Capacity expansion device and discharge method

Abstract

The present invention discloses a capacity expansion device and discharge method, comprising a pulse capacitor for expanding the capacity of a high-voltage signal generator. A protective discharge gap and a protective resistor are connected in parallel between the two electrodes of the pulse capacitor, and an adjustable gap, whose opening and closing are wirelessly controlled, is connected in series between the high-voltage electrode of the pulse capacitor and the faulty cable. By increasing the capacity of the energy storage capacitor and thereby increasing the discharge energy, the present invention ensures that the signal emitted by the high-voltage signal generator during fault testing has sufficient energy at a relatively low voltage, ensuring test signal strength while protecting the cable from overvoltage shocks.

Description

Technical Field

[0001] The present invention relates to the field of cable fault testing equipment, and in particular to a capacity expansion device and a discharge method. Background Art

[0002] With the development of the power and energy industries and the accelerated pace of urban transformation, the length of power cables installed is increasing year by year, and various cables are increasingly used in various areas of production and life. Once a cable fault occurs, it is difficult to locate it. How to accurately, quickly, and economically locate cable faults has become a growing concern for power supply departments.

[0003] During cable fault testing, a high-voltage signal generator stores energy in a pulse capacitor. This energy is then released into the cable through a high-voltage switch, briefly bringing the faulty cable back online and puncturing the fault point. The resulting signal is then used for fault location and pinpointing. In actual cable fault testing, the signal strength of the high-voltage signal generator is highly dependent on the signal energy. This is due to factors such as varying cable burial depths, water ingress into the cable joints, high noise levels near the test site, and poor environmental conditions. To facilitate fault testing, the high-voltage signal strength can be enhanced by increasing the DC voltage of the high-voltage signal generator or increasing the pulse capacitor capacitance. However, simply increasing the discharge voltage for low-voltage cables can cause unnecessary damage to the cable's integrity. Currently, most DC high-voltage signal generators used for cable fault testing utilize fixed capacitors, resulting in higher single-shot energy at the highest voltage and lower single-shot energy at lower voltages. This makes fault testing on low-voltage cables more difficult. Summary of the Invention

[0004] In order to overcome the defects and shortcomings of the prior art, the present invention provides a capacity expansion device and a discharge method for storing energy in a DC high-voltage signal generator.

[0005] This capacity expansion device is mainly suitable for low-voltage cable fault testing. It is used to quickly expand the pulse capacitor capacity of the high-voltage signal generator and release the capacitor capacity to the cable under test through an adjustable gap.

[0006] The present invention adopts the following technical solutions:

[0007] A capacity expansion device includes a pulse capacitor for expanding the capacity of a high-voltage signal generator. A protective discharge gap and a protective resistor are connected in parallel between the two poles of the pulse capacitor, and an adjustable gap that uses wireless control to open and close the gap is connected in series between the high-voltage pole of the pulse capacitor and the fault cable.

[0008] Furthermore, the pulse capacitor has a capacity of 32 μF and a withstand voltage of 15 kV.

[0009] Furthermore, the protective discharge gap includes two copper ball heads fixed on an insulating bracket, with screws welded to the ends of the copper ball heads. The distance between the two copper ball heads is adjusted by rotating the screws so that the breakdown voltage is 15kV. The two copper ball heads are respectively connected to the two poles of the pulse capacitor.

[0010] Furthermore, the protective resistor is a high-voltage resistor of 10MΩ and a withstand voltage of 32kV.

[0011] Furthermore, the pulse capacitor is provided with two charging plates, which are fixed to the casing at both ends through insulating plates. When charging, the output end of the high-voltage signal generator is connected to the two charging plates respectively.

[0012] Furthermore, the adjustable gap includes a wireless controller part and a high-voltage discharge gap part.

[0013] Furthermore, the wireless controller part includes a fixed receiving end and a movable remote control end, the input end of the fixed receiving end is connected to the 220V mains electricity, and the output end is connected to the power supply of the electromagnet with adjustable gap.

[0014] Furthermore, the screw is made of copper.

[0015] A discharge method for a capacity expansion device is disclosed. The input end of the capacity expansion device is respectively connected to the output end and the ground end of a high-voltage signal generator, and the output end is connected to a cable under test and the ground end. The high-voltage signal generator is adjusted to a DC output position. At this time, a built-in capacitor of the high-voltage signal generator is connected in parallel with the capacitor of the capacity expansion device. After the voltage of the high-voltage signal generator is adjusted to a preset value, a discharge remote control of the capacity expansion device is clicked. The adjustable gaps in the capacity expansion device are brought closer together, and the energy on the capacitor is released into the cable under test.

[0016] Furthermore, the working process of the adjustable gap is:

[0017] A fixed copper ball head is installed at the bottom of the high-voltage discharge gap, and a copper ball head that can move up and down is connected to the top through the electromagnet armature. When the electromagnet is energized, the upper copper ball head moves with the electromagnet armature and is separated from the fixed copper ball head by a distance of 10 mm. When the electromagnet is powered off, the upper copper ball head falls due to gravity and contacts the lower copper ball head, completing the discharge action.

[0018] Beneficial effects of the present invention:

[0019] (1) The present invention improves the discharge energy by increasing the capacity of the energy storage capacitor, so that the signal emitted by the high-voltage signal generator during the fault test has sufficient energy at a lower voltage, thereby ensuring the strength of the test signal while protecting the cable from overvoltage impact;

[0020] (2) The protection gap is connected in parallel at both ends of the pulse capacitor of the present invention, so that the voltage at both ends of the extended capacitor can be automatically discharged after exceeding the rated voltage of the capacitor. Therefore, this device can be adapted to high-voltage signal generators of different voltage levels from different manufacturers.

[0021] (3) The protective resistor is connected in parallel at both ends of the pulse capacitor of the present invention to ensure that during the cable fault test, if the high voltage fails to break down, the pulse capacitor can discharge itself.

[0022] (4) By remotely controlling the discharge of the discharge device, the operator is ensured to stay away from the high-voltage part, thereby improving the safety of personnel during the high-voltage test. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 It is a schematic diagram of a high voltage signal generator in the prior art;

[0025] Figure 3 It is a simplified schematic diagram of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0027] Example

[0028] like Figure 1 As shown, a capacity expansion device is specifically used to expand the stored energy of a DC high-voltage signal generator. Specifically comprising:

[0029] Pulse capacitor 4 is used to expand the capacity of the high-voltage signal generator. It has a capacity of 32μF and a withstand voltage of 15kV.

[0030] The protective discharge gap 1 is connected in parallel between the two poles of the pulse capacitor to prevent the capacitor from overshooting.

[0031] The protection resistor 2 is connected in parallel between the two electrodes of the pulse capacitor and is used for self-discharging the capacitor. The protection resistor is a high-energy 305 protection resistor with a resistance of 10MΩ and a withstand voltage of 32kV.

[0032] The adjustable gap 3 is connected in series between the high-voltage pole of the pulse capacitor and the fault cable, and is used for a discharge gap with wirelessly controlled gap opening and closing for capacitor discharge.

[0033] Further protection of the discharge gap includes two copper ball heads fixed on the insulating bracket, with copper screws welded to the ends of the copper ball heads. The distance between the copper ball heads is adjusted by rotating the copper screws, and the breakdown voltage between the two ball heads is controlled to be 15kV. A high-voltage cable is fixed to one end of the copper screw, and the two ball heads are respectively connected to the two poles of the pulse capacitor.

[0034] Furthermore, the adjustable gap includes a wireless controller and a high-voltage discharge gap. The wireless controller includes a fixed receiving end and a movable remote control end. The receiving end input is connected to 220V AC power, and the output is connected to the electromagnet power supply of the discharge gap.

[0035] A fixed copper ball head is installed at the bottom of the high-voltage discharge gap, and a copper ball head that can move up and down is connected to the top through an electromagnet armature. When the electromagnet is energized, the upper copper ball head moves with the electromagnet armature and is separated from the fixed copper ball head by a distance of 10 mm. When the electromagnet is de-energized, the upper copper ball head falls due to gravity and contacts the lower copper ball head, completing the discharge action.

[0036] Specifically, the breakdown voltage and the distance between the two ball heads are suitable for safe and efficient fault location of low-voltage cables.

[0037] Furthermore, the charging plates are high-quality copper rods, which are fixed to the casing at both ends of the capacitor through insulating plates. When charging, the output ends of the high-voltage signal generator are connected to the copper rods at both ends respectively.

[0038] In the prior art, the high-voltage signal generator has a structure with a pulse capacitor, that is, the high-voltage unit and the pulse capacitor are combined together, and the pulse capacitor is built into the high-voltage signal generator. Since the capacitor is built into the integrated structure, the capacity expansion function cannot be achieved through conventional parallel capacitors.

[0039] The wiring method of the capacity expansion device of the present invention is as follows: the input end is connected to the output of the signal generator and the ground respectively, and the output end is connected to the cable core wire and the ground. The working process is as follows: the high-voltage signal generator is adjusted to the DC output gear. At this time, the built-in capacitor of the high-voltage generator is connected in parallel with the capacitor of the capacity expansion device. After the generator adjusts the voltage to a preset value, the discharge remote control of the capacity expansion device is clicked, and the adjustable gap in the capacity expansion device is closed to release the energy on the capacitor into the cable under test.

[0040] like Figure 2 The figure shows the principle of the high-voltage signal generator. Switch K1 and switch K2 are switches of the high-voltage signal generator, and C1 is a built-in pulse capacitor.

[0041] When the high-voltage generator is charging, switches K1 and K2 are disconnected. After the capacitor C1 is fully charged, switch K1 is closed, and the capacitor C1 discharges to the cable via Hv and GND. Switch K2 is used for automatic discharge after shutdown.

[0042] like Figure 3 As shown, a simplified schematic diagram of the capacity expansion device.

[0043] When switch K1 is closed and switch K2 is open, that is, when the high-voltage signal generator is working in DC state, capacitor C2 is connected in parallel between Hv and GND to complete the capacity expansion function of the high-voltage signal generator. At this time, a high-voltage switch K3 needs to be added. This switch is disconnected when the capacitor is charging, isolating the capacitor from the cable. After the capacitor is fully charged, the switch can be controlled to close to release the energy stored in the capacitor into the cable. When the machine is shut down, switch K2 can still complete the self-discharge function of the capacitor. Figure 3 shown.

[0044] The high voltage switch K3 is an adjustable gap. The capacitor C2 is a pulse capacitor connected in parallel with the device.

[0045] The adjustable gap is a ball gap composed of two copper balls, one moving and one static. The static copper ball is fixed on the base plate, and the moving copper ball is connected to a traction electromagnet vertically above through an insulating rod. When the electromagnet is powered on, the two copper balls separate. When the electromagnet is powered off, the two copper balls approach each other and eventually contact each other.

[0046] When implementing the present invention, a self-resetting switch is first used to manually control the electromagnet of switch K3 to control capacitor discharge. However, since this capacity expansion device is generally installed at the output end of the high-voltage generator, a certain distance from the high-voltage generator control end, for ease of operation and safety considerations, it was decided to use a device with remote power control to control the electromagnet on and off. After the high-voltage signal generator completes the boost, the discharge can be remotely controlled. Since people do not directly contact the capacity expansion device, safety risks are greatly eliminated. The remote control device can use a common remote control power supply on the market.

[0047] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A discharge method for a capacity expansion device, characterized in that: The capacity expansion device includes a pulse capacitor for expanding the capacity of the high-voltage signal generator, a protective discharge gap and a protective resistor are connected in parallel between the two poles of the pulse capacitor, and an adjustable gap with wireless control of gap opening and closing is connected in series between the high-voltage pole of the pulse capacitor and the fault cable; The input end of the capacity expansion device is respectively connected to the output end and the ground end of the high-voltage signal generator, and the output end of the capacity expansion device is connected to the cable under test and the ground end. The high-voltage signal generator is adjusted to the DC output gear. At this time, the built-in capacitor of the high-voltage signal generator is connected in parallel with the capacitor of the capacity expansion device. After the high-voltage signal generator adjusts the voltage to the preset value, the discharge remote control of the capacity expansion device is clicked, and the adjustable gaps in the capacity expansion device are close to each other, releasing the energy on the capacitor into the cable under test.

2. The discharge method according to claim 1, wherein: The working process of adjustable gap is: A fixed copper ball head is installed at the bottom of the high-voltage discharge gap, and a copper ball head that can move up and down is connected to the top through the electromagnet armature. When the electromagnet is energized, the upper copper ball head moves with the electromagnet armature and is separated from the fixed copper ball head by a distance of 10 mm. When the electromagnet is powered off, the upper copper ball head falls due to gravity and contacts the lower copper ball head, completing the discharge action.

3. The discharge method according to claim 1, wherein: The pulse capacitor has a capacity of 32 μF and a withstand voltage of 15 kV.

4. The discharge method according to claim 1, wherein: The protective discharge gap includes two copper ball heads fixed on an insulating bracket, with screws welded to the ends of the copper ball heads. The distance between the two copper ball heads is adjusted by rotating the screws so that the breakdown voltage is 15kV. The two copper ball heads are respectively connected to the two poles of the pulse capacitor.

5. The discharge method according to claim 1, characterized in that: The protective resistor is a 10MΩ high-voltage resistor with a withstand voltage of 32kV.

6. The discharge method according to claim 1, characterized in that: The pulse capacitor is provided with two charging plates, which are fixed to the casing at both ends through insulating plates. When charging, the output end of the high-voltage signal generator is connected to the two charging plates respectively.

7. The discharge method according to claim 1, wherein: The adjustable gap includes a wireless controller part and a high-voltage discharge gap part.

8. The discharge method according to claim 7, characterized in that: The wireless controller part includes a fixed receiving end and a movable remote control end. The input end of the fixed receiving end is connected to the 220V mains electricity, and the output end is connected to the power supply of the electromagnet with adjustable gap.

9. The discharge method according to claim 4, characterized in that: The screw is made of copper.

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