CN103558493A - Extra-high voltage zinc oxide arrester leakage current measurement device and method - Google Patents

Abstract

The invention discloses an extra-high voltage zinc oxide arrester leakage current measurement device and method to solve the problems that test reading of an extra-high voltage zinc oxide arrester used in an extra-high voltage transformer substation can not be conveniently conducted and the influence of a leakage current is interfered with. The extra-high voltage zinc oxide arrester leakage current measurement device comprises a voltage regulator (1), a high-voltage silicon pile rectifier (10) and the extra-high voltage zinc oxide arrester (8). An alternating current power supply is connected to a primary edge of the voltage regulator, one end of a secondary edge of the voltage regulator is connected with an input end of the high-voltage silicon pile rectifier, an output end of the high-voltage silicon pile rectifier is connected with one end of the extra-high voltage zinc oxide arrester, the other end of the extra-high voltage zinc oxide arrester is connected with the ground, the other end of the secondary edge of the voltage regulator is connected with the ground after being sequentially connected with a milliammeter (2), a microammeter (3) and an inductor (5) in series, and a voltmeter (9) is connected between the output end of the high-voltage silicon pile rectifier and a connecting end of the milliammeter and the microammeter in parallel. According to the extra-high voltage zinc oxide arrester leakage current measurement device and method, reading can be conveniently and easily conducted, and the influences of a high voltage on measurement of the microammeter do not exist.

Description

UHV zinc oxide surge arrester leakage current measuring device and its measuring method

technical field

The invention relates to a circuit device for measuring leakage current of an ultra-high voltage zinc oxide arrester and a detection method thereof.

Background technique

In AC power transmission and transformation projects, in order to ensure the safety of power transformation equipment and avoid damage to equipment by external lightning shocks, zinc oxide arresters are installed near equipment. Zinc oxide surge arrester is one of the basic electrical components of substations. It is made of non-linear zinc oxide resistors to prevent external lightning strikes or internal overvoltage shocks from damaging electrical equipment. In the handover or diagnostic test, it is necessary to test the DC reference voltage of the zinc oxide arrester at the DC reference current (milliamp level) and the leakage current measurement (microamp level) at 0.75 times the DC reference voltage. The current existing DC high-voltage generators measure the leakage current by installing a microammeter on the high-voltage side of the arrester for measurement. inconvenient. The microammeter is always connected in series in the test circuit, and the microammeter is required to withstand a large DC reference current. The reference current of the UHV surge arrester reaches 8mA, and it is at the high voltage end, so the requirements for the microammeter are very high. The microammeter is connected to the high-voltage end of the arrester, and the leakage current tested will include the stray interference leakage current of the arrester itself to the surrounding air or equipment, and the measurement error is large.

Contents of the invention

The invention provides an ultra-high voltage zinc oxide arrester leakage current measuring device and a measurement method thereof, which solves the problems of inconvenient test readings and interference leakage current influences of the ultra-high voltage zinc oxide arrester applied in an ultra-high voltage substation.

The present invention solves the above technical problems through the following technical solutions:

A leakage current measurement device for an UHV zinc oxide arrester, comprising a voltage regulator, a high voltage silicon stack rectifier and an UHV zinc oxide arrester, an AC power supply is connected to the primary side of the voltage regulator, and one end of the secondary side of the voltage regulator is connected to the The input end of the high-voltage silicon stack rectifier is connected, the output end of the high-voltage silicon stack rectifier is connected to one end of the UHV zinc oxide arrester, the other end of the UHV zinc oxide arrester is grounded, and the other end of the secondary side of the voltage regulator is connected in series with a mA meter , the microammeter and the inductor are connected to the ground, a voltmeter is connected in parallel between the connection end of the milliampere meter and the microammeter and the output end of the high-voltage silicon stack rectifier, and a hand press is connected in parallel at both ends of the microammeter close the switch.

A capacitor and a discharge fuse are respectively connected in parallel between the connection terminals of the milliammeter and the microammeter and the ground.

A method for measuring the leakage current of a UHV zinc oxide arrester, comprising the following steps:

The first step is to connect the AC power supply on the primary side of the voltage regulator. One end of the secondary side of the voltage regulator is connected to the input end of the high-voltage silicon stack rectifier, and the output end of the high-voltage silicon stack rectifier is connected to one end of the UHV zinc oxide arrester. , the other end of the UHV zinc oxide surge arrester is grounded, and the other end of the secondary side of the voltage regulator is connected to the ground in series with the milliammeter, microammeter and inductor in sequence. A voltmeter is connected in parallel between the output terminals of the silicon stack rectifier, and a normally closed switch is pressed in parallel at both ends of the microammeter;

The second step is to control the voltage output of the voltage regulator to rise steadily. When the mA meter reaches 8 mA, read the voltage value of the parallel voltmeter between the output terminals of the high-voltage silicon stack rectifier, that is, the DC reference current under the DC reference current of the arrester. Voltage value;

The third step is to control the voltage of the voltage regulator to reduce the voltage value of the parallel voltmeter to 75% of the DC reference voltage value, press the hand-pressed normally closed switch connected in parallel at both ends of the microammeter, and connect the microammeter to the measurement circuit , read the current value of the microammeter, that is, the leakage current value at 0.75 times the DC reference voltage;

The fourth step is to reset the normally closed switch by hand, control the voltage of the voltage regulator, and slowly reduce the voltage value of the parallel voltmeter to zero, disconnect the power supply, and the test is over.

In the invention, the microammeter is connected to the low-voltage end of the test circuit in the measuring circuit, the reading is convenient and simple, and there is no influence of high voltage on the measurement of the microammeter. the

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

Detailed ways

The present invention is described in detail below in conjunction with accompanying drawing:

A leakage current measurement device for an UHV zinc oxide arrester, comprising a voltage regulator 1, a high voltage silicon stack rectifier 10 and an UHV zinc oxide arrester 8, an AC power supply is connected to the primary side of the voltage regulator 1, and the voltage regulator 1 One end of the secondary side is connected to the input end of the high-voltage silicon stack rectifier 10, the output end of the high-voltage silicon stack rectifier 10 is connected to one end of the UHV zinc oxide arrester 8, the other end of the UHV zinc oxide arrester 8 is grounded, and the voltage regulator 1 The other end of the secondary side is connected in series with the milliampere meter 2, the microammeter meter 3 and the inductor 5 in series, and connected in parallel between the connection end of the milliampere meter 2 and the microammeter meter 3 and the output end of the high-voltage silicon stack rectifier 10 There is a voltmeter 9, and a hand press normally closed switch 4 is connected in parallel at the two ends of the microammeter 3.

A capacitor 7 and a discharge fuse 6 are respectively connected in parallel between the connection terminals of the milliampere meter 2 and the microammeter 3 and the ground.

In the microammeter protection control circuit, the capacitor filters out the AC component in the measurement circuit, stabilizes the reading of the microammeter 3 and ensures the voltage stability of the discharge fuse 6 . The discharge fuse 6 protects the microammeter 3 and short-circuits the microampmeter 3 when passing an over-range current, protects the microampmeter 3, and the inductor 5 prevents the discharge fuse 6 from acting in a sudden short circuit and damages the microammeter 3 by an inrush current when the discharge fuse 6 is too late to act.

A method for measuring the leakage current of a UHV zinc oxide arrester, comprising the following steps:

The first step is to connect the AC power supply on the primary side of the voltage regulator 1, one end of the secondary side of the voltage regulator 1 is connected to the input end of the high-voltage silicon stack rectifier 10, and the output end of the high-voltage silicon stack rectifier 10 is connected to the UHV zinc oxide One end of the surge arrester 8 is connected, the other end of the UHV zinc oxide arrester 8 is grounded, and the other end of the secondary side of the voltage regulator 1 is connected in series with the milliampere meter 2, the microampere meter 3 and the inductor 5, and then connected to the ground. A voltmeter 9 is connected in parallel between the connection end of the meter 2 and the microammeter 3 and the output end of the high-voltage silicon stack rectifier 10, and the two ends of the microammeter 3 are connected in parallel to press the normally closed switch 4;

The second step, control the voltage output of the voltage regulator 1 to rise steadily, until the measured mA meter 2 reaches 8 mA, read the voltage value of the parallel voltmeter 9 between the output terminals of the high-voltage silicon stack rectifier 10, that is, the DC reference current of the arrester The DC reference voltage value under;

The third step is to control the voltage of the voltage regulator 1, so that the voltage value of the parallel voltmeter 9 drops to 75% of the DC reference voltage value, press the hand-pressed normally closed switch 4 connected in parallel at both ends of the microammeter 3, and turn the microammeter 3 Connect to the measurement circuit, read the current value of the microammeter 3, that is, the leakage current value at 0.75 times the DC reference voltage;

The fourth step is to reset the normally closed switch 4 by hand, control the voltage of the voltage regulator 1, and slowly reduce the voltage value of the parallel voltmeter 9 to zero, disconnect the power supply, and the test ends.

Claims (3)

1. a ZnO Arrester for UHV leakage current measurement device, comprise pressure regulator (1), high-voltage silicon rectifier stack (10) and ZnO Arrester for UHV (8), it is characterized in that, on the former limit of pressure regulator (1), be connected with AC power, the one end on the inferior limit of pressure regulator (1) is connected with the input end of high-voltage silicon rectifier stack (10), the output terminal of high-voltage silicon rectifier stack (10) is connected with one end of ZnO Arrester for UHV (8), the other end ground connection of ZnO Arrester for UHV (8), the other end on the inferior limit of pressure regulator (1) milliammeter (2) of connecting successively, microampere meter (3) is connected with ground with inductor (5) is rear, between the link of milliammeter (2) and microampere meter (3) and the output terminal of high-voltage silicon rectifier stack (10), be parallel with voltage table (9), at the two ends of microampere meter (3), be parallel with hand by normally closed switch (4).

2. a kind of ZnO Arrester for UHV leakage current measurement device according to claim 1, is characterized in that, is parallel with respectively capacitor (7) and electric discharge fuse (6) between the link of milliammeter (2) and microampere meter (3) and ground.

3. a ZnO Arrester for UHV leakage current measuring method, comprises the following steps:

The first step, on the former limit of pressure regulator (1), connect AC power, the one end on the inferior limit of pressure regulator (1) is connected with the input end of high-voltage silicon rectifier stack (10), the output terminal of high-voltage silicon rectifier stack (10) is connected with one end of ZnO Arrester for UHV (8), the other end ground connection of ZnO Arrester for UHV (8), the other end on the inferior limit of pressure regulator (1) milliammeter (2) of connecting successively, microampere meter (3) is connected with ground with inductor (5) is rear, shunt voltage table (9) between the link of milliammeter (2) and microampere meter (3) and the output terminal of high-voltage silicon rectifier stack (10), normally closed switch (4) is also jointly pressed at two ends at microampere meter (3),

The stable rising of Voltage-output of second step, control pressure regulator (1), milliammeter to be measured (2) reaches 8 milliamperes, read the magnitude of voltage of shunt voltage table (9) between high-voltage silicon rectifier stack (10) output terminal, i.e. DC reference voltage value under the direct-current reference current of lightning arrester;

The voltage of the 3rd step, control pressure regulator (1), make the magnitude of voltage of shunt voltage table (9) be down to 75% DC reference voltage value, press the hand of microampere meter (3) two ends parallel connection and press normally closed switch (4), by microampere meter (3) access measuring circuit, read the current value of microampere meter (3), i.e. leakage current values under 0.75 times of DC reference voltage;

The 4th step, hand is resetted by normally closed switch (4), control the voltage of pressure regulator (1), make the magnitude of voltage of shunt voltage table (9) slowly be down to zero, deenergization, test finishes.

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