CN101707348A - Intelligent integrated circuit with leakage protection and reactive compensation - Google Patents

Abstract

The invention discloses an intelligent integrated circuit with leakage protection and reactive compensation, which comprises a sampling mutual inductor and a dynamic controller, wherein the sampling mutual inductor is connected to a three-phase line, the output end of the sampling mutual inductor is respectively connected to a sampling signal interface of the dynamic controller, and a main circuit consists of an isolation knife switch, a leakage protection switch, a double-head knife switch and a reactive compensation circuit. The control signal interface of the dynamic controller is connected with the dynamic reactive power compensation unit through a control line, the dynamic compensation unit is composed of a plurality of capacitor switching switches and compensation capacitors connected with the capacitor switching switches, the switching of the compensation capacitors is controlled through a thyristor compound switch, and the thyristor compound switch is controlled through the dynamic controller. The invention has the functions of leakage protection and reactive power compensation, greatly improves the compensation effect and avoids the defects of over-compensation, under-compensation and the like caused by three-phase common compensation. The intelligent compound switch adopted by the switching device, zero-crossing switching of the thyristor and passive switching reduce the occurrence of operation overvoltage, and has high reliability and long service life.

Description

Intelligent integrated circuit with leakage protection and reactive power compensation

technical field

The invention belongs to a power distribution system used for leakage protection and phase-separated reactive power compensation in three-phase lines.

Background technique

The economy and power quality of power system operation have a great relationship with reactive power. Reactive power is an indispensable power in the power system. A large number of inductive loads and reactive power loss in the grid require the system to provide sufficient reactive power, otherwise the grid voltage will drop and the voltage quality will not be guaranteed. At the same time, the unreasonable distribution of reactive power will also increase the line loss and reduce the economy of power system operation.

The reactive power provided by the generator is far from enough for the reactive power demand of the load and the network, and it is extremely uneconomical. Therefore, various reactive power compensation devices are used for reactive power compensation in the power system. It is an important means to ensure the power quality and realize the economical operation of the power system. The on-site compensation of reactive power in the low-voltage power grid is an important part of the reactive power compensation of the entire power system. It mainly uses shunt capacitors, which includes fixed capacitor compensation, dynamic compensation of automatic switching capacitors, and mixed compensation of the two. The electric load changes instantaneously, and the reactive power it needs also changes at any time. In order to maintain the reactive power balance, the capacitor must be switched in time according to the change of the reactive load. The traditional low-voltage dynamic reactive power compensation equipment uses a mechanical switch as the capacitor. Switching switches and mechanical switches are not only slow in action, but also produce inrush impact, overvoltage, arc reignition, etc., and the switch itself and the power capacitor are easily damaged. According to statistics, the damage rate of the automatic switching capacitor reactive power compensation device used in the past reaches 75% after 3 years, which is extremely high.

Contents of the invention

The purpose of the present invention is to provide an intelligent integrated circuit with leakage protection and reactive power compensation, which has the functions of leakage protection and power compensation at the same time, greatly improves the compensation effect, and avoids overcompensation and undercompensation caused by three-phase co-compensation. defect. The switching device adopts an intelligent composite switch, thyristor zero-crossing switching, passive switching, which reduces the occurrence of operating overvoltage, high reliability and long service life.

Technical scheme of the present invention is as follows:

An intelligent integrated circuit with leakage protection and reactive power compensation, including a sampling transformer and a dynamic controller, the sampling transformer is connected to a three-phase line, and the output terminals are respectively connected to the sampling signals of the dynamic controller Interface, the main circuit is composed of isolating knife switch, leakage protection switch, double-ended knife switch and reactive power compensation circuit. The control signal interface of the dynamic controller is connected to the dynamic reactive power compensation unit through the control line. The dynamic compensation unit is composed of a plurality of capacitor switching switches and compensation capacitors connected thereto. The switching of the compensation capacitors is controlled by a thyristor composite switch. The thyristor composite switch described above is controlled by a dynamic controller.

In the circuit, the leakage protection main circuit and the phase-splitting compensation circuit are installed in a power distribution cabinet. A sampling transformer is connected to the three-phase line, and the sampling signal is fed back to the dynamic controller to control switching of the compensation unit.

The compensation response speed of the invention is fast, the power factor is improved in real time, and the energy-saving effect is more remarkable. Capacitor switching has no impact, no inrush current, no transition process switching, high operating reliability, low operating cost, long service life, suppressing harmonics, and running It is safe and reliable. It is equipped with a discharge resistor (that is, a discharge signal lamp), and the capacitor does not need to be pre-charged. It can suppress voltage fluctuations, improve voltage quality, reduce network loss and transformer loss, and increase transformer load capacity. Implement phase-separated dynamic hybrid compensation. Automatic exit, automatically resume operation after power transmission; multi-level compensation is in place at one time, and the power factor after compensation is greater than 0.95 (under the condition of appropriate capacity configuration).

Description of drawings

Fig. 1 is a circuit structure diagram of the present invention.

Detailed ways

Referring to the accompanying drawings, the intelligent integrated circuit with leakage protection and reactive power compensation includes three sampling transformers 2 and a dynamic controller 3. The circuit is composed of an isolating knife switch 12, a leakage protection switch 4, a double-throwing knife switch 8 and a reactive power compensation circuit. The dynamic compensation unit is composed of an air switch 10, a dynamic controller 3, a miniature circuit breaker 13, and a number of capacitor switching circuits connected to the compensation capacitor 5. The dynamic controller 3 is connected to the dynamic compensation unit through a control line, and the switching of the compensation capacitor is through The thyristor composite switch 9 is controlled, and the thyristor composite switch 9 is controlled by the dynamic controller 3 . An indicating transformer 1, an indicating ammeter 6, a transfer switch 11, and an indicating voltmeter 7 are respectively connected to the secondary auxiliary circuit.

Claims (2)

1. be with the intelligent integrative circuit of earth leakage protective, reactive power compensation; it is characterized in that: include sampling mutual inductor, dynamic controller; sampling mutual inductor inserts on the three-phase line; output is linked into the sampled signal interface of described dynamic controller respectively, and main circuit is made up of disconnection switch, earth leakage circuit-breaker, double end knife switch and reactive power compensation circuit.The control signal interface of described dynamic controller connects the dynamic passive compensation unit by control line, the dynamic compensation unit is to be made of some capacitor switching switches and coupled building-out capacitor, the switching of building-out capacitor is by the control of thyristor combination switch, and described thyristor combination switch is controlled by dynamic controller.

2. the intelligent integrative circuit of band earth leakage protective according to claim 1, reactive power compensation is characterized in that: described circuit is installed in earth leakage protective main circuit and phase splitting compensation circuit in the one station power distribution cabinet.Be connected with sampling mutual inductor on the three-phase line, sampled signal is fed back to dynamic controller, the switching of control compensation unit.

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