阅读说明：本技术 一种±800kV输变电主设备空载试验用陷波装置 (Trap device for no-load test of +/-800 kV power transmission and transformation main equipment ) 是由 王生杰 王理丽 于鑫龙 王生富 沈洁 林万德 杨放南 马旭东 包正红 张成磊 蒋 于 2019-12-04 设计创作，主要内容包括：一种±800kV输变电主设备空载试验用陷波装置,涉及电气试验设备技术领域,其结构为：由3次谐波滤波器和5次谐波滤波器并联组成；3次谐波滤波器和5次谐波滤波器均由电容器组和电抗器串联组成。本发明的有益效果在于：本发明的使用,电压波形校正因素d的绝对值和电压波形畸变率THD均会大幅度减小,能够满足标准要求使得电压波形校正因素d小于等于±3%,3次谐波滤波器和5次谐波滤波器并联使用,能够很明显的减少试验电源的容量,对于现场试验有很大的辅助作用。(The utility model provides a +/-800 kV power transmission and transformation main equipment is trapped wave device for no-load test, relates to electrical test equipment technical field, and its structure is: the filter is formed by connecting a 3-order harmonic filter and a 5-order harmonic filter in parallel; the 3 rd harmonic filter and the 5 th harmonic filter are both formed by connecting a capacitor bank and a reactor in series. The invention has the beneficial effects that: when the voltage waveform correction factor d is used, the absolute value of the voltage waveform correction factor d and the voltage waveform distortion rate THD are both greatly reduced, the standard requirement can be met, the voltage waveform correction factor d is less than or equal to +/-3%, the 3-order harmonic filter and the 5-order harmonic filter are used in parallel, the capacity of a test power supply can be obviously reduced, and the auxiliary effect on a field test is realized.)

1. The utility model provides a +/-800 kV power transmission and transformation main equipment is trapped wave device for no-load test which characterized in that: the filter is formed by connecting a 3-order harmonic filter and a 5-order harmonic filter in parallel; the 3 rd harmonic filter and the 5 th harmonic filter are both formed by connecting a capacitor bank and a reactor in series.

2. The notch device for the no-load test of the +/-800 kV power transmission and transformation main equipment as claimed in claim 1, wherein: the capacitor bank is formed by connecting a plurality of capacitors in series, when the wiring mode of the test sample valve side is D connection, 10 identical capacitors are selected to be connected in series to form the capacitor bank, and when the wiring mode of the test sample valve side is Y connection, 7 identical capacitors are selected to be connected in series to form the capacitor bank.

3. The notch device for the no-load test of the +/-800 kV power transmission and transformation main equipment as claimed in claim 2, wherein: the voltage at the bottommost part of the capacitor bank is the highest point and is a resonance point, and the resonance point is connected with one reactor or 2 reactors connected in series; the bottom of the reactor at the lowest end is directly grounded.

4. The notch device for the no-load test of the +/-800 kV power transmission and transformation main equipment as claimed in claim 3, wherein: when the wiring mode of the test sample valve side is D connection, the resonance point is connected with 2 reactors connected in series, and the reactance values of the two reactors are different; when the wiring mode of the sample valve side is Y connection, the resonance point is connected with a reactor.

5. The notch device for the no-load test of the +/-800 kV power transmission and transformation main equipment as claimed in claim 4, wherein: a plurality of taps are reserved in each reactor, and proper taps can be selected according to the field condition to finely adjust the reactance value of the reactor, so that the resonant frequencies of the two filters are close to 150Hz and 250Hz respectively.

6. The notch device for the no-load test of the +/-800 kV power transmission and transformation main equipment as claimed in claim 5, wherein: the capacitors are all mounted on the fixed frame, a safety distance is reserved, and the position of the reactor can be adjusted according to specific conditions.

7. The notch device for the no-load test of the +/-800 kV power transmission and transformation main equipment as claimed in claim 6, wherein: the 3-order and 5-order harmonic filters can realize switching by manually switching the high-voltage incoming busbar according to the reactive load demand and the harmonic content of the 3-order and 5-order harmonic filters, the 3-order branch is switched firstly during switching, and the 5-order branch is cut firstly during cutting.

Technical Field

The invention relates to the technical field of electrical test equipment, in particular to a trap device for a +/-800 kV power transmission and transformation main equipment no-load test.

Background

When +/-800 kV power transmission and transformation main equipment performs a no-load test at 1.1 times of rated voltage, the requirement on the power supply capacity during a field test is high, and the good waveform of the voltage needs to be ensured. Usually, a capacitor is used for reactive compensation, but due to the particularity of the main equipment of the power transmission and transformation, the existing technology, such as the method for improving the power supply capacity and using the capacitor compensation, has poor effect on the actual no-load test.

The harmonic content of the no-load current of the power transmission and transformation main equipment is higher, the influence on the test voltage waveform of the no-load test is larger, the waveform control difficulty in the no-load test is larger, the harmonic current of 3 times, 5 times and 7 times accounts for the proportion of the fundamental wave current to be higher, so that the test voltage waveform is distorted, and the voltage waveform is difficult to reach the standard requirement in the no-load test.

In the prior art, for example, the capacity of a test power supply is increased, the requirement on field test conditions is very high, and the difficulty in field implementation is higher. The method of adopting the capacitor to perform reactive compensation on the basis of the capacity of the field allowable test power supply cannot properly reduce the capacity of the test power supply, has insignificant influence on the actual test result, and cannot enable the voltage waveform to reach the standard waveform. If a high-voltage filter is not used, the correction factor d of the waveform in the no-load test, and the relative deviation between the average value of the voltage and the effective value are not less than 3%, and the total harmonic content of the voltage is still higher.

If the requirement on the capacity of a test power supply during the no-load test of the main power transmission and transformation equipment is reduced only by using capacitance compensation according to the conventional no-load test method of the power transformer, the effect is not obvious because the capacitance only provides power frequency compensation current under the power frequency voltage similar to sine wave and has no practical effect on the generated harmonic current, so that the waveform correction factor d cannot be ensured to meet the standard requirement.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a trap device for a no-load test of +/-800 kV power transmission and transformation main equipment, which can solve the problems.

The invention provides a trap device for a no-load test of +/-800 kV power transmission and transformation main equipment, which is connected into a system after a fixed capacitor bank and a variable reactor are connected in series, namely, the trap device is carried out at the valve side or the low and medium voltage sides of a test article;

the device is formed by connecting a 3 rd harmonic filter and a 5 th harmonic filter in parallel; the 3 rd harmonic filter and the 5 th harmonic filter are both formed by connecting a capacitor bank and a reactor in series;

the capacitor bank is formed by connecting a plurality of capacitors in series, when the wiring mode of the test sample valve side is D connection, 10 identical capacitors are selected to be connected in series to form the capacitor bank, and when the wiring mode of the test sample valve side is Y connection, 7 identical capacitors are selected to be connected in series to form the capacitor bank.

The voltage at the bottommost part of the capacitor bank is the highest point and is a resonance point, and the resonance point is connected with one reactor or 2 reactors connected in series; the bottom of the reactor at the lowest end is directly grounded.

When the wiring mode of the test sample valve side is D connection, the resonance point is connected with 2 reactors connected in series, and the reactance values of the two reactors are different; when the wiring mode of the sample valve side is Y connection, the resonance point is connected with a reactor.

A plurality of taps are reserved in each reactor, and proper taps can be selected according to the field condition to finely adjust the reactance value of the reactor, so that the resonance frequencies of the two filters are close to 150Hz and 250Hz respectively;

the capacitors are all mounted on the fixed frame, a safety distance is reserved, and the position of the reactor can be adjusted according to specific conditions.

The 3-order and 5-order harmonic filters can realize switching by manually switching the high-voltage incoming busbar according to the reactive load demand and the harmonic content of the 3-order and 5-order harmonic filters, the 3-order branch is switched firstly during switching, and the 5-order branch is cut firstly during cutting.

The invention has the beneficial effects that: when a +/-800 kV power transmission and transformation main equipment no-load test is carried out, the wave trap device is used, the absolute value of the waveform correction factor d and the waveform distortion rate THD are both greatly reduced, and the standard requirement can be met so that the waveform correction factor d is less than or equal to +/-3%.

The waveform generated by the adopted filter is better if the capacity of the filter is larger, the waveform generated by the 3 rd harmonic filter and the 5 th harmonic filter which are connected in parallel is better than the waveform generated by the 3 rd harmonic filter which is used alone, if the capacity of the matched filter is in an optimal value, the capacity of a test power supply can be obviously reduced, and the auxiliary effect on a field test is realized.

Drawings

FIG. 1 is a circuit diagram of the present invention;

FIG. 2 is a schematic circuit diagram according to embodiment 1 of the present invention;

FIG. 3 is a schematic circuit diagram according to embodiment 2 of the present invention;

in the figure, a1-a2 are capacitor banks, and b1-b4 are reactors.

Detailed Description