CN211701473U - Zero-loss deep current-limiting switch device - Google Patents

Abstract

The utility model relates to a circuit protection device, in particular to a zero-loss depth current-limiting switch device, which comprises a high-fidelity current collector and a depth current limiter which are sequentially connected in series with an A phase, a B phase or a C phase; connected in parallel to the depth current limiter is a fast inverter; one end of the fast recognizer is connected with the high-fidelity current collector, and the other end of the fast recognizer is connected with the measurement and control substation through an optical fiber; and the measurement and control substation is connected to the monitoring background through an optical fiber. The device can solve the defects of a high-impedance transformer, a common series current-limiting reactor and an explosive type high-capacity high-speed switching-on and switching-off device, and can utilize the deep current-limiting reactor of the device to increase the system impedance when a new power supply system is designed and an enterprise system is transformed, so that the switching-on and switching-off current of the load side circuit breaker is further reduced, and the manufacturing cost is reduced. When the short circuit takes place the utility model discloses can drop into female antithetical couplet degree of depth current-limiting reactor fast, increase the systematic internal resistance, fault point excision back, degree of depth current-limiting reactor withdraws from, does not influence entire system's normal operating.

Description

Zero-loss deep current-limiting switch device

Technical Field

The utility model relates to a circuit protection device especially relates to a zero loss degree of depth current-limiting switching device.

Background

When short-circuit faults occur in operation in a power system, the short-circuit current is generally dozens of times of rated current, great damage is caused to electrical equipment such as transformers, generators, circuit breakers, power transmission lines and the like, the breaking capacity of the conventional economical and practical vacuum circuit breaker is below 40KA, and the breaking time needs to be nearly hundred milliseconds. Along with the development and growth of various types of power utilization enterprises, the power load is greatly increased, the capacity of a main transformer is correspondingly increased, and power grid systems of various enterprises face the problems that the short-circuit current approaches and reaches the maximum use limit of a load vacuum circuit breaker, the on-off capacity of the load side vacuum circuit breaker is insufficient, the design of the short-circuit current impact resistance capacity of the transformer is insufficient, and the like, so that the safe operation of the enterprises is seriously threatened.

The problem that the short-circuit current exceeds the standard increasingly seriously is faced, a plurality of enterprises limit the short-circuit current of the system by adopting a high-impedance transformer, but the problem of current limiting depth is not finally solved by increasing the impedance of the transformer, the electric power is reduced, and active and reactive power loss and investment cost rise are brought. The series current-limiting reactor in the prior art does not fundamentally solve the problem of current-limiting depth (the reactance rate is about ten percent), brings the defects of active and reactive power loss, bus voltage drop, magnetic leakage field and the like, can not effectively protect main electrical equipment such as a generator, a transformer and the like due to insufficient current-limiting depth when a system is in short circuit, and generates winding deformation and damage under the impact of huge short-circuit current, thereby causing catastrophic accidents.

Disclosure of Invention

The utility model aims at solving the not enough of prior art, and provide one kind can be at short-circuit current's initial stage, drop into degree of depth current-limiting reactor fast and restrict short-circuit current in reliable within range to the zero loss degree of depth current-limiting switching device who has reached protection distribution equipment and power supply line.

In order to solve the technical problem, the utility model discloses take following technical scheme:

a zero-loss depth current-limiting switch device comprises a high-fidelity current collector and a depth current limiter which are sequentially connected in series with an A phase, a B phase or a C phase; connected in parallel to the depth current limiter is a fast inverter; one end of the fast recognizer is connected with the high-fidelity current collector, and the other end of the fast recognizer is connected with the measurement and control substation through an optical fiber; and the measurement and control substation is connected to the monitoring background through an optical fiber.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model relates to a zero loss degree of depth current-limiting switching device can solve high impedance transformer, ordinary series connection current-limiting reactor, the high-speed cut-off device of explosion type large capacity not enough, when new power supply system design and enterprise's system reform transform, usable this device degree of depth current-limiting reactor increases system impedance, makes the cut-off current of load side circuit breaker further reduce, reduces the cost. When the short circuit takes place the utility model discloses can drop into female antithetical couplet degree of depth current-limiting reactor fast, increase the systematic internal resistance, fault point excision back, degree of depth current-limiting reactor withdraws from, does not influence entire system's normal operating.

Drawings

Fig. 1 is a schematic view of the electrical connection structure of the present invention.

Detailed Description

Referring to fig. 1, a zero-loss depth current-limiting switching device comprises a high-fidelity current collector and a depth current limiter which are sequentially connected in series with an A phase, a B phase or a C phase; connected in parallel to the depth current limiter is a fast inverter; one end of the fast recognizer is connected with the high-fidelity current collector, and the other end of the fast recognizer is connected with the measurement and control substation through an optical fiber; and the measurement and control substation is connected to the monitoring background through an optical fiber.

Components and parts such as high-fidelity current collector, degree of depth current limiter, quick transverter, quick recognizer and high-fidelity current collector are general components and parts on the market, observe and control the sub-station and be computer control with the control backstage, the utility model discloses pass through optical fiber communication with quick recognizer and the measurement and control sub-station of installing at the master control room, observe and control the sub-station and also can carry out data transfer through optical fiber communication with the control backstage, constitute monitored control system. When the device works, the high-fidelity current collector continuously detects the system current and transmits the system current data to the measurement and control substation and the monitoring background through the optical fiber; when the current is larger than a set value, the rapid recognizer rapidly calculates the short-circuit current and the accurate time of the current zero crossing point within 2ms through a high-speed DSP technology and a special algorithm, sends an action signal before the zero crossing point, drives the rapid current converter to cut off a circuit at the zero crossing point, ensures the shortest arcing time, changes the short-circuit current into a deep current-limiting reactor within 7-15 ms, and simultaneously transmits the switching state to a measurement and control substation and a monitoring background through optical fibers.

Claims (1)

1. A zero-loss depth current-limiting switch device is characterized by comprising a high-fidelity current collector and a depth current limiter which are sequentially connected in series with an A phase, a B phase or a C phase; connected in parallel to the depth current limiter is a fast inverter; one end of the fast recognizer is connected with the high-fidelity current collector, and the other end of the fast recognizer is connected with the measurement and control substation through an optical fiber; and the measurement and control substation is connected to the monitoring background through an optical fiber.

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