Instantaneous feedback depth pressure limiting device

Abstract

The utility model provides an instantaneous feedback depth voltage limiting device, which comprises an instantaneous feedback depth voltage limiting circuit, and the instantaneous feedback depth voltage limiting circuit comprises an isolation vacuum circuit breaker handcart GL connected with a medium-voltage power system bus, and a lightning arrester and an RC loop which are connected with the isolation vacuum circuit breaker handcart GL. According to the utility model, the capacitor and the resistor are connected in series and then are connected to the wire inlet end of the load, and when the vacuum circuit breaker cuts off the load, an R-L-C oscillation circuit is formed; when arc breaking suddenly occurs, energy stored in a load inductor can be subjected to damped oscillation at a low frequency, operation overvoltage is safely limited and gradually released, the amplitude and frequency of the overvoltage are effectively reduced, the waveform of the overvoltage is slowed down, and the rising gradient of the overvoltage is limited. The winding load equipment is prevented from being damaged due to the operation overvoltage; meanwhile, the residual voltage value is further reduced through the large-capacity lightning arrester, safe operation of system equipment is protected, and a good protection effect on reignition overvoltage is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to power system overvoltage protection technical field, concretely relates to a kind of instantaneous feedback depth voltage limiting device. BACKGROUND

[0002] In the medium voltage field, due to the arc extinguishing ability of vacuum switch device (vacuum circuit breaker, vacuum contactor, vacuum load switch, etc.) is particularly strong, thus when breaking motor, transformer, reactor, capacitor and other loads, it is easy to cause current chopping overvoltage, multiple reignition overvoltage and operating overvoltage generated when three-phase is disconnected, and the amplitude of the operating overvoltage can cause motor and other equipment insulation breakdown, phase-to-phase conductor flashover, causing accidents to expand, causing unnecessary losses.

[0003] With the increasing importance of stable and safe power supply of power system, the requirements for improving system reliability and safety are increasingly strict. Operating overvoltage is extremely harmful, and to a great extent, it affects the stability, safety and reliability of the system. Using a separate arrester or overvoltage protector can only limit the amplitude of the overvoltage, but has no limiting effect on the operating high-frequency oscillation overvoltage. Therefore, a kind of instantaneous feedback depth voltage limiting device is developed, which can effectively limit the operating overvoltage of vacuum circuit breaker. It not only can reduce the amplitude of incoming wave, but also can reduce the steepness of incoming wave front. SUMMARY

[0004] The utility model aims at providing a kind of instantaneous feedback depth voltage limiting device to solve the above-mentioned prior art deficiencies.

[0005] To achieve the above object, the utility model adopts the following technical solutions:

[0006] A kind of instantaneous feedback depth voltage limiting device, including switch cabinet cabinet body and the instantaneous feedback depth voltage limiting circuit being arranged in the switch cabinet cabinet body, the instantaneous feedback depth voltage limiting circuit includes the isolation vacuum circuit breaker handcar GL being connected with medium voltage power system bus and the arrester and RC loop being connected with the isolation vacuum circuit breaker handcar GL.

[0007] Further, the isolation vacuum circuit breaker handcar GL includes vacuum circuit breaker one, vacuum circuit breaker two and vacuum circuit breaker three, one end of the vacuum circuit breaker one, vacuum circuit breaker two and vacuum circuit breaker three is respectively connected with the A, B, C three-phase of system bus by contact.

[0008] Further, the arrester includes MOV1, MOV2, MOV3, the input end of the arrester MOV1, MOV2, MOV3 is connected with the other end of the vacuum circuit breaker one, vacuum circuit breaker two and vacuum circuit breaker three by contact respectively, and the output end of the arrester MOV1, MOV2, MOV3 is grounded.

[0009] Further, the RC circuit comprises resistors R1, R2 and R3 and capacitors C1, C2, C3 and C4, the positive poles of the resistors R1, R2 and R3 are connected with the contacts of the other ends of the vacuum circuit breakers one, two and three respectively, the negative poles of the resistors R1, R2 and R3 are connected with the positive poles of the capacitors C1, C2 and C3 respectively, the negative poles of the capacitors C1, C2 and C3 are connected with the positive pole of the capacitor C4, and the negative pole of the capacitor C4 is grounded.

[0010] From the above technical solution, the utility model discloses a moment feedback depth voltage limiting device, which is connected in series with capacitors and resistors after being connected to the load inlet end, and when the vacuum circuit breaker cuts off the load, an R-L-C oscillation circuit is formed. When the arc is suddenly broken, the energy stored in the load inductor can attenuate and oscillate at a low frequency, safely limiting the operating overvoltage and gradually releasing it. The utility model discloses a moment feedback depth voltage limiting device reduces the overvoltage amplitude and the overvoltage frequency at the same time, slows down the overvoltage waveform, limits the rising steepness of the overvoltage, and further avoids the damage of the winding load equipment caused by the operating overvoltage through the reduction of the amplitude and the steepness. Meanwhile, a large-capacity lightning arrester is built-in, which can further reduce the residual voltage value, protect the safe operation of the system equipment, and has a good protective effect on the heavy burning overvoltage. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a line connection schematic diagram of the utility model discloses a moment feedback depth voltage limiting circuit. DETAILED DESCRIPTION

[0012] The utility model discloses a moment feedback depth voltage limiting device, which is connected in series with capacitors and resistors after being connected to the load inlet end, and when the vacuum circuit breaker cuts off the load, an R-L-C oscillation circuit is formed. When the arc is suddenly broken, the energy stored in the load inductor can attenuate and oscillate at a low frequency, safely limiting the operating overvoltage and gradually releasing it. The utility model discloses a moment feedback depth voltage limiting device reduces the overvoltage amplitude and the overvoltage frequency at the same time, slows down the overvoltage waveform, limits the rising steepness of the overvoltage, and further avoids the damage of the winding load equipment caused by the operating overvoltage through the reduction of the amplitude and the steepness. Meanwhile, a large-capacity lightning arrester is built-in, which can further reduce the residual voltage value, protect the safe operation of the system equipment, and has a good protective effect on the heavy burning overvoltage.

[0013] A moment feedback depth voltage limiting device, comprising a switch cabinet body and a moment feedback depth voltage limiting circuit arranged in the switch cabinet body. Figure 1 As shown in the figure, the moment feedback depth voltage limiting circuit comprises an isolated vacuum circuit breaker trolley GL connected with a medium-voltage power system bus and a lightning arrester and an RC circuit connected with the isolated vacuum circuit breaker trolley GL.

[0014] The isolated vacuum circuit breaker handcart GL of the preferred embodiment comprises a vacuum circuit breaker one, a vacuum circuit breaker two and a vacuum circuit breaker three, one end of the vacuum circuit breaker one, the vacuum circuit breaker two and the vacuum circuit breaker three is connected with A, B, C three phases of a system bus through contact (contact 1, 3, 5) respectively; the arrester comprises MOV1, MOV2, MOV3, the input end of the arrester MOV1, MOV2, MOV3 is connected with the other end of the vacuum circuit breaker one, the vacuum circuit breaker two and the vacuum circuit breaker three through contact (contact 2, 4, 6) respectively, and the output end of the arrester MOV1, MOV2, MOV3 is grounded; the RC loop comprises resistance R1, R2, R3 and capacitance C1, C2, C3, C4, the positive pole of the resistance R1, R2, R3 is connected with the contact (contact 2, 4, 6) of the other end of the vacuum circuit breaker one, the vacuum circuit breaker two and the vacuum circuit breaker three respectively, the negative pole is connected with the positive pole of the capacitance C1, C2, C3 respectively, the negative pole of the capacitance C1, C2, C3 is connected with the positive pole of the capacitance C4, and the negative pole of the capacitance C4 is grounded.

[0015] In specific use, the instant feedback depth limiting voltage circuit of the utility model connects the capacitor and the resistance in series after connecting at the load incoming line end, when the operating overvoltage or other overvoltage occurs, that is, when the vacuum circuit breaker cuts off the load, the RC loop and the arrester are immediately connected into the oscillation loop simultaneously, forming an R-L-C oscillation loop; the oscillation frequency and the rising steepness of the overvoltage wave head are reduced through the capacitor, the turn-to-turn insulation of the equipment is protected, and the oscillation of the overvoltage is effectively damped and attenuated through the resistance; the energy stored in the load inductance attenuates at a lower frequency, safely limits the operating overvoltage, and gradually releases the energy, reduces the overvoltage amplitude, and reduces the overvoltage frequency, so that the overvoltage waveform is slowed down, the rising steepness of the overvoltage is limited, and the winding load equipment is protected from damage caused by the operating overvoltage through the reduction of the amplitude and the steepness; meanwhile, a large-capacity arrester is built-in, which can further reduce the residual voltage value, the arrester can quickly reduce the overvoltage amplitude to a certain level, the large flow of the arrester can quickly release the energy stored in the equipment end to the ground when the vacuum circuit breaker is disconnected at a non-zero point, effectively protecting the electrical equipment in the Central Asian power system operation, and the RC loop and the arrester can also protect each other, and have a good protection effect on the heavy burning overvoltage.

[0016] The above-described embodiments only describe the preferred embodiments of the utility model, and do not limit the scope of the utility model, and various modifications and improvements to the technical solutions of the utility model made by those skilled in the art without departing from the design spirit of the utility model shall fall within the protection scope of the claims of the utility model.

Claims

1. A transient feedback depth voltage limiting device, comprising a switch cabinet body and a transient feedback depth voltage limiting circuit disposed in the switch cabinet body, characterized in that: The instantaneous feedback deep voltage limiting circuit includes an isolating vacuum circuit breaker trolley GL connected to the medium voltage power system busbar, and a lightning arrester and an RC circuit connected to the isolating vacuum circuit breaker trolley GL.

2. The instantaneous feedback depth pressure limiting device according to claim 1, characterized in that: The isolating vacuum circuit breaker trolley GL includes vacuum circuit breaker 1, vacuum circuit breaker 2 and vacuum circuit breaker 3. One end of the vacuum circuit breaker 1, vacuum circuit breaker 2 and vacuum circuit breaker 3 are respectively connected to the A, B and C phases of the system bus through contacts.

3. The instantaneous feedback depth pressure limiting device according to claim 2, characterized in that: The lightning arrester includes MOV1, MOV2, and MOV3. The input ends of the lightning arresters MOV1, MOV2, and MOV3 are respectively connected to the other ends of the vacuum circuit breaker 1, vacuum circuit breaker 2, and vacuum circuit breaker 3 through contacts, and the output ends of the lightning arresters MOV1, MOV2, and MOV3 are grounded.

4. The instantaneous feedback depth pressure limiting device according to claim 2, characterized in that: The RC circuit includes resistors R1, R2, R3 and capacitors C1, C2, C3, and C4. The positive terminals of the resistors R1, R2, and R3 are respectively connected to the contacts at the other ends of the vacuum circuit breaker 1, vacuum circuit breaker 2, and vacuum circuit breaker 3, and the negative terminals are respectively connected to the positive terminals of the capacitors C1, C2, and C3. The negative terminals of the capacitors C1, C2, and C3 are all connected to the positive terminal of the capacitor C4, and the negative terminal of the capacitor C4 is grounded.

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