CN206023211U - A kind of little bar coupler blocking device of direct current - Google Patents

Abstract

The utility model discloses a kind of little bar coupler blocking device of direct current, including #1 DC chargings module and its accumulator battery, #2 DC chargings module and its accumulator battery, D.C. contactor DL, direct current mother feeder switch 1ZK, direct current mother feeder switch 2ZK, interconnection switch, with first group of contact of operating handle QK after normally closed auxiliary contact 1Z1 and normally closed auxiliary contact 2Z1 parallel connections, D.C. contactor closing coil HQ, normally closed auxiliary contact D1 is followed in series to form closing circuit, with second group of contact shunt of operating handle QK after normally opened auxiliary contact 1Z2 and normally opened auxiliary contact 2Z2 series connection, so successively with D.C. contactor breaking coil TQ, normally opened auxiliary contact D2 sub-gate circuit in series；Effectively avoiding artificial maloperation interconnection switch causes looped network of DC power to run.

Description

A locking device for a DC small bus tie switch

technical field

The utility model relates to a locking device for a DC small bus connection switch, which belongs to the technical field of power supply.

Background technique

The DC power supply system is one of the indispensable secondary equipment in power plants and substations. It provides control, protection, and signal power for power equipment in normal operation, so that high-voltage circuit breakers can operate normally, especially when the power system accident AC When the power supply fails, a safe and reliable DC power supply is needed, and its reliability directly affects the safe and reliable operation of power plants and substation equipment.

For substations with voltage levels of 330kV and above and important 220kV substations, a DC system powered by two sets of storage batteries should be used. Each set of storage batteries should be connected to a section of DC bus respectively. Set a contact switch between them, and the switch is strictly prohibited to close the ring during normal operation. At present, there are many phenomena in the DC system that two sets of DC power sources are closed to form a ring network, which leads to frequent occurrence of ring network faults in the DC system.

Utility model content

The technical problem to be solved by the utility model is to provide a DC small bus connection switch locking device for the deficiencies of the prior art.

A DC small bus tie switch locking device, including #1 DC charging module and its battery pack, #2 DC charging module and its battery pack, DC contactor DL, DC bus feeder switch 1ZK, DC bus feeder switch 2ZK, tie switch , the DC contactor has an operating handle QK, the operating handle QK includes 2 sets of contacts: the first set of contacts, the second set of contacts, the DC contactor DL includes a normally open auxiliary contact D2 and a normally closed auxiliary contact D1, DC bus feeder switch 1ZK includes normally closed auxiliary contact 1Z1 and normally open auxiliary contact 1Z2, DC bus feeder switch 2ZK includes normally closed auxiliary contact 2Z1 and normally open auxiliary contact 2Z2, normally closed auxiliary contact 1Z1 and normally closed auxiliary contact The contact 2Z1 is connected in parallel with the first set of contacts of the operating handle QK, the DC contactor closing coil HQ, and the normally closed auxiliary contact D1 in series to form a closing circuit, and the normally open auxiliary contact 1Z2 is connected in series with the normally open auxiliary contact 2Z2 Then it is connected in parallel with the second group of contacts of the operating handle QK, and then connected in series with the trip coil TQ of the DC contactor and the normally open auxiliary contact D2 to form the opening circuit.

For low and medium voltage equipment, the ring network power supply based on this scheme is more reliable than the radial DC power supply. By adopting the DC contactor that controls opening and closing, the auxiliary normally closed nodes of the two sets of DC feeder screens leading to the air switch of the switch cabinet are introduced into the DC contactor closing circuit and used in parallel to achieve the connection switch when the two bus feeder lines are closed. It cannot be closed; at the same time, its auxiliary normally open node is introduced into the trip circuit of the DC contactor and used in series to realize the automatic state. When the two bus feeders close the loop, the tie switch can automatically trip to ensure the independent operation of the two DC systems. Compared with the traditional tie switch, it effectively avoids the operation of the DC ring network caused by human misoperation of the tie switch.

The installation of this device does not require a new screen cabinet, it only needs to be replaced at the original contact switch position, but the auxiliary contact of the feeder circuit breaker needs to be connected to the device through a new control cable.

Description of drawings

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

Fig. 2 is a schematic diagram of the utility model;

Fig. 3 is the schematic diagram of the control circuit and the position table of the operating handle QK of the utility model.

detailed description

Below in conjunction with specific embodiment, the utility model is described in detail.

Referring to Fig. 1 and Fig. 2, the locking device of DC small bus tie switch includes #1 DC charging module and its battery pack, #2 DC charging module and its battery pack, DC contactor DL, DC bus feeder switch 1ZK, DC bus feeder Switch 2ZK, tie switch, DC contactor with operating handle QK, DC power supply system adopts single-bus section operation mode, each bus section should be powered by an independent battery pack, and a tie switch is set between the two sections of DC busbar, The operating handle QK includes 2 sets of contacts: the first set of contacts ①②, the second set of contacts ③④, the DC contactor DL includes the normally open auxiliary contact D2 and the normally closed auxiliary contact D1, and the DC bus feeder switch 1ZK includes the normally closed Auxiliary contact 1Z1 and normally open auxiliary contact 1Z2, DC bus feeder switch 2ZK includes normally closed auxiliary contact 2Z1 and normally open auxiliary contact 2Z2, normally closed auxiliary contact 1Z1 and normally closed auxiliary contact 2Z1 are connected in parallel with the operating handle The first group of QK contacts ①②, DC contactor closing coil HQ, and normally closed auxiliary contact D1 are connected in series to form a closing circuit, and the normally open auxiliary contact 1Z2 and normally open auxiliary contact 2Z2 are connected in series with the second operating handle QK The group contacts ③④ are connected in parallel, and then connected in series with the trip coil TQ of the DC contactor and the normally open auxiliary contact D2 to form the opening circuit.

Generally, 35kV and 110kV equipment adopts non-radiative DC power supply, but each section of DC busbar leads out the feeder to adopt split ring network DC power supply, as shown in Figure 2. The utility model is to prevent the DC ring network from running due to the wrong closing of the feeder contact switch under the DC power supply mode.

Referring to Fig. 3 is the schematic diagram of the control circuit of the utility model and the QK position table of the operating handle. The symbols in the figure are: QK operating handle contacts ①, ②, ③, ④, DC bus feeder switch auxiliary normally open contacts 1Z2, 2Z2, Normally closed contacts 1Z1, 2Z1, DC contactor closing coil HQ, DC contactor tripping coil TQ, DC contactor switch normally open contact D2, normally closed contact D1; control circuit diagram mainly includes closing circuit and opening circuit. The closing circuit is mainly composed of the operating handle QK contact ①②, the DC contactor closing coil HQ, and the DC contactor normally closed contact D1 connection; the opening circuit is mainly composed of the QK operating handle contact ③④, the DC contactor tripping coil TQ , The normally open contact D2 of the DC contactor is connected.

Operating handle QK contact position table, the operating handle QK includes 2 sets of contacts, when operating QK to the 45° (closing) position, the first set of contacts ①② conduction, when QK is operating to -45° (opening) ) position, the second group of contacts ③④ conduction.

The action principle of the circuit: when the DC system is running normally, the feeder switches 1ZK and 2ZK are closed, the normally closed auxiliary contacts 1Z1 and 2Z1 are disconnected, the normally open contact D2 of the DC contactor is divided, the operating handle QK is closed, and the circuit is closed If it is blocked, it can effectively prevent the DC contactor DL from closing.

When the feeder switch 1ZK (or 2ZK) is divided, the normally closed auxiliary contact 1Z1 (or 2Z1) is closed. At this time, turn the operating handle QK clockwise to the 45° (closing) position, and the first set of contacts ①② are turned on. The positive power supply is connected to the closing coil HQ, and the DC contactor DL is closed.

After the closing is in place, the DC contactor normally closed contact D1 of the closing circuit disconnects the closing current, one is to prevent the first group of contacts ①② from sticking and causing the closing coil to burn out; the other is to prevent the closing coil from being burned by the operating handle The QK contact breaks the closing current, and the QK contact of the operating handle is easy to burn out due to the insufficient arc breaking capacity of the QK contact of the operating handle. When the DC bus feeder switch 1ZK (or 2ZK) is closed and the DC contactor DL is closed, the normally open contact D2 of the DC contactor is closed, and the normally open auxiliary contact 1Z2 (or 2Z2) is closed. At this time, if the II When the female (or I female) feeder circuit breaker 2ZK (or 1ZK) is closed, the opening circuit is turned on, the positive power supply is connected to the trip coil TQ, the DC contactor switch is opened, and the closing circuit is disconnected. After the opening is in place, the normally open auxiliary contact D2 of the DC contactor disconnects the opening current to prevent the closing current from being disconnected by the auxiliary contact 1ZK or 2ZK of the DC bus feeder switch, and to avoid the failure due to insufficient arc breaking capacity of the auxiliary contact. Burn out auxiliary contacts.

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present utility model.

Claims (1)

1. the little bar coupler blocking device of a kind of direct current, it is characterised in that including #1 DC chargings module and its accumulator Group, #2 DC chargings module and its accumulator battery, D.C. contactor DL, direct current mother feeder switch 1ZK, direct current mother's feeder switch 2ZK, interconnection switch, D.C. contactor carry operating handle QK, and operating handle QK includes 2 groups of contacts：First group of contact, second group Contact, D.C. contactor DL include that normally opened auxiliary contact D2 and normally closed auxiliary contact D1, direct current mother feeder switch 1ZK include normally closed Auxiliary contact 1Z1 and normally opened auxiliary contact 1Z2, direct current mother feeder switch 2ZK include that normally closed auxiliary contact 2Z1 and normally opened auxiliary are touched With operating handle QK first group of contact, D.C. contactor after point 2Z2, normally closed auxiliary contact 1Z1 and normally closed auxiliary contact 2Z1 parallel connection Closing coil HQ, normally closed auxiliary contact D1 are followed in series to form closing circuit, normally opened auxiliary contact 1Z2 and normally opened auxiliary contact 2Z2 series connection after with second group of contact shunt of operating handle QK, so successively with D.C. contactor breaking coil TQ, normally opened auxiliary contact D2 sub-gate circuits in series.