Remote power supply voltage regulation and control device

Abstract

The remote power supply voltage regulation and control device comprises an inverter, an input reactor, an output reactor, a dry-type transformer, an input contactor, an output contactor and an isolating switch, and is characterized in that the dry-type transformer is arranged close to a motor load; the output end of the inverter is connected with the input end of the output reactor, the output end of the output reactor is connected to a primary winding of the dry-type transformer, one end of a secondary winding of the dry-type transformer is connected with a three-phase power supply, and the other end of the secondary winding of the dry-type transformer is connected with a motor load through the output contactor. According to the remote power supply voltage regulation and control device, the inverter and the dry-type transformer are used for compensating the voltage signal input to the motor load, the phenomenon that the voltage of the motor load is too low is avoided, the situation that the current in a power supply line between the power supply equipment and the motor load is too large is avoided, the electric energy loss of the power supply line is reduced, and the service life of the power supply line is prolonged. And the electricity utilization cost is saved for coal mine enterprises.

Description

A long-distance power supply voltage regulation device Technical Field

[0001] This utility model relates to a voltage regulation device, and more specifically, to a long-distance power supply voltage regulation device. Background Technology

[0002] During coal mining, as the mining roadways extend, the distance between mining and tunneling equipment and power supply equipment continuously increases, leading to a series of long-distance power supply problems. Long-distance power transmission results in significant power loss in mine power transmission and distribution lines, greatly increasing power consumption and losses, causing substantial economic losses to related coal mining enterprises. Therefore, there is an urgent need to develop a long-distance power supply voltage regulation device to compensate for the voltage at the load end, thereby reducing the energy loss caused by long-distance power transmission in coal mine roadways. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned technical problems, this utility model provides a long-distance power supply voltage regulation device.

[0004] This utility model discloses a long-distance power supply voltage regulation device, comprising an inverter, an input reactor, an output reactor, a dry-type transformer, an input contactor, an output contactor, and a disconnecting switch. The input terminal of the input reactor is connected to a three-phase power supply via the input contactor and the disconnecting switch in sequence, and the output terminal of the input reactor is connected to the input terminal of the inverter. The device is characterized in that: the dry-type transformer is positioned close to the motor load; the output terminal of the inverter is connected to the input terminal of the output reactor; the output terminal of the output reactor is connected to the primary winding of the dry-type transformer; one end of the secondary winding of the dry-type transformer is connected to the three-phase power supply; and the other end of the secondary winding of the dry-type transformer is connected to the motor load via the output contactor.

[0005] The present invention relates to a long-distance power supply voltage regulation device, which includes a buffer contactor and a buffer resistor. The two ends of the buffer contactor and the buffer resistor connected in series are connected to the two ends of the input contactor.

[0006] The present invention relates to a long-distance power supply voltage regulation device, which includes a filter capacitor and a three-phase voltage and current sampling circuit. The filter capacitor is connected to the connection line between the output reactor and the dry-type transformer, and the three-phase voltage and current sampling circuit is used to collect the voltage and current signals at the output terminal of the dry-type transformer.

[0007] The long-distance power supply voltage regulation device of this utility model has a three-phase power supply voltage level of 660V, 1140V, 3.3kV, 6kV or 10kV.

[0008] The present invention relates to a long-distance power supply voltage regulation device, including a load reactor used for reactive load testing of the long-distance power supply voltage regulation device; when conducting a reactive load test on the long-distance power supply voltage regulation device: the secondary winding of the dry-type transformer is connected to the connection terminal of the three-phase power supply in a star configuration, and the other end of the secondary winding of the dry-type transformer is connected to the load reactor via an output contactor.

[0009] The present invention relates to a long-distance power supply voltage regulation device, comprising a motor power frequency operation unit, a test motor, and a feedback unit for performing active load tests on the long-distance power supply voltage regulation device. When the long-distance power supply voltage regulation device performs an active load test: the long-distance power supply voltage regulation device is connected to the test motor via the motor power frequency operation unit; the feedback power supply consists of a test motor and a four-quadrant frequency converter; the rotating shaft of the test motor is connected to the rotating shaft of the test motor; and the power supply terminal of the test motor is connected to the input terminal of the four-quadrant frequency converter.

[0010] The remote power supply voltage regulation device of this utility model comprises a motor power frequency operation unit consisting of contactor KM5, contactor KM6 and a current-limiting reactor connected together. The two ends of the contactor KM5 and the current-limiting reactor connected in series and then in parallel with the contactor KM6 are respectively connected to the output terminal of the remote power supply voltage regulation device and the power input terminal of the motor under test.

[0011] The beneficial effects of this utility model are as follows: The long-distance power supply voltage regulation device of this utility model is equipped with an inverter, an input reactor, an output reactor, and a dry-type transformer. The input terminal of the inverter is connected to the three-phase power supply in sequence through the input reactor, the input contactor, and the disconnecting switch. The output terminal of the inverter is connected to the primary winding of the dry-type transformer through the output reactor. One end of the secondary winding of the dry-type transformer is connected to the three-phase power supply, and the other end is connected to the motor load through the output contactor. In this way, by measuring the voltage and current signals at the output terminal of the dry-type transformer (i.e., the input terminal of the motor load), the inverter and the dry-type transformer are used to compensate the voltage signal input to the motor load to avoid the phenomenon of low motor load voltage. Therefore, excessive current in the power supply line between the power supply equipment and the motor load is avoided, effectively reducing the power loss of the power supply line and saving electricity costs for coal mining enterprises.

[0012] Furthermore, by setting up a load reactor and connecting it to the secondary winding of the dry-type transformer, and simultaneously sealing the connection between the secondary winding of the dry-type transformer and the three-phase power supply, the reactive power loading test of the remote power supply voltage regulation device of this utility model can be completed. By setting up a motor power frequency operation unit, a tested motor, and a feedback unit, with the feedback unit consisting of a test motor and a four-quadrant frequency converter, the output of the remote power supply voltage regulation device is connected to the power input terminal of the tested motor via the motor power frequency operation unit, and the rotating shafts of the tested motor and the test motor are connected. In this way, the active power loading test of the remote power supply voltage regulation device is achieved. Attached Figure Description

[0013] Figure 1 is a circuit diagram of the long-distance power supply voltage regulation device of this utility model;

[0014] Figure 2 is a circuit diagram of the long-distance power supply voltage regulation device of this utility model during reactive power loading test;

[0015] Figure 3 is a circuit diagram of the long-distance power supply voltage regulation device of this utility model during active loading test.

[0016] In the diagram: 1 Inverter, 2 Input reactor, 3 Output reactor, 4 Dry-type transformer, 5 Disconnector, 6 Input contactor, 7 Buffer contactor, 8 Output contactor, 9 Bypass contactor, 10 Motor load, 11 Three-phase power supply, 12 Load reactor, 13 Remote power supply voltage regulation device, 14 Motor power frequency operation unit, 15 Test motor, 16 Feedback unit, 17 Accompanying test motor, 18 Four-quadrant frequency converter. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 shows the circuit diagram of the long-distance power supply voltage regulation device of this utility model. The long-distance power supply voltage regulation device consists of an inverter 1, an input reactor 2, an output reactor 3, a dry-type transformer 4, a disconnecting switch 5, an input contactor 6, a buffer contactor 7, an output contactor 8, and a bypass contactor 9. The input terminal of the input reactor 2 is connected to the three-phase power supply 11 via the input contactor 6 and the disconnecting switch 5. The output terminal of the input reactor 2 is connected to the input terminal of the inverter 1. The output terminal of the inverter 1 is connected to the input terminal of the output reactor 3. The output terminal of the output reactor 3 is connected to the primary winding of the dry-type transformer 4. One end of the secondary winding of the dry-type transformer 4 is connected to the three-phase power supply 11, and the other end of the secondary winding of the dry-type transformer 4 is connected to the power supply terminal of the motor load 10 via the output contactor 8.

[0019] The dry-type transformer 4 is positioned close to the motor load 10. The inverter 1 has both rectification and inversion functions. The inverter 1 first rectifies the AC power input through the input reactor 2, and then inverts the rectified DC power to convert it into AC power with controllable phase and magnitude, which is then input to the input terminal of the dry-type transformer 4. This ensures that the output voltage of the dry-type transformer 4 meets the voltage requirements of the motor load 10, thus avoiding insufficient voltage at the motor load 10 due to excessively long power supply lines and preventing excessive power consumption caused by insufficient voltage.

[0020] The input contactor 6 is connected in parallel with a buffer contactor 7, which is connected in series with a buffer resistor. The two ends of the series connection between the buffer contactor 7 and the buffer resistor are then connected in parallel with the input contactor 6. When powering on the inverter 1, the buffer contactor 7 is closed first, and the input contactor 6 is opened, allowing the three-phase power supply 11 to power on the inverter 1 through the buffer resistor. After powering on, the input contactor 6 is closed again, and the buffer contactor 7 is opened.

[0021] A filter capacitor is connected in parallel on the line connecting the output reactor 3 and the dry-type transformer 4. To measure the voltage and current signals output from the dry-type transformer 4 to the motor load 10, a three-phase voltage and current sampling circuit is installed at the output terminal of the dry-type transformer 4. The voltage levels of the three-phase power supply 11 shown are 660V, 1140V, 3.3kV, 6kV, or 10kV.

[0022] To evaluate the long-distance power supply voltage regulation device 13 of this utility model, reactive and active load tests are required. Figure 2 shows the circuit diagram of the long-distance power supply voltage regulation device of this utility model during the reactive load test. It is additionally equipped with a load reactor 12, which is connected to the output terminal of the secondary winding of the dry-type transformer 4. The connection terminal between the secondary winding of the dry-type transformer 4 and the three-phase power supply 11 is star-sealed. During the reactive load test, the target output voltage value of the inverter 1 is first set to a lower voltage value to establish excitation for the load reactor 12. Then, the output voltage of the inverter 1 is gradually increased until the output voltage of the inverter 1 reaches the rated voltage of the dry-type transformer 4 and the output current of the inverter 1 reaches the rated current of the dry-type transformer 4.

[0023] Figure 3 shows the circuit diagram of the remote power supply voltage regulation device of this utility model during active power loading test. During the active power loading test, it is additionally equipped with a motor frequency operation unit 14, a test motor 15, and a feedback unit 16. The feedback unit 16 consists of a test motor 17 and a four-quadrant frequency converter 18. The remote power supply voltage regulation device 13 is connected to the power input terminal of the test motor 15 via the motor frequency operation unit 14. The rotation shaft of the test motor 15 is connected to the rotation shaft of the test motor 17. The output terminal of the test motor 17 is connected to the output segment of the four-quadrant frequency converter 18, and the output of the four-quadrant frequency converter 18 serves as the power output. The motor frequency operation unit 14 consists of contactors KM5 and KM6 and a current-limiting reactor. The current-limiting reactor is connected in series with contactor KM5 and then in parallel with contactor KM6.

[0024] After the remote power supply voltage regulation device 13 is turned on, KM5 is closed first, and the tested motor 15 is started via the current-limiting reactor. After the tested motor 15 starts running smoothly, KM6 is closed, bypassing KM5 and the current-limiting reactor branch. After KM6 is closed, KM5 is disconnected. After the tested motor 15 is running normally at the power frequency driven by the remote power supply voltage regulation device 13, the four-quadrant frequency converter 18 starts and drives the auxiliary motor 17 to run. By gradually reducing the operating frequency of the four-quadrant frequency converter 18, the speed of the tested motor 15 is made higher than that of the auxiliary motor 17, and the slip between the two loads the entire system.

[0025] In summary, the long-distance power supply voltage regulation device of this utility model uses a reactor as the load for reactive power loading. With appropriate modifications to the topology of the voltage regulation device, full-load testing of the inverter and dry-type transformer in the voltage regulation device can be achieved. For active power loading, a driven motor is used as the load. A current-limiting reactor and a bypass contactor are used as the power frequency operation unit for the driven motor of the voltage regulation device, and a four-quadrant frequency converter is used as the feedback unit for the test motor. This allows for full-load testing of all main circuit components in the voltage regulation device. The reactive and active power loading methods can be selected according to actual test conditions, thus solving the loading problem of the voltage regulation device.

Claims

1. A long-distance power supply voltage regulation device, comprising an inverter (1), an input reactor (2), an output reactor (3), a dry-type transformer (4), an input contactor (6), an output contactor (8), and a disconnecting switch (5), wherein the input terminal of the input reactor is connected to a three-phase power supply (11) in sequence via the input contactor and the disconnecting switch, and the output terminal of the input reactor is connected to the input terminal of the inverter; characterized in that: The dry-type transformer is located close to the motor load; the output terminal of the inverter is connected to the input terminal of the output reactor, the output terminal of the output reactor is connected to the primary winding of the dry-type transformer, one end of the secondary winding of the dry-type transformer is connected to the three-phase power supply, and the other end of the secondary winding of the dry-type transformer is connected to the motor load (10) via the output contactor.

2. The long-distance power supply voltage regulation device according to claim 1, characterized in that: It includes a buffer contactor (7) and a buffer resistor. The two ends of the buffer contactor and the buffer resistor connected in series are connected to the two ends of the input contactor (6).

3. The remote powered voltage regulating device of claim 1 or 2, wherein: It includes a filter capacitor and a three-phase voltage and current sampling circuit. The filter capacitor is connected to the line between the output reactor (3) and the dry-type transformer (4). The three-phase voltage and current sampling circuit is used to collect the voltage and current signals at the output of the dry-type transformer.

4. The long-distance power supply voltage regulation device according to claim 1 or 2, characterized in that: The voltage level of the three-phase power supply (11) is 660V, 1140V, 3.3kV, 6kV or 10kV.

5. The long-distance power supply voltage regulation device according to claim 1 or 2, characterized in that: Including the load reactor (12) used when conducting a reactive load test on the remote power supply voltage regulation device (13); when conducting a reactive load test on the remote power supply voltage regulation device: the secondary winding of the dry-type transformer (4) is connected to the connection terminal of the three-phase power supply (11) by a star connection, and the other end of the secondary winding of the dry-type transformer is connected to the load reactor (12) via the output contactor (8).

6. The remote powered voltage regulating device of claim 1 or 2, wherein: The system includes a motor frequency operation unit (14), a test motor (15), and a feedback unit (16) used for active loading tests of the remote power supply voltage regulation device (13). When the remote power supply voltage regulation device (13) is subjected to an active loading test: the remote power supply voltage regulation device is connected to the test motor via the motor frequency operation unit. The feedback power supply consists of a test motor (17) and a four-quadrant frequency converter (18). The rotating shaft of the test motor is connected to the rotating shaft of the test motor, and the power supply terminal of the test motor is connected to the input terminal of the four-quadrant frequency converter.

7. The remote powered voltage regulating device of claim 6, wherein: The motor power frequency operation unit (14) is connected by contactor KM5, contactor KM6 and current limiting reactor. The two ends of the contactor KM5 and the current limiting reactor connected in series and then connected in parallel with contactor KM6 are respectively connected to the output end of the remote power supply voltage regulation device (13) and the power input end of the tested motor (15).

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