CN103760402B

CN103760402B - Voltage compensating method is affected based on the threephase potential transformer of D_dot principle and three-phase

Info

Publication number: CN103760402B
Application number: CN201410029535.1A
Authority: CN
Inventors: 汪金刚; 白云洁; 范禹邑; 朱丽云
Original assignee: Chongqing University
Current assignee: Chongqing Kang Feida Information Technology Co Ltd
Priority date: 2014-01-22
Filing date: 2014-01-22
Publication date: 2016-04-13
Anticipated expiration: 2034-01-22
Also published as: CN103760402A

Abstract

The invention provides a three-phase voltage transformer based on the D_dot principle and a three-phase influence voltage compensation method, wherein the three-phase voltage transformer includes a ring electrode I, a ring electrode II, an insulating support and a grounding capacitor, and the insulating support includes a semicircular support I , semicircle support II and support arm, support arm is arranged on the sidewall of semicircle support I, semicircle support II, and semicircle support I, semicircle support II are concentrically arranged to form a through hole for the conductor to pass through, ring electrode I 1. The ring electrode II is arranged concentrically, and is respectively embedded in the semicircle support I and the semicircle support II. The ring electrode I and the ring electrode II are connected in series with the grounding capacitor and the ground through wires. The three-phase voltage transformer of the present invention has small volume and simple structure , good insulation performance and measurement safety, etc., the three-phase influence voltage compensation method of the present invention analyzes the mutual influence between the three-phase lines during measurement, so as to obtain measured values close to the real situation.

Description

Three-phase voltage transformer and three-phase influence voltage compensation method based on D_dot principle

技术领域technical field

本发明涉及电力设备技术领域，尤其涉及一种基于D_dot原理的三相电压互感器及三相影响电压补偿方法。The invention relates to the technical field of power equipment, in particular to a three-phase voltage transformer based on the D_dot principle and a three-phase influence voltage compensation method.

背景技术Background technique

传统的电压互感器包括：电磁式电压互感器、电容式电压互感器和电子式传感器，等等。其中电磁式电压互感器存在绝缘难度大和易产生铁磁谐振等问题，其中电容式电压互感器由于带许多储能元件，瞬变响应特性差，需要在二次回路加装阻尼装置以改善瞬变响应特性，其中电子式传感器存在测量误差大等问题。Traditional voltage transformers include: electromagnetic voltage transformers, capacitive voltage transformers and electronic sensors, etc. Among them, the electromagnetic voltage transformer has problems such as difficult insulation and easy to generate ferromagnetic resonance. Among them, the capacitive voltage transformer has poor transient response characteristics due to many energy storage components, and it is necessary to install a damping device in the secondary circuit to improve the transient. Response characteristics, among which electronic sensors have problems such as large measurement errors.

因此，基于D_dot原理的电压传感器（简称：D_dot传感器）由于采用电荷感应原理实现测量，而非能量传递，因此可以实现无接触测量，将其应用于高电压等级的变电站内时，可以使得二次侧几乎没有任何电流输出，实现二次侧安全检测的同时，保证对一次侧不造成影响，并且由于整个传感器不存在电感性的器件，避免了传感器产生的铁磁谐振的威胁，等等。Therefore, the voltage sensor based on the D_dot principle (abbreviation: D_dot sensor) uses the principle of charge induction to achieve measurement instead of energy transfer, so it can achieve non-contact measurement. When it is applied to a high-voltage substation, it can make secondary There is almost no current output on the secondary side, while realizing the safety detection of the secondary side, it is guaranteed not to affect the primary side, and because the entire sensor does not have inductive devices, the threat of ferromagnetic resonance generated by the sensor is avoided, and so on.

具体的，基于D_dot原理的电压传感器具体是采用电荷感应原理，通过测量与测量电极相连的接地匹配电阻上的输出电压，来测量与该输出电压积分量成正比的导体附近的电位移矢量，从而得到导体电压的时域波形，由于其输出电压与电位移矢量对时间的微分成正比，故称为基于原理的电压传感器。Specifically, the voltage sensor based on the D_dot principle uses the charge induction principle to measure the electric displacement vector near the conductor which is proportional to the integral of the output voltage by measuring the output voltage on the ground matching resistance connected to the measuring electrode, thereby The time-domain waveform of the conductor voltage is obtained. Since its output voltage is proportional to the differential of the electric displacement vector to time, it is called based on Principle voltage sensor.

但是，目前的D_dot传感器结构普遍存在结构复杂、绝缘性有待提高等问题。However, the current D_dot sensor structure generally has problems such as complex structure and poor insulation.

发明内容Contents of the invention

有鉴于此，本发明提供了一种基于D_dot原理的三相电压互感器及三相影响电压补偿方法，其中三相电压互感器具有体积小、结构简单、绝缘性能好和测量安全等特点，其中三相影响电压补偿方法对测量时三相线路间的相互影响作出分析，以此获得接近真实情况的测量值。In view of this, the present invention provides a three-phase voltage transformer based on the D_dot principle and a three-phase influence voltage compensation method, wherein the three-phase voltage transformer has the characteristics of small size, simple structure, good insulation performance and safe measurement, among which The three-phase influence voltage compensation method analyzes the mutual influence between the three-phase lines during the measurement, so as to obtain the measured value close to the real situation.

本发明提供一种基于D_dot原理的三相电压互感器，包括：环形电极I、环形电极II、绝缘支架、接地电容，所述绝缘支架包括：半圆支架I、半圆支架II和支撑臂，所述支撑臂设置在所述半圆支架I、半圆支架II的侧壁上，且所述半圆支架I、半圆支架II同心设置形成用于供被测导体穿过的通孔，所述环形电极I、环形电极II同心设置，且分别嵌在所述半圆支架I和半圆支架II内，所述环形电极I、环形电极II通过导线与所述接地电容和地串联，所述示波器和所述接地电容并联。The present invention provides a three-phase voltage transformer based on the D_dot principle, comprising: a ring electrode I, a ring electrode II, an insulating support, and a grounding capacitor, and the insulating support includes: a semicircular support I, a semicircular support II and a support arm. The support arms are arranged on the side walls of the semicircle support I and the semicircle support II, and the semicircle support I and the semicircle support II are concentrically arranged to form a through hole for the conductor to be tested to pass through. The ring electrode I, the ring electrode Electrode II is arranged concentrically and is respectively embedded in the semicircle support I and semicircle support II. The ring electrode I and ring electrode II are connected in series with the ground capacitor and ground through wires, and the oscilloscope is connected in parallel with the ground capacitor.

进一步，所述环形电极I、环形电极II为形状相同的金属铝环。Further, the ring electrodes I and II are metal aluminum rings with the same shape.

进一步，所述环形电极I、环形电极II的内径在60至70mm之间，外径在70至80mm之间。Further, the inner diameter of the ring electrode I and the ring electrode II is between 60 and 70 mm, and the outer diameter is between 70 and 80 mm.

进一步，还包括：设置在所述支撑臂上用于调节所述半圆支架II的调节旋钮，紧固螺钉的松紧程度可调节，螺钉松的时候，半圆支架II可上下移动，当达到合适位置的时候将螺钉旋紧。Further, it also includes: an adjustment knob arranged on the support arm for adjusting the semicircle support II, the tightness of the fastening screw can be adjusted, when the screw is loose, the semicircle support II can move up and down, and when it reaches a suitable position Time to tighten the screws.

进一步，所述半圆支架I、II之间的调节距离范围在0至50mm之间。Further, the adjustment distance between the semicircular brackets I and II ranges from 0 to 50mm.

本发明还提供了一种基于D_dot原理的三相影响电压补偿方法，包括如下步骤：The present invention also provides a three-phase influence voltage compensation method based on the D_dot principle, comprising the following steps:

将三相电压的其中一相电压V₁接入如上所述的基于D_dot原理的三相电压互感器；One of the phase voltage V1 _of the three-phase voltage is connected to the three-phase voltage transformer based on the D_dot principle as described above;

采用示波器测量所述三相电压互感器的接地电容两端的电压V_out；Using an oscilloscope to measure the voltage V _out at both ends of the grounding capacitor of the three-phase voltage transformer;

采用公式：Using the formula:

${\overset{\cdot &Center Dot;}{V V}}_{out out} = = \overset{\cdot \cdot}{Z Z} * * [\begin{matrix} 11 & 11 & 11 & 11 \end{matrix}] * * {[\begin{matrix} {\overset{\cdot \cdot}{Z Z}}_{a a} & 00 & 00 & - - {\overset{\cdot \cdot}{Z Z}}_{d d} \\ {\overset{\cdot \cdot}{Z Z}}_{a a} + + r r & - - {\overset{\cdot \cdot}{Z Z}}_{b b} - - r r & - - r r & r r \\ \overset{\cdot \cdot}{Z Z} & \overset{\cdot &Center Dot;}{Z Z} + + r r & {\overset{\cdot \cdot}{Z Z}}_{c c} + + \overset{\cdot &Center Dot;}{Z Z} + + r r & \overset{\cdot \cdot}{Z Z} \\ - - \overset{\cdot \cdot}{Z Z} - - r r & - - \overset{\cdot \cdot}{Z Z} & - - \overset{\cdot \cdot}{Z Z} & - - {\overset{\cdot \cdot}{Z Z}}_{d d} - - \overset{\cdot \cdot}{Z Z} - - r r \end{matrix}]}^{- - 11} * * \{\begin{matrix} {\overset{\cdot \cdot}{V V}}_{11} \\ 00 \\ 00 \\ 00 \end{matrix}\}$

计算V₁;compute V ₁ ;

其中，与分别为电容C₁₄和C₁₅，为C₂₅与C₃₅并联值，为C₂₄与C₃₄的并联电容，r为连接电极的同轴导线上的电阻，为C_m,C_p,R₀,R_p,C₀构成的综合参数，其中C_ij表示i号电线与j号电极的电容，C_m为接地电容，R_P和C_P分别为接入示波器时引入的测量探头引入的电阻、电容，R_o和C₀分别为接入示波器引入的电阻、电容。in, and capacitors C ₁₄ and C ₁₅ , respectively, is the parallel value of C ₂₅ and C ₃₅ , is the parallel capacitance of C ₂₄ and C ₃₄ , r is the resistance on the coaxial wire connecting the electrodes, is a comprehensive parameter composed of C _m , C _p , R ₀ , R _p , and C ₀ , where C _ij represents the capacitance between wire i and electrode j, C _m is the grounding capacitance, and R _P and C _P are the oscilloscope connection parameters respectively. R _o and C ₀ are the resistance and capacitance introduced by the oscilloscope respectively.

本发明的有益效果：Beneficial effects of the present invention:

本发明的基于D_dot原理的三相电压互感器主要由环形电极、绝缘支架和接地电容等少数几个部件构成，其具有体积小、结构简单等特性，尤其是环形的电极可以降低最高电场强度以达到提高绝缘水平的目的，具有良好的动态范围和暂态特征，同时保证测量安全性。The three-phase voltage transformer based on the D_dot principle of the present invention is mainly composed of a few parts such as ring electrodes, insulating supports and grounding capacitors, and has characteristics such as small volume and simple structure, especially the ring electrodes can reduce the highest electric field intensity by less than To achieve the purpose of improving the insulation level, it has good dynamic range and transient characteristics, while ensuring measurement safety.

同时，本发明对测量时三相线路间的相互影响作分析，由此提出一种补偿方法，对示波器测量结果加以修正，获得接近真实情况的测量值，能够较为准确地反映电缆上电压波形变化情况。At the same time, the present invention analyzes the mutual influence between the three-phase lines during measurement, thus proposes a compensation method, corrects the measurement results of the oscilloscope, obtains measurement values close to the real situation, and can more accurately reflect the voltage waveform changes on the cable Condition.

附图说明Description of drawings

下面结合附图和实施例对本发明作进一步描述：The present invention will be further described below in conjunction with accompanying drawing and embodiment:

图1是D_dot传感器原理示意图。Figure 1 is a schematic diagram of the D_dot sensor principle.

图2是基于D_dot原理的三相电压互感器的结构示意图。Fig. 2 is a schematic structural diagram of a three-phase voltage transformer based on the D_dot principle.

图3是基于D_dot原理的三相电压互感器的检测简图。Figure 3 is a schematic diagram of the detection of a three-phase voltage transformer based on the D_dot principle.

图4是不考虑邻相影响时的D_dot传感器测量等效电路图。Figure 4 is an equivalent circuit diagram of the D_dot sensor measurement without considering the influence of adjacent phases.

图5是考虑邻相影响时的D_dot传感器测量等效电路图。Fig. 5 is an equivalent circuit diagram of D_dot sensor measurement when considering the influence of adjacent phases.

图6是考虑邻相影响时的某一相D_dot传感器测量等效电路图。Fig. 6 is an equivalent circuit diagram of a certain phase D_dot sensor measurement when considering the influence of adjacent phases.

图7是试验装置图。Figure 7 is a diagram of the test setup.

具体实施方式：detailed description:

如图1所示，是D_dot传感器的原理示意图，其将具有高电导率的金属导体1封入绝缘体2中构成最简单的D_dot传感器，其中为被测量点的电场强度，在金属导体表面做一闭合高斯面4，并对其使用高斯定理可以得到：As shown in Figure 1, it is a schematic diagram of the principle of the D_dot sensor, which encapsulates a metal conductor 1 with high conductivity in an insulator 2 to form the simplest D_dot sensor, where For the electric field strength of the measured point, make a closed Gaussian surface 4 on the surface of the metal conductor, and use Gaussian law on it to get:

(公式1)。 (Formula 1).

公式（1）中q为闭合高斯面4内即金属导体1上的感应电荷，A_eq为传感器的等效面积，其与传感器中金属导体1的形状结构以及高斯面与电场强度矢量方向的夹角有关。In the formula (1), q is the induced charge on the metal conductor 1 in the closed Gaussian surface 4, and A _eq is the equivalent area of the sensor, which is related to the shape and structure of the metal conductor 1 in the sensor and the clamping distance between the Gaussian surface and the direction of the electric field intensity vector. Angle related.

当金属导体1通过电缆3与接地匹配电阻R连接后，金属导体1中电荷移动形成电流并在接地匹配电阻R上产生压降：When the metal conductor 1 is connected to the grounding matching resistor R through the cable 3, the charge in the metal conductor 1 moves to form a current and creates a voltage drop across the ground matching resistor R:

$V_{0} = ϵ_{0} A_{eq} R \frac{d}{dt} \overset{&RightArrow;}{E}$ (公式2)。 $V_{0} = ϵ_{0} A_{eq} R \frac{d}{dt} \overset{&Right Arrow;}{E.}$ (Formula 2).

因此，D_dot传感器输出V₀与被测量点的电场强度对时间的导数呈线性关系，因此该D_dot传感器可以用于电场测量。Therefore, the D_dot sensor output V ₀ is related to the electric field strength of the measured point The derivative with respect to time is linear, so the D_dot sensor can be used for electric field measurements.

由于D_dot传感器的测量是通过电荷耦合检测被测电压，其与通过能量传递实现测量的CVT(CapacitorVoltageTransformer,电容式电压互感器)不同，其可以实现无接触测量，因此将其应用于高电压等级的变电站内时，可以使得二次侧几乎没有任何电流输出，实现二次侧安全检测的同时，保证对一次侧不造成影响，并且由于整个传感器不存在电感性的器件，避免了传感器产生的铁磁谐振的威胁。Since the measurement of the D_dot sensor is to detect the measured voltage through charge coupling, it is different from the CVT (CapacitorVoltageTransformer, capacitive voltage transformer) that realizes the measurement through energy transfer, and it can realize non-contact measurement, so it is applied to high voltage level When in the substation, it can make the secondary side have almost no current output, realize the safety detection of the secondary side, and ensure that the primary side will not be affected, and because the entire sensor does not have inductive devices, the ferromagnetism generated by the sensor is avoided. Resonant threat.

如图2和3所示，本发明提供的基于D_dot原理的三相电压互感器包括：环形电极I1、环形电极II2、绝缘支架和接地电容4。As shown in FIGS. 2 and 3 , the three-phase voltage transformer based on the D_dot principle provided by the present invention includes: a ring electrode I1 , a ring electrode II2 , an insulating support and a grounding capacitor 4 .

其中，绝缘支架包括：半圆支架I31、半圆支架II32和支撑臂33，支撑臂33设置在半圆支架I31和半圆支架II32的侧壁上，且半圆支架I31、半圆支架II32同心设置形成用于供被测导体6穿过的通孔，该通孔的大小在12至16mm之间。Wherein, insulating support comprises: semicircle support I31, semicircle support II32 and support arm 33, support arm 33 is arranged on the side wall of semicircle support I31 and semicircle support II32, and semicircle support I31, semicircle support II32 are concentrically arranged and formed for being used for Measure the through hole that conductor 6 passes through, the size of this through hole is between 12 to 16mm.

其中，在支撑臂33上设置有用于调节半圆支架II位置的调节旋钮，且半圆支架I、II之间的调节距离范围在0至50mm之间。具体的，调节旋钮可以为紧固螺钉，其松紧程度可调节，螺钉松的时候，半圆支架II可上下移动，当达到合适位置的时候将螺钉旋紧。Wherein, an adjustment knob for adjusting the position of the semicircle bracket II is provided on the support arm 33, and the adjustment distance between the semicircle brackets I and II ranges from 0 to 50 mm. Specifically, the adjusting knob can be a fastening screw whose degree of tightness can be adjusted. When the screw is loose, the semicircle bracket II can move up and down, and the screw can be tightened when reaching a proper position.

其中，环形电极I1、环形电极II2同心设置，且分别嵌在半圆支架I31和半圆支架II32内，环形电极I1、环形电极II2通过导线（例如：同轴导线）与接地电容4和地串联。Among them, the ring electrode I1 and the ring electrode II2 are arranged concentrically, and are respectively embedded in the semicircle support I31 and the semicircle support II32, and the ring electrode I1 and the ring electrode II2 are connected in series with the grounding capacitor 4 and the ground through wires (for example: coaxial wires).

其中，环形电极I1、环形电极II2为形状相同的金属铝环。Wherein, the ring electrode I1 and the ring electrode II2 are metal aluminum rings with the same shape.

其中，环形电极I1、环形电极II2的内径在60至70mm之间，外径在70至80mm之间。Wherein, the inner diameter of the ring electrode I1 and the ring electrode II2 is between 60 and 70 mm, and the outer diameter is between 70 and 80 mm.

图3中环形电极I1、II2和导体6之间为绝缘材料制成的绝缘环，用于钳紧和固定导体6（例如：铜棒），另外图3中的A_eq为电线上电压。In Fig. 3, an insulating ring made of insulating material is used between ring electrodes I1, II2 and conductor 6 to clamp and fix conductor 6 (for example: copper rod). In addition, A _eq in Fig. 3 is the voltage on the wire.

另外，测量时，如图3所示，将示波器5与接地电容4并联，即可以测三相电压互感器输出的电压。In addition, during measurement, as shown in Figure 3, the oscilloscope 5 is connected in parallel with the grounding capacitor 4, that is, the output voltage of the three-phase voltage transformer can be measured.

本实施例，主要由环形电极、绝缘支架和接地电容等少数几个部件构成，其具有体积小、结构简单等特性，尤其是环形的电极可以降低最高电场强度以达到提高绝缘水平的目的，具有良好的动态范围和暂态特征，同时保证测量安全性。This embodiment is mainly composed of a few parts such as ring electrodes, insulating brackets and grounding capacitors. It has the characteristics of small size and simple structure, especially the ring electrodes can reduce the maximum electric field intensity to achieve the purpose of improving the insulation level. Good dynamic range and transient characteristics, while ensuring measurement security.

将图3中接地电容4两端输出的电压接入示波器，可观测输出电压波形。同时由图3可知，电压互感器上电极的输出电压可表示为：Connect the voltage output from both ends of the grounding capacitor 4 in FIG. 3 to an oscilloscope to observe the output voltage waveform. At the same time, it can be seen from Figure 3 that the output voltage of the upper electrode of the voltage transformer can be expressed as:

$V_{out} = \frac{C_{1}}{C_{1} + C_{2}} V_{pow}$ (公式3) $V_{out} = \frac{C_{1}}{C_{1} + C_{2}} V_{pow}$ (Formula 3)

其中C₁为图3所示上下两电极（即电极I、电极II）之间的电容，C₂为图3所示输出端电容（即接地电容）。Among them, C ₁ is the capacitance between the upper and lower electrodes (ie, electrode I and electrode II) shown in Figure 3, and C ₂ is the capacitance of the output terminal shown in Figure 3 (ie, the grounding capacitance).

本发明对测量时三相线路间的相互影响作分析，由此提出一种补偿方法，对示波器测量结果加以修正，获得接近真实情况的测量值，较为准确地反映电缆线上电压波形变化情况。The invention analyzes the mutual influence between the three-phase lines during the measurement, thus proposes a compensation method, corrects the measurement result of the oscilloscope, obtains the measurement value close to the real situation, and more accurately reflects the voltage waveform variation on the cable line.

具体流程如下：The specific process is as follows:

若考虑同轴导线上电阻、示波器等测量装置的影响，可得输出电压U_o(s)：If the influence of measuring devices such as resistance on the coaxial wire and oscilloscope is considered, the output voltage U _o (s) can be obtained:

${U u}_{o o} ((s the s)) = = \frac{{Z Z}_{22} ((s the s))}{{Z Z}_{11} ((s the s)) + + {Z Z}_{22} ((s the s))} {U u}_{i i} ((s the s)) = = \frac{\frac{{Z Z}_{sc sc}}{11 + + {Z Z}_{sc sc} {C C}_{m m} s the s}}{\frac{{s the s}^{22} {R R}_{11} {R R}_{22} {C C}_{11} {C C}_{22} + + s the s (({R R}_{11} {C C}_{11} + + {R R}_{22} {C C}_{22})) + + 11}{{s the s}^{22} {C C}_{11} {C C}_{22} (({R R}_{11} + + {R R}_{22})) + + s the s (({C C}_{11} + + {C C}_{22}))}} {U u}_{i i} ((s the s))$

即： $U_{o} (s) = Z_{sc} \cdot \frac{s^{2} C_{1} C_{2} (R_{1} + R_{2}) + s (C_{1} + C_{2})}{(1 + Z_{sc} C_{m} s) (s^{2} R_{1} R_{2} C_{1} C_{2} + s (R_{1} C_{1} + R_{2} C_{2}) + 1)} U_{i} (s)$ (公式4)which is: $u_{o} (the s) = Z_{sc} &Center Dot; \frac{{the s}^{2} C_{1} C_{2} (R_{1} + R_{2}) + the s (C_{1} + C_{2})}{(1 + Z_{sc} C_{m} the s) ({the s}^{2} R_{1} R_{2} C_{1} C_{2} + the s (R_{1} C_{1} + R_{2} C_{2}) + 1)} u_{i} (the s)$ (Formula 4)

如图4，其中C₁、C₂为上下半圆金属环与导线的电容，R₁、R₂为连接上下半圆金属环的同轴导线上的电阻，C_m为电压互感器与地之间的电容，同时也是用于测量输出电压的测量电容，Z_sc为测量用示波器的等效阻抗，它与C_m并联用于测量。As shown in Figure 4, where C ₁ and C ₂ are the capacitances between the upper and lower semicircular metal rings and the wires, R ₁ and R ₂ are the resistances on the coaxial wires connecting the upper and lower semicircular metal rings, and C _m is the capacitance between the voltage transformer and the ground Capacitance is also the measurement capacitance used to measure the output voltage. Z _sc is the equivalent impedance of the oscilloscope for measurement, which is connected in parallel with C _m for measurement.

若再考虑三相线路上其他两相对电压互感器的影响，可得测量电路图5。If the influence of the other two phase voltage transformers on the three-phase line is considered, the measurement circuit diagram 5 can be obtained.

将A、B、C电缆线进行编号为1,2,3，各层电极分别编号为4,5,6,7,8,9，电路中的V₁、V₂、V₃分别为各相电缆线上的实际电压，C_ij表示i号电缆线与j号电极的电容，例如：C₁₄表示1号电缆线与4号电极的电容，C_m为传感器测量中输出电压上的电容元件，R_P和C_P分别为10倍探头（接入示波器时连接了扩大10倍波形的测量探头）引入的电阻、电容，R_o和C₀分别为接入示波器引入的电阻、电容，由此考虑邻相线路与该相上传感器的电极之间的互电容，并对此作分析，通过修正示波器测量结果，可进行补偿，获得接近真实情况的电压波形。Number the cables A, B, and C as 1, 2, and 3, and number the electrodes of each layer as 4, 5, 6, 7, 8, and 9 respectively. V ₁ , V ₂ , and V ₃ in the circuit are the The actual voltage on the cable, C _ij represents the capacitance between the i cable and the j electrode, for example: C ₁₄ represents the capacitance between the 1 cable and the 4 electrode, C _m is the capacitive element on the output voltage of the sensor measurement, R _P and C _P are the resistance and capacitance introduced by the 10-times probe (when connected to the oscilloscope, the measuring probe with a 10-times enlarged waveform is connected), and R _o and C ₀ are the resistance and capacitance introduced by the oscilloscope respectively. Considering this The mutual capacitance between the adjacent phase line and the electrode of the sensor on the phase is analyzed. By correcting the measurement results of the oscilloscope, compensation can be made to obtain a voltage waveform close to the real situation.

上述电路中各电极与导体的互电容均为固有参数，可通过对电场进行有限元分析求解得到，且测量装置示波器参数已知，故最终能够对电压互感器的测量结果进行修正，并通过补偿测量值使得结果接近真实情况。The mutual capacitance of each electrode and conductor in the above circuit is an inherent parameter, which can be obtained by finite element analysis of the electric field, and the parameters of the oscilloscope of the measuring device are known, so the measurement results of the voltage transformer can be corrected finally, and through compensation The measured values make the results close to the real situation.

实验中，我们利用电磁场分析软件构建模型，求解出各电极与导体之间的互电容，其等效电路如图5所示。In the experiment, we used the electromagnetic field analysis software to build a model to solve the mutual capacitance between each electrode and the conductor, and its equivalent circuit is shown in Figure 5.

若取A相线路（对应电压为V₁）进行分析（令B、C两相输入电压源为0），其等效电路如附图6，将有如下关系：If the A-phase line (corresponding voltage is V ₁ ) is taken for analysis (let the B and C two-phase input voltage sources be 0), its equivalent circuit is shown in Figure 6, and the relationship will be as follows:

$[\begin{matrix} {\overset{\cdot}{Z}}_{a} & 0 & 0 & - {\overset{\cdot}{Z}}_{d} \\ {\overset{\cdot}{Z}}_{a} + r & - {\overset{\cdot}{Z}}_{b} - r & - r & r \\ \overset{\cdot}{Z} & \overset{\cdot}{Z} + r & {\overset{\cdot}{Z}}_{c} + \overset{\cdot}{Z} + r & \overset{\cdot}{Z} \\ - \overset{\cdot}{Z} - r & - \overset{\cdot}{Z} & - \overset{\cdot}{Z} & - {\overset{\cdot}{Z}}_{d} - \overset{\cdot}{Z} - r \end{matrix}] \{\begin{matrix} {\overset{\cdot}{I}}_{1} \\ {\overset{\cdot}{I}}_{2} \\ {\overset{\cdot}{I}}_{3} \\ - {\overset{\cdot}{I}}_{4} \end{matrix}\} = \{\begin{matrix} {\overset{\cdot}{V}}_{1} \\ 0 \\ 0 \\ 0 \end{matrix}\}$ (公式5) $[\begin{matrix} {\overset{\cdot}{Z}}_{a} & 0 & 0 & - {\overset{\cdot}{Z}}_{d} \\ {\overset{&Center Dot;}{Z}}_{a} + r & - {\overset{&Center Dot;}{Z}}_{b} - r & - r & r \\ \overset{\cdot}{Z} & \overset{\cdot}{Z} + r & {\overset{\cdot}{Z}}_{c} + \overset{&Center Dot;}{Z} + r & \overset{\cdot}{Z} \\ - \overset{\cdot}{Z} - r & - \overset{\cdot}{Z} & - \overset{\cdot}{Z} & - {\overset{\cdot}{Z}}_{d} - \overset{&Center Dot;}{Z} - r \end{matrix}] \{\begin{matrix} {\overset{\cdot}{I}}_{1} \\ {\overset{&Center Dot;}{I}}_{2} \\ {\overset{&Center Dot;}{I}}_{3} \\ - {\overset{&Center Dot;}{I}}_{4} \end{matrix}\} = \{\begin{matrix} {\overset{\cdot}{V}}_{1} \\ 0 \\ 0 \\ 0 \end{matrix}\}$ (Formula 5)

$V_{out} = Z^{\cdot} ({I^{\cdot}}_{1} + {I^{\cdot}}_{2} + {I^{\cdot}}_{3} - {I^{\cdot}}_{4})$ (公式6) $V_{out} = Z^{&Center Dot;} ({I^{&Center Dot;}}_{1} + {I^{\cdot}}_{2} + {I^{\cdot}}_{3} - {I^{\cdot}}_{4})$ (Formula 6)

即：which is:

$\begin{matrix} {\overset{\cdot \cdot}{V V}}_{out out} = = [\begin{matrix} \overset{\cdot \cdot}{Z Z} & \overset{\cdot \cdot}{Z Z} & \overset{\cdot \cdot}{Z Z} & \overset{\cdot \cdot}{Z Z} \end{matrix}] * * [\begin{matrix} {\overset{\cdot \cdot}{I I}}_{11} \\ {\overset{\cdot \cdot}{I I}}_{22} \\ {\overset{\cdot \cdot}{I I}}_{33} \\ {- - \overset{\cdot &Center Dot;}{I I}}_{44} \end{matrix}] \\ = = \overset{\cdot &Center Dot;}{Z Z} * * [\begin{matrix} 11 & 11 & 11 & 11 \end{matrix}] * * {[\begin{matrix} {\overset{\cdot &Center Dot;}{Z Z}}_{a a} & 00 & 00 & - - {\overset{\cdot &Center Dot;}{Z Z}}_{d d} \\ {\overset{\cdot \cdot}{Z Z}}_{a a} + + r r & - - {\overset{\cdot &Center Dot;}{Z Z}}_{b b} - - r r & - - r r & r r \\ \overset{\cdot &Center Dot;}{Z Z} & \overset{\cdot &Center Dot;}{Z Z} + + r r & {\overset{\cdot &Center Dot;}{Z Z}}_{c c} + + \overset{\cdot &Center Dot;}{Z Z} + + r r & \overset{\cdot &Center Dot;}{Z Z} \\ - - \overset{\cdot &Center Dot;}{Z Z} - - r r & - - \overset{\cdot &Center Dot;}{Z Z} & - - \overset{\cdot &Center Dot;}{Z Z} & - - {\overset{\cdot &Center Dot;}{Z Z}}_{d d} - - \overset{\cdot &Center Dot;}{Z Z} - - r r \end{matrix}]}^{- - 11} * * \{\begin{matrix} {\overset{\cdot &Center Dot;}{V V}}_{11} \\ 00 \\ 00 \\ 00 \end{matrix}\} \end{matrix}$

(公式7)(Formula 7)

式中与分别为图5中的电容C₁₄和C₁₅，为C₂₅与C₃₅并联值，为C₂₄与C₃₄的并联电容，为C_m,C_p,R₀,R_p,C₀构成的综合参数。In the formula and are capacitors C ₁₄ and C ₁₅ in Figure 5, respectively, is the parallel value of C ₂₅ and C ₃₅ , is the parallel capacitance of C ₂₄ and C ₃₄ , is a comprehensive parameter composed of C _m , C _p , R ₀ , R _p , and C ₀ .

由此可看出V_out与V₁存在固定的关系，可表示成传递函数的形式，该传递函数与r有关，若已知这些参数，可知V₁与V_out的关系。It can be seen that there is a fixed relationship between V _out and V ₁ , which can be expressed in the form of a transfer function, which is related to r is related, if these parameters are known, the relationship between V ₁ and V _out can be known.

为了使式子得到简化，若三相线路位置对称，即令图中那么In order to simplify the formula, if the position of the three-phase line is symmetrical, that is, in the figure So

$\begin{matrix} {\overset{\cdot &Center Dot;}{V V}}_{out out} = = \overset{\cdot &Center Dot;}{Z Z} * * [\begin{matrix} 11 & 11 & 11 & 11 \end{matrix}] * * {[\begin{matrix} {\overset{\cdot &Center Dot;}{Z Z}}_{a a} & 00 & 00 & - - {\overset{\cdot &Center Dot;}{Z Z}}_{c c} \\ {\overset{\cdot &Center Dot;}{Z Z}}_{a a} + + r r & - - {\overset{\cdot \cdot}{Z Z}}_{a a} - - r r & - - r r & r r \\ \overset{\cdot \cdot}{Z Z} & \overset{\cdot \cdot}{Z Z} + + r r & {\overset{\cdot \cdot}{Z Z}}_{c c} + + \overset{\cdot &Center Dot;}{Z Z} + + r r & \overset{\cdot \cdot}{Z Z} \\ - - \overset{\cdot &Center Dot;}{Z Z} - - r r & - - \overset{\cdot &Center Dot;}{Z Z} & - - \overset{\cdot &Center Dot;}{Z Z} & - - {\overset{\cdot &Center Dot;}{Z Z}}_{c c} - - \overset{\cdot &Center Dot;}{Z Z} - - r r \end{matrix}]}^{- - 11} \\ = = {\overset{\cdot &Center Dot;}{V V}}_{11} \cdot &Center Dot; \frac{11}{((\frac{{\overset{\cdot &Center Dot;}{Z Z}}_{a a}}{{\overset{\cdot &Center Dot;}{Z Z}}_{c c}} + + 11)) ((\frac{r r}{22 \overset{\cdot &Center Dot;}{Z Z}} + + 11))} \end{matrix} * * \{\begin{matrix} {\overset{\cdot &Center Dot;}{V V}}_{11} \\ 00 \\ 00 \\ 00 \end{matrix}\}$

(公式8)(Formula 8)

由以上的分析，本发明提供了一种基于D_dot原理的三相影响电压补偿方法，其包括如下步骤：By above analysis, the present invention provides a kind of three-phase influence voltage compensation method based on D_dot principle, and it comprises the following steps:

步骤1、将三相电压的其中一相电压V₁接入如上所述的基于D_dot原理的三相电压互感器。Step 1. Connect one phase voltage V ₁ of the three-phase voltage to the above-mentioned three-phase voltage transformer based on the D_dot principle.

步骤2、采用示波器测量所述三相电压互感器的接地电容两端的电压V_out。Step 2. Using an oscilloscope to measure the voltage V _out across the grounding capacitor of the three-phase voltage transformer.

步骤3、采用公式（7）或（8）计算V₁，即所测相的电压。Step 3. Using formula (7) or (8) to calculate V ₁ , that is, the voltage of the phase to be measured.

下面举一示例，对该过程进行说明：Here is an example to illustrate the process:

如附图7所示试验装置中，由安装在三相电线上的三个电压传感器和地面与架空线的避雷装置构成。其中三条水平放置的电线距离地面有10米远，电缆导体上电压幅值约5.78KV，频率50Hz，每相自左向右分别为A,B,C。As shown in Figure 7, the test device consists of three voltage sensors installed on three-phase wires and lightning protection devices for ground and overhead wires. The three horizontal wires are 10 meters away from the ground. The voltage amplitude on the cable conductor is about 5.78KV, the frequency is 50Hz, and each phase is A, B, and C from left to right.

仿真试验中，我们使用X1000高压探头测量三相线路上的电压值以及相位，测量结果V₁如表1所示。In the simulation experiment, we use the X1000 high-voltage probe to measure the voltage value and phase on the three-phase line, and the measurement result V1 is shown in Table ₁ .

表一：Table I:

通过多次仿真和试验，我们得到当电线上和电极间（包括电极I、电极II与三条电线电容的综合参数，可通过戴维宁定理求得）构成的电容C₁₀与传感器制造厂商耐压试验得到的电容C_1M（即接地电容）满足如下关系时：Through multiple simulations and experiments, we have obtained the capacitance C ₁₀ formed on the wire and between the electrodes (including the comprehensive parameters of electrode I, electrode II and the capacitance of the three wires, which can be obtained through Thevenin's theorem) and the withstand voltage test of the sensor manufacturer. When the capacitance C _1M (that is, the ground capacitance) satisfies the following relationship:

C_1M=0.17C₁₀(公式8)C _1M =0.17C ₁₀ (Formula 8)

此时，三相电压互感器输出电压在示波器上显示如下：At this time, the output voltage of the three-phase voltage transformer is displayed on the oscilloscope as follows:

表二：Table II:

通过公式7的V₁与V_out的关系，计算得到电极上的电压V₁'的电压值与相位偏移量，如下：Through the relationship between V ₁ and V _out in formula 7, the voltage value and phase offset of the voltage V ₁ ' on the electrode are calculated as follows:

表三：Table three:

对比表一与表三得到的数据可知，按上述方法,计算传感器输出V_out对应的V₁'，与实际值V₁相比较，电压值与相位偏移量相差很小，提高了传感器的测量精度。由此能够较为准确地反映电缆线上电压波形的变化情况。Comparing the data obtained in Table 1 and Table 3, it can be seen that according to the above method, the V ₁ ' corresponding to the sensor output V _out is calculated. Compared with the actual value V ₁ , the difference between the voltage value and the phase offset is very small, which improves the measurement of the sensor. precision. Therefore, the variation of the voltage waveform on the cable line can be reflected more accurately.

本发明，通过改善D_dot传感器结构并考虑分析三相线路上邻相电场以及测量装置对测量电路的影响，由此提出一种补偿方法，对示波器测量结果进行修正，由此得到接近真实情况的数值，有利于继保系统中跟踪电压变化以及故障诊断与在线监测和捕捉到高频的过电压波形，对电网电压测量具有重大的意义。In the present invention, by improving the structure of the D_dot sensor and considering the analysis of the adjacent phase electric field on the three-phase line and the influence of the measurement device on the measurement circuit, a compensation method is proposed to correct the measurement results of the oscilloscope, thereby obtaining a value close to the real situation , which is conducive to tracking voltage changes in relay protection systems, fault diagnosis and on-line monitoring, and capturing high-frequency overvoltage waveforms, which is of great significance to grid voltage measurement.

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，尽管参照较佳实施例对本发明进行了详细说明，本领域的普通技术人员应当理解，可以对本发明的技术方案进行修改或者等同替换，而不脱离本发明技术方案的宗旨和范围，其均应涵盖在本发明的权利要求范围当中。Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims

1. A three-phase voltage transformer based on D_dot principle, is characterized in that: comprise: ring electrode I, ring electrode II, insulating support and grounding capacitor, and described insulating support comprises: semicircle support I, semicircle support II and support arm , the support arm is arranged on the side walls of the semicircle support I and the semicircle support II, and the semicircle support I and the semicircle support II are concentrically arranged to form a through hole for the conductor to pass through, and the ring electrode 1. The ring electrode II is arranged concentrically, and is respectively embedded in the semicircle support I and the semicircle support II, and the ring electrode I and the ring electrode II are connected in series with the grounding capacitor and the ground through wires;

It also includes: an adjustment knob arranged on the support arm for adjusting the position of the semicircle support II.

2. The three-phase voltage transformer based on D_dot principle according to claim 1, characterized in that: said ring electrode I and ring electrode II are metal aluminum rings with the same shape.

3. The three-phase voltage transformer based on the D_dot principle according to claim 2, characterized in that: the inner diameter of the ring electrode I and the ring electrode II is between 60 and 70 mm, and the outer diameter is between 70 and 80 mm.

4. The three-phase voltage transformer based on the D_dot principle according to claim 1, characterized in that: the adjustment distance between the semicircular brackets I and II is between 0 and 50 mm.

5. a kind of three-phase influence voltage compensation method based on D_dot principle, is characterized in that: comprise the steps:

One of the phase voltages V _of the three-phase voltage is connected to the three-phase voltage transformer based on the D_dot principle as described in any one of claims 1 to 4;

Using an oscilloscope to measure the voltage V _out at both ends of the grounding capacitor of the three-phase voltage transformer;

Using the formula:

{\overset{\cdot &Center Dot;}{V V}}_{o o u u t t} = = \overset{\cdot &Center Dot;}{Z Z} * * [\begin{matrix} 11 & 11 & 11 & 11 \end{matrix}] * * {[\begin{matrix} {\overset{\cdot &Center Dot;}{Z Z}}_{a a} & 00 & 00 & - - {\overset{\cdot &Center Dot;}{Z Z}}_{d d} \\ {\overset{\cdot &Center Dot;}{Z Z}}_{a a} + + r r & - - {\overset{\cdot &Center Dot;}{Z Z}}_{b b} - - r r & - - r r & r r \\ \overset{\cdot &Center Dot;}{Z Z} & \overset{\cdot &Center Dot;}{Z Z} + + r r & {\overset{\cdot &Center Dot;}{Z Z}}_{c c} + + \overset{\cdot &Center Dot;}{Z Z} + + r r & \overset{\cdot &Center Dot;}{Z Z} \\ - - \overset{\cdot &Center Dot;}{Z Z} - - r r & - - \overset{\cdot &Center Dot;}{Z Z} & - - \overset{\cdot &Center Dot;}{Z Z} & - - {\overset{\cdot &Center Dot;}{Z Z}}_{d d} - - \overset{\cdot &Center Dot;}{Z Z} - - r r \end{matrix}]}^{- - 11} * * \{\begin{matrix} {\overset{\cdot &Center Dot;}{V V}}_{11} \\ 00 \\ 00 \\ 00 \end{matrix}\}

Compute V1 _;

in, and capacitors C ₁₄ and C ₁₅ , respectively, is the parallel value of C ₂₅ and C ₃₅ , is the parallel capacitance of C ₂₄ and C ₃₄ , r is the resistance on the coaxial wire connecting the electrodes, is a comprehensive parameter composed of C _m , C _p , R ₀ , R _p , and C ₀ , where C _ij represents the capacitance between wire i and electrode j, C _m is the grounding capacitance, and R _P and C _P are the oscilloscope connection parameters respectively. R _o and C ₀ are the resistance and capacitance introduced by the oscilloscope respectively.