CN204190393U - The meticulous reactive power compensator of low pressure - Google Patents

Abstract

The utility model relates to a low-voltage fine reactive power compensation device, which comprises a reactive power compensation controller and a low-voltage fine reactive power compensation unit. The low-voltage fine reactive power compensation unit includes a fuse arranged in series, a thyristor switching trigger circuit, a capacitor, The switching trigger circuit includes a photoelectric coupler, an interrupt detection execution circuit, a zero-crossing detection correction circuit, and a thyristor protection circuit. The interruption detection execution circuit includes a magnetic latching relay. A circuit breaker is provided on the three-phase bus of the low-voltage fine reactive power compensation unit. The utility model is suitable for power distribution systems with small reactive power requirements, can realize single-phase compensation and three-phase simultaneous compensation, small size, modular structure, simple wiring, convenient maintenance, low power consumption, strong anti-interference ability, and switch module action Fast response, frequent operation, minimum 1kVar reactive power compensation, high compensation accuracy, and fine compensation.

Description

Low voltage fine reactive power compensation device

technical field

The utility model relates to the field of low-voltage reactive power compensation, in particular to a low-voltage fine reactive power compensation device.

Background technique

The role of the reactive power compensation device in the electronic power supply system is to improve the power factor of the power grid, reduce the loss of power supply transformers and transmission lines, improve power supply efficiency, and improve the power supply environment. Therefore, the reactive power compensation device is in an indispensable and very important position in the power supply system. Reasonable selection of compensation devices can minimize the loss of the network and improve the quality of the power grid. On the contrary, if it is improperly selected or used, it may cause voltage fluctuations in the power supply system, harmonics increase and many other factors. The existing low-voltage reactive power compensation equipment is bulky, heavy in structure, high in power consumption, expensive in price, inflexible in use, inconvenient in maintenance, short in service life, and low in reliability. For long-distance transmission lines, small-capacity transformers, small Large-scale factories and residential areas and other power distribution systems with small reactive power requirements for distribution lines lack tailor-made reactive power compensation devices.

Utility model content

Aiming at the deficiencies in the above-mentioned prior art, the utility model aims to provide a low-voltage power distribution system with small size, low price, low power consumption and flexible use, which is suitable for fine reactive power compensation for power distribution systems with small reactive power requirements. Fine reactive power compensation device.

In order to achieve the above purpose, the technical solution of the utility model includes a reactive power compensation controller and a low-voltage fine reactive power compensation unit, and the low-voltage fine reactive power compensation unit includes a series-connected fuse, a thyristor switching trigger circuit, and a capacitor The thyristor switching trigger circuit includes a photocoupler, an interrupt detection execution circuit, a zero-crossing detection correction circuit, and a thyristor protection circuit. The primary terminal of the thyristor switching trigger circuit is electrically connected to the capacitor, and the thyristor The secondary terminal of the switching trigger circuit is electrically connected with the reactive power compensation controller.

Further, the incoming terminal of the thyristor switching trigger circuit is electrically connected to the fuse.

Further, the interrupt detection execution circuit includes a magnetic latching relay.

Further, a circuit breaker is provided on the three-phase bus of the low-voltage fine reactive power compensation unit.

Beneficial effects of the utility model: the low-voltage fine reactive power compensation unit in the utility model is a modular structure, small in size, simple in wiring, and convenient in maintenance. The thyristor switching trigger circuit realizes zero-cross switching without overvoltage, spark, No interference, "zero switching" of capacitors, no inrush impact during switching, no operation overvoltage, fast action response, frequent operation, separate incoming lines for weak current and strong current, effectively preventing the primary line from secondary signal line Interference, which greatly improves the anti-interference ability of the whole machine. The low-voltage fine reactive power compensation unit has built-in multi-channel capacitors and multi-channel zero-crossing switching synchronous switches. According to the control command, the output capacitors with different capacities can be adjusted, and the minimum reactive power of 1kVar can be compensated, and single-phase can be realized. Compensation and three-phase compensation at the same time, so as to achieve fine compensation for the grid.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a wiring diagram of the utility model;

Fig. 2 is the secondary wiring diagram of the utility model;

Fig. 3 is a block diagram of the utility model;

In the figure, 1. reactive power compensation controller, 2. low-voltage fine reactive power compensation unit, 3. circuit breaker; 21. thyristor switching trigger circuit, 22. capacitor, 23. fuse; 211 photoelectric coupler, 212. interrupt Detection execution circuit, 213, zero-crossing detection correction circuit, 214, thyristor protection circuit.

Detailed ways

The utility model will be described in further detail below in conjunction with specific embodiments and accompanying drawings.

A low-voltage fine reactive power compensation device as shown in Figures 1-3, including a reactive power compensation controller 1 and a low-voltage fine reactive power compensation unit 2, the low-voltage fine reactive power compensation unit 2 includes fuses arranged in series device 23, thyristor switching trigger circuit 21, capacitor 22, the capacitor 22 on each single-phase line performs single-phase reactive power compensation to each phase line, the minimum can compensate 1kVar reactive power, and the fuse 23 on each single-phase line is in current When it rises abnormally to a certain height, it will fuse itself to cut off the current, thereby protecting the safe operation of the circuit and preventing the rising current from damaging important components in the circuit. The thyristor switching trigger circuit 21 includes a photocoupler 211 , an interruption detection execution circuit 212 , a zero-crossing detection correction circuit 213 , and a thyristor protection circuit 214 . The primary terminal of the thyristor switching trigger circuit 21 is electrically connected to the capacitor 22, and the photocoupler 211 uses light as a medium to transmit electrical signals, and has a good photoelectric isolation effect on input and output electrical signals, realizing reactive power compensation control circuit 1 Reliable electrical isolation from the thyristor switching trigger circuit 21, the interrupt detection execution circuit 212 includes a magnetic latching relay, the open and closed states of the contacts of the magnetic latching relay are held by the magnetic force generated by the permanent magnet, no power is required, and the power consumption Low, to realize the interruption detection of the controlled circuit, automatically turn on or cut off the circuit, and the zero-crossing detection correction circuit 213 realizes the conduction of the thyristor at the zero position of the alternating current, reduces the damage of the surge impact energy to the thyristor, and reduces the loss of the thyristor Minimize and prolong the service life of the thyristor, the thyristor protection circuit 214 is the prior art, and will not be repeated here. The secondary terminal of the thyristor switching trigger circuit 21 is electrically connected to the reactive power compensation controller 1 , and the reactive power compensation controller 1 controls the switching of the thyristor switching trigger circuit 21 . Thyristor switching trigger circuit 21 has a fast action response speed and can be operated frequently to realize zero-crossing voltage input and zero-crossing current cut-off of capacitor 22. The voltage zero-crossing input will not generate inrush current, and zero-crossing current cut-off realizes arc-free breaking of switch contacts , Zero-crossing switching has the effect of no overvoltage, no spark, and no interference. A circuit breaker 3 is provided on the three-phase bus of the low-voltage fine reactive power compensation unit 2, and the circuit breaker 3 realizes overload, short circuit and undervoltage protection, with adjustable operating value, high breaking capacity, convenient operation and safety.

The low-voltage fine reactive power compensation device is suitable for distribution systems with small reactive power requirements, such as long-distance transmission lines, small-capacity transformers, small-scale factories, residential areas, etc., and can realize single-phase compensation and three-phase simultaneous Compensation, small size, modular structure, simple wiring, convenient maintenance, low power consumption, cost saving, separate incoming lines with weak current and strong current, prevent primary line from interfering with secondary signal lines, significantly improve anti-interference ability, switch module The action response speed is fast, and it can be operated frequently. The low-voltage fine reactive power compensation unit has built-in multi-channel capacitors and multi-channel zero-crossing switching synchronous switches. According to the control command, the output capacitors with different capacities can be adjusted, and the minimum reactive power of 1kVar can be compensated. Fine compensation of the grid.

The technical solutions provided by the embodiments of the present invention have been introduced in detail above. In this paper, specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the above embodiments are only applicable to help understand the present invention. The principle of the embodiment; at the same time, for those of ordinary skill in the art, according to the embodiment of the present invention, there will be changes in the specific implementation and the scope of application. Utility model restrictions.

Claims (4)

1. the meticulous reactive power compensator of low pressure, it is characterized in that, include idle compensating control (1) and the meticulous reactive compensation unit of low pressure (2), the meticulous reactive compensation unit of described low pressure (2) includes the fuse (23) be arranged in series, thuristor throw-in and throw-off circuits for triggering (21), capacitor (22), described thuristor throw-in and throw-off circuits for triggering (21) include photoelectrical coupler (211), interrupt detecting executive circuit (212), zero passage detection correction circuit (213), thyristor protection circuit (214), the primary connection end of described thuristor throw-in and throw-off circuits for triggering (21) is electrically connected with described capacitor (22), the secondary connection end of described thuristor throw-in and throw-off circuits for triggering (21) is electrically connected with described idle compensating control (1).

2. the meticulous reactive power compensator of low pressure as claimed in claim 1, it is characterized in that, the end of incoming cables of described thuristor throw-in and throw-off circuits for triggering (21) is electrically connected with described fuse (23).

3. the meticulous reactive power compensator of low pressure as claimed in claim 1, is characterized in that, described interruption detects executive circuit (212) and includes magnetic latching relay.

4. the meticulous reactive power compensator of low pressure as claimed in claim 1, it is characterized in that, the three-phase bus of the meticulous reactive compensation unit of described low pressure (2) is provided with circuit breaker (3).