequency measurement module, which receives a secondary voltage signal collected by a corresponding voltage transformer to perform frequency measurement;
所述单相测频模块包括降压单元、整流单元、滤波单元、放大单元、光 耦以及测量单元；The single-phase frequency measurement module includes a step-down unit, a rectifier unit, a filter unit, an amplifier unit, an optical coupler and a measurement unit;
所述降压单元将电压互感器输出的二次电压信号进行降压后输入到整流 单元，所述整流单元整流为直流信号输出；所述滤波单元对所述直流信号进 行滤波，所述放大单元对滤波后的信号进行放大，经光耦隔离后输入到所述 测量单元；所述测量单元进行对输入信号进行频率测量。The step-down unit steps down the secondary voltage signal output by the voltage transformer and inputs it into the rectifier unit, and the rectifier unit rectifies it into a DC signal for output; the filter unit filters the DC signal, the amplification unit amplifies the filtered signal, and inputs it into the measurement unit after optical coupling isolation; the measurement unit measures the frequency of the input signal.
进一步地，单相测频模块为3个，分别连接到3相的电压互感器。Furthermore, there are three single-phase frequency measurement modules, which are respectively connected to the three-phase voltage transformers.
进一步地，所述降压单元为串联电阻分压。Furthermore, the voltage-reducing unit is a series resistor voltage divider.
进一步地，整流单元为四个二极管构成的全波整流桥。Furthermore, the rectifying unit is a full-wave rectifying bridge composed of four diodes.
进一步地，所述滤波单元包括电阻R1、电阻R2、电容C1和电容C2；电 阻R1的一端连接全波整流桥的一个输出端，电阻R1的另一端连接电容C1 的一端，电容C1的另一端全波整流桥的另一个输出端并接地；电阻R2的一 端连接C1的一端，另一端连接电容C2的一端；电容C2的另一端接地。Further, the filtering unit includes a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2; one end of the resistor R1 is connected to an output end of the full-wave rectifier bridge, the other end of the resistor R1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to another output end of the full-wave rectifier bridge and grounded; one end of the resistor R2 is connected to one end of C1, and the other end is connected to one end of the capacitor C2; the other end of the capacitor C2 is grounded.
进一步地，所述放大单元包括运算放大器、电阻R3和电阻R4；Further, the amplification unit includes an operational amplifier, a resistor R3 and a resistor R4;
电阻R3的一端连接电容C2的一端，电阻R3的另一端连接运算放大器的 正输入端，运算放大器的负输入端接地；所述电阻R4连接在运算放大器的正 输入端和输出端之间。One end of the resistor R3 is connected to one end of the capacitor C2, and the other end of the resistor R3 is connected to the positive input end of the operational amplifier, and the negative input end of the operational amplifier is grounded; the resistor R4 is connected between the positive input end and the output end of the operational amplifier.
进一步地，还包括二极管D2和限流电阻R5；所述二极管D2的正极连接 运算放大器的输出端，负极连接限流电阻R5的一端，限流电阻R5的另一端 连接光耦的正输入端。Furthermore, it also includes a diode D2 and a current limiting resistor R5; the positive electrode of the diode D2 is connected to the output end of the operational amplifier, the negative electrode is connected to one end of the current limiting resistor R5, and the other end of the current limiting resistor R5 is connected to the positive input end of the optical coupler.
进一步地，所述光耦的负输入端接地；所述光耦的正输出端连接测量单 元的输入端口，测量单元对输入信号的频率进行测量。Furthermore, the negative input terminal of the optocoupler is grounded; the positive output terminal of the optocoupler is connected to the input port of the measuring unit, and the measuring unit measures the frequency of the input signal.
本发明的上述技术方案具有如下有益的技术效果：The above technical solution of the present invention has the following beneficial technical effects:
本发明利用模拟电路把电力系统的频率信号，转换成处理器可直接处理 的数字信号，并且采用三种相同回路提高频率测量的稳定性、精度，而且还 能在系统发生故障时准确为处理器提供可靠的频率计算信号源，能实时、可 靠转换电力系统的频率变化。采用的模拟回路与数字回路的隔离方法，能进一步提高电路运行的稳定性与可靠性。The present invention uses analog circuits to convert the frequency signal of the power system into a digital signal that can be directly processed by the processor, and uses three identical circuits to improve the stability and accuracy of frequency measurement. It can also accurately provide a reliable frequency calculation signal source for the processor when a system failure occurs, and can convert the frequency change of the power system in real time and reliably. The isolation method of the analog circuit and the digital circuit can further improve the stability and reliability of the circuit operation.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1是单相硬件测频电路示意图。Figure 1 is a schematic diagram of a single-phase hardware frequency measurement circuit.
具体实施方式Detailed ways
为使本发明的目的、技术方案和优点更加清楚明了，下面结合具体实施 方式并参照附图，对本发明进一步详细说明。应该理解，这些描述只是示例 性的，而并非要限制本发明的范围。此外，在以下说明中，省略了对公知结 构和技术的描述，以避免不必要地混淆本发明的概念。In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.
图1是单相测频模块示意图。可单独测试某一相的电压频率，可采用三 个相同的单相测频模块分别测量3相的电压频率，防止某相接地造成频率采 样信号不稳定，也可提高频率计算的可靠性。Figure 1 is a schematic diagram of a single-phase frequency measurement module. The voltage frequency of a certain phase can be tested separately, and three identical single-phase frequency measurement modules can be used to measure the voltage frequency of the three phases respectively, to prevent the frequency sampling signal from being unstable due to the grounding of a certain phase, and to improve the reliability of frequency calculation.
所述单相测频模块包括降压单元、整流单元、滤波单元、放大单元、光 耦以及测量单元；所述降压单元将电压互感器输出的二次电压信号进行降压 后输入到整流单元，所述整流单元整流为直流信号输出；所述滤波单元对所 述直流信号进行滤波，所述放大单元对滤波后的信号进行放大，经光耦隔离 后输入到所述测量单元；所述测量单元进行对输入信号进行频率测量。The single-phase frequency measurement module includes a step-down unit, a rectifier unit, a filter unit, an amplifier unit, an optical coupler and a measuring unit; the step-down unit steps down the secondary voltage signal output by the voltage transformer and inputs it into the rectifier unit, and the rectifier unit rectifies it into a DC signal for output; the filter unit filters the DC signal, the amplifier unit amplifies the filtered signal, and inputs it into the measuring unit after optical coupler isolation; the measuring unit measures the frequency of the input signal.
降压单元包括降压电阻R8、R9，三相电压互感输出的二次电压信号U分 别经过降压电阻R8、R9接入全波整流桥，整流桥输出脉动的直流信号经过电 阻电容进行滤波，输出硬件测频电路基本电信号。滤波单元包括电阻R1、电 阻R2、电容C1和电容C2；电阻R1的一端连接全波整流桥的一个输出端，电 阻R1的另一端连接电容C1的一端，电容C1的另一端全波整流桥的另一个输 出端并接地；电阻R2的一端连接C1的一端，另一端连接电容C2的一端；电 容C2的另一端接地。The step-down unit includes step-down resistors R8 and R9. The secondary voltage signal U output by the three-phase voltage mutual inductance is connected to the full-wave rectifier bridge through the step-down resistors R8 and R9 respectively. The pulsating DC signal output by the rectifier bridge is filtered through the resistor and capacitor to output the basic electrical signal of the hardware frequency measurement circuit. The filtering unit includes resistor R1, resistor R2, capacitor C1 and capacitor C2; one end of the resistor R1 is connected to an output end of the full-wave rectifier bridge, the other end of the resistor R1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the other output end of the full-wave rectifier bridge and grounded; one end of the resistor R2 is connected to one end of C1, and the other end is connected to one end of the capacitor C2; the other end of the capacitor C2 is grounded.
输出的硬件测频电路基本电信号，放大单元包括运算放大器、电阻R3 和电阻R4；电阻R3的一端连接电容C2的一端，电阻R3的另一端连接运算 放大器的正输入端，运算放大器的负输入端接地；所述电阻R4连接在运算放 大器的正输入端和输出端之间。电阻R4调节放大器的放大倍数。The output hardware frequency measurement circuit basic electrical signal, the amplification unit includes an operational amplifier, a resistor R3 and a resistor R4; one end of the resistor R3 is connected to one end of the capacitor C2, the other end of the resistor R3 is connected to the positive input end of the operational amplifier, and the negative input end of the operational amplifier is grounded; the resistor R4 is connected between the positive input end and the output end of the operational amplifier. The resistor R4 adjusts the amplification factor of the amplifier.
运算放大器输出的信号经过反向二极管D2，再经限流电阻R5接入光耦 U1的发射极，作为光耦隔离器的驱动和判别信号。The signal output by the operational amplifier passes through the reverse diode D2, and then through the current limiting resistor R5 to the emitter of the optocoupler U1, serving as the driving and discrimination signal of the optocoupler isolator.
光耦U1的接收级经过限流电阻和电阻电容滤波回路，输出频率波峰波谷 的判别信号，判别信号可输入至微处理器的I/O引脚，电路采用两路隔离电 源供电，隔离模拟电路和数字电路。The receiving stage of the optocoupler U1 outputs a frequency peak and trough discrimination signal through a current limiting resistor and a resistor-capacitor filtering circuit. The discrimination signal can be input to the I/O pin of the microprocessor. The circuit is powered by two isolated power supplies to isolate the analog circuit and the digital circuit.
整流桥把交流的波峰波谷信号转换成脉动的直流信号，使后级电路不需 要正负双电源，也提高了产品的频率采样判别速度。The rectifier bridge converts the peak and trough signals of the AC into pulsating DC signals, so that the subsequent circuit does not need positive and negative dual power supplies, and also improves the frequency sampling and judgment speed of the product.
反向二极管采用快速二极管提高电路的可靠性，也可防止电信号反向倒 流。The reverse diode uses a fast diode to improve the reliability of the circuit and also prevent the electrical signal from flowing in reverse.
交流的电压信号经过整流桥输出脉动的直流信号，该脉动的直流信号经 过运算放大器比较放大回路输出到光耦隔离器件，为系统频率采样计算处理 器提供稳定和可靠的信号源。The AC voltage signal outputs a pulsating DC signal through a rectifier bridge. The pulsating DC signal is output to the optocoupler isolation device through an operational amplifier comparison amplification circuit, providing a stable and reliable signal source for the system frequency sampling calculation processor.
综上所述，本发明涉及一种高压变频继电保护装置的硬件测频电路，包 括单相测频模块，单相测频模块接收对应电压互感器采集的二次电压信号， 进行频率测量；降压单元将电压互感器输出的二次电压信号进行降压后输入 到整流单元，整流单元整流为直流信号输出；经滤波单元滤波，放大单元对 信号放大后，经光耦隔离输入到测量单元；测量单元进行对输入信号进行频率测量。采用三种相同回路可提高频率测量的稳定性、精度，而且还能在系 统发生故障时准确为处理器提供可靠的频率计算信号源，能实时、可靠转换 电力系统的频率变化。采用的模拟回路与数字回路的隔离方法，能进一步提 高电路运行的稳定性与可靠性。In summary, the present invention relates to a hardware frequency measurement circuit of a high-voltage variable frequency relay protection device, including a single-phase frequency measurement module, which receives a secondary voltage signal collected by a corresponding voltage transformer to perform frequency measurement; a step-down unit steps down the secondary voltage signal output by the voltage transformer and inputs it to a rectifier unit, which rectifies it into a DC signal for output; after filtering by a filter unit, the signal is amplified by an amplifier unit and then input to a measurement unit through optical coupling isolation; the measurement unit performs frequency measurement on the input signal. The use of three identical circuits can improve the stability and accuracy of frequency measurement, and can also accurately provide a reliable frequency calculation signal source for the processor when a system failure occurs, and can convert the frequency change of the power system in real time and reliably. The isolation method of the analog circuit and the digital circuit used can further improve the stability and reliability of circuit operation.
应当理解的是，本发明的上述具体实施方式仅仅用于示例性说明或解释 本发明的原理，而不构成对本发明的限制。因此，在不偏离本发明的精神和 范围的情况下所做的任何修改、等同替换、改进等，均应包含在本发明的保 护范围之内。此外，本发明所附权利要求旨在涵盖落入所附权利要求范围和 边界、或者这种范围和边界的等同形式内的全部变化和修改例。It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.
| Application Number | Priority Date | Filing Date | Title |
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| CN202011076926.0ACN112269056B (en) | 2020-10-10 | 2020-10-10 | A hardware frequency measurement circuit for high voltage variable frequency relay protection device |
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| CN202011076926.0ACN112269056B (en) | 2020-10-10 | 2020-10-10 | A hardware frequency measurement circuit for high voltage variable frequency relay protection device |
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| CN112269056Btrue CN112269056B (en) | 2024-04-12 |
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| CN202011076926.0AActiveCN112269056B (en) | 2020-10-10 | 2020-10-10 | A hardware frequency measurement circuit for high voltage variable frequency relay protection device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114578114A (en)* | 2022-02-28 | 2022-06-03 | 特变电工西安电气科技有限公司 | SVG power module bypass state detection circuit |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3991365A (en)* | 1974-10-31 | 1976-11-09 | Hewlett-Packard Company | Instantaneous frequency measurement system |
| CN201859177U (en)* | 2010-09-29 | 2011-06-08 | 南京安能电气控制设备有限公司 | Measurement module for low-frequency alternating current signal in relay protection device |
| CN103913659A (en)* | 2014-03-30 | 2014-07-09 | 河北工业大学 | Instantaneous protection tester and operation method thereof |
| CN204241562U (en)* | 2014-11-19 | 2015-04-01 | 瓮福（集团）有限责任公司 | A kind of frequency detection circuit based on LPC2132 microcontroller |
| CN209624682U (en)* | 2019-01-18 | 2019-11-12 | 华能瑞金发电有限责任公司 | A kind of electric system primary frequency control system frequency measuring device |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3991365A (en)* | 1974-10-31 | 1976-11-09 | Hewlett-Packard Company | Instantaneous frequency measurement system |
| CN201859177U (en)* | 2010-09-29 | 2011-06-08 | 南京安能电气控制设备有限公司 | Measurement module for low-frequency alternating current signal in relay protection device |
| CN103913659A (en)* | 2014-03-30 | 2014-07-09 | 河北工业大学 | Instantaneous protection tester and operation method thereof |
| CN204241562U (en)* | 2014-11-19 | 2015-04-01 | 瓮福（集团）有限责任公司 | A kind of frequency detection circuit based on LPC2132 microcontroller |
| CN209624682U (en)* | 2019-01-18 | 2019-11-12 | 华能瑞金发电有限责任公司 | A kind of electric system primary frequency control system frequency measuring device |
| Publication number | Publication date |
|---|---|
| CN112269056A (en) | 2021-01-26 |
| Publication | Publication Date | Title |
|---|---|---|
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