阅读说明：本技术 一种基于cvt电容电流的谐波电压测量误差计算方法及装置 (Harmonic voltage measurement error calculation method and device based on CVT capacitance current ) 是由 张科 郭磊 原会静 董曼玲 丁国君 刘阳 张懂 耿成舟 白俊丽 张笑颜 于 2020-04-16 设计创作，主要内容包括：本申请涉及电能质量技术领域,具体涉及一种基于CVT电容电流的谐波电压测量误差计算方法,首先获取高、中压电容电流测量用电流互感器误差ε<Sub>I1</Sub>和ε<Sub>I2</Sub>,计算由电流互感器误差引起的第h次谐波电压测量误差ε<Sub>ih</Sub>；然后获取高压电容、中压电容容值偏差ε<Sub>C1</Sub>和ε<Sub>C2</Sub>,计算由电容容值变化引起的第h次谐波电压测量误差ε<Sub>ch</Sub>；最后根据ε<Sub>ih</Sub>和ε<Sub>ch</Sub>的计算结果,计算基于CVT电容电流的第h次谐波电压测量误差ε<Sub>h</Sub>。本发明的一种基于CVT电容电流的谐波电压测量误差计算方法,可用于分析电流互感器测量误差和电容容值偏差对谐波电压测量误差的影响,评估测量误差是否满足相关标准要求,进而通过优化设计提升该测量方法的准确性,为高压电网谐波测量提供一种新的技术手段,具有一定的经济效益。(The application relates to the technical field of electric energy quality, in particular to a harmonic voltage measurement error calculation method based on CVT (constant voltage transformer) capacitive current I1 And I2 calculating the h-th harmonic voltage measurement error caused by the current transformer error ih (ii) a Then, the capacitance value deviation of the high-voltage capacitor and the medium-voltage capacitor is obtained C1 And C2 calculating the h-th harmonic voltage measurement error caused by capacitance value change of the capacitor ch (ii) a Finally according to ih And ch based on the calculation result of (1), calculating the h-th harmonic voltage measurement error based on the CVT capacitance current h . The method for calculating the harmonic voltage measurement error based on the CVT capacitance current can be used for analyzing the influence of the measurement error of the current transformer and the capacitance value deviation on the harmonic voltage measurement error, evaluating whether the measurement error meets the relevant standard requirements, further improving the accuracy of the measurement method through the optimization design, and providing a method for measuring the harmonic wave of the high-voltage power gridThe new technical means has certain economic benefit.)

1. A harmonic voltage measurement error calculation method based on CVT capacitance current is characterized by comprising the following steps:

s1: obtaining current transformer error for measuring high-voltage capacitance current_I1And current transformer error for medium voltage capacitance current measurement_I2Calculating the h-th harmonic voltage measurement error caused by the current transformer error_ih；

S2: obtaining the capacitance value deviation of the high-voltage capacitor_C1And deviation of capacitance value of medium voltage capacitor_C2Calculating the h-th harmonic voltage measurement error caused by capacitance value change of the capacitor_ch；

S3: calculating an h-th harmonic voltage measurement error based on the CVT capacitor current according to the calculation results of the steps S1 and S2_h。

2. The CVT capacitance current based harmonic voltage measurement error calculation method of claim 1,_h＝_ih+_ch。

3. the CVT capacitance current based harmonic voltage measurement error calculation method of claim 2,

C₁is the rated capacitance value of the high-voltage capacitor, C₂Is the rated capacity value of the medium-voltage capacitor.

4. The CVT capacitance current based harmonic voltage measurement error calculation method of claim 2,

in the formula:

_C1＝(C_1s-C₁)/C₁，C_1sthe measured capacitance value of the high-voltage capacitor is obtained;

_C2＝(C_2s-C₂)/C₂，C_2sis the measured capacitance value of the medium voltage capacitor.

5. The CVT capacitance current based harmonic voltage measurement error calculation method of any one of claims 1-4,

current transformer error for measuring high-voltage capacitance current_I1Current transformer error for measuring medium-voltage capacitor current_I2And obtaining parameters of a nameplate of the current transformer.

6. The CVT capacitance current based harmonic voltage measurement error calculation method of any one of claims 3-4,

rated capacity C of high-voltage capacitor₁Rated capacitance value C of medium-voltage capacitor₂The measured capacitance value C of the high-voltage capacitor is obtained by the parameters of the nameplate of the CVT mutual inductor_1sMeasured capacitance value C of medium-voltage capacitor_2sAnd the CVT can be obtained through CVT parameter testing.

7. A harmonic voltage measurement error calculation apparatus based on CVT capacitance current, comprising:

a parameter acquisition module for acquiring the error of the current transformer for measuring the high-voltage capacitance current_I1Current transformer error for measuring medium-voltage capacitor current_I2Capacitance deviation of high-voltage capacitor_C1And deviation of capacitance value of medium voltage capacitor_C2；

A calculation module for calculating the h-th harmonic voltage measurement error caused by the current transformer error_ihH-th harmonic voltage measurement error caused by capacitance value change of capacitor_chAnd according to_ihAnd_chcalculating the h-th harmonic voltage measurement error based on the CVT capacitance current_h。

8. The CVT capacitance current based harmonic voltage measurement error calculation apparatus of claim 7 wherein the parameter acquisition module includes an actual parameter measurement module for obtaining a measured capacitance value of the high voltage capacitance and a measured capacitance value of the medium voltage capacitance by measuring a CVT transformer.

9. The CVT capacitance current based harmonic voltage measurement error calculation apparatus of claim 8, wherein the parameter acquisition module includes a data input unit that is capable of inputting a current transformer nameplate parameter, a CVT transformer nameplate parameter, and a CVT transformer actual measurement parameter via a keyboard.

Technical Field

The invention belongs to the technical field of power quality measurement, and particularly relates to a harmonic voltage measurement error calculation method based on CVT capacitance current.

Background

A Capacitance Voltage Transformer (CVT) is a voltage signal measuring device widely used in power systems at present. When the CVT is used for harmonic measurement, the variable ratio amplitude frequency and phase frequency characteristics of the CVT present serious nonlinearity, so that the harmonic measurement has large errors. Therefore, the national standard GB/T14549 + 1993 harmonic of electric energy quality public power grid is definitely specified: CVTs cannot be used for harmonic measurement.

Related researchers have proposed a harmonic voltage measurement method based on CVT capacitance current to solve the problem that the harmonic measurement error of the CVT is large. The principle of the method is as follows: 2 current transformers are arranged on the secondary side of the CVT, currents flowing through a high-voltage capacitor C1 and a medium-voltage capacitor C2 are measured respectively, harmonic analysis is carried out on the measured currents, and then primary side harmonic voltage is obtained through calculation according to capacitance reactance values of the capacitors. According to the measurement principle, when a current transformer has measurement errors or capacitance values have deviations, the harmonic measurement precision of the method is influenced. Therefore, it is necessary to calculate the harmonic voltage measurement error based on the CVT capacitance current, evaluate whether the measurement error meets the requirements of the relevant standards, and further improve the accuracy of the measurement method through the optimization design, thereby providing a new technical means for the harmonic measurement of the high-voltage power grid.

Disclosure of Invention

The invention aims to provide a CVT capacitance current-based harmonic voltage measurement error calculation method, which is used for analyzing the influence of a current transformer measurement error and capacitance value deviation on a harmonic voltage measurement error, evaluating whether the measurement error meets the relevant standard requirements, improving the accuracy of the measurement method through optimization design and providing a new technical means for high-voltage power grid harmonic measurement.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a harmonic voltage measurement error calculation method based on CVT capacitance current comprises the following steps:

s1: obtaining current transformer error for measuring high-voltage capacitance current_I1And current transformer error for medium voltage capacitance current measurement_I2Calculating the h-th harmonic voltage measurement error caused by the current transformer error_ih；

S2: obtaining the capacitance value deviation of the high-voltage capacitor_C1And deviation of capacitance value of medium voltage capacitor_C2Calculating the h-th harmonic voltage measurement error caused by capacitance value change of the capacitor_ch；

S3: calculating an h-th harmonic voltage measurement error based on the CVT capacitor current according to the calculation results of the steps S1 and S2_h。

Preferably, the method for calculating the harmonic voltage measurement error based on the CVT capacitance current of the present invention,_h＝_ih+_ch。

preferably, the present invention is based on harmonics of the CVT capacitance currentA method for calculating the error of voltage measurement,

C₁is the rated capacitance value of the high-voltage capacitor, C₂Is the rated capacity value of the medium-voltage capacitor.

Preferably, the method for calculating the harmonic voltage measurement error based on the CVT capacitance current of the present invention,

in the formula:

_C1＝(C_1s-C₁)/C₁，C_1sthe measured capacitance value of the high-voltage capacitor is obtained;

_C2＝(C_2s-C₂)/C₂，C_2sis the measured capacitance value of the medium voltage capacitor.

Preferably, the method for calculating the harmonic voltage measurement error based on the CVT capacitance current of the present invention,

current transformer error for measuring high-voltage capacitance current_I1Current transformer error for measuring medium-voltage capacitor current_I2And obtaining parameters of a nameplate of the current transformer.

Preferably, the method for calculating the harmonic voltage measurement error based on the CVT capacitance current of the present invention,

rated capacity C of high-voltage capacitor₁Rated capacitance value C of medium-voltage capacitor₂And obtaining the parameters of the nameplate of the CVT mutual inductor.

A CVT capacitance current based harmonic voltage measurement error calculation apparatus comprising:

a parameter acquisition module for acquiring the error of the current transformer for measuring the high-voltage capacitance current_I1Current transformer error for measuring medium-voltage capacitor current_I2Capacitance deviation of high-voltage capacitor_C1And deviation of capacitance value of medium voltage capacitor_C2；

A calculation module for calculating the h-th harmonic voltage measurement error caused by the current transformer error_ihCaused by capacitance variationH-th harmonic voltage measurement error_chAnd according to_ihAnd_chcalculating the h-th harmonic voltage measurement error based on the CVT capacitance current_h。

Preferably, the parameter obtaining module includes an actual parameter measuring module, and the actual parameter measuring module is configured to obtain an actual measured capacitance value of the high-voltage capacitor and an actual measured capacitance value of the medium-voltage capacitor by measuring a CVT transformer.

Preferably, the parameter obtaining module of the harmonic voltage measurement error calculation apparatus based on CVT capacitor current of the present invention comprises a data input unit, and the data input unit can input the name plate parameter of the current transformer, the name plate parameter of the CVT transformer, and the actual measurement parameter of the CVT transformer through a keyboard.

Preferably, the device for calculating the harmonic voltage measurement error based on the CVT capacitive current further comprises a nameplate scanning module, and the nameplate scanning module can record the parameters of the CVT mutual inductor by scanning the nameplate of the CVT mutual inductor.

The invention has the beneficial effects that: the method for calculating the harmonic voltage measurement error based on the CVT capacitor current is characterized in that the influence of the current transformer measurement error and the capacitance value deviation on the harmonic voltage measurement error is analyzed, whether the measurement error meets the relevant standard requirements or not is evaluated, the accuracy of the measurement method is improved through optimization design, a new technical means is provided for the harmonic measurement of a high-voltage power grid, and certain economic benefits are achieved.

Drawings

The technical solution of the present application is further explained below with reference to the drawings and the embodiments.

FIG. 1 is a schematic flow chart of a method for calculating a harmonic voltage measurement error based on CVT capacitance current according to the present invention;

fig. 2 is a technical schematic diagram of the harmonic voltage measurement method based on the CVT capacitor current of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be considered limiting of the scope of the present application. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art through specific situations.

The technical solutions of the present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.