Configuration structure of frequency converter of circulating water pump motor

Abstract

The utility model discloses a circulating water pump motor frequency converter configuration structure which comprises a first high-voltage circuit and a second high-voltage circuit, the first high-voltage circuit and the second high-voltage circuit are connected to a frequency converter in parallel, and the first high-voltage circuit comprises a trolley switch QF1, an isolation switch QS1, an isolation switch QS3, a vacuum contactor KM1, a vacuum contactor KM3 and a vacuum contactor KM5. And the second high-voltage circuit comprises a trolley switch QF2, a vacuum contactor KM2, an isolation disconnecting link QS2, an isolation disconnecting link QS4, a vacuum contactor KM4 and a vacuum contactor KM6. According to the utility model, the frequency converters of the circulating water pump motor A and the circulating water pump motor B are optimized by adopting the first high-voltage circuit and the second high-voltage circuit; therefore, the configuration number of the high-voltage frequency converter equipment is reduced, the purchase cost can be saved, and the subsequent equipment maintenance workload is reduced at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency converters for water pump motors in power plants, in particular to a configuration structure of frequency converters for circulating water pump motors. Background Art

[0002] A power plant, also known as a power station, is a factory that converts various primary energy sources in nature into electrical energy (secondary energy). There are many ways for power plants to generate electricity: thermal power plants that rely on thermal power, hydropower plants that rely on hydropower, and some that rely on solar energy (photovoltaic), wind power, tidal power, and steam power.

[0003] At present, when steam is used for power generation, a circulating water pump motor is needed to transport water. However, in order to ensure the stable operation of the circulating water pump, each water pump is usually equipped with a frequency converter one by one. However, this method not only requires a large number of frequency converters, but also increases energy consumption. Therefore, a circulating water pump motor frequency converter configuration structure is provided to solve the above problems. Utility Model Content

[0004] In order to solve the problems in the above background technology, the technical solution adopted by the utility model to solve the technical problems is: a circulating water pump motor inverter configuration structure, which includes: a first high-voltage circuit and a second high-voltage circuit, the first high-voltage circuit and the second high-voltage circuit are connected in parallel to the inverter, the first high-voltage circuit includes a trolley switch QF1, an isolating knife gate QS1, an isolating knife gate QS3, a vacuum contactor KM1, a vacuum contactor KM3, and a vacuum contactor KM5, the second high-voltage circuit includes a trolley switch QF2, a vacuum contactor KM2, an isolating knife gate QS2, an isolating knife gate QS4, a vacuum contactor KM4, and a vacuum contactor KM6, the isolating knife gate QS1, the vacuum contactor KM1 and the isolating knife gate QS3, the vacuum contactor KM3 are connected in parallel on both sides of the vacuum contactor KM5, the isolating knife gate QS2 of the vacuum contactor KM2 and the isolating knife gate QS4, the vacuum contactor KM4 are connected in parallel on both sides of the vacuum contactor KM6.

[0005] As a preferred technical solution of the utility model, the trolley switch QF1 is connected in series with the vacuum contactor KM5, and the trolley switch QF2 is connected in series with the vacuum contactor KM6.

[0006] As a preferred technical solution of the utility model, a second indicator light DXN2 is provided in the circuit between the trolley switch QF1 and the isolating knife switch QS1, and a third indicator light DXN3 is provided in the circuit between the trolley switch QF2 and the isolating knife switch QS2.

[0007] As a preferred technical solution of the present utility model, the isolating switch QS3 and the vacuum contactor KM3 are connected in parallel with the isolating switch QS4 and the vacuum contactor KM4 at the output end of the frequency converter. The isolating switch QS3 is connected in series with the vacuum contactor KM3, and the isolating switch QS4 is connected in series with the vacuum contactor KM4. A fourth indicator light DXN4 is provided in the circuit between the vacuum contactor KM3 and the frequency converter, and a fifth indicator light DXN5 is provided in the circuit between the vacuum contactor KM4 and the frequency converter.

[0008] As a preferred technical solution of the present utility model, the isolating switch QS1, the vacuum contactor KM1 are connected in parallel with the isolating switch QS2 and the vacuum contactor KM2 at the input end of the frequency converter. The isolating switch QS1, the vacuum contactor KM1 and the isolating switch QS2, the vacuum contactor KM2 are connected in series through wires, and a first indicator light DXN1 is provided in the circuit of the input end of the vacuum contactor KM1, the vacuum contactor KM2 and the frequency converter.

[0009] As a preferred technical solution of the present utility model, a sixth indicator light DXN6 is connected in the circuit between the vacuum contactor KM5 and the isolating switch QS1, and a seventh indicator light DXN7 is connected in the circuit between the vacuum contactor KM6 and the isolating switch QS2. The trolley switches QF1 and QF2 are both connected to the high-voltage power supply, and the output end of the frequency converter is connected to the reactor.

[0010] As a preferred technical solution of the present utility model, the motor A is connected between the isolating switch QS2 and the vacuum contactor KM5 through a wire, and the motor B is connected between the isolating switch QS4 and the vacuum contactor KM6 through a wire.

[0011] The present utility model has the following advantages: By optimizing the configuration of the first high-voltage circuit and the second high-voltage circuit for the frequency converters of the circulating water pump motor A and the circulating water pump motor B, the present utility model reduces the number of configured high-voltage frequency converter devices, thereby not only saving the procurement cost, but also reducing the subsequent equipment maintenance workload. Description of the Drawings

[0012] Figure 1 is a schematic diagram of the operating principle of the frequency converter in the preferred embodiment of the present utility model.

[0013] Figure 2 is the primary circuit diagram of the preferred embodiment of the present utility model. Detailed Embodiment

[0014] The technical solutions in the embodiments of the present utility model will be clearly and completely described below. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model. In the following description, many specific details are set forth to facilitate a full understanding of the present utility model. However, the present utility model may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present utility model is not limited by the specific embodiments disclosed below.

[0015] In the description of the present utility model, it should be noted that, unless otherwise clearly defined and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0016] The present utility model will be further described below with reference to the accompanying drawings.

[0017] Please refer to Figure 1 - Figure 2 , the configuration structure of the frequency converter for the circulating water pump motor of the present utility model includes: a first high-voltage circuit and a second high-voltage circuit. The first high-voltage circuit and the second high-voltage circuit are connected in parallel to the frequency converter. The first high-voltage circuit includes a trolley switch QF1, isolating switches QS1, QS3, vacuum contactors KM1, KM3, KM5. The second high-voltage circuit includes a trolley switch QF2, vacuum contactor KM2, isolating switches QS2, QS4, vacuum contactors KM4, KM6. Isolating switch QS1, vacuum contactor KM1 and isolating switches QS3, vacuum contactor KM3 are connected in parallel on both sides of vacuum contactor KM5. Vacuum contactor KM2, isolating switch QS2 and isolating switches QS4, vacuum contactor KM4 are connected in parallel on both sides of vacuum contactor KM6.

[0018] Among them, trolley switch QF1 is connected in series with vacuum contactor KM5, trolley switch QF2 is connected in series with vacuum contactor KM6. A second indicator light DXN2 is provided in the circuit between trolley switch QF1 and isolating switch QS1. A third indicator light DXN3 is provided in the circuit between trolley switch QF2 and isolating switch QS2. Isolating switches QS3, vacuum contactor KM3 and isolating switches QS4, vacuum contactor KM4 are connected in parallel to the output end of the frequency converter. Isolating switch QS3 is connected in series with vacuum contactor KM3, isolating switch QS4 is connected in series with vacuum contactor KM4. A fourth indicator light DXN4 is provided in the circuit between vacuum contactor KM3 and the frequency converter. A fifth indicator light DXN5 is provided in the circuit between vacuum contactor KM4 and the frequency converter.

[0019] Among them, the isolating switch QS1, the vacuum contactor KM1, the isolating switch QS2, and the vacuum contactor KM2 are connected in parallel to the input end of the frequency converter. The isolating switch QS1, the vacuum contactor KM1, the isolating switch QS2, and the vacuum contactor KM2 are connected in series through wires. A first indicator light DXN1 is provided in the circuit between the vacuum contactor KM1, the vacuum contactor KM2, and the input end circuit of the frequency converter. A sixth indicator light DXN6 is connected in the circuit between the vacuum contactor KM5 and the isolating switch QS1. A seventh indicator light DXN7 is connected in the circuit between the vacuum contactor KM6 and the isolating switch QS2. The trolley switches QF1 and QF2 are both connected to the high-voltage power supply. The output end of the frequency converter is connected to the reactor. The motor A is connected through a wire between the isolating switch QS2 and the vacuum contactor KM5. The motor B is connected through a wire between the isolating switch QS4 and the vacuum contactor KM6.

[0020] Among them, KM1 and KM2 are interlocked, that is, after KM1 is closed, KM2 cannot be closed, and after KM2 is closed, KM1 cannot be closed. KM3 and KM4 are interlocked, that is, after KM3 is closed, KM4 cannot be closed, and after KM4 is closed, KM3 cannot be closed. KM1 and KM3 are interlocked, that is, after KM1 is closed, KM3 can be closed. KM2 and KM4 are interlocked, that is, after KM2 is closed, KM4 can be closed. The interlock of the isolating switch QS1 (QS2, QS3, QS4) uses the auxiliary contacts of the vacuum contactor KM1 (KM2, KM3, KM4), that is, after KM1 (KM2, KM3, KM4) is closed, QS1 (QS2, QS3, QS4) cannot be operated. QF1, QF2, and the bypass cabinet door are interlocked, that is, after QF1 or QF2 is closed, the bypass cabinet cannot be opened.

[0021] Specifically, when the present utility model is in use, first ensure that QF1 (QF2), KM1 (KM2), KM3 (KM4), and KM5 (KM6) are in the off state, close QS1 (QS2) and QS3 (QS4), then close QF1 (QF2), select the A (B) motor, and operate the running command and the frequency converter;

[0022] After the charging is completed, KM1 (KM2) and KM3 (KM4) are automatically closed, and the frequency converter drives the motor to run to the specified frequency, and the motors A and B run in variable frequency;

[0023] When the motor stops running in variable frequency, during the variable-frequency operation of the motors A and B, operate the stop command. After the operating frequency of the frequency converter drops to 0 Hz, KM1 (KM2) and KM3 (KM4) are disconnected, and the motors A and B stop running;

[0024] When switching from variable frequency to power frequency, while motors A and B are operating at variable frequency, operate the variable-frequency-to-power-frequency command. The frequency converter runs to 50 Hz and automatically completes synchronization and grid connection. At this time, close KM5 (KM6), and then the frequency converter disconnects KM1 (KM2) and KM3 (KM4). Motors A and B operate at power frequency;

[0025] When operating the power-frequency-to-variable-frequency switchover, while motors A and B are operating at power frequency, the operator issues the switchover command. The frequency converter starts charging. After the charging is completed, KM1 (KM2) is automatically closed and it automatically runs to 49 Hz. Then KM5 (KM6) is disconnected, and KM3 (KM4) is closed. The frequency converter searches for the current residual voltage of the motor and tracks the operation, and then runs to the specified frequency. Motors A (B) operate at variable frequency;

[0026] When starting the motors at power frequency, first ensure that QF1 (QF2), KM1 (KM2), and KM3 (KM4) are in the off state. Operate the closing command of the bypass switch of motors A and B to close KM5 (KM6), and then close QF1 (QF2). Motors A (B) operate at power frequency;

[0027] When stopping the motors at power frequency, while motors A and B are operating at power frequency, disconnect QF1 (QF2). Motors A (B) stop running. Operate the opening command of the bypass switch of motors A and B to disconnect KM5 (KM6).

[0028] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

[0029] Other parts not detailed in the present invention belong to the prior art and will not be elaborated here.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Configuration structure of the frequency converter for the circulating water pump motor, characterized in that, Including: A first high-voltage circuit and a second high-voltage circuit. The first high-voltage circuit and the second high-voltage circuit are connected in parallel to the frequency converter. The first high-voltage circuit includes a trolley switch QF1, isolating switches QS1, QS3, vacuum contactors KM1, KM3, KM5. The second high-voltage circuit includes a trolley switch QF2, vacuum contactor KM2, isolating switches QS2, QS4, vacuum contactors KM4, KM6. The isolating switch QS1, vacuum contactor KM1 and the isolating switch QS3, vacuum contactor KM3 are connected in parallel on both sides of the vacuum contactor KM5. The vacuum contactor KM2, isolating switch QS2 and the isolating switch QS4, vacuum contactor KM4 are connected in parallel on both sides of the vacuum contactor KM6.

2. The configuration structure of the variable frequency drive for the circulating water pump motor according to claim 1, characterized in that, The trolley switch QF1 is connected in series with the vacuum contactor KM5, and the trolley switch QF2 is connected in series with the vacuum contactor KM6.

3. The configuration structure of the frequency converter for the circulating water pump motor according to claim 1, wherein, A second indicator light DXN2 is arranged in the circuit between the trolley switch QF1 and the isolating switch QS1, and a third indicator light DXN3 is arranged in the circuit between the trolley switch QF2 and the isolating switch QS2.

4. The configuration structure of the variable frequency drive for the circulating water pump motor according to claim 1, characterized in that, The isolating switch QS3, vacuum contactor KM3 and the isolating switch QS4, vacuum contactor KM4 are connected in parallel to the output end of the frequency converter. The isolating switch QS3 is connected in series with the vacuum contactor KM3, and the isolating switch QS4 is connected in series with the vacuum contactor KM4. A fourth indicator light DXN4 is arranged in the circuit between the vacuum contactor KM3 and the frequency converter, and a fifth indicator light DXN5 is arranged in the circuit between the vacuum contactor KM4 and the frequency converter.

5. The configuration structure of the variable frequency drive for the circulating water pump motor according to claim 1, characterized in that, The isolating switch QS1, vacuum contactor KM1 and the isolating switch QS2, vacuum contactor KM2 are connected in parallel to the input end of the frequency converter. The isolating switch QS1, vacuum contactor KM1 and the isolating switch QS2, vacuum contactor KM2 are connected in series through a wire. A first indicator light DXN1 is arranged in the circuit of the vacuum contactor KM1, vacuum contactor KM2 and the input end of the frequency converter.

6. The configuration structure of the variable frequency drive for the circulating water pump motor according to claim 1, characterized in that, A sixth indicator light DXN6 is connected in the circuit between the vacuum contactor KM5 and the isolating switch QS1, and a seventh indicator light DXN7 is connected in the circuit between the vacuum contactor KM6 and the isolating switch QS2. Both the trolley switch QF1 and the trolley switch QF2 are connected to the high-voltage power supply, and the output end of the frequency converter is connected to the reactor.

7. The configuration structure of the variable frequency drive for the circulating water pump motor according to claim 1, characterized in that, The isolating switch QS2 and the vacuum contactor KM5 are connected to the motor A through a wire, and the isolating switch QS4 and the vacuum contactor KM6 are connected to the motor B through a wire.

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