CN218886001U - Used variable low-voltage side no-load impact test device with time delay protection function - Google Patents

Abstract

The utility model discloses a no-load impact test device on the low-voltage side of the variable voltage with the function of delay protection, which includes a box body and an internal electrical circuit. The internal electrical circuit includes a main circuit and a delay control circuit. The main The loop connects the variable low-voltage incoming line switch and the low-voltage AC power supply. The delay control loop is connected to the A-phase and N-phase of the low-voltage AC power supply. The delay control loop controls the delay conduction of the main loop through the delay relay. The box body Reserve external test wiring and operation interface. The beneficial effects of the utility model include: it has the function of delay protection, and if the transformer used is abnormal during the pressurization process, it can effectively protect the safety of the person; the impact of no-load from the low-voltage side reduces the operation risk, improves the work efficiency, and ensures the safety of the power grid and equipment. and personal safety.

Description

A no-load impact test device on the low-voltage side of the transformer with time-delay protection function

technical field

The utility model relates to the technical field of the no-load impact test of the transformer used in the substation, in particular to a no-load impact test device on the low-voltage side of the transformer used with the function of delay protection.

Background technique

The substation is used as the "power source" of the substation, which is directly related to the power supply of production, living and primary and secondary operation equipment in the substation. Once a failure occurs, the entire substation may lose power and cause a large-scale power outage. In order to improve the power supply reliability of equipment and ensure reliable power consumption for production and life in the station, the work of replacing and increasing the capacity of old transformers is increasing. After the used replacement is completed, the no-load impact test is a necessary means to verify whether its function is normal and to ensure its operation. It can find out whether its coil insulation is good, whether the wiring is correct, and a series of abnormal operating conditions.

For a long time, the variable no-load impact test used adopts the traditional method of applying pressure from the high pressure side. The traditional no-load impact test method used needs to change the operation mode of the system. With the increasing number of replacement work used, the traditional method has brought a lot of work burden and operational risk to the operation and maintenance personnel, not only the large amount of operation , the risk is high, and all the loads on one bus are transferred to other buses for operation, which will increase the burden on the equipment and bring considerable risks to the safe operation of the equipment and the power grid.

Therefore, there is an urgent need for a new test device that can avoid changing the operating mode of the high-voltage side of the transformer used, thereby reducing the amount of operation caused by changing the operating mode of the system, reducing operational risks, and ensuring the safety of the power grid, equipment and people.

Utility model content

Aiming at the problems of large amount of operation and low safety in the prior art, the utility model provides a no-load impact test device on the low-voltage side of the variable voltage with the function of time-delay protection, aiming at avoiding changing the operation mode of the system, reducing operation risks, and improving Work efficiency, guarantee the safety of power grid, equipment and personal.

Below is the technical scheme of the utility model.

A no-load impact test device on the low-voltage side of the transformer with time-delay protection function, which includes a box body and an internal electrical circuit. The internal electrical circuit includes a main circuit and a delay control circuit. The main circuit is connected to the low-voltage transformer used. Incoming line switch and low-voltage AC power supply, the delay control circuit is connected to phase A and phase N of the low-voltage AC power supply, the delay control circuit controls the delay conduction of the main circuit through the delay relay, and the external test wiring is reserved for the box and operation interface.

Preferably, the main circuit includes a low-voltage incoming line terminal, a miniature circuit breaker, an AC contactor normally open main contact, and a low-voltage outgoing line terminal. The low-voltage incoming line terminal is connected to a low-voltage AC power supply. The miniature circuit breaker and the AC contactor are normally The open main contacts are all connected in series between the low-voltage incoming line terminal and the low-voltage outgoing line terminal, and the low-voltage outgoing line terminal is connected to the variable low-voltage incoming line switch used.

Preferably, the delay control loop includes a delay control circuit breaker, an AC contactor coil and a delay relay connected in series in sequence, the delay control circuit breaker is connected to the neutral line, and the delay relay is connected to the low-voltage incoming line terminal any phase.

As a preference, the low-voltage incoming terminal of the main circuit adopts a three-phase four-wire wiring system (A/B/C/N), wherein N is a neutral line for grounding protection; the low-voltage outgoing terminal of the main circuit adopts a three-phase Three-wire wiring (A/B/C); the delay control loop adopts single-phase wiring (L/N), where the L terminal is connected to any phase on the low-voltage incoming line terminal, and the N terminal of the delay control loop is connected to N terminal on the low-voltage incoming line terminal.

Preferably, the box is a stainless steel portable box, and the internal electrical circuit is fixed and packaged. The external test wiring interface reserved by the stainless steel portable box includes a low-voltage incoming line terminal interface and a low-voltage outgoing line terminal interface. The reserved operation interface includes Miniature circuit breaker operation button, delay control air switch operation button, delay relay time adjustment operation button.

The beneficial effects of the utility model include:

1) When the used transformer is abnormal, in the traditional high-voltage side no-load impact test process, the bus breaker on the high-voltage side or the low-voltage side switch of the main transformer will be tripped, but using the device to carry out the no-load impact test on the low-voltage side, only need to jump Open the air circuit breaker on the low-voltage side of the device, which greatly reduces the tripping range of the equipment.

2) With delay protection function, the pressurized main circuit will be automatically connected after the set delay, so as to reserve time for the test personnel to transfer to a safe position. Therefore, if the variable used is in an abnormal state during the pressurization process, personal safety can be effectively protected.

3) Reduce operational risk, improve work efficiency, and greatly reduce test time. The traditional method takes about 6 hours as a whole, but the new method only takes about 30 minutes, and the test efficiency is increased by more than 10 times.

Description of drawings

Fig. 1 is the electrical schematic diagram of the embodiment of the present application;

Figure 2 is a schematic diagram of a station power system with a third power supply;

Fig. 3 is a schematic diagram of a station power system without a third power supply.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In addition, in order to better illustrate the present utility model, numerous specific details are given in the following specific embodiments. It will be understood by those skilled in the art that the present invention may be practiced without some of the specific details. In some instances, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

Among them, in the description of the embodiments of this application, unless otherwise specified, "/" means or means, for example, A/B can mean A or B; "and/or" in this article is only a description of associated objects The association relationship of indicates that there may be three kinds of relationships, for example, A and/or B may indicate: A exists alone, A and B exist simultaneously, and B exists independently.

Hereinafter, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

Example:

The utility model relates to a no-load impact test device on the low-voltage side of a transformer with a time-delay protection function, which includes a box body, a main circuit, and a time-delay control circuit. As shown in Figure 1 is the electrical schematic diagram of the embodiment of the present application, wherein QF1 is a miniature circuit breaker, KM is an AC contactor, TOD is a time delay relay, S1 is a time delay control circuit breaker, and A1 and A2 are AC contactor coils contact.

Specifically, the main circuit of this embodiment includes a low-voltage incoming line terminal, a miniature circuit breaker, an AC contactor normally open main contact, and a low-voltage outgoing line terminal. The low-voltage incoming line terminals (A/B/C/N) are connected to a low-voltage AC power supply , the low-voltage outgoing line terminal (A/B/C) is connected to the variable low-voltage incoming line switch, and the miniature circuit breaker and the normally open main contact of the AC contactor are connected in series between the low-voltage incoming line terminal and the low-voltage outgoing line terminal.

The delay control loop of this embodiment includes a delay control circuit breaker, an AC contactor coil, and a delay relay in series in sequence, and adopts a single-phase wiring form (L/N), wherein the L terminal is connected to any of the low-voltage incoming line terminals. For one phase, the N terminal is connected to the N terminal on the low-voltage incoming line terminal, and the delay time of the delay relay can be adjusted manually.

The box body of this embodiment is a stainless steel portable box body, and the internal electrical circuit is fixed and packaged. The external test wiring interface reserved for the stainless steel portable box body includes a low-voltage incoming line terminal interface and a low-voltage outgoing line terminal interface. The reserved operation interface includes micro Circuit breaker operation button, delay control air switch operation button, delay relay time adjustment operation button.

Accompanying drawings 2 and 3 show a typical AC system for substations, and the use method and advantages of this application are explained by taking #2 substation power outage maintenance as an example.

After the replacement work of the used substation is completed, no-load impact test is carried out on the used substation of #2. The traditional high-voltage side pressurization test needs to change the system operation mode, that is, all loads on the bus section II need to be transferred to other power supply buses, and the bus breaker is changed to run At this time, the second-section busbar is powered by the I-section busbar through the bus breaker with operating voltage. At the same time, the switch knife trolley in the switch cabinet used by #2 needs to be pushed to the working position, and the low-voltage side incoming line switch used by #2 is disconnected. , Low-voltage AC I and II busbars are powered by #1 transformer. When pressurizing, if the transformer used in #2 is abnormal, the high-voltage side of the used transformer will trip, that is, the bus breaker will be tripped, and the busbar of section II will lose power.

This application adopts a new idea of pressurization test from the low pressure side of the transformer used:

(1) Before the test starts, check the status of the equipment, pull the knife trolley in the switchgear used to the maintenance or test position, and disconnect the high voltage side of the used transformer from the bus bar;

(2) Turn on the outlet switch on the low-voltage side of the transformer used by #2, and disconnect the incoming switch on the low-voltage side of the transformer used by #2 (inside the electric screen cabinet). At this time, the low-voltage AC I and II busbars are powered by the transformer used by #1 ;

(3) For the station power system with the third power supply: the low-voltage incoming line terminal interface on the device proposed in this application is connected to the third power supply air switch interface of the variable screen used, and the low-voltage outgoing line terminal interface is connected to the low-voltage transformer used in #2 The interface of the incoming line switch is shown in Figure 2; for the power system of a station without a third power supply: the low-voltage incoming line terminal interface on the device proposed in this application is connected to an external three-phase power supply, and the low-voltage outgoing line terminal interface is connected to #2 The switch interface of the low-voltage incoming line is shown in Figure 3;

(4) After checking that the test wiring is correct, first close the miniature circuit breaker on the device proposed by this application, and then close the circuit breaker of the delay control circuit. Pressurize the low pressure side. If there is an abnormality in the transformer used, the miniature circuit breaker in the device will trip to realize the protection function;

(5) During the pressurization process, measure the voltage on the low-voltage side of the transformer used, and check the status of the high-voltage live display.

This application realizes the verification of the no-load impact test by applying pressure from the low-voltage side of the variable variable, without any operation on the high-voltage side system operation mode, which greatly reduces the amount of operation and operation risk, and saves the time for changing the system operation mode , Work efficiency and safety are greatly improved.

It should be noted that the usage method involved in this embodiment is only a supplementary description of the device, and does not limit the scope of protection.

Through the description of the above embodiments, those skilled in the art can understand that for the convenience and brevity of the description, only the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned functions can be assigned to different Module completion means that the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

A unit described as a separate component may or may not be physically separated, and a component shown as a unit may be one physical unit or multiple physical units, which may be located in one place or distributed to multiple different places. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above content is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application, and should covered within the scope of protection of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (5)

1. The no-load impact test device with the time-delay protection function at the low-voltage side is characterized by comprising a box body and an internal electric loop, wherein the internal electric loop comprises a main loop and a time-delay control loop, the main loop is connected with a low-voltage incoming switch and a low-voltage alternating-current power supply, the time-delay control loop is connected with an A phase and an N phase of the low-voltage alternating-current power supply, the time-delay control loop controls the time-delay conduction of the main loop through a time-delay relay, and an external test wiring and an operation interface are reserved in the box body.

2. The no-load impact test device for the transformer low-voltage side with the time delay protection function as claimed in claim 1, wherein the main loop comprises a low-voltage incoming line terminal, a miniature circuit breaker, a normally-open main contact of an alternating current contactor, and a low-voltage outgoing line terminal, the low-voltage incoming line terminal is connected with a low-voltage alternating current power supply, the miniature circuit breaker and the normally-open main contact of the alternating current contactor are connected in series between the low-voltage incoming line terminal and the low-voltage outgoing line terminal, and the low-voltage outgoing line terminal is connected with a low-voltage incoming line switch for use.

3. The no-load impact test device with the time delay protection function for the low voltage side of the transformer of claim 2, wherein the time delay control loop comprises a time delay control air switch, an alternating current contactor coil and a time delay relay which are sequentially connected in series, the time delay control air switch is connected with a zero line, and the time delay relay is connected with any phase of a low voltage wire inlet terminal.

4. The no-load impact test device for the low-voltage side of a transformer with a time delay protection function according to claim 3, wherein a three-phase four-wire connection mode A/B/C/N is adopted for a low-voltage incoming terminal of the main circuit, wherein N is a zero line and is used for grounding protection and forming a time delay control circuit path; the low-voltage outlet terminal of the main loop adopts a three-phase three-wire wiring A/B/C; the delay control loop adopts a single-phase wiring form L/N, wherein L is connected to any phase on the low-voltage incoming line terminal, and N is connected to N on the low-voltage incoming line terminal.

5. The no-load impact test device with the time delay protection function on the low-voltage side of the transformer used as claimed in claim 3, wherein the box body is a stainless steel portable box body, an internal electric loop is fixedly packaged, an external test wiring interface reserved in the stainless steel portable box body comprises a low-voltage wire inlet terminal interface and a low-voltage wire outlet terminal interface, and a reserved operation interface comprises a miniature circuit breaker operation button, a time delay control idle opening operation button and a time delay relay time adjustment operation button.

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