Voltage and power factor adjustment device and method for long-distance equipment side of tunneling working face

Abstract

The present invention belongs to the technical field of underground power supply in coal mines, and discloses a voltage and power factor regulating device for long-distance power supply equipment side, comprising: a three-phase transformer, a three-phase regulator and a voltage regulating controller, wherein the three-phase regulator comprises three-phase AC switches S1, S2, S3 and a three-phase series compensator; the input ends of the three-phase transformer and the voltage regulating controller are connected to an external input voltage bus, and the output end of the three-phase transformer is sequentially connected to the three-phase AC switch S2, the three-phase regulator and the three-phase AC switch S3; the output end of the three-phase transformer is also connected to the output end of S3 through the three-phase AC switch S1, and the output end of the voltage regulating controller is connected to the three-phase regulator, which is used to output an inverted high-frequency AC signal to the three-phase regulator, so as to realize the regulation of the voltage and power factor of the combined switch equipment side of the tunneling machine. The present invention can automatically adjust the voltage and power factor on the equipment side, reduce the number of transformer movements, and thus improve the efficiency of tunneling equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground power supply in coal mines, and specifically relates to a device and method for realizing voltage stability and power factor adjustment functions on the equipment side of long-distance power supply for underground excavation working faces in coal mines. The device and method are used for adjusting the terminal voltage and power factor of the power supply line of a complete set of equipment under the condition of AC power supply over a long distance, thereby reducing line losses. Background Art

[0002] As the requirements for intelligent coal mine construction continue to increase, the demand for coal resources is also gradually increasing, and the speed requirements for underground coal mine excavation equipment are also gradually increasing. At present, the excavation equipment is limited by the power distribution system settings of the underground excavation working face. Usually, when the excavation distance exceeds 1 kilometer, it is necessary to move the transformer in the distribution system forward and shorten the length of the connecting cable so that the distance from the excavation equipment does not exceed 1 kilometer. For this reason, it is necessary to dig a new transformer chamber at the destination after the move, and lay temporary support and power supply cables at the same time. This is because as the power supply distance increases, the active power loss and reactive power exchange on the power supply line will cause the voltage on the equipment side to drop, so the equipment cannot start normally. When the excavation tunnel is long or inconvenient to move, the operation of moving the transformer forward will delay more working hours and reduce the efficiency of excavation work.

[0003] In order to improve the efficiency of excavation operations and achieve the goal of excavating a tunnel to the bottom without moving the transformer, it is necessary to adjust the voltage and power factor on the excavation equipment side to achieve a steady-state voltage on the excavation equipment side within its working range, reduce the workload caused by moving the transformer, and reduce the number of front-line personnel. Summary of the invention

[0004] The present invention overcomes the shortcomings of the existing power distribution system of the tunneling working face, and the technical problem to be solved is: to provide a voltage and power factor adjustment device and method for the long-distance equipment side of the underground tunneling working face of a coal mine, to cooperate with the operating process requirements of the tunneling equipment, to add a voltage and power factor adjustment device in the front stage of the combination switch of the tunneling equipment, thereby adjusting the terminal voltage of the tunneling equipment, so that it can be smoothly started and operated within the entire length of the tunnel.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a voltage and power factor regulating device for long-distance equipment side of a tunneling working face, comprising: a three-phase transformer, a three-phase regulator and a voltage regulating controller, wherein the three-phase regulator comprises a three-phase AC switch S1, S2, S3 and a three-phase series compensator;

[0006] The input ends of the three-phase transformer and the voltage regulating controller are connected to the external voltage bus, and the output end of the three-phase transformer is connected to the three-phase AC switch S2, the three-phase series compensator, the three-phase AC switch S3 and the equipment combination switch in sequence; the output end of the three-phase transformer is also connected to the output end of the three-phase AC switch S3 through the three-phase AC switch S1, and the output end of the voltage regulating controller is connected to the three-phase series compensator, which is used to output the inverted high-frequency AC signal to the three-phase series compensator to achieve the adjustment of the voltage and power factor on the equipment side combination switch side.

[0007] The voltage regulating controller comprises: a three-level rectifier arranged at the front stage, a DC buck arranged in the middle and a three-phase four-bridge-arm inverter arranged at the rear stage.

[0008] The three-phase series compensator includes three inductors L1, L2, L3 and three capacitors C1, C2, C3 respectively connected in series in one of the phases. One end of the inductors L1, L2, L3 is respectively connected to the first to third output ends of the three-phase four-bridge-arm inverter, and the other ends of the inductors L1, L2, L3 are respectively connected to the input ends of the capacitors C1, C2, C3. The output ends of the capacitors C1, C2, C3 are respectively connected to the input end of the three-phase AC switch S3 as the three-phase output ends of the three-phase series compensator, and the output ends of the capacitors C1, C2, C3 are connected in parallel to the fourth output end of the three-phase four-bridge-arm inverter.

[0009] The input of the three-phase transformer is an AC voltage of 3300V, and the output is a voltage of 1250V.

[0010] In addition, the present invention also provides a method for adjusting voltage and power factor on the long-distance equipment side of a tunneling working face, which is implemented based on the above-mentioned device and includes the following steps:

[0011] Step 1: After receiving the power-on command, the three-phase transformer works and outputs voltage; the voltage regulator controller is powered on and starts to perform the power factor adjustment function, and at the same time prepares to collect the voltage Us3 on the input side and the voltage Us1 on the output side of the three-phase AC switch S3;

[0012] Step 2: Close the three-phase AC switch S1 and collect the voltage Us1;

[0013] Step 3: determine whether the collected voltage Us1 meets the power supply voltage requirement of the equipment combination switch. If so, the current switch state remains unchanged; if not, proceed to the next step;

[0014] Step 4: close the three-phase AC switch S2, collect the voltage Us3, input the inverted high-frequency AC signal to the three-phase series compensator through the voltage regulator controller, and adjust the voltage at the output end of the three-phase line;

[0015] Step 5: When it is detected that the voltage Us3 is consistent with the voltage Us1, the three-phase AC switch S3 is closed, and then the three-phase AC switch S1 is opened;

[0016] Step 6: Continue to output the inverted high-frequency AC signal to the three-phase series compensator through the voltage regulator controller, and perform closed-loop regulation on the voltage on the capacitor of the three-phase series compensator so that the output terminal voltage meets the power supply requirement of the equipment combination switch.

[0017] In the step 1, the voltage regulating controller adjusts the power factor by controlling the three-level rectifier at the front stage.

[0018] In step 4 and step 6, the voltage regulating controller controls the three-phase four-bridge-arm inverter of the subsequent stage, thereby outputting the inverted high-frequency AC signal to the three-phase series compensator to adjust the output voltage of the three-phase AC line.

[0019] In step 5, when it is detected that the voltage Us3 is consistent in amplitude and phase with the voltage Us1, the three-phase AC switch S3 is closed, and then the three-phase AC switch S1 is opened.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a voltage and power factor regulating device and method for long-distance equipment side of tunneling working face, which performs primary voltage regulation through a three-phase transformer to basically meet the power supply voltage requirement of tunneling equipment, and then adjusts the power factor by performing reactive power compensation in the input line through a rectifier circuit in a voltage regulator controller, thereby reducing reactive power loss in the line. At this time, the intermediate and rear circuits of the voltage regulator controller stop working; when the voltage regulator controller detects that the voltage on the equipment side drops to a certain limit value as the power supply distance increases, the intermediate and rear circuits of the voltage regulator controller start working, inverting the high-frequency AC voltage required for compensation, and the voltage acts on the series circuit of the inductor and capacitor in the three-phase regulator, so that the output ABC terminal voltage meets the operating voltage of the tunneling equipment, and the output electric energy is connected to the power supply combination switch box of the tunneling equipment for use. The voltage regulator controller takes power from the input 3300V AC bus. Compared with the current solution of manually adjusting the transformation ratio of the transformer equipped with the tunneling equipment, the present invention has the characteristics of automatically adjusting the voltage and power factor as the power supply distance changes, so that the tunneling operation can run continuously and stably, and there is no need to move the transformer forward, thereby improving the efficiency of the tunneling equipment and reducing the labor intensity of production personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A topological wiring diagram of a voltage and power factor adjustment device at a long-distance power supply equipment side provided in Embodiment 1 of the present invention;

[0023] Figure 2A topological diagram of a voltage regulating controller according to an embodiment of the present invention;

[0024] Figure 3 This is a flow chart of the adjustment method according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Embodiment 1

[0027] like Figure 1 As shown, the first embodiment of the present invention provides a voltage and power factor adjustment device and method for long-distance equipment side of the tunneling working face in a coal mine, including: a three-phase transformer, a three-phase regulator and a voltage regulator controller, wherein the three-phase regulator includes a three-phase AC switch S1, S2, S3 and a three-phase series compensator. The three-phase transformer is independently packaged in an explosion-proof housing, and the three-phase regulator and the voltage regulator controller are combined and packaged in an explosion-proof housing. The following takes a tunneling machine as an example to illustrate the specific implementation of the present invention.

[0028] In this embodiment, the input ends of the three-phase transformer and the voltage regulator controller are connected in parallel to the external input voltage bus, and the output end of the three-phase transformer is connected to the three-phase AC switch S2, the three-phase series compensator, the three-phase AC switch S3 and the combined power supply switch of the tunnel boring machine in sequence; the output end of the three-phase transformer is also connected to the output end of the three-phase AC switch S3 through the three-phase AC switch S1. The output end of the voltage regulator controller is connected to the three-phase series compensator, and is used to output the inverted high-frequency AC signal to the three-phase series compensator to achieve the regulation of the voltage and power factor on the electrical equipment side.

[0029] Specifically, in this embodiment, the three-phase series compensator includes three inductors L1, L2, and L3 and three capacitors C1, C2, and C3 respectively connected in series in one of the phases. One end of the inductors L1, L2, and L3 are respectively connected to the first to third output ends of the three-phase four-bridge-arm inverter, and the other ends of the inductors L1, L2, and L3 are respectively connected to one phase of the output end of the three-phase AC switch S2 (the input end of the capacitors C1, C2, and C3). The output ends of the capacitors C1, C2, and C3 are respectively connected to the input end of the three-phase AC switch S3 as the three-phase output ends of the three-phase series compensator, and the output ends of the three capacitors C1, C2, and C3 are also connected in parallel to the fourth output end of the three-phase four-bridge-arm inverter.

[0030] In this embodiment, the voltage after inversion output by the voltage regulator controller passes through the inductors L1, L2, and L3 respectively, and generates the required compensation power frequency AC voltage at both ends of the capacitors C1, C2, and C3. The three-phase AC switch S1 is a bypass switch of the three-phase regulator. When the switch is closed, the three-phase regulator does not work. When the three-phase AC switch S1 is turned on and the three-phase AC switch S2 and the three-phase AC switch S3 are closed, the three-phase regulator is put into operation, and the controlled AC voltage at both ends of the capacitors C1, C2, and C3 in the three-phase regulator is superimposed on the AC line, so that the input voltage of the tunnel boring machine combination switch is within the required range. The input of the voltage regulator controller is an AC voltage of 3300V, which is also the power supply of the control system of the entire device; the voltage regulator controller has two functions: one is power factor regulation, and the other is to generate the AC voltage required for regulation.

[0031] Specifically, Figure 2 As shown, in this embodiment, the voltage regulator controller includes: a three-level rectifier arranged at the front stage, a DC buck arranged in the middle, and a three-phase four-bridge-arm inverter arranged at the rear stage. The front stage adopts a three-level structure to better meet the requirements of voltage level and economy, and the middle stage can better match the range of DC voltage at both ends through buck regulation.

[0032] Specifically, in this embodiment, the input of the three-phase transformer is an AC voltage of 3300 V, and the output thereof is connected to the input of the three-phase regulator, and the output is a voltage of 1250 V. The transformation ratio of the transformer is fixed at 3300:1250.

[0033] Embodiment 2

[0034] like Figure 3 As shown, the second embodiment of the present invention provides a method for adjusting the voltage and power factor of a long-distance equipment side of a tunneling working face, based on Figures 1-2 The implementation of the device comprises the following steps:

[0035] Step 1: After receiving the power-on command, the three-phase transformer starts working and outputs voltage; the voltage regulator controller is powered on and starts to perform the power factor adjustment function, while preparing to collect the voltage Us3 on the input side and the voltage Us1 on the output side of the three-phase AC switch S3.

[0036] In step 1, the voltage regulator controller adjusts the power factor by controlling the rectifier at the front stage.

[0037] Step 2: Close the three-phase AC switch S1 and collect the voltage Us1.

[0038] Step 3: determine whether the collected voltage Us1 meets the power supply voltage requirement of the tunneling equipment. If so, the current switch state remains unchanged; if not, proceed to the next step.

[0039] Step 4: close the three-phase AC switch S2, collect the voltage Us3, input the inverted high-frequency AC signal to the three-phase series compensator through the voltage regulator controller, and adjust the output voltage of the three-phase line.

[0040] Step 5: When it is detected that the voltage Us3 is consistent with the voltage Us1, the three-phase AC switch S3 is closed, and then S1 is opened;

[0041] Specifically, in this embodiment, in step 5, when it is detected that the voltage Us3 is consistent in amplitude and phase with the voltage Us1, the three-phase AC switch S3 is closed and then S1 is opened.

[0042] Step 6: Continue to output the inverted high-frequency AC signal to the three-phase series compensator through the voltage regulator controller, and perform closed-loop regulation on the output voltage of the three-phase series compensator so that the output voltage of the three-phase series compensator meets the power supply requirement of the tunnel boring machine combination switch.

[0043] Specifically, in the present embodiment, in step 4 and step 6, the voltage regulating controller controls the three-phase four-bridge-arm inverter of the subsequent stage, thereby outputting the inverted high-frequency AC signal to the three-phase series compensator to adjust the output voltage of the three-phase series compensator.

[0044] In this embodiment, the input voltage of the voltage regulating controller is 3300V. After the control system is powered on, it controls the front stage to perform the power factor adjustment function, and then closes the three-phase AC switch S1, the three-phase transformer outputs the voltage, and the tunnel boring machine combination switch inputs a voltage of 1250V. At the same time, the voltage regulating controller collects the output voltage Us1 of the three-phase AC switch S1 (which is also equal to the voltage on the output side of the three-phase AC switch S3). When the voltage Us1 meets the power supply voltage requirement of the tunnel boring machine combination switch, the current switch state remains unchanged; when the voltage Us1 is lower than the power supply voltage requirement of the tunnel boring machine combination switch, the three-phase AC switch S2 is closed, and the voltage regulating controller is started to adjust the voltage. When it is detected that the voltage Us3 is consistent with Us1, S3 is closed, and then the three-phase AC switch S1 is disconnected, and the output voltage of the voltage regulator controller is continuously adjusted in a closed loop so that the output voltage meets the power supply requirement of the tunnel boring machine combination switch.

[0045] In summary, the present invention provides a method for regulating voltage and power factor on the long-distance power supply equipment side of an excavation working face, which mainly aims to improve the voltage regulation and reactive power compensation capabilities of the long-distance power supply equipment side of an underground coal mine excavation working face. It can also be widely used for other similar equipment designed and upgraded on the equipment side, including long-distance power supply scenarios of different forms, voltage levels and capacity levels.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A voltage and power factor regulating device for long-distance equipment side of excavation working face, characterized in that: include: A three-phase transformer, a three-phase regulator and a voltage regulator controller, wherein the three-phase regulator includes three-phase AC switches S1, S2, S3 and a three-phase series compensator; The input ends of the three-phase transformer and the voltage regulator controller are connected to the external voltage bus, and the output end of the three-phase transformer is connected to the three-phase AC switch S2, the three-phase series compensator, the three-phase AC switch S3 and the equipment combination switch in sequence; the output end of the three-phase transformer is also connected to the output end of the three-phase AC switch S3 through the three-phase AC switch S1, and the output end of the voltage regulator controller is connected to the three-phase series compensator, which is used to output the inverted high-frequency AC signal to the three-phase series compensator to achieve the adjustment of the voltage and power factor on the equipment side combination switch side; the voltage regulator controller includes: a three-level rectifier arranged at the front stage, a DC buck arranged in the middle and a three-phase four-bridge arm inverter arranged at the rear stage.

2. A voltage and power factor regulating device for long-distance equipment side of a tunneling working face according to claim 1, characterized in that: The three-phase series compensator includes three inductors L1, L2, and L3 and three capacitors C1, C2, and C3 respectively connected in series in one of the phases. One end of the inductors L1, L2, and L3 is respectively connected to the first to third output ends of the three-phase four-bridge-arm inverter, and the other ends of the inductors L1, L2, and L3 are respectively connected to the input ends of the capacitors C1, C2, and C3. The output ends of the capacitors C1, C2, and C3 are respectively connected to the input end of the three-phase AC switch S3 as the three-phase output ends of the three-phase series compensator, and the output ends of the capacitors C1, C2, and C3 are connected in parallel to the fourth output end of the three-phase four-bridge-arm inverter.

3. A voltage and power factor regulating device for long-distance equipment side of a tunneling working face according to claim 1, characterized in that: The input of the three-phase transformer is an AC voltage of 3300V, and the output is a voltage of 1250V.

4. A method for adjusting voltage and power factor on the long-distance equipment side of a tunneling working face, characterized in that: A device according to claim 1 is implemented, comprising the following steps: Step 1: After receiving the power-on command, the three-phase transformer works and outputs voltage; the voltage regulator controller is powered on and starts to perform the power factor adjustment function, and at the same time prepares to collect the voltage Us3 on the input side and the voltage Us1 on the output side of the three-phase AC switch S3; Step 2: Close the three-phase AC switch S1 and collect the voltage Us1; Step 3: determine whether the collected voltage Us1 meets the power supply voltage requirement of the equipment combination switch. If so, the current switch state remains unchanged; if not, proceed to the next step; Step 4: close the three-phase AC switch S2, collect the voltage Us3, input the inverted high-frequency AC signal to the three-phase series compensator through the voltage regulator controller, and adjust the voltage at the output end of the three-phase line; Step 5: When it is detected that the voltage Us3 is consistent with the voltage Us1, the three-phase AC switch S3 is closed, and then the three-phase AC switch S1 is opened; Step 6: Continue to output the inverted high-frequency AC signal to the three-phase series compensator through the voltage regulator controller, and perform closed-loop regulation on the voltage on the capacitor of the three-phase series compensator so that the output terminal voltage meets the power supply requirement of the equipment combination switch.

5. A method for adjusting voltage and power factor at the long-distance equipment side of a tunneling working face according to claim 4, characterized in that: In the step 1, the voltage regulating controller adjusts the power factor by controlling the three-level rectifier at the front stage.

6. A method for adjusting voltage and power factor on the long-distance equipment side of a tunneling working face according to claim 4, characterized in that: In step 4 and step 6, the voltage regulating controller controls the three-phase four-bridge-arm inverter of the subsequent stage, thereby outputting the inverted high-frequency AC signal to the three-phase series compensator to adjust the output voltage of the three-phase AC line.

7. A method for adjusting voltage and power factor at the long-distance equipment side of a tunneling working face according to claim 4, characterized in that: In step 5, when it is detected that the voltage Us3 is consistent in amplitude and phase with the voltage Us1, the three-phase AC switch S3 is closed, and then the three-phase AC switch S1 is opened.

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