CN106680566A - Spark gap insulation recovery voltage detection device and detection method thereof - Google Patents

Abstract

The present invention provides a spark gap insulation recovery voltage detection device and a detection method thereof. The detection device includes: a current generating device: the output end of which is connected in series with a controllable switch K1 and connected in parallel with the spark gap for outputting current to the spark gap; voltage Generating device: its output end is connected in parallel with the spark gap after the controllable switch K2 is connected in series, and is used to output voltage to the spark gap; voltage dividing device: connected in parallel at the output end of the voltage generating device, used to detect the output voltage of the voltage generating device; Control circuit: connected to the voltage generating device, used to detect the alternating current at the output end of the voltage generating device and the output voltage of the voltage regulator, and control the opening of the voltage generating device according to the alternating current and the output voltage or off. The detection device and method provided by the invention can obtain a series of effective data points for each detection, which reduces the detection cost and improves the detection efficiency.

Description

A spark gap insulation recovery voltage detection device and detection method thereof

technical field

The invention relates to a detection device and a detection method thereof, in particular to a spark gap insulation recovery voltage detection device and a detection method thereof.

Background technique

The China Electric Power Research Institute applied the series compensation device to the UHV demonstration project for the first time. Although the performance parameters of the current series compensation device can meet the requirements of the project, with the continuous development of the UHV series compensation technology, the follow-up The requirements for the rated voltage and rated current of the UHV series compensator will be higher and higher. In order to improve the rated voltage and rated current of the series compensator, it is necessary to conduct in-depth research on the performance of the UHV series compensator.

Generally, the series compensator is put into use after the line fault is cleared, but sometimes in order to improve the stability of the system, the series compensator is required to be put into the line before the line is successfully re-introduced, which is harmful to the series compensator. The re-commissioning time of the spark gap puts forward higher requirements, and the spark gap insulation recovery voltage is the main factor affecting the re-commissioning time of the series compensator. Therefore, it is necessary to study the insulation recovery voltage of the spark gap to improve the reliability of the series compensator. sex.

The spark gap insulation recovery voltage refers to the voltage that restores the spark gap insulation medium after the spark gap is broken down. In the prior art, the detection of the insulation recovery voltage of the spark gap is carried out by estimating the method. The specific method is: firstly, the insulation recovery time and the insulation recovery voltage of the fire gap are estimated; after the initial arcing of the spark gap, the estimated insulation recovery After a period of time, apply a voltage according to the estimated value of the insulation recovery voltage; pressurize and measure from a range with a large margin near the estimated value of the insulation recovery voltage, and narrow the range step by step for detection until the insulation performance of the spark gap is restored. Record the applied voltage at this time as Spark gap insulation recovery voltage: The specific way to judge whether the insulation performance of the spark gap is restored is as follows: when a voltage is applied to the spark gap, if the gap continues to discharge, the insulation performance has not recovered. If the gap no longer discharges, it means that the insulation performance is restored, and it also means that the insulation performance of the spark gap can be restored under the conditions of greater than the estimated insulation recovery time and less than the applied voltage, but this range is too wide. If you need more accurate data, it is necessary to repeatedly debug the applied voltage and time interval; the detection efficiency is particularly low, and the detection cost is high; Time arcing has a great influence on the insulation performance of the gap, and the obtained insulation recovery voltage data is not accurate.

Contents of the invention

In order to solve the above-mentioned problems existing in the prior art, the present invention provides a spark gap insulation recovery voltage detection device and its detection method. Through this detection device and detection method, a series of effective data points can be obtained for each detection , after the gap is burnt by a high-current arc, the quantitative rule of the gap insulation recovery voltage changing with time can be obtained, the detection cost is reduced, and the detection efficiency and detection accuracy are improved.

The technical solution provided by the present invention is: a spark gap insulation recovery voltage detection device, the improvement of which is that the detection device includes:

Current generating device: its output end is connected in parallel with the spark gap after the controllable switch K1 is connected in series, and is used to output current to the spark gap;

Voltage generating device: its output end is connected in parallel with the spark gap after the controllable switch K2 is connected in series, and is used to output voltage to the spark gap;

Voltage dividing device: connected in parallel to the output terminal of the voltage generating device, used to detect the output voltage of the voltage generating device;

Control circuit: connected to the voltage generating device, used to detect the alternating current at the output end of the voltage generating device and the output voltage of the voltage regulator, and control the opening of the voltage generating device according to the alternating current and the output voltage or off.

Preferably, the current generating device includes a current source, a current booster and a circuit breaker; the output terminal of the current source is connected in parallel with the input terminal of the current booster, and the output terminal of the current booster is connected to the incoming line side of the circuit breaker In parallel connection, the outlet side of the circuit breaker is connected in series with the controllable switch K1 and then connected in parallel with the spark gap, the low voltage end of the spark gap is grounded, and the high voltage end is connected to the controllable switch K1.

Preferably, the voltage generating device includes a voltage source, a voltage regulator and a voltage booster; the output terminal of the voltage source is connected in parallel with the input terminal of the voltage regulator, and the output terminal of the voltage regulator is connected with the voltage booster The input terminal of the booster is connected in parallel, and the output terminal of the booster is connected in parallel with the spark gap after being connected in series with the controllable switch K2.

Preferably, the control circuit includes a current detection loop, a quick-break control switch and an isolated power supply; the isolated power supply is connected to the quick-break control switch for providing working power to the quick-break control switch; the current detection loop is connected to The output end of the booster and the input end of the quick-break control switch are used to detect the current at the output end of the booster, and transmit the detected current to the quick-break control switch; An output of the voltage generating means is controlled.

Further, the current detection loop includes a passive current transformer, a rectifier circuit, a shunt circuit and an optical fiber transceiver circuit; the input end of the passive current transformer is connected in series between the output end of the booster and the low-voltage end of the spark gap On the line, its output end is connected in parallel with the input end of the rectification circuit; the output end of the rectification circuit is connected in parallel with the input end of the shunt circuit; the output end of the shunt circuit is connected in parallel with the input end of the optical fiber transceiver circuit; the optical fiber The output end of the transceiver circuit is connected to the input end of the quick-break control switch through an optical fiber.

Further, the passive current transformer detects the AC current output by the booster, and transmits the AC current to the rectification circuit; the rectification circuit converts the AC current into a DC current and outputs it to the The shunt circuit; the shunt circuit shunts the direct current and outputs it to the optical fiber transceiver circuit, and the optical fiber transceiver circuit converts the received direct current signal into an optical signal and transmits it to the quick-break control switch through an optical fiber.

Further, the shunt circuit includes resistors R1 and R2, and a diode series branch; the resistor R1 is connected in parallel with the diode series branch and then connected in parallel with the output end of the rectifier circuit; one end of the diode series branch is connected in series The other end of the resistor R2 is grounded, and the input end of the optical fiber transceiver circuit is connected in parallel between the other end of the resistor R2 and the grounding end.

Further, the quick-break control switch includes a voltage zero-crossing detection circuit, a photoelectric conversion circuit, a control chip, a driving and protection circuit, and a power switch; the input end of the voltage zero-crossing detection circuit is connected in parallel with the output end of the voltage regulator, and the output end Connected with the control chip, used to detect the output voltage of the voltage regulator, and send the detected voltage to the control chip; the input end of the photoelectric conversion circuit communicates with the output of the optical fiber transceiver circuit through the optical fiber The output end is connected to the control chip, and is used to convert the optical signal output by the optical fiber transceiver circuit into a current signal and then transmit it to the control chip; the control chip communicates with the power switch through the drive protection circuit The control terminal is connected, and the power switch is connected in series with the output terminal of the voltage regulator; the control chip controls the power switch to turn on or off according to the current signal output by the optical fiber transceiver circuit and the voltage signal output by the voltage regulator off.

Preferably, both the controllable switch K1 and the controllable switch K2 are 35KV circuit breakers; the output end of the voltage divider is connected to the recording and broadcasting equipment, and the voltage detected by the voltage divider is analyzed and analyzed by the recording and broadcasting equipment. Record.

Another object of the present invention is to provide a spark gap insulation recovery voltage detection method, the method includes: installing a fuse for the spark gap; ensuring that the current generating device and the voltage generating device are disconnected; Spark gap input current; after current arcing occurs in the spark gap, disconnect the current generating device, connect the voltage generating device, and input voltage to the spark gap; detect the output terminal current of the voltage generating device and adjust The output voltage of the voltage regulator, when detecting that the output current is a pulse current, turn off the power switch, and when detecting that the output voltage of the voltage regulator crosses zero, turn on the power switch; record the voltage generated The output voltage of the device; when the power switch is turned on and the output current of the voltage generating device is 0, the output voltage of the voltage generating device is the spark gap insulation recovery voltage.

Compared with the closest prior art, the present invention has following remarkable progress:

The detection method and detection device provided by the present invention adopt digital control technology to precisely control the moment when the gap voltage is applied, and immediately cut off the voltage circuit after arcing to shorten the gap arcing time and minimize the impact of arcing on the gap and the environment. Influenced by the influence, the voltage loop is opened again at the zero-crossing point of the input voltage, and the voltage is applied at both ends of the gap. According to the gap voltage waveform recorded by the oscilloscope, the recovery process of the gap voltage insulation performance can be clearly obtained. Therefore, the obtained data is more effective, the detection cost is reduced, and the detection efficiency is improved.

Description of drawings

Fig. 1 is the circuit schematic diagram of the spark gap insulation recovery voltage detection device provided by the present invention;

Fig. 2 is a circuit schematic diagram of the current detection loop in Fig. 1;

Fig. 3 is a block diagram of the hardware structure of the quick-break control switch in Fig. 1 .

1-voltage source; 2-voltage regulator; 3-booster; 4-voltage divider; 5-controllable switch K2; 6-controllable switch K1; 7-current booster; 8-current source; 9- circuit breaker; 10-passive current transformer.

detailed description

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

In order to thoroughly understand the embodiments of the present invention, the detailed structure will be set forth in the following description. Obviously, the practice of the embodiments of the invention is not limited to specific details familiar to those skilled in the art. Preferred embodiments of the present invention are described in detail below, however, the present invention may have other embodiments besides these detailed descriptions.

The schematic diagram of the circuit principle of the spark gap insulation recovery voltage detection device provided by the present invention is shown in Figure 1, and the detection device includes:

Current generating device: its output end is connected in parallel with the spark gap after the controllable switch K1 is connected in series, and is used to output current to the spark gap;

Voltage generating device: its output end is connected in parallel with the spark gap after the controllable switch K2 is connected in series, and is used to output voltage to the spark gap;

Voltage dividing device: connected in parallel to the output terminal of the voltage generating device, used to detect the output voltage of the voltage generating device;

Control circuit: connected to the voltage generating device, used to detect the alternating current at the output end of the voltage generating device and the output voltage of the voltage regulator, and control the opening of the voltage generating device according to the alternating current and the output voltage or off.

Both the controllable switch K1 and the controllable switch K2 are 35KV circuit breakers; the output end of the voltage divider is connected to the recording and broadcasting equipment, and the output voltage of the voltage generating device detected by the voltage divider passes through the recording broadcast equipment analysis and recording.

The current generating device includes a current source, a current booster and a circuit breaker; the output terminal of the current source is connected in parallel with the input terminal of the current booster, and the output terminal of the current booster is connected in parallel with the incoming line side of the circuit breaker. The outlet side of the circuit breaker is connected in series with the controllable switch K1 and then in parallel with the spark gap, the low voltage end of the spark gap is grounded, and the high voltage end is connected to the controllable switch K1.

The voltage generating device includes a voltage source, a voltage regulator and a voltage booster; the output end of the voltage source is connected in parallel with the input end of the voltage regulator, and the output end of the voltage regulator is connected to the input end of the voltage booster connected in parallel, the output end of the booster is connected in parallel with the spark gap after being connected in series with the controllable switch K2.

The control circuit includes a current detection loop, a quick-break control switch and an isolated power supply; the isolated power supply is connected to the quick-break control switch and is used to provide working power for the quick-break control switch; the current detection loop is respectively connected to a booster The output end of the quick-break control switch and the input end of the quick-break control switch are used to detect the current at the output end of the booster, and transmit the detected current to the quick-break control switch; the quick-break control switch controls the The output of the voltage generating device.

The circuit schematic diagram of the current detection loop is as shown in Figure 2: the current detection loop includes a passive current transformer, a rectifier circuit, a shunt circuit and an optical fiber transceiver circuit; On the connecting line between the output end of the voltage transformer and the low voltage end of the spark gap, its output end is connected in parallel with the input end of the rectification circuit; the output end of the rectification circuit is connected in parallel with the input end of the shunt circuit; the output end of the shunt circuit is connected with the The input end of the optical fiber transceiver circuit is connected in parallel; the output end of the optical fiber transceiver circuit is connected to the input end of the quick-break control switch through an optical fiber.

The passive current transformer detects the AC current output by the booster, and transmits the AC current to the rectifier circuit; the rectifier circuit converts the AC current into a DC current and outputs it to the shunt circuit; the shunt circuit shunts the direct current and outputs it to the optical fiber transceiver circuit, and the optical fiber transceiver circuit converts the received direct current signal into an optical signal and transmits it to the quick-break control switch through an optical fiber.

The shunt circuit includes resistors R1 and R2, and a diode series branch; the resistor R1 is connected in parallel with the diode series branch and then connected in parallel with the output end of the rectifier circuit; one end of the diode series branch is connected in series with a resistor R2 , the other end is grounded, and the other end of the resistor R2 is connected in parallel with the input end of the optical fiber transceiver circuit; the resistance value of the resistor R1 is 10KΩ; the resistance value of the resistor R2 is 100Ω; the diode series branch Including four diodes in series: D5, D6, D7, D8.

The rectifier circuit includes a capacitor C1, diodes D1, D2, D3 and D4, the capacitor C1 is connected in parallel to the output end of the passive current transformer, the cathode of the diode D1 is connected to the cathode of the diode D3 and one end of the resistor R1, Its anode is connected to one end of the capacitor C1 and the anode of the diode D2; the cathode of the diode D2 is connected to the anode of the diode D4 and the other end of the resistor R1; the cathode of the diode D4 is connected to the anode of the diode D3 and the capacitor The other end of C1; the capacitance of the capacitor C1 is 33nF; the capacitor C1 is used for current signal filtering; the rectifier bridge composed of the diodes D1, D2, D3, and D4 is used for converting AC current into DC current.

The optical fiber transceiver circuit includes a capacitor C2, a diode D9 and a fiber optic transceiver U1; after the capacitor C2 and the diode D9 are connected in parallel, one end thereof is connected to the input interface An of the fiber optic transceiver U1, and the other end is connected to the input interface of the fiber optic transceiver U1 Ca; the capacitance of the capacitor C2 is 0.1 μF. Capacitor C2 and diode D9 are used to filter and prevent the reverse voltage from passing through; optical fiber transceiver U1 converts the spark gap current signal into an optical signal and sends it to the photoelectric conversion circuit of the quick-break control switch.

The hardware block diagram of the quick-break control switch is shown in Figure 3: the quick-break control switch includes a voltage zero-crossing detection circuit, a photoelectric conversion circuit, a control chip, a driving and protection circuit, and a power switch; The output terminal of the voltage regulator is connected in parallel, and its output terminal is connected with the control chip for detecting the output voltage of the voltage regulator, and sending the detected voltage to the control chip; the input terminal of the photoelectric conversion circuit Connect to the output end of the optical fiber transceiver circuit through an optical fiber, and its output end is connected to the control chip, and is used to convert the optical signal output by the optical fiber transceiver circuit into a current signal and then transmit it to the control chip; the control chip passes The drive protection circuit is connected to the control terminal of the power switch, and the power switch is connected in series with the output terminal of the voltage regulator; The voltage signal controls the power switch to be turned on or off.

The present invention also provides a detection method implemented by using the above-mentioned spark gap insulation recovery voltage detection device, the method mainly includes the following steps: installing a fuse for the spark gap; ensuring that the current generating device and the voltage generating device are disconnected; connecting the current generating device , input current to the spark gap; after the current arcing occurs in the spark gap, disconnect the current generating device, connect the voltage generating device, and input voltage to the spark gap; detect the output of the voltage generating device terminal current and the output voltage of the voltage regulator, when detecting that the output current is a pulse current, turn off the power switch, and when detecting that the output voltage of the voltage regulator crosses zero, turn on the power switch; record The output voltage of the voltage generating device; and so on. When there is no detection current (pulse current) after turning on the power switch, it can be considered that the gap insulation performance has been restored. Use a voltage recording instrument (such as an oscilloscope or oscilloscope) to record the output voltage of the voltage generating device (that is, the voltage at both ends of the spark gap). The spark gap is in a short circuit state at the moment of breakdown, and the voltage at both ends is zero. When the insulation performance is restored , the voltage at both ends appears a continuous sinusoidal voltage waveform, and the continuous sinusoidal waveform voltage that appears in the voltage recorder at this time is the spark gap insulation recovery voltage.

Installing a fuse to the spark gap is to install the fuse at both ends of the gap, which is used for the initial arcing of the spark gap by the high-current test power supply.

To ensure that the current generating device is disconnected is to ensure that the controllable switch K1 is disconnected, to ensure that the current source in the current generating device is in a disconnected state; to ensure that the circuit breaker between the current booster and the controllable switch K1 is disconnected.

To ensure that the voltage generating device is disconnected is to ensure that the controllable switch K2 is disconnected, and to ensure that the voltage source in the voltage generating device is in a disconnected state.

First connect the current generating device, and after a period of time, after the current arcing occurs in the spark gap, the controllable switch K1 is disconnected, and the controllable switch K2 and the voltage source are connected in conjunction with each other, and the voltage generating device is connected;

The output current of the voltage generating device and the output voltage of the voltage regulator are detected by the quick-break control switch; the power switch is in the on state under normal circumstances, and when the quick-break control switch detects that the output current is a pulse current, the power switch is turned off to make the boost The voltage regulator no longer provides energy to the spark gap that is broken down; after the power switch is disconnected for a period of time, the output voltage of the voltage regulator will drop to zero, and when it is detected that the output voltage of the voltage regulator crosses zero, turn on the power again switch, so that the booster gradually pressurizes the spark gap until the spark gap breaks down again;

The voltage divider has been detecting the output voltage of the voltage generating device throughout the detection process, and it is displayed and analyzed by the recording and broadcasting equipment; the output voltage of the voltage generating device is the voltage at both ends of the spark gap, and a voltage recording instrument (such as an oscilloscope or recording oscilloscope) to record the voltage at both ends of the spark gap. The spark gap is in a short-circuit state at the moment of breakdown, and the voltage at both ends is 0. When the insulation performance is restored, the voltage at both ends appears a continuous sinusoidal voltage waveform. At this time, the continuous The sinusoidal waveform voltage is the insulation recovery voltage.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still implement the present invention Any modification or equivalent replacement that does not deviate from the spirit and scope of the present invention is within the protection scope of the pending claims.

Claims (10)

1. A spark gap insulation recovery voltage detection device, characterized in that: the detection device comprises: Current generating device: its output end is connected in parallel with the spark gap after the controllable switch K1 is connected in series, and is used to output current to the spark gap; Voltage generating device: its output end is connected in parallel with the spark gap after the controllable switch K2 is connected in series, and is used to output voltage to the spark gap; Voltage dividing device: connected in parallel to the output terminal of the voltage generating device, used to detect the output voltage of the voltage generating device; Control circuit: connected to the voltage generating device, used to detect the alternating current at the output end of the voltage generating device and the output voltage of the voltage regulator, and control the opening of the voltage generating device according to the alternating current and the output voltage or off. 2. A spark gap insulation recovery voltage detection device according to claim 1, characterized in that: The current generating device includes a current source, a current booster and a circuit breaker; the output terminal of the current source is connected in parallel with the input terminal of the current booster, and the output terminal of the current booster is connected in parallel with the incoming line side of the circuit breaker. The outlet side of the circuit breaker is connected in series with the controllable switch K1 and then in parallel with the spark gap, the low voltage end of the spark gap is grounded, and the high voltage end is connected to the controllable switch K1. 3. A spark gap insulation recovery voltage detection device according to claim 1, characterized in that: The voltage generating device includes a voltage source, a voltage regulator and a voltage booster; the output end of the voltage source is connected in parallel with the input end of the voltage regulator, and the output end of the voltage regulator is connected to the input end of the voltage booster connected in parallel, the output end of the booster is connected in parallel with the spark gap after being connected in series with the controllable switch K2. 4. A spark gap insulation recovery voltage detection device according to claim 1, characterized in that: The control circuit includes a current detection loop, a quick-break control switch and an isolated power supply; the isolated power supply is connected to the quick-break control switch and is used to provide working power for the quick-break control switch; the current detection loop is respectively connected to a booster The output end of the quick-break control switch and the input end of the quick-break control switch are used to detect the current at the output end of the booster, and transmit the detected current to the quick-break control switch; the quick-break control switch controls the The output of the voltage generating device. 5. A spark gap insulation recovery voltage detection device according to claim 4, characterized in that: The current detection circuit includes a passive current transformer, a rectifier circuit, a shunt circuit and an optical fiber transceiver circuit; the input end of the passive current transformer is connected in series on the connection line between the output end of the booster and the low voltage end of the spark gap , the output end of which is connected in parallel with the input end of the rectification circuit; the output end of the rectification circuit is connected in parallel with the input end of the shunt circuit; the output end of the shunt circuit is connected in parallel with the input end of the optical fiber transceiver circuit; the optical fiber transceiver circuit The output end of the optical fiber is connected with the input end of the quick-break control switch. 6. A spark gap insulation recovery voltage detection device according to claim 5, characterized in that: The passive current transformer detects the AC current output by the booster, and transmits the AC current to the rectifier circuit; the rectifier circuit converts the AC current into a DC current and outputs it to the shunt circuit; the shunt circuit shunts the direct current and outputs it to the optical fiber transceiver circuit, and the optical fiber transceiver circuit converts the received direct current signal into an optical signal and transmits it to the quick-break control switch through an optical fiber. 7. A spark gap insulation recovery voltage detection device according to claim 5, characterized in that: The shunt circuit includes resistors R1 and R2, and a diode series branch; the resistor R1 is connected in parallel with the diode series branch and then connected in parallel with the output end of the rectifier circuit; one end of the diode series branch is connected in series with a resistor R2 , the other end is grounded, and the input end of the optical fiber transceiver circuit is connected in parallel between the other end of the resistor R2 and the ground end. 8. The spark gap insulation recovery voltage detection device according to any one of claims 4-7, characterized in that: The quick-break control switch includes a voltage zero-crossing detection circuit, a photoelectric conversion circuit, a control chip, a driving and protection circuit, and a power switch; the input end of the voltage zero-crossing detection circuit is connected in parallel with the output end of the voltage regulator, and its output end is connected to the control chip for detecting the output voltage of the voltage regulator and sending the detected voltage to the control chip; the input end of the photoelectric conversion circuit is connected to the output end of the optical fiber transceiver circuit through an optical fiber , the output end of which is connected to the control chip, and is used to convert the optical signal output by the optical fiber transceiver circuit into a current signal and then transmit it to the control chip; the control chip is controlled by the drive protection circuit and the power switch The power switch is connected in series with the output terminal of the voltage regulator; the control chip controls the power switch to be turned on or off according to the current signal output by the optical fiber transceiver circuit and the voltage signal output by the voltage regulator . 9. A spark gap insulation recovery voltage detection device according to claim 1, characterized in that: Both the controllable switch K1 and the controllable switch K2 are 35KV circuit breakers; the output end of the voltage divider is connected to the recording and broadcasting equipment, and the voltage detected by the voltage divider is analyzed and recorded by the recording and broadcasting equipment. 10. A spark gap insulation recovery voltage detection method realized by the detection device according to any one of claims 1-9, characterized in that: the method includes: installing a fuse for the spark gap; ensuring that the current generating device and The voltage generating device is disconnected; the current generating device is connected, and current is input to the spark gap; after the current arcing occurs in the spark gap, the current generating device is disconnected, and the voltage generating device is connected, and the current is supplied to the spark gap. Input voltage: detect the output terminal current of the voltage generating device and the output voltage of the voltage regulator, when detecting that the output current is a pulse current, disconnect the power switch, and when detecting that the output voltage of the voltage regulator is too high At zero time, turn on the power switch; record the output voltage of the voltage generating device; when the power switch is turned on, the output current of the voltage generating device is 0, the output voltage of the voltage generating device That is the spark gap insulation recovery voltage.