Magnetic balance protection control system of compressor motor

Abstract

The utility model discloses a magnetic balance protection control system of a compressor motor, which belongs to the technical field of electrical relay protection and comprises a main starting loop and a frequency converter protection device. A head end motor, a first starting loop, a head end magnetic balance differential protection device and a head end operation loop; and a plurality of intermediate end motors, a plurality of second starting loops, a plurality of intermediate end magnetic balance differential protection devices, and a plurality of intermediate end operation loops. According to the utility model, the front-end motor and each middle-end motor are respectively connected to the main starting loop provided with the frequency converter protection device through the first starting loop and each second starting loop to protect each starting loop; a head-end magnetic balance differential protection device is installed on a head-end operation loop, middle-end magnetic balance differential protection devices are installed on middle-end operation loops, and a tail-end magnetic balance differential protection device is installed on a tail-end motor operation loop, so that continuous differential protection of a compressor motor set in the starting stage to the operation stage is met.

Description

Technical Field

[0001] The utility model relates to a magnetic balance protection control system for a compressor motor, belonging to the technical field of electrical relay protection. Background Art

[0002] Compressed Air Energy Storage (CAES) is a large-scale physical energy storage technology with the advantages of low unit cost, short construction period, long system life, and good energy storage effect. It is currently receiving more and more attention and development. The compressor is the core equipment of the compressed air energy storage power station. When the grid load is at a low point, the air is compressed by the compressor, the high-pressure air is stored in the gas storage reservoir, and the compression heat is recovered using the heat storage medium. During periods of high grid load, the high-pressure gas is put into the air turbine to expand and do work, driving the generator to transmit electricity to the grid. Therefore, the stable operation of the compressor is crucial to the entire power station.

[0003] At present, the electrical protection of compressor motors has the following main problems compared with conventional motors: first, the capacity of compressor motors is in the range of 10 to 80MW, which is much larger than motors in ordinary applications; second, compressor motors need to rely on variable frequency speed regulation systems to start, while ordinary motors can be started directly; in addition, ordinary longitudinal differential protection is mostly used in stable power frequency operation and is not suitable for variable frequency starting. Moreover, the current at the neutral point and switchgear of the motor collected by ordinary longitudinal differential protection will increase significantly when the circuit power supply distance is far, the protection sensitivity is reduced and the setting is difficult. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a magnetic balance protection control system for a compressor motor, which can provide continuous differential protection during the startup and operation stages of a large-capacity compressor motor, thereby solving the problem that the current ordinary longitudinal differential protection cannot meet the needs of rapid startup, safe and stable operation of the compressor unit.

[0005] In order to achieve the above purpose / solve the above technical problems, the utility model is implemented by adopting the following technical solutions: a magnetic balance protection control system for a compressor motor, comprising:

[0006] Main starting circuit, inverter protection device for protecting the main starting circuit;

[0007] A first-end motor, a first starting circuit for starting the first-end motor, a first-end magnetic balance differential protection device for protecting the first-end motor, and a first-end operating circuit for maintaining continuous operation of the first-end motor after the first-end motor is started;

[0008] A plurality of intermediate-end motors, a second starting circuit corresponding to the plurality of intermediate-end motors for starting the intermediate-end motors, an intermediate-end magnetic balance differential protection device corresponding to the plurality of intermediate-end motors for protecting the intermediate-end motors, and an intermediate-end operating circuit corresponding to the plurality of intermediate-end motors for maintaining the operation of the intermediate-end motors after the intermediate-end motors are started;

[0009] Terminal motor, terminal motor running circuit, terminal magnetic balance differential protection device for protecting the terminal motor;

[0010] The main starting circuit is connected to the terminal motor running circuit through a cable, and the terminal motor is electrically connected to the terminal motor running circuit;

[0011] The plurality of intermediate end motors are connected to the corresponding intermediate end running circuits through cables, and the plurality of intermediate end motors are connected to the main starting circuit through the corresponding second starting circuits;

[0012] The first end motor is connected to the first end running circuit through a cable, and the first end motor is connected to the main starting circuit through the first starting circuit.

[0013] Optionally, the first starting circuit includes a first-end starting circuit breaker; the first-end starting circuit breaker is electrically connected to the main starting circuit and the first-end motor through cables.

[0014] Optionally, the first-end operation circuit includes a first-end operation circuit breaker and a first-end high-voltage industrial frequency power supply; the first-end operation circuit breaker is connected to the first-end high-voltage industrial frequency power supply and the first-end motor through cables respectively.

[0015] Optionally, the first-end magnetic balance differential protection device is electrically connected to the first-end power frequency current transformer, the first-end zero-sequence current transformer and the first-end magnetic balance current transformer; the first-end power frequency current transformer and the first-end zero-sequence current transformer are installed in the cable between the first-end operating circuit breaker and the first-end motor; the first-end magnetic balance current transformer is installed at the incoming line end of the first-end motor.

[0016] Optionally, the second starting circuit includes an intermediate-end starting circuit breaker; the intermediate-end starting circuit breaker is electrically connected to the main starting circuit and the intermediate-end motor through cables.

[0017] Optionally, the intermediate end operation circuit includes an intermediate end operation circuit breaker and an intermediate end high voltage power frequency power supply; the intermediate end operation circuit breaker is connected to the intermediate end high voltage power frequency power supply and the intermediate end motor through cables respectively.

[0018] Optionally, the intermediate-end magnetic balance differential protection device is electrically connected to an intermediate-end power frequency current transformer, an intermediate-end zero-sequence current transformer and an intermediate-end magnetic balance current transformer; the intermediate-end power frequency current transformer and the intermediate-end zero-sequence current transformer are installed on the cable between the intermediate-end operating circuit breaker and the intermediate-end motor; the intermediate-end magnetic balance current transformer is installed at the incoming line end of the intermediate-end motor.

[0019] Optionally, the main starting circuit includes a terminal high-voltage industrial frequency power supply, a main circuit breaker A, a high-voltage inverter, and a main circuit breaker B connected in sequence; the inverter protection device is electrically connected to a terminal industrial frequency current transformer and a terminal zero-sequence current transformer; the terminal industrial frequency current transformer and the terminal zero-sequence current transformer are installed in the cable between the main circuit breaker A and the high-voltage inverter.

[0020] Optionally, the terminal motor operation circuit includes a terminal circuit breaker; the terminal circuit breaker is electrically connected to the main circuit breaker B and the terminal motor through cables.

[0021] Optionally, the terminal magnetic balance differential protection device is electrically connected to a terminal magnetic balance current transformer; the terminal magnetic balance current transformer is installed at the incoming line terminal of the terminal motor.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] The utility model connects the front-end motor and each intermediate-end motor to the main starting circuit through the first starting circuit and each second starting circuit respectively, and the main starting circuit is provided with a frequency converter protection device, so as to protect each starting circuit while satisfying the sequential starting of the front-end motor and each intermediate-end motor; by installing a head-end magnetic balance differential protection device on the head-end running circuit, installing an intermediate-end magnetic balance differential protection device on each intermediate-end running circuit and installing a terminal magnetic balance differential protection device on the terminal motor running circuit, the continuous differential protection of the compressor motor unit during the startup and transition to the running stage is satisfied, and the problem that the current ordinary longitudinal differential protection cannot satisfy the rapid starting, safe and stable operation of the compressor unit is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a magnetic balance protection control system for a compressor motor provided by an embodiment of the utility model.

[0025] In the figure: 1. main starting circuit; 101. terminal high-voltage power supply; 102. main circuit breaker A; 103. high-voltage inverter; 104. main circuit breaker B; 2. head end motor; 3. first starting circuit; 301. head end starting circuit breaker; 4. head end running circuit; 401. head end running circuit breaker; 402. head end high-voltage power supply; 5. first middle end motor; 6. second middle end motor; 7. second starting circuit A; 701. middle end starting circuit breaker A; 8. second starting circuit B; 801. middle end starting circuit breaker B; 9. first middle end running circuit; 901. middle end running circuit breaker A; 902. middle end high-voltage power supply A; 10. second middle end running circuit; 1001. middle end running circuit breaker B; 1002. middle end high-voltage power supply B; 11. terminal motor; 12. terminal motor Running circuit; 1201, terminal circuit breaker; 13, inverter protection device; 1301, terminal power frequency current transformer; 1302, terminal zero sequence current transformer; 14, terminal magnetic balance differential protection device; 1401, terminal magnetic balance current transformer; 15, head end magnetic balance differential protection device; 1501, head end power frequency current transformer; 1502, head end zero sequence current transformer; 1503, head end magnetic balance current transformer; 16, first middle end magnetic balance differential protection device; 1601, middle end power frequency current transformer A; 1602, middle end zero sequence current transformer A; 1603, middle end magnetic balance current transformer A; 17, second middle end magnetic balance differential protection device; 1701, middle end power frequency current transformer B; 1702, middle end zero sequence current transformer B; 1703, middle end magnetic balance current transformer B. DETAILED DESCRIPTION

[0026] The utility model is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model.

[0027] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the feature. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0029] Example

[0030] like Figure 1 As shown, a magnetic balance protection control system for a compressor motor comprises:

[0031] Main starting circuit 1, head end motor 2, first starting circuit 3, head end running circuit 4, first intermediate end motor 5, second intermediate end motor 6, second starting circuit A7, second starting circuit B8, first intermediate end running circuit 9, second intermediate end running circuit 10, terminal motor 11, terminal motor running circuit 12;

[0032] The main starting circuit 1 is provided with a frequency converter protection device 13, wherein: the main starting circuit 1 comprises a terminal high-voltage power frequency power supply 101, a main circuit breaker A102, a high-voltage frequency converter 103, and a main circuit breaker B104 connected in sequence through cables; the frequency converter protection device 13 is electrically connected with a terminal power frequency current transformer 1301 and a terminal zero-sequence current transformer 1302; the terminal power frequency current transformer 1301 and the terminal zero-sequence current transformer 1302 are installed in the cable between the main circuit breaker A102 and the high-voltage frequency converter 103;

[0033] The terminal motor running circuit 12 is equipped with a terminal magnetic balance differential protection device 14, wherein: the terminal motor running circuit 12 includes a terminal circuit breaker 1201; the terminal circuit breaker 1201 is electrically connected to the main circuit breaker B104 and the terminal motor 11 through cables; the terminal magnetic balance differential protection device 14 is electrically connected to the terminal magnetic balance current transformer 1401; the terminal magnetic balance current transformer 1401 is installed at the incoming line end of the terminal motor 11; when the terminal circuit breaker 1201 is closed, the terminal motor running circuit 12 is connected to the main starting circuit 1;

[0034] The first starting circuit 3 includes a first-end starting circuit breaker 301; the first-end starting circuit breaker 301 is electrically connected to the main starting circuit 1 and the first-end motor 2 through cables; when the first-end starting circuit breaker 301 is closed, the first starting circuit 3 is connected to the main starting circuit 1;

[0035] The first-end operation circuit 4 is equipped with a first-end magnetic balance differential protection device 15, wherein: the first-end operation circuit 4 includes a first-end operation circuit breaker 401 and a first-end high-voltage power frequency power supply 402, and the first-end operation circuit breaker 401 is respectively connected to the first-end high-voltage power frequency power supply 402 and the first-end motor 2 through cables; the first-end magnetic balance differential protection device 15 is electrically connected to the first-end power frequency current transformer 1501, the first-end zero-sequence current transformer 1502 and the first-end magnetic balance current transformer 1503; the first-end power frequency current transformer 1501 and the first-end zero-sequence current transformer 1502 are installed on the cable between the first-end operation circuit breaker 401 and the first-end motor 2; the first-end magnetic balance current transformer 1503 is installed at the incoming line end of the first-end motor 2;

[0036] The second starting circuit A7 includes an intermediate end starting circuit breaker A701; the intermediate end starting circuit breaker A701 is electrically connected to the main starting circuit 1 and the first intermediate end motor 5 through cables; when the intermediate end starting circuit breaker A701 is closed, the second starting circuit A7 is connected to the main starting circuit 1;

[0037] The first intermediate end operation circuit 9 is provided with a first intermediate end magnetic balance differential protection device 16, wherein: the first intermediate end operation circuit 9 comprises an intermediate end operation circuit breaker A901 and an intermediate end high voltage power frequency power supply A902, and the intermediate end operation circuit breaker A901 is electrically connected to the intermediate end high voltage power frequency power supply A902 and the first intermediate end motor 5 through cables;

[0038] The first intermediate end magnetic balance differential protection device 16 is electrically connected with the intermediate end power frequency current transformer A1601, the intermediate end zero sequence current transformer A1602 and the intermediate end magnetic balance current transformer A1603; the intermediate end power frequency current transformer A1601 and the intermediate end zero sequence current transformer A1602 are installed in the cable between the intermediate end operating circuit breaker A901 and the first intermediate end motor 5; the intermediate end magnetic balance current transformer A1603 is installed at the incoming line end of the first intermediate end motor 5;

[0039] The second starting circuit B8 includes an intermediate end starting circuit breaker B801; the intermediate end starting circuit breaker B801 is electrically connected to the main starting circuit 1 and the second intermediate end motor 6 through cables; when the intermediate end starting circuit breaker B801 is closed, the second starting circuit B8 is connected to the main starting circuit 1;

[0040] The second intermediate end operation circuit 10 is provided with a second intermediate end magnetic balance differential protection device 17, wherein: the second intermediate end operation circuit 10 comprises an intermediate end operation circuit breaker B1001 and an intermediate end high voltage power frequency power supply B1002, and the intermediate end operation circuit breaker B1001 is electrically connected to the intermediate end high voltage power frequency power supply B1002 and the second intermediate end motor 6 through cables;

[0041] The second intermediate-end magnetic balance differential protection device 17 is electrically connected to the intermediate-end power frequency current transformer B1701, the intermediate-end zero-sequence current transformer B1702 and the intermediate-end magnetic balance current transformer B1703; the intermediate-end power frequency current transformer B1701 and the intermediate-end zero-sequence current transformer B1702 are installed on the cable between the intermediate-end operating circuit breaker B1001 and the first intermediate-end motor 5; the intermediate-end magnetic balance current transformer B1703 is installed at the incoming line end of the first intermediate-end motor 5.

[0042] How it works

[0043] The main circuit breaker A102 is closed, and the inverter protection device 13 is connected to the main starting circuit 1;

[0044] The main circuit breaker B104 is closed, the first-end starting circuit breaker 301 is closed, the first-end motor 2 is connected to the main starting circuit 1, and after the first-end motor 2 starts to 50HZ, the first-end running circuit breaker 401 is closed. After the first-end magnetic balance differential protection device 15 is connected to the first-end running circuit 4, the first-end starting circuit breaker 301 is disconnected, and the first-end motor 2 operates stably at the power frequency;

[0045] The intermediate end starting circuit breaker A701 is closed, and the first intermediate end motor 5 is connected to the main starting circuit 1. After the first intermediate end motor 5 is started to 50HZ, the intermediate end running circuit breaker A901 is closed. After the first intermediate end magnetic balance differential protection device 16 is connected to the first intermediate end running circuit 9, the intermediate end starting circuit breaker A701 is disconnected, and the first intermediate end motor 5 operates stably at the industrial frequency;

[0046] The middle end starting circuit breaker B801 is closed, and the second middle end motor 6 is connected to the main starting circuit 1. After the second middle end motor 6 starts to 50HZ, the middle end running circuit breaker B1001 is closed. After the second middle end magnetic balance differential protection device 17 is connected to the second middle end running circuit 10, the middle end starting circuit breaker B801 is disconnected, and the second middle end motor 6 operates stably at the industrial frequency.

[0047] The terminal circuit breaker 1201 is closed, the terminal motor running circuit 12 is connected to the main starting circuit 1, the terminal motor 11 is started and the terminal magnetic balance differential protection device 14 is connected to the terminal motor running circuit 12, and the terminal motor 11 enters the variable frequency operation state.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A magnetic balance protection control system for a compressor motor, characterized in that: include: Main starting circuit, inverter protection device for protecting the main starting circuit; A first-end motor, a first starting circuit for starting the first-end motor, a first-end magnetic balance differential protection device for protecting the first-end motor, and a first-end operating circuit for maintaining continuous operation of the first-end motor after the first-end motor is started; A plurality of intermediate-end motors, a second starting circuit corresponding to the plurality of intermediate-end motors for starting the intermediate-end motors, an intermediate-end magnetic balance differential protection device corresponding to the plurality of intermediate-end motors for protecting the intermediate-end motors, and an intermediate-end operating circuit corresponding to the plurality of intermediate-end motors for maintaining the operation of the intermediate-end motors after the intermediate-end motors are started; Terminal motor, terminal motor running circuit, terminal magnetic balance differential protection device for protecting the terminal motor; The main starting circuit is connected to the terminal motor running circuit through a cable, and the terminal motor is electrically connected to the terminal motor running circuit; The plurality of intermediate end motors are connected to the corresponding intermediate end running circuits through cables, and the plurality of intermediate end motors are connected to the main starting circuit through the corresponding second starting circuits; The first end motor is connected to the first end running circuit through a cable, and the first end motor is connected to the main starting circuit through the first starting circuit.

2. The magnetic balance protection control system for the compressor motor according to claim 1, characterized in that: The first starting circuit includes a first-end starting circuit breaker; the first-end starting circuit breaker is electrically connected to the main starting circuit and the first-end motor through cables.

3. The magnetic balance protection control system for the compressor motor according to claim 1, characterized in that: The first-end operation circuit includes a first-end operation circuit breaker and a first-end high-voltage power frequency power supply; the first-end operation circuit breaker is connected to the first-end high-voltage power frequency power supply and the first-end motor through cables.

4. The magnetic balance protection control system for the compressor motor according to claim 3, characterized in that: The first-end magnetic balance differential protection device is electrically connected to the first-end power frequency current transformer, the first-end zero-sequence current transformer and the first-end magnetic balance current transformer; the first-end power frequency current transformer and the first-end zero-sequence current transformer are installed in the cable between the first-end operating circuit breaker and the first-end motor; the first-end magnetic balance current transformer is installed at the incoming line end of the first-end motor.

5. The magnetic balance protection control system for the compressor motor according to claim 1, characterized in that: The second starting circuit includes an intermediate-end starting circuit breaker; the intermediate-end starting circuit breaker is electrically connected to the main starting circuit and the intermediate-end motor through cables.

6. The magnetic balance protection control system for a compressor motor according to claim 1, characterized in that: The intermediate end operation circuit includes an intermediate end operation circuit breaker and an intermediate end high voltage power frequency power supply; the intermediate end operation circuit breaker is connected to the intermediate end high voltage power frequency power supply and the intermediate end motor through cables.

7. The magnetic balance protection control system for the compressor motor according to claim 6, characterized in that: The intermediate-end magnetic balance differential protection device is electrically connected to the intermediate-end power frequency current transformer, the intermediate-end zero-sequence current transformer and the intermediate-end magnetic balance current transformer; the intermediate-end power frequency current transformer and the intermediate-end zero-sequence current transformer are installed on the cables between the intermediate-end operating circuit breaker and the intermediate-end motor; the intermediate-end magnetic balance current transformer is installed at the incoming line end of the intermediate-end motor.

8. The magnetic balance protection control system for a compressor motor according to claim 1, characterized in that: The main starting circuit includes a terminal high-voltage industrial frequency power supply, a main circuit breaker A, a high-voltage inverter, and a main circuit breaker B connected in sequence; the inverter protection device is electrically connected to a terminal industrial frequency current transformer and a terminal zero-sequence current transformer; the terminal industrial frequency current transformer and the terminal zero-sequence current transformer are installed in the cable between the main circuit breaker A and the high-voltage inverter.

9. The magnetic balance protection control system for a compressor motor according to claim 1, characterized in that: The terminal motor operation circuit includes a terminal circuit breaker; the terminal circuit breaker is electrically connected to the main circuit breaker B and the terminal motor through cables.

10. The magnetic balance protection control system for a compressor motor according to claim 1, characterized in that: The terminal magnetic balance differential protection device is electrically connected to the terminal magnetic balance current transformer; The terminal magnetic balance current transformer is installed at the incoming line end of the terminal motor.

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