CN115940384A

CN115940384A - Spare power automatic switching control circuit of power supply

Info

Publication number: CN115940384A
Application number: CN202211624021.1A
Authority: CN
Inventors: 李传东; 李永晨; 庞怀江; 李传红; 尹克进
Original assignee: Shandong Iron and Steel Co Ltd
Current assignee: Shandong Iron and Steel Co Ltd
Priority date: 2022-12-15
Filing date: 2022-12-15
Publication date: 2023-04-07

Abstract

The invention belongs to the technical field of power supply technology application, and relates to a power supply spare power automatic switching control circuit which comprises a direct-current power supply positive electrode + KM, a Q1 control loop, a Q2 control loop, a Q automatic switching control loop and a direct-current power supply negative electrode-KM, wherein the direct-current power supply positive electrode + KM is connected with the Q1 control loop, and the Q2 control loop and the Q automatic switching control loop are connected in parallel and return to the direct-current power supply negative electrode-KM to form a loop. The invention has simple and feasible implementation and low investment cost, and when distribution transformer faults lose electricity or power line faults lose electricity, and two conditions of 'distribution transformer low-voltage relay kV voltage loss' and 'distribution transformer low-voltage side circuit breaker tripping' are met, the low-voltage bus-bar circuit breaker Q spare power automatic switching can be automatically put into use, thereby ensuring safe, continuous and stable power supply of a power supply system.

Description

Spare power automatic switching control circuit of power supply

Technical Field

The invention belongs to the technical field of power supply technology application, and particularly relates to a spare power automatic switching control circuit of a power supply.

Background

In order to improve the reliability of power supply, most important high-voltage power distribution users are powered by two power supplies, in a high-voltage power supply and distribution system, when the high-voltage power supply and distribution system is in normal power supply operation, a 10kV I incoming line supplies power to a 0.4kV low-voltage bus W1 through a distribution transformer (hereinafter referred to as distribution transformer) T1, a 10kV II incoming line supplies power to a 0.4kV low-voltage bus W2 through a distribution transformer T2, a 10kV I and II section bus-coupled circuit breaker is QF for hot standby, a 0.4kV low-voltage bus W1 and W2 bus-coupled circuit breaker is Q for hot standby, and other circuit breakers are all in closing operation.

When a 10kV I (or II) incoming line loses power or a distribution transformer T1 (or T2) fails, all loads of a 0.4kV low-voltage bus W1 (or W2) lose power, a low-voltage circuit breaker of the distribution transformer T1 (or T2) needs to be disconnected, and a 0.4kV low-voltage bus coupler circuit breaker needs to be switched on, so that power failure of a user load of the 0.4kV low-voltage bus W1 (or W2) within a period of time is caused, and power supply reliability is affected. Therefore, in order to improve the reliability of the power supply operation of the device, it is necessary to provide a power supply backup automatic switching control circuit.

Disclosure of Invention

The invention aims to provide a power supply backup power automatic switching control circuit, which can automatically switch in a low-voltage bus-coupled circuit breaker Q backup power automatic switching when the power distribution transformer fails or the power line fails and meets two conditions of 'distribution transformer low-voltage relay kV voltage loss' and 'distribution transformer low-voltage side circuit breaker tripping', ensures safe, continuous and stable power supply of a power supply system, and solves the problem that the user load of a 0.4kV low-voltage bus W1 (or W2) in the prior art has power failure within a period of time.

In order to achieve the above object, the invention provides a power supply backup power automatic switching control circuit, which includes a direct-current power supply positive electrode + KM, a Q1 control loop, a Q2 control loop, a Q automatic switching control loop and a direct-current power supply negative electrode-KM, wherein the direct-current power supply positive electrode + KM is connected with the Q1 control loop, and the Q2 control loop and the Q automatic switching control loop are connected in parallel and return to the direct-current power supply negative electrode-KM to form a loop;

the Q1 control loop comprises a group of contacts of a linkage switch SA1 of an automatic switching device of the T1 low-voltage circuit breaker Q1, a first normally closed contact KV11 of a low-voltage relay KV1, an auxiliary normally open contact of the low-voltage circuit breaker Q1, a time relay KT1 and a closing coil HQ1 of the low-voltage circuit breaker Q1; the Q2 control loop comprises a group of contacts of a T2 low-voltage circuit breaker Q2 automatic switching device linkage switch SA2, a first normally closed contact KV21 of a low-voltage relay KV2, an auxiliary normally open contact of the low-voltage circuit breaker Q2, a time relay KT2 and a closing coil HQ2 of the low-voltage circuit breaker Q2; the Q automatic switching control circuit comprises a first group of contacts and a second group of contacts of a linkage switch SA of the automatic switching device of the low-voltage bus coupler circuit breaker Q, a second normally closed contact KV12 of a low-voltage relay KV1, a second normally closed contact KV22 of a low-voltage relay KV2, an auxiliary normally closed contact of the low-voltage circuit breaker Q1, an auxiliary normally closed contact of the low-voltage circuit breaker Q2, an auxiliary normally closed contact of the low-voltage bus coupler circuit breaker Q and a closing coil HQ of the low-voltage bus coupler circuit breaker Q.

Further, T1 low-voltage circuit breaker Q1 is from a set of contact of throwing device linkage switch SA1 includes contact a1, contact b1, and T2 low-voltage circuit breaker Q2 is from a set of contact of throwing device linkage switch SA2 and including contact a2, contact b2, and the first set of contact of low-pressure female antithetical couplet circuit breaker Q is from throwing device linkage switch SA includes contact a, contact b, and the second set of contact of low-pressure female antithetical couplet circuit breaker Q is from throwing device linkage switch SA includes contact c, contact d, time relay KT1 includes time relay KT 1's coil and the closed normally open contact of time delay, time relay KT2 includes time relay KT 2's coil and the closed normally open contact of time delay.

Furthermore, a contact b1 of a group of contacts of the T1 low-voltage circuit breaker Q1 automatic throw device linkage switch SA1 is connected with a first normally closed contact KV11 of a low-voltage relay KV1, and the first normally closed contact KV11 of the low-voltage relay KV1 is connected with a coil of an auxiliary normally open contact series time relay KT1 of the low-voltage circuit breaker Q1 and a closing coil HQ1 of a time relay KT1 after a time delay closing normally open contact series low-voltage circuit breaker Q1 are connected in parallel.

Furthermore, a contact b2 of a group of contacts of the T2 low-voltage circuit breaker Q2 automatic throw device linkage switch SA2 is connected with a first normally closed contact KV21 of a low-voltage relay KV2, and the first normally closed contact KV21 of the low-voltage relay KV2 is connected with a coil of an auxiliary normally open contact series time relay KT2 of the low-voltage circuit breaker Q2 and a closing coil HQ2 of a time relay KT2 after a time delay closing normally open contact series low-voltage circuit breaker Q2 are connected in parallel.

Furthermore, the connection point b of the first group of connection points of the low-voltage bus tie breaker Q automatic switching device linkage switch SA is connected with the second normally closed connection point KV12 of the low-voltage relay KV1, the series connection of the auxiliary normally closed connection point of the low-voltage circuit breaker Q1 and the connection point d of the second group of connection points of the low-voltage bus tie breaker Q automatic switching device linkage switch SA are connected with the second normally closed connection point KV22 of the low-voltage relay KV2 and the series connection of the auxiliary normally closed connection point of the low-voltage circuit breaker Q2 in parallel and then connected with the auxiliary normally closed connection point of the low-voltage bus tie breaker Q, and the auxiliary normally closed connection point of the low-voltage bus tie breaker Q is connected with the closing coil HQ of the low-voltage bus tie breaker Q.

Further, the operating voltage of the direct current power supply is 220V.

Further, a direct current breaker is configured between the positive pole of the direct current power supply + KM and the negative pole of the direct current power supply-KM.

Compared with the prior art, the invention has the advantages and positive effects that,

1. the invention is simple and feasible to implement and has low investment cost;

2. according to the invention, when the two high-voltage incoming line power supplies lose power or the distribution transformer (T1 or T2) loses power, the low-voltage bus coupler circuit breaker Q can be automatically switched on, and the reliable operation of a power supply system is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

FIG. 1 is a diagram of a typical dual power supply and distribution system in the prior art;

fig. 2 is a primary wiring diagram of a power supply backup power automatic switching control circuit according to an embodiment;

fig. 3 is a circuit diagram of a control circuit of a backup power automatic switching device according to an embodiment;

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be further described with reference to the accompanying drawings and examples. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments of the present disclosure.

As shown in fig. 1, in a typical dual power supply and distribution system in the prior art, when a 10kV power supply and distribution system normally supplies power, a 10kV i incoming line supplies power to a 0.4kV low-voltage bus W1 and operates under load through a distribution transformer (hereinafter referred to as distribution transformer) T1 and a circuit breaker Q1, a 10kV ii incoming line supplies power to a 0.4kV low-voltage bus W2 and operates under load through a distribution transformer T2 and a circuit breaker Q2, a 10kV i and ii section buscouple circuit breaker QF is in hot standby, a 0.4kV low-voltage bus W1 and a W2 buscouple circuit breaker Q are in hot standby, and other circuit breakers are both in closed operation. When a 10kV I (or II) incoming line loses power or a distribution transformer T1 (or T2) fails, all loads of a 0.4kV low-voltage bus W1 (or W2) lose power, at the moment, a distribution transformer T1 (or T2) low-voltage circuit breaker needs to be disconnected, and a 0.4kV low-voltage bus-coupled circuit breaker needs to be switched on, so that power failure of a user load of the 0.4kV low-voltage bus W1 (or W2) within a period of time is caused, and the power supply reliability is influenced. Therefore, a spare power automatic switching control circuit for a power supply is needed.

In the embodiment, as shown in fig. 2-3, the automatic switching devices of the low-voltage circuit breaker Q1, the low-voltage circuit breaker Q2 and the low-voltage bus tie circuit breaker Q corresponding to the low-voltage side of the distribution transformer T1 and the distribution transformer T2 are respectively installed on the automatic switching cabinet and are respectively controlled by a group of contacts of the automatic switching device linkage switch SA1 of the T1 low-voltage circuit breaker Q1, a group of contacts of the automatic switching device linkage switch SA2 of the T2 low-voltage circuit breaker Q2 and a first group of contacts and a second group of contacts of the automatic switching device linkage switch SA of the low-voltage bus tie circuit breaker Q.

Under the condition of normal power supply operation, the T1 low-voltage circuit breaker Q1 automatic switching device linkage switch SA1 is arranged at a gear position of 3, namely the circuit breaker is in an automatic switching and automatic resetting state, and at the moment, a contact a1 and a contact b1 of a group of contacts of the T1 low-voltage circuit breaker Q1 automatic switching device linkage switch SA1 are switched on; the T2 low-voltage circuit breaker Q2 automatic switching device linkage switch SA2 is arranged at a 3 gear, namely, the circuit breaker is in an automatic switching and automatic resetting position, and at the moment, a contact b1 and a contact b2 of one group of contacts of the T2 low-voltage circuit breaker Q2 automatic switching device linkage switch SA2 are switched on; the low-voltage bus tie circuit breaker Q is set at a 3 gear position, namely, the circuit breaker is in a self-throw and self-reset state, at the moment, the contact a and the contact b of the first group of contacts of the low-voltage bus tie circuit breaker Q is connected with the contact b of the self-throw device linkage switch SA, and the contact c and the contact d of the second group of contacts of the low-voltage bus tie circuit breaker Q is connected with the contact d of the self-throw device linkage switch SA.

When the normal power supply operates, the automatic switching device is completely arranged at a 3 gear, the distribution transformer T1 and the distribution transformer T2 respectively carry 0.4kV low-voltage buses W1 and W2 to operate through the circuit breaker Q1 and the circuit breaker Q2, the 10kV bus-tie circuit breaker QF and the 0.4kV system bus-tie circuit breaker Q are in hot standby, and other circuit breakers are all switched on to operate. At the moment, the coil of the low-voltage relay KV1 of the distribution transformer T1 is electrified, the first normally closed contact KV11 of the low-voltage relay KV1 is disconnected, the auxiliary normally open contact of the distribution transformer T1 low-voltage circuit breaker Q1 is closed, and the auxiliary normally closed contact of the low-voltage circuit breaker Q1 is disconnected; the coil of the low-voltage relay KV2 of the distribution transformer T2 is electrified, the first normally closed contact KV21 of the low-voltage relay KV2 is disconnected, the auxiliary normally open contact of the distribution transformer T2 low-voltage circuit breaker Q2 is closed, and the auxiliary normally closed contact of the low-voltage circuit breaker Q2 is disconnected.

When the distribution transformer T1 loses power due to faults or a 10kV I incoming line power line fails, a coil of a low-voltage relay KV1 of the distribution transformer T1 loses power, a first normally closed contact KV11 of the low-voltage relay KV1 returns to be closed and connected, a coil of a time relay KT1 gets power, after a certain time delay, a closing coil HQ1 of a low-voltage circuit breaker Q1 of the distribution transformer T1 gets power, and the low-voltage circuit breaker Q1 of the distribution transformer T1 trips; the auxiliary normally closed contact of the low-voltage circuit breaker Q1 is reset and closed to be connected, at the moment, the auxiliary normally closed contact of the bus coupler circuit breaker Q is in a closed connection position due to the fact that the bus coupler circuit breaker is in a disconnection position, the direct-current power supply positive electrode + KM is connected with a circuit of a closing coil HQ of the low-voltage bus coupler circuit breaker Q through a first group of contact a and a contact b of a linkage switch SA of a low-voltage bus coupler circuit breaker Q automatic switching device, the closing coil HQ of the low-voltage bus coupler circuit breaker Q is electrified, and the low-voltage bus coupler circuit breaker Q is automatically closed to be operated to supply power to a W1 bus. Therefore, when two conditions of 'distribution transformer T1 low-voltage relay kV voltage loss' and 'distribution transformer T1 low-voltage side circuit breaker tripping' are met, the low-voltage bus-coupled circuit breaker Q backup power automatic switching can be automatically switched in, a 10kV II incoming line and a distribution transformer T2 supply all loads with a low-voltage bus W1 through the low-voltage bus-coupled circuit breaker Q of 0.4kV, and the whole power supply system is ensured to supply power safely, continuously and stably.

When the low-voltage circuit breaker Q1 of the distribution transformer T1 is singly tripped due to the fault of the 0.4kV low-voltage W1 bus, the distribution transformer Tl and the low-voltage relay KV1 still run in a charged mode, the spare power automatic switching condition of the low-voltage side bus-coupled circuit breaker Q is not met, the low-voltage side bus-coupled circuit breaker Q cannot be automatically switched, and therefore the expansion of the accident range caused by the automatic switching of the spare power automatic switching when the W1 bus is in the fault is avoided.

The working principle of the spare power automatic switching device when the distribution transformer T2 loses power due to faults or the power line of the distribution transformer loses power due to faults is the same as the above.

Those not described in detail in this specification are within the skill of the art.

The above description is only a preferred embodiment of the present invention, and not intended to limit the present invention in other forms, and any person skilled in the art may apply the above modifications or changes to the equivalent embodiments with equivalent changes, without departing from the technical spirit of the present invention, and any simple modification, equivalent change and change made to the above embodiments according to the technical spirit of the present invention still belong to the protection scope of the technical spirit of the present invention.

Claims

1. The power supply backup power automatic switching control circuit is characterized by comprising a direct-current power supply positive electrode + KM, a Q1 control loop, a Q2 control loop, a Q automatic switching control loop and a direct-current power supply negative electrode-KM, wherein the direct-current power supply positive electrode + KM is connected with the Q1 control loop, and the Q2 control loop and the Q automatic switching control loop are connected in parallel and return to the direct-current power supply negative electrode-KM to form a loop;

2. The power supply backup power automatic switching control circuit of claim 1, wherein a set of contacts of the T1 low-voltage circuit breaker Q1 automatic switching device linkage switch SA1 comprises a contact a1 and a contact b1, a set of contacts of the T2 low-voltage circuit breaker Q2 automatic switching device linkage switch SA2 comprises a contact a2 and a contact b2, a first set of contacts of the low-voltage bus bar circuit breaker Q automatic switching device linkage switch SA comprises a contact a and a contact b, a second set of contacts of the low-voltage bus bar circuit breaker Q automatic switching device linkage switch SA comprises a contact c and a contact d, the time relay KT1 comprises a coil of the time relay KT1 and a normally open contact of time delay closing, and the time relay KT2 comprises a coil of the time relay KT2 and a normally open contact of time delay closing.

3. The power supply backup power automatic switching control circuit according to claim 1, characterized in that a contact b1 of a group of contacts of the T1 low-voltage circuit breaker Q1 automatic switching device linkage switch SA1 is connected with a first normally closed contact KV11 of a low-voltage relay KV1, the first normally closed contact KV11 of the low-voltage relay KV1 is connected with a coil of an auxiliary normally open contact series time relay KT1 of the low-voltage circuit breaker Q1 and a closing coil HQ1 of the time relay KT1 after a time delay closing normally open contact series low-voltage circuit breaker Q1 are connected in parallel.

4. The power supply backup power automatic switching control circuit according to claim 1, characterized in that a contact b2 of a group of contacts of the T2 low-voltage circuit breaker Q2 automatic switching device linkage switch SA2 is connected with a first normally closed contact KV21 of a low-voltage relay KV2, the first normally closed contact KV21 of the low-voltage relay KV2 is connected with a coil of an auxiliary normally open contact series time relay KT2 of the low-voltage circuit breaker Q2, and the coil of a time delay closed normally open contact series low-voltage circuit breaker Q2 is connected with a closing coil HQ2 of the low-voltage circuit breaker Q2 in parallel.

5. The power backup power automatic switching control circuit according to claim 1, wherein a contact b of a first group of contacts of the low-voltage bus tie breaker Q automatic switching device linkage switch SA, a second normally closed contact KV12 of the low-voltage relay KV1, a series connection of an auxiliary normally closed contact of the low-voltage breaker Q1, a contact d of a second group of contacts of the low-voltage bus tie breaker Q automatic switching device linkage switch SA, a second normally closed contact KV22 of the low-voltage relay KV2, and a series connection of an auxiliary normally closed contact of the low-voltage breaker Q2 are connected in parallel and then connected with an auxiliary normally closed contact of the low-voltage bus tie breaker Q, and the auxiliary normally closed contact of the low-voltage bus tie breaker Q is connected with a switching-on coil HQ of the low-voltage bus tie breaker Q.

6. The power supply backup power automatic switching control circuit according to claim 1, wherein the operating voltage of the dc power supply is 220V.

7. The power supply backup power automatic switching control circuit according to claim 1, wherein the dc power positive electrode + KM and the dc power negative electrode-KM are configured with dc circuit breakers.