CN203312809U - A Shunt Reactor Operation Overvoltage Control Circuit - Google Patents

Abstract

The utility model discloses a shunt reactor operation overvoltage control circuit, which comprises a busbar, on which a first switch is installed; the first switch is connected with a shunt reactor through a cable, and the shunt reactor is connected with a second One end of the switch is connected to a line, and the other end of the second switch is three-phase short-circuited as a neutral point; the shunt reactor and the second switch are connected to one end of an arrester, and the other end of the arrester is grounded. The utility model provides a shunt reactor operation overvoltage control loop, the first switch provided in it is responsible for protection breaking, and the second switch is responsible for normal switching; by curbing the continuous development of the first open-phase reburning, the control operation overvoltage is realized It is especially effective to control the threat of operating overvoltage of the switching shunt reactor on the empty busbar to the busbar side.

Description

A Shunt Reactor Operation Overvoltage Control Circuit

technical field

The utility model relates to a shunt reactor operation overvoltage control circuit, which belongs to the technical field of power transmission, transformation and distribution of power systems.

Background technique

In order to adjust voltage and reactive power, my country's power grid generally configures shunt reactors on the 35kV side of 220kV substations, uses vacuum circuit breakers for switching, and connects shunt reactors and vacuum circuit breakers through cables.

When the vacuum circuit breaker breaks the shunt reactor of the 35kV neutral point ungrounded system, due to the free oscillation of the load side, the recovery voltage of the first open phase fracture rises much faster than the dielectric strength growth rate of the interrupter fracture during normal breaking. In the partial arcing time range, the first open phase will have re-ignition breakdown.

After the re-ignition occurs in the first open phase, due to the voltage escalation effect, the re-ignition occurs continuously and the intensity is continuously enhanced. Equivalent interception causes strong equivalent interception overvoltage, which causes continuous breakdown of the three-phase fracture of the circuit breaker and affects all equipment on both sides of the circuit breaker.

The simulation evaluation shows that the vacuum circuit breaker breaks the 35kV shunt reactor operation overvoltage, the reactor side relative ground overvoltage is about 100kV, the phase-to-phase overvoltage is about 200kV, and the reactor turn-to-turn overvoltage is about 150kV; when the system is When there is an empty bus with no lines, the phase-to-ground overvoltage on the bus side is about 100 kV, and the phase-to-phase overvoltage is about 180 kV.

The field measurement shows that when the vacuum circuit breaker breaks the 35kV shunt reactor, about 90% of the first open phase will have re-ignition, and about 80% will appear as continuous re-ignition of the first open phase → the latter two phases will be effectively closed, resulting in strong overvoltage. The continuous re-ignition of the first open phase → the equivalent cut-off of the second phase is the most important form of overvoltage when the vacuum circuit breaker breaks the 35kV shunt reactor, which will cause the surge arrester on the reactor side to operate, which is the root cause of the parallel operation overvoltage accident or abnormality. When the system is an empty bus with no lines, since the ground capacitance of the system on the bus side is very small, the continuous breakdown of the circuit breaker will also have a strong impact on the bus side.

The actual operation shows that the operation overvoltage phenomenon of the vacuum circuit breaker breaking 35kV shunt reactor is common, which frequently causes the inter-turn short circuit damage of the shunt reactor, and the disconnection and resistance of the empty busbar, which causes the change damage of the busbar side, etc., especially for the empty busbar. Line switching and anti-busbar side constitute a special risk, which seriously affects the normal operation and system safety of the 35kV anti-corrosion device, and urgently needs to be rectified.

The actual measurement and evaluation show that the performance of the conventional vacuum circuit breaker is mature and stable, and the re-ignition phenomenon of breaking the 35kV shunt reactor is inevitable. Conventional treatment methods such as installing RC absorbers and overvoltage protectors on the side of the reactor are not enough to effectively control the operating overvoltage of the vacuum circuit breaker breaking the 35kV shunt reactor.

Utility model content

In order to solve the above problems, the purpose of this utility model is to provide a shunt reactor operation overvoltage control circuit, the first switch provided in it is responsible for protection breaking, and the second switch is responsible for normal switching; Development, to achieve the purpose of controlling the operating overvoltage, especially effective in controlling the threat of the operating overvoltage of the switching shunt reactor of the empty bus to the bus side.

The utility model is for achieving above-mentioned purpose, and the utility model adopts following technical scheme:

A shunt reactor operation overvoltage control circuit, including a busbar, on which a first switch is installed; the first switch is connected to a shunt reactor through a cable, and the shunt reactor is connected to a line at one end of a second switch, And the other end of the second switch is three-phase short-circuited as a neutral point; the shunt reactor and the second switch are connected to one end of the arrester, and the other end of the arrester is grounded.

The bus bar is an empty bus bar.

The beneficial effects of the utility model are as follows: the utility model provides a shunt reactor operation overvoltage control circuit, the first switch provided in the utility model is responsible for protection breaking, and the second switch is responsible for normal switching; by using a circuit breaker in the reactor The method of switching on the neutral point side changes the system-circuit breaker-reactor transient circuit characteristics when the circuit breaker breaks down during the breaking process of the shunt reactor, and realizes the development of power frequency freewheeling after the first phase re-ignites , the normal break after the transfer of the first open phase, block the continuous development of the first open phase re-ignition phenomenon and the triggering of the equivalent cut-off of the last two phases, achieve the purpose of controlling and resisting the operation overvoltage, and can completely eliminate the operating overvoltage of the shunt reactor switching on the empty bus The threat of voltage to the busbar side can effectively ensure the normal operation of the system and shunt reactor device.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Example 1

As shown in Figure 1, a shunt reactor operation overvoltage control circuit provided in this embodiment includes an empty bus 1, on which a first switch 2 is installed; the first switch 2 communicates with the The shunt reactor 4 is connected, and the shunt reactor 4 is connected to the line at one end of the second switch 5, and the other end of the second switch 5 is three-phase short-circuited as a neutral point; the shunt reactor 4 is connected to the second switch 5 5 is connected to one end of the lightning arrester 6, and the other end of the lightning arrester 6 is grounded.

The treatment method for the overvoltage control circuit operated by a shunt reactor includes the following steps: firstly, the first switch 2 is switched on to transmit power; when normal switching is required, the second switch 5 switches the shunt reactor Switching at the neutral point side; when the first opening phase only occurs once or several times of re-ignition, it will turn to power frequency freewheeling. After the first opening phase is transferred, it will be disconnected normally. The equivalent cut-off current, the overvoltage development process is contained, only a low operating overvoltage on the side of the shunt reactor 4 and the neutral point, and on the bus side due to the blocking effect of the shunt reactor 4 on high-frequency transients, the overvoltage can be Neglect, so as to achieve the purpose of controlling the operation overvoltage of the shunt reactor 4.

In the overvoltage management circuit for shunt reactor operation described in this embodiment, the first switch provided in it is responsible for protection breaking, and the second switch is responsible for normal switching; Method, change the system--circuit breaker--reactor transient circuit characteristics when the circuit breaker breaks down in the breaking process of the shunt reactor, and realize the power frequency freewheeling after the first open phase re-ignites, and normal after the first open phase transfer Breaking, blocking the continuous development of the first open-phase re-ignition phenomenon and the initiation of the equivalent cut-off of the latter two phases, to achieve the purpose of controlling and resisting operating overvoltage, and can completely eliminate the threat of operating overvoltage of the shunt reactor switching on the empty bus to the bus side , effectively guarantee the normal operation of the system and shunt reactor device.

Claims (2)

1. A shunt reactor operation overvoltage control circuit, characterized in that: it includes a busbar, and a first switch (2) is installed on the busbar; the first switch (2) is connected to the shunt reactor through a cable (3) (4) connected, the shunt reactor (4) is connected to the line at one end of the second switch (5), and the other end of the second switch (5) is three-phase short-circuited as a neutral point; the shunt reactor (4) and the second switch (5) are connected to one end of the arrester (6), and the other end of the arrester (6) is grounded. 2. The shunt reactor operation overvoltage control circuit according to claim 1, characterized in that: the busbar is an empty busbar (1).

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