CN205160080U - Intelligent low tension circuit of drawer type combination - Google Patents

Abstract

The utility model discloses a drawer-type combined intelligent low-voltage circuit, which includes an incoming line and an air switch. The outlet end of the air switch is connected with a current transformer and a busbar in sequence, and a sampling transformer and a busbar are connected in parallel to the current transformer. The first, second, third, and fourth incoming line primary wiring terminals are connected to the top, and the outgoing lines of the first, second, and third incoming line primary wiring terminals are respectively connected with residual current operated circuit breakers and outgoing line primary wiring terminals; the fourth incoming line The outlet ends of the primary terminal are respectively connected in parallel with split-complement intelligent intensive capacitors, common-complement intelligent intensive capacitors, circuit breakers and self-healing capacitors connected in series; The outlet ends of the connection terminals are respectively connected with the sampling terminals of the sub-compensation intelligent intensive capacitor and the co-complement intelligent intensive capacitor. The circuit structure of the utility model is simple, economical and safe, reduces power outage time, and improves power supply reliability of rural power grids.

Description

Drawer-type combined intelligent low-voltage circuit

technical field

The utility model relates to the field of low-voltage power distribution equipment in a low-voltage power supply system, in particular to a drawer-type combined intelligent low-voltage circuit suitable for a power distribution system for leakage protection and reactive power compensation in a three-phase four-wire agricultural distribution network circuit.

Background technique

Low-voltage power distribution equipment is responsible for completing power control, protection, measurement, conversion and distribution in the low-voltage power supply system. It involves all aspects of national construction and people's lives. Its development is closely related to the development of national economy, science and technology and people's living standards.

With the increase of residential electricity load, the requirements for the insulation degree of the distribution station area are getting higher and higher, and the level of safe electricity consumption in rural areas has been continuously improved. In the existing technology, the units of the low-voltage power distribution cabinet are fixedly arranged, and the connection of the incoming and outgoing busbars is not protected by insulation, and the live parts are exposed. During maintenance, the operator is easy to touch the live parts by mistake, and there is a big safety hazard; maintenance More troublesome, and poor security protection measures.

The power distribution cabinet is widely used in the distribution network of rural distribution transformer outlets. It is generally equipped with 3 outlets. When the residual current action circuit breaker body of any outlet fails, it is necessary to accompany the adjacent outlet of the fault circuit breaker in the cabinet. Maintenance can only be carried out later, which expands the scope of power outages and greatly affects the reliability of power supply in rural power grids.

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 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 reached 75% after 3 years, and the damage rate was extremely high.

Utility model content

The purpose of this utility model is to provide a drawer-type combined intelligent low-voltage circuit to simplify the electrical circuit of the power distribution cabinet, and to design a modular intelligent circuit that is closed and isolated, simple to exchange, and easy to disperse and transport, so as to improve the reliability of power supply in rural power grids , reduce the power outage time of users, improve the safety prevention and control level of on-site operation and maintenance personnel; and design a modular intelligent integrated low-voltage reactive power compensation device to improve the compensation effect and avoid over-compensation and under-compensation caused by three-phase co-compensation. Defects; at the same time, realize the zero-crossing switching technology of low-voltage power capacitors based on mechanical contacts, which integrates intelligence, miniaturization, and modularization, reduces operating overvoltage, high reliability, and long service life.

The technical scheme of the utility model is as follows:

A drawer-type combined intelligent low-voltage circuit, including an incoming line, characterized in that: the incoming line is connected with an air switch, and the outlet end of the air switch is connected with a current transformer and a busbar in sequence. The first, second, and third sampling transformers are respectively connected in parallel on the current transformers of The outlet ends of the primary wiring terminals are respectively connected to the first, second and third residual current operated circuit breakers, and the incoming terminals of the first, second and third residual current operated circuit breakers are respectively connected to the first, second and third arresters, The outlet ends of the first, second, and third residual current operated circuit breakers are respectively connected with the first, second, and third outlet primary terminals; the outlet terminals of the fourth incoming line primary terminals are respectively connected in parallel with a split-complement intelligent intensive capacitor, Co-complementing intelligent intensive capacitors, circuit breakers and self-healing capacitors in series; the first, second, and third sampling transformers are connected to the secondary connection terminals of the incoming line through wires, and the secondary connection terminals of the incoming line The outlet terminals are respectively connected to the sampling terminals of the sub-compensation intelligent intensive capacitor and the co-complement intelligent intensive capacitor.

The drawer-type combined intelligent low-voltage circuit is characterized in that: the current transformer is connected to an ammeter through a wire.

In the utility model, the incoming air switch is designed as an incoming room module, and the three-phase indication value of the air switch is displayed by the ammeter installed in the incoming room; the first, second, and third residual current action circuit breakers are designed as the same three The sub-complement intelligent intensive capacitor, the co-complement intelligent intensive capacitor, and the circuit breaker and self-healing capacitor connected in series form the co-complement, sub-complement and fixed compensation modules respectively, and form an intelligent integrated low-voltage reactive power compensation device.

The beneficial effects of the utility model:

1. In terms of economic benefits, it is mainly reflected in the reduction of losses. The outlet and capacitor units are designed with closed insulation modules. When an internal fault occurs, it will not affect adjacent units, avoiding the common fault range of the original open fixed power distribution cabinet circuit Expand the accident and reduce the scope of power outage; it can be directly replaced with a spare drawer, without on-site fault repair, shortening the power outage time.

2. In terms of safety benefits, it is divided into independent studios according to functions, and the live parts are isolated from the external operation interface. The live parts such as busbars are completely "insulated", which reduces the risk of touching live parts during operation; the power distribution cabinet The outgoing line is designed as a modular drawer, which avoids the risk of pulling and closing the switch with load, ensures the safe, stable operation and convenient operation of the power distribution cabinet, and eliminates the potential safety hazard of unauthorized power stop and transmission that easily occurs in rural areas.

3. In terms of social benefits, the scope of power outages in the maintenance station area is reduced, the power outage time is reduced, and the reliability of power supply in rural power grids is improved. The drawer-type functional modules designed to facilitate decentralized transportation and on-site combination improve the protection of personnel. The safety of the equipment makes the grounding operation on the job site simple, fast and reliable.

Description of drawings

Fig. 1 is the circuit schematic diagram of the utility model.

detailed description

Referring to Figure 1, a drawer-type combined intelligent low-voltage circuit includes an incoming line, an air switch 1 is connected to the incoming line, and the outlet end of the air switch 1 is connected to a current transformer 3 and a busbar 4 in turn, and the current transformer 3 are connected in parallel with the first, second and third sampling transformers 12 respectively, the busbar 4 is connected with the first, second, third and fourth incoming line primary terminal 5, and the first, second and third incoming line primary terminal 5 is connected to the outgoing line The terminals are respectively connected with the first, second and third residual current operated circuit breakers 6, and the incoming terminals of the first, second and third residual current operated circuit breakers 6 are respectively connected with the first, second and third arresters 7. The outlet ends of the three residual current operated circuit breakers 6 are respectively connected with the first, second, and third outlet primary terminals 14; type capacitor 9, circuit breaker 10 and self-healing capacitor 11 connected in series; the first, second and third sampling transformers 12 are connected to the secondary terminal 13 of the incoming line through wires, and the outgoing lines of the secondary terminal 13 of the incoming line are respectively It is connected with the sampling terminals of the sub-compensation intelligent intensive capacitor 8 and the common complementary intelligent intensive capacitor 9 .

In the utility model, the current transformer 3 is connected with the ammeter 2 through wires, and the three-phase indication value of the air switch 1 is displayed by the ammeter.

Claims (2)

1. A drawer-type combined intelligent low-voltage circuit, including an incoming line, is characterized in that: an air switch is connected to the incoming line, and the outlet end of the air switch is connected with a current transformer and a busbar in sequence, The first, second, and third sampling transformers are respectively connected in parallel on the current transformers, the first, second, third, and fourth incoming line primary terminals are connected to the bus bars, and the first, second, and third The outlet terminals of the primary terminal of the three incoming lines are respectively connected to the first, second and third residual current operated circuit breakers, and the incoming terminals of the first, second and third residual current operated circuit breakers are respectively connected to the first, second and third residual current operated circuit breakers. In the lightning arrester, the outlet ends of the first, second and third residual current operated circuit breakers are respectively connected with the first, second and third outlet terminals; Capacitors, co-complementary intelligent intensive capacitors, circuit breakers in series and self-healing capacitors; the first, second, and third sampling transformers are connected to the secondary terminal of the incoming line through wires, and the secondary wiring of the incoming line The outlet ends of the terminals are respectively connected to the sampling terminals of the sub-compensation intelligent intensive capacitor and the co-complement intelligent intensive capacitor. 2. The drawer-type combined intelligent low-voltage circuit according to claim 1, wherein the current transformer is connected with an ammeter through a wire.