Generator AC voltage withstand test control circuit and AC voltage withstand test device

Abstract

The utility model relates to a generator AC voltage withstand test control circuit and an AC voltage withstand test device, and the control circuit comprises a test voltage regulation module, a test current limiting module, a test voltage measurement module, and a monitoring control module. The test voltage adjusting module is used for adjusting the output voltage of an external AC power supply to a target voltage. The test current limiting module is connected with the test voltage adjusting module and is used for limiting target current corresponding to the target voltage; the test voltage measuring module is connected with the test current limiting module and is used for measuring the test voltage flowing through the tested generator; the monitoring control module is connected with the test voltage adjusting module, the test current limiting module and the test voltage measuring module, and is used for controlling the test voltage adjusting module to boost or buck and monitoring the voltage and current of the control circuit. The reliability of the measurement result of the finally output test voltage can be improved, so that the reliability of the detection result of the insulation defect of the generator is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of generators, in particular to a generator AC withstand voltage test control circuit and an AC withstand voltage test device. BACKGROUND

[0002] With the development of power systems, large-capacity steam turbine generator units (such as 150MW, 300MW, 600MW, 1000MW and above) have become the main generator units in China. The rated voltage range of the stator winding of these generators is wide, ranging from 16kV to 27kV. When performing power frequency AC withstand voltage test, due to the high capacitance and high voltage of the stator winding, the traditional test equipment is large in size and heavy in weight, and requires complex wiring and high-capacity transformers, which greatly increases the difficulty of test implementation.

[0003] In related technologies, in order to solve the problem of large size and heavy weight of power frequency AC withstand voltage test equipment, a frequency modulation series resonance method is usually used for withstand voltage test. The test circuit is resonated by adjusting the frequency of the test voltage, so that the generator obtains high voltage. The electrical equipment handover test standard requires that the generator AC withstand voltage test be performed under power frequency conditions, and the frequency modulation series resonance withstand voltage method can only adjust the test voltage frequency to be close to the power frequency, but not 50Hz. That is, the voltage waveform output by the frequency modulation series resonance withstand voltage test is not a strict sense of power frequency waveform, resulting in low reliability of the detection result of the generator insulation defect. CONTENT OF THE UTILITY MODEL

[0004] Therefore, it is necessary to provide a generator AC withstand voltage test control circuit and an AC withstand voltage test device to solve the technical problem of low reliability of the detection result of the generator insulation defect.

[0005] In a first aspect, the present application provides a generator AC withstand voltage test control circuit, comprising:

[0006] A test voltage adjusting module is configured to be externally connected to an AC power source required for AC withstand voltage test of a measured generator, and to adjust the output voltage of the AC power source to a target voltage, wherein the voltage waveform of the target voltage is a power frequency waveform meeting preset requirements;

[0007] A test current limiting module is connected to the test voltage adjusting module, and is configured to limit a target current corresponding to the target voltage;

[0008] A test voltage measuring module is connected to the test current limiting module, and is configured to measure the test voltage flowing through the measured generator; and

[0009] The monitoring control module is connected with the test voltage adjusting module, the test current limiting module and the test voltage measuring module, and is configured to send a control signal to the test voltage adjusting module to control the test voltage adjusting module to boost or step down, and to monitor the voltage and current of the control circuit.

[0010] In one of the embodiments, the test voltage adjusting module comprises:

[0011] The power input submodule is configured to externally connect an AC power source required when performing the AC voltage withstand test on the generator under test.

[0012] The voltage regulating submodule is connected with the power input submodule, and is configured to regulate the output voltage of the AC power source to a target voltage.

[0013] In one of the embodiments, the voltage regulating submodule comprises:

[0014] The motor voltage regulating unit is connected with the power input submodule, and is configured to regulate the output voltage of the AC power source to a reference voltage.

[0015] The excitation voltage transforming unit is connected with the motor voltage regulating unit, and is configured to regulate the reference voltage to the target voltage.

[0016] In one of the embodiments, the test current limiting module comprises:

[0017] The inductance adjusting submodule is connected with the voltage regulating submodule, and is configured to adjust the inductance to achieve parallel resonance with the stator winding of the generator under test.

[0018] The current limiting submodule is connected with the inductance adjusting submodule and the stator winding of the generator under test, and is configured to limit the discharge current of the stator winding.

[0019] In one of the embodiments, the test current limiting module further comprises an overvoltage protection submodule connected with the current limiting submodule, and configured to limit the discharge voltage of the stator winding.

[0020] In one of the embodiments, the test voltage measuring module comprises:

[0021] The capacitor voltage dividing submodule is connected with the current limiting submodule, and is configured to convert the output voltage signal of the current limiting submodule into a low-voltage signal.

[0022] The voltage measuring submodule is connected with the capacitor voltage dividing submodule, and is configured to measure the low-voltage signal to obtain the test voltage.

[0023] In a second aspect, the application provides an alternating current withstand voltage test device, which is applied to any one of the generator alternating current withstand voltage test control circuits provided in the first aspect, and further comprises:

[0024] a test platform configured to receive the generator alternating current withstand voltage test control circuit;

[0025] a universal wheel arranged at a bottom wall of the test platform.

[0026] In one of the embodiments, the alternating current withstand voltage test device further comprises a hoisting component arranged on the test platform, and the hoisting component is configured to cooperate with hoisting the alternating current withstand voltage test device.

[0027] In one of the embodiments, the alternating current withstand voltage test device further comprises an insulating support component configured to support a high-voltage wire in the generator alternating current withstand voltage test control circuit.

[0028] In one of the embodiments, the alternating current withstand voltage test device further comprises a terminal post arranged at a side of the alternating current withstand voltage test device close to a stator winding of the generator to be tested, and the terminal post is configured to be connected to the stator winding of the generator to be tested through the high-voltage wire.

[0029] The generator alternating current withstand voltage test control circuit comprises a test voltage adjustment module, a test current limiting module, a test voltage measurement module, and a monitoring control module. The test voltage adjustment module is configured to externally connect an alternating current power supply required when performing the alternating current withstand voltage test on the generator to be tested, and adjust an output voltage of the alternating current power supply to a target voltage, and a voltage waveform of the target voltage is a power frequency waveform meeting preset requirements. The test current limiting module is connected to the test voltage adjustment module, and the test current limiting module is configured to limit a target current corresponding to the target voltage. The test voltage measurement module is connected to the test current limiting module, and the test voltage measurement module is configured to measure a test voltage flowing through the generator to be tested. The monitoring control module is connected to the test voltage adjustment module, the test current limiting module, and the test voltage measurement module, and the monitoring control module is configured to send a control signal to the test voltage adjustment module to control the test voltage adjustment module to perform voltage boosting or voltage reduction, and to monitor the voltage and the current of the control circuit. The application adjusts the output voltage of the alternating current power supply in real time through the cooperation of the test voltage adjustment module, the test current limiting module, the test voltage measurement module, and the monitoring control module, so as to ensure that a voltage waveform of the withstand voltage test output is a power frequency waveform meeting preset requirements, thereby improving the reliability of a measurement result of the test voltage finally output, and further improving the reliability of a detection result of the insulation defect of the generator. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0031] Figure 1 A module schematic diagram of the generator AC withstand voltage test control circuit in some embodiments of the present application;

[0032] Figure 2 A structure schematic diagram of the test voltage regulating module in some embodiments of the present application;

[0033] Figure 3 A structure schematic diagram of the voltage regulating sub-module in some embodiments of the present application;

[0034] Figure 4 A structure schematic diagram of the test current limiting module in some embodiments of the present application;

[0035] Figure 5 A structure schematic diagram of the test voltage measuring module in some embodiments of the present application;

[0036] Figure 6 A circuit connection diagram of the generator AC withstand voltage test control circuit in some embodiments of the present application;

[0037] Figure 7 A structure schematic diagram of the AC withstand voltage test device in some embodiments of the present application.

[0038] Explanation of the drawing reference numerals:

[0039] 100, test voltage regulating module; 110, power input sub-module; 120, voltage regulating sub-module; 122, electric voltage regulating unit; 124, excitation transformer unit; 200, test current limiting module; 210, inductance adjusting sub-module; 220, current limiting sub-module; 230, overvoltage protection sub-module; 300, test voltage measuring module; 310, capacitance voltage dividing sub-module; 320, voltage measuring sub-module; 400, monitoring control module; 500, test platform; 510, universal wheel; 520, hoisting part; 530, insulating support part; 540, high-voltage wire; 550, terminal post; 560, insulating plate; 600, stator winding. DETAILED DESCRIPTION

[0040] In order to make the above objectives, features and advantages of the present application more clear and understandable, the detailed description of the specific embodiments of the present application is made below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in many different manners and forms without departing from the spirit or scope of the present application, and those skilled in the art can make similar improvements and modifications without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0041] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0042] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0043] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0045] It is to be understood that when an element as a preamble is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or there can be intervening elements. When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements can be present. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms as used herein are for descriptive purposes only and not meant to be limiting.

[0046] With the development of power systems, large-capacity steam turbine generator units (such as 150MW, 300MW, 600MW, 1000MW and above) have become the main power generation units in China. The rated voltage range of the stator winding of these generators is wide, ranging from 16kV to 27kV. When performing power frequency AC withstand voltage test, due to the high capacitance and high voltage of the stator winding, the traditional test equipment is large in size and heavy in weight, and requires complex wiring and high-capacity transformers, which greatly increases the difficulty of test implementation.

[0047] In the related art, to solve the problem of large size and heavy weight of the power frequency AC withstand voltage test equipment, the method of frequency modulation series resonance is usually used for withstand voltage test. By adjusting the frequency of the test voltage to make the test circuit resonate, the generator obtains high voltage. The electrical equipment handover test standard requires that the generator AC withstand voltage test be performed under power frequency conditions, and the frequency modulation series resonance withstand voltage method can only adjust the test voltage frequency to be close to the power frequency, not 50Hz. That is, the voltage waveform output by the frequency modulation series resonance withstand voltage test is not a strict sense of power frequency waveform, which leads to low reliability of the detection result of the generator insulation defect.

[0048] To solve the technical problem of low reliability of the detection result of the generator insulation defect in the related art, in a first aspect, referring to Figure 1In an embodiment of the present application, a generator AC withstand voltage test control circuit is provided, which comprises a test voltage adjusting module 100, a test current limiting module 200, a test voltage measuring module 300 and a monitoring control module 400. The test voltage adjusting module 100 is used to connect an external AC power source required for the AC withstand voltage test of the measured generator, and adjust the output voltage of the AC power source to a target voltage, and the voltage waveform of the target voltage is a power frequency waveform meeting preset requirements. The test current limiting module 200 is connected with the test voltage adjusting module 100, and the test current limiting module 200 is used to limit a target current corresponding to the target voltage. The test voltage measuring module 300 is connected with the test current limiting module 200, and the test voltage measuring module 300 is used to measure the test voltage flowing through the measured generator. The monitoring control module 400 is connected with the test voltage adjusting module 100, the test current limiting module 200 and the test voltage measuring module 300, and the monitoring control module 400 is used to send a control signal to the test voltage adjusting module 100 to control the test voltage adjusting module 100 to step up or step down, and is used to monitor the voltage and current of the control circuit.

[0049] Specifically, when receiving the output voltage of the external AC power source, the test voltage adjusting module 100 converts the voltage waveform into a power frequency waveform meeting preset requirements, i.e., a target voltage. During the test, the monitoring control module 400 controls the test voltage adjusting module 100 to gradually increase the test voltage, and the monitoring control module 400 monitors the voltage and current of the control circuit. In the process of voltage step-up, in order to ensure the safety of the test, the test current limiting module 200 is used to limit the discharge current of the circuit to ensure the safety of the test. During the test, if the test result is an abnormal increase in current or a sudden drop in voltage, it indicates that the generator stator winding 600 has insulation defects, such as insulation damage, breakdown, etc. That is, by monitoring the changes of the current and voltage through the test voltage measuring module 300, it can be determined whether there is an insulation defect. In addition, after the test is completed, the electrically operated console is used to control the electrically operated voltage regulator to gradually reduce the test voltage, so as to ensure the safety of the entire test process.

[0050] The target voltage is not unique, but is the voltage value required to be reached each time in the process of voltage step-up, and the voltage waveforms of these voltages are power frequency waveforms meeting requirements.

[0051] The generator AC withstand voltage test control circuit in the embodiment can adjust the output voltage of the AC power source in real time through the cooperation of the test voltage adjusting module 100, the test current limiting module 200, the test voltage measuring module 300 and the monitoring control module 400, so as to ensure that the voltage waveform of the test output is a power frequency waveform meeting requirements, thereby improving the reliability of the measurement result of the final output test voltage, and further improving the reliability of the detection result of the insulation defects of the generator.

[0052] Referring to Figure 2 In some embodiments, the test voltage regulating module 100 comprises a power input submodule 110 and a voltage regulating submodule 120. The power input submodule 110 is configured to externally connect an alternating current (AC) power source required for an AC withstand voltage test of the generator under test. The voltage regulating submodule 120 is connected to the power input submodule 110 and configured to regulate the output voltage of the AC power source to a target voltage.

[0053] In some embodiments, the voltage regulating submodule 120 is connected to the output of the power input submodule 110. When the power input submodule 110 receives the voltage from the externally connected AC power source, the voltage regulating submodule 120 regulates the output voltage of the AC power source to the target voltage.

[0054] Referring to Figure 3 In some embodiments, the voltage regulating submodule 120 comprises an electric voltage regulating unit 122 and an excitation voltage transforming unit 124. The electric voltage regulating unit 122 is connected to the power input submodule 110 and configured to regulate the output voltage of the AC power source to a reference voltage. The excitation voltage transforming unit 124 is connected to the electric voltage regulating unit 122 and configured to regulate the reference voltage to the target voltage.

[0055] In particular, the electric voltage regulating unit 122 is connected to the output of the power input submodule 110. The electric voltage regulating unit 122 first raises the output voltage of the power input submodule 110 to a preset suitable voltage, i.e., the reference voltage, and then raises the reference voltage to the target voltage through the excitation voltage transforming unit 124.

[0056] Referring to Figure 4 In some embodiments, the test current limiting module 200 comprises an inductance regulating submodule 210 and a current limiting submodule 220. The inductance regulating submodule 210 is connected to the voltage regulating submodule 120 and configured to regulate the inductance to achieve parallel resonance with the stator winding 600 of the generator under test. The current limiting submodule 220 is connected to the inductance regulating submodule 210 and the stator winding 600 of the generator under test and configured to limit the discharge current of the stator winding 600.

[0057] In particular, the inductance regulating submodule 210 is connected to the output of the voltage regulating submodule 120 and in parallel with the stator winding 600 of the generator under test. The current limiting submodule 220 is connected between the output of the inductance regulating submodule 210 and the stator winding 600 of the generator under test. During the test, the current limiting submodule 220 limits the discharge current of the test circuit to protect the test circuit from excessive current.

[0058] Reference Figure 4 In some embodiments, the test current limiting module 200 further includes an overvoltage protection submodule 230, which is connected to the current limiting submodule 220 and is used to limit the discharge voltage of the stator winding 600.

[0059] Specifically, the overvoltage protection submodule 230 is connected to the input terminal of the current limiting submodule 220. The overvoltage protection submodule 230 provides overvoltage protection to prevent excessive voltage from damaging the insulation of the test device and the stator winding 600 of the generator under test.

[0060] Reference Figure 5 In some embodiments, the test voltage measurement module 300 includes a capacitive voltage divider submodule 310 and a voltage measurement submodule 320. The capacitive voltage divider submodule 310 is connected to the current limiting submodule 220 and is used to convert the output voltage signal of the current limiting submodule 220 into a low voltage signal. The voltage measurement submodule 320 is connected to the capacitive voltage divider submodule 310 and is used to measure the low voltage signal to obtain the test voltage value.

[0061] Specifically, the input terminal of the capacitive voltage divider submodule 310 is connected to the output terminal of the current limiting submodule 220, and the output terminal of the capacitive voltage divider submodule 310 is connected to the input terminal of the voltage measurement submodule 320. The capacitive voltage divider submodule 310 and the voltage measurement submodule 320 work together to measure the test voltage.

[0062] Figure 6 The diagram shown below illustrates the connection of the generator AC withstand voltage test control circuit in one embodiment. Figure 6 As an example, the generator AC withstand voltage test control circuit of this application will be described in detail.

[0063] In one embodiment, such as Figure 6 As shown, the power input submodule 110 is the power input interface, the electric voltage regulating unit 122 is an electric voltage regulator, the excitation transformer unit 124 is an excitation transformer, the inductance adjustment submodule 210 is an adjustable reactor, the current limiting submodule 220 is a current limiting resistor, the overvoltage protection submodule 230 is a discharge protection spherical gap, the capacitor voltage divider submodule 310 is a capacitor voltage divider, and the voltage measurement submodule 320 is a peak voltage meter. The monitoring and control module 400 is an electric operating console.

[0064] The electric operating platform is used for boosting, reducing and other operations of the test device, and monitors the voltage and current of the control circuit. The electric operating platform is connected with the electric voltage regulator through a signal cable. The operating platform changes the output voltage of the electric voltage regulator by controlling the voltage regulating mechanism of the electric voltage regulator. The electric operating platform is connected with the adjustable reactor through a signal cable. The operating platform changes the inductance value of the adjustable reactor by controlling the inductance adjusting mechanism of the adjustable reactor.

[0065] The electric voltage regulator is a dry contact type electric voltage regulator. The electric voltage regulator serves to deliver power to the input end of the excitation transformer and adjust the output voltage in the control circuit. The rated capacity of the electric voltage regulator is 40 kVA, the output range of the current is 0-95 A, and the output range of the voltage is 0-420 V.

[0066] The excitation transformer is an oil-immersed double-winding single-phase transformer, which is used to raise the voltage output by the electric voltage regulator to a suitable test voltage. The rated frequency of the excitation transformer is 50 Hz, and the rated capacity is 60 kVA. The high-voltage output is designed with A1 terminal and A2 terminal. The current output range of the A1 terminal is 0-1.5 A, and the voltage output range is 0-40 kV. The current output range of the A2 terminal is 0-1 A, and the voltage output range is 0-60 kV. According to different test voltage requirements, the corresponding high-voltage output terminal is selected.

[0067] The adjustable reactor is an oil-immersed reactor with core spacing and continuous non-polar fine adjustment. The adjustable reactor is connected in parallel with the generator stator winding 600, and provides test current for the generator stator winding 600 by adjusting the inductance and generating parallel resonance with the generator, which greatly reduces the capacity of the test power supply and the excitation transformer. The rated frequency of the adjustable reactor is 50 Hz, and the rated capacity is 360 kVA. The high-voltage output is designed with B1 terminal and B2 terminal. The current output range of the B1 terminal is 0-9 A, and the voltage output range is 0-40 kV. The adjustable inductance range is 19-169 H. The current output range of the B2 terminal is 0-6 A, and the voltage output range is 0-60 kV. The adjustable inductance range is 19-31.9 H. The adjustable reactor B1 terminal is used in cooperation with the excitation transformer A1 terminal, which is suitable for generators with a capacitance of 0.06-0.318 μF. The adjustable reactor B2 terminal is used in cooperation with the excitation transformer A2 terminal. It is suitable for generators with a capacitance of 0.06-0.53 μF. The adjustable reactor can meet the requirements of power frequency resonance voltage withstand test of generators with different voltage grades and capacitances according to the capacitance and voltage grade of large-capacity generators.

[0068] The current-limiting resistor is a high-voltage current-limiting resistor, which is used for limiting the discharge current and protecting the test circuit from being damaged by excessive current. The withstand voltage range of the high-voltage current-limiting resistor is 0-100 kV. The discharge protection sphere gap is used for providing overvoltage protection to prevent the test device and the generator stator winding 600 from being damaged due to excessive voltage. The withstand voltage range of the discharge protection sphere gap is 0-100 kV. The capacitive voltage divider is used in cooperation with the peak voltage meter to measure the test voltage. The capacitive voltage divider is composed of a high-voltage capacitor and a low-voltage capacitor connected in series, and the high voltage is converted into low voltage by using the capacitive voltage division principle. The division ratio of the capacitive voltage divider is 1000:1, and the voltage measurement range is 0-60 kV. The peak voltage meter is used in cooperation with the capacitive voltage divider to measure and display the test voltage. The peak voltage meter is arranged above the motorized voltage regulator.

[0069] Specifically, the interface of the power input can be externally connected to a 380V alternating current power supply, and the 380V alternating current power supply can be connected to the input end of the motorized voltage regulator through a power cable. The output end of the motorized voltage regulator is connected to the low-voltage side of the excitation transformer. The high-voltage side head end of the excitation transformer, the high-voltage end of the adjustable reactor, and the high-voltage end of the discharge protection sphere gap are connected to one end of the current-limiting resistor. The other end of the current-limiting resistor is connected to the high-voltage end of the capacitive voltage divider and the generator stator winding 600. The high-voltage side tail end of the excitation transformer, the low-voltage end of the adjustable reactor, the low-voltage end of the discharge protection sphere gap, and the low-voltage end of the voltage divider are collectively connected and grounded. The peak voltage meter is connected in parallel with the low-voltage capacitor of the capacitive voltage divider. The signal end of the motorized operating platform is connected to the signal end of the motorized voltage regulator and the signal end of the adjustable reactor, respectively. The connections between the motorized operating platform, the motorized voltage regulator, the excitation transformer, the adjustable reactor, the current-limiting resistor, the discharge protection sphere gap, the capacitive voltage divider, and the peak voltage meter are fixedly connected through cables, and no additional wiring is required for each test device.

[0070] The generator AC withstand voltage test control circuit in the application adjusts the output voltage of the AC power supply in real time through the cooperation of the test voltage adjustment module 100, the test current limiting module 200, the test voltage measurement module 300, and the monitoring control module 400, to ensure that the voltage waveform of the withstand voltage test output is a required power frequency waveform, thereby improving the reliability of the measurement result of the final output test voltage, and further improving the reliability of the detection result of the generator insulation defect.

[0071] In a second aspect, with reference to Figure 7 An embodiment of the application provides an AC withstand voltage test device, which is applied to any one of the generator AC withstand voltage test control circuits provided in the first aspect. The AC withstand voltage test device further comprises a test platform 500 and a plurality of universal wheels 510. The test platform 500 is used for receiving the generator AC withstand voltage test control circuit. The number of the universal wheels 510 is four, which are respectively installed at the four corners of the bottom wall of the test platform 500.

[0072] Specifically, the test platform 500 is used to install and fix each test equipment of the withstand voltage test device. The electric operating platform, the electric voltage regulator, the excitation transformer, the adjustable reactor, the capacitor voltage divider, the current limiting resistor and the discharge gap are fixed and installed on the upper surface of the trolley test platform 500.

[0073] The conventional frequency modulation series resonance complete equipment is composed of a variable frequency power supply, an excitation transformer, a reactor, a voltage divider. When the test is performed on site, each test equipment needs to be transported to the test site one by one, and then the wiring of each equipment is installed and connected. Since each equipment needs to be loaded, unloaded and hoisted, it is time-consuming and laborious, and the work efficiency is low. Moreover, the test wiring is complicated, and wiring errors are prone to occur. In the embodiment, the wiring between the electric operating platform, the electric voltage regulator, the excitation transformer, the adjustable reactor, the current limiting resistor, the discharge protection gap, the capacitor voltage divider and the peak voltage meter is fixedly connected through the cable, and no additional wiring of each test equipment is needed. Before the test, through the cooperation of the test platform 500 and the universal wheel 510, the test device only needs to be transported to the vicinity of the generator, and then the power cable is connected to the external 380V test power supply, and the high-voltage lead 540 is connected to the generator stator winding, so that the withstand voltage test can be performed. After the test is completed, there is no need to remove the connection cable between each equipment. The hoisting of the test equipment and the wiring and disconnection of the test equipment are greatly reduced, and the test work efficiency is improved.

[0074] Referring to Figure 7 In some embodiments, the alternating withstand voltage test device further comprises a hoisting member 520, which is arranged on the test platform 500 and is used to cooperate with the hoisting of the alternating withstand voltage test device.

[0075] The hoisting member 520 comprises four lifting rings, which are fixedly connected to four corner positions on the upper surface of the test platform 500, so as to hoist the alternating withstand voltage test device.

[0076] In the embodiment, the hoisting member 520 is arranged, so as to facilitate the transfer of the alternating withstand voltage test device.

[0077] Referring to Figure 7 In some embodiments, the alternating withstand voltage test device further comprises an insulating support member 530, which is used to support the high-voltage lead 540 in the generator alternating withstand voltage test control circuit.

[0078] The insulating support member 530 comprises an insulating support rod, which is used to support and fix the high-voltage lead 540, and is vertically installed on the side of the capacitor voltage divider away from the electric operating platform.

[0079] Specifically, the high-voltage conductor 540 is supported by the insulating support rod, which helps to ensure the stability of the high-voltage conductor 540 after laying.

[0080] Referring to Figure 7 In some embodiments, the AC withstand voltage test device further comprises a terminal post 550 arranged on the side of the AC withstand voltage test device close to the stator winding of the generator to be tested, and the terminal post 550 is used to connect the high-voltage conductor 540.

[0081] Specifically, the terminal post 550 is arranged at the top end of the insulating support rod, one end of the terminal post 550 is connected to the capacitor divider through the high-voltage conductor 540, and the other end is connected to the stator winding of the generator through the high-voltage conductor 540.

[0082] Referring to Figure 7 In some embodiments, the AC withstand voltage test device further comprises an insulating plate 560 vertically arranged between the excitation transformer and the adjustable reactor. The insulating plate 560 is an epoxy insulating plate 560, which is used to increase the insulation distance between the test voltage and the test personnel and improve the test safety. The insulating plate 560 is arranged between the excitation transformer and the motor voltage regulator and is made of glass fiber cloth bonded with epoxy resin, which has good insulation performance.

[0083] The AC withstand voltage test device in the present application uses an adjustable reactor with adjustable inductance connected in parallel with the stator winding of the generator. By adjusting the inductance of the adjustable reactor, the adjustable reactor and the generator resonate at 50 Hz to generate a power frequency high voltage, and the test effect is real and effective. In addition, the device only needs a small-capacity test power supply and an excitation transformer to perform a generator power frequency withstand voltage test. The inductance adjustment range of the reactor is wide, and it has overcurrent and overvoltage protection functions, which is suitable for power frequency withstand voltage tests of generators of different voltage classes and different capacities. In addition, the AC withstand voltage test device adds a trolley component to the original parallel resonance withstand voltage test equipment. Each test equipment is fixedly installed on the movable test platform 500, and the wiring between each equipment is complete. There is no need to reconnect the equipment wiring, which greatly reduces the test equipment hoisting and wiring work, avoids test wiring errors and other problems, and improves the test work efficiency.

[0084] In summary, the AC withstand voltage test device of the present application has the following beneficial effects:

[0085] 1. The withstand voltage test device of the present application uses a parallel reactor to compensate the capacitive current of the parallel circuit, which greatly reduces the capacity of the excitation transformer and the test power supply.

[0086] 2. The withstand voltage test device of the present application outputs a test voltage frequency and waveform consistent with the operation of the generator, which can effectively evaluate the generator insulation and has good detection effect.

[0087] 3. The pressure test device of the present application is designed with a current-limiting resistor and a discharge protection gap, which can effectively limit the discharge current and overvoltage, and reliably protect the test device.

[0088] 4. The pressure test device of the present application is complete in equipment, complete in wiring connection, convenient in overall hoisting and transportation, greatly saves the time spent on loading and unloading of test equipment and on hoisting at the site, and improves the test work efficiency.

[0089] In the description of the specification, the description referring to the terms "some embodiments", "other embodiments" and the like is intended to mean that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0090] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present application.

[0091] The above-described embodiments only express several implementation manners of the present application, the description is relatively specific and detailed, but it should not be understood as a limitation on the patent application scope. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A control circuit for an AC voltage withstand test of a generator, characterized by The test voltage regulating module is configured to connect an alternating current (AC) power source required for an AC withstand voltage test of the generator under test and to regulate an output voltage of the AC power source to a target voltage, wherein a voltage waveform of the target voltage is a power frequency waveform meeting preset requirements. The test current limiting module is connected to the test voltage regulating module, and is configured to limit a target current corresponding to the target voltage. The test voltage measuring module is connected to the test current limiting module, and is configured to measure a test voltage flowing through the generator under test. The monitoring control module is connected to the test voltage regulating module, the test current limiting module, and the test voltage measuring module, and is configured to send a control signal to the test voltage regulating module to control the test voltage regulating module to boost or step down, and to monitor a voltage and a current of the control circuit. The test voltage regulating module comprises: The power input submodule is configured to connect the AC power source required for the AC withstand voltage test of the generator under test.

2. The generator AC voltage withstand test control circuit of claim 1, wherein, The voltage regulating submodule is connected to the power input submodule, and is configured to regulate the output voltage of the AC power source to the target voltage. The voltage regulating submodule comprises: The motor voltage regulating unit is connected to the power input submodule, and is configured to regulate the output voltage of the AC power source to a reference voltage.

3. The generator AC voltage withstand test control circuit of claim 2, wherein, The excitation voltage transforming unit is connected to the motor voltage regulating unit, and is configured to regulate the reference voltage to the target voltage. The test current limiting module comprises: The inductance adjusting submodule is connected to the voltage regulating submodule, and is configured to adjust an inductance to achieve parallel resonance with a stator winding of the generator under test.

4. The generator AC voltage withstand test control circuit of claim 2, wherein, The current limiting submodule is connected to the inductance adjusting submodule and the stator winding of the generator under test, and is configured to limit a discharge current of the stator winding. The test current limiting module further comprises an overvoltage protection submodule connected to the current limiting submodule, and configured to limit a discharge voltage of the stator winding. The test voltage measuring module comprises:

5. The generator AC voltage withstand test control circuit of claim 4, wherein, The capacitor voltage dividing submodule is connected to the current limiting submodule, and is configured to convert an output voltage signal of the current limiting submodule into a low-voltage signal.

6. The generator AC voltage withstand test control circuit of claim 4, wherein, The voltage measuring submodule is connected to the capacitor voltage dividing submodule, and is configured to measure the low-voltage signal to obtain the test voltage. The AC withstand voltage test device further comprises: The test platform is configured to accommodate the generator AC withstand voltage test control circuit.

7. An AC voltage withstand test device, characterized by The universal wheels are arranged at four corners of a bottom wall of the test platform. The AC withstand voltage test device further comprises a lifting component arranged on the test platform, and configured to cooperate with a crane to lift the AC withstand voltage test device. ​ 8. The AC voltage withstand test device according to claim 7, characterized in that ​ 9. The AC voltage withstand test device of claim 7, wherein, The alternating current withstand voltage test device further comprises an insulation support for supporting a high-voltage wire in the generator alternating current withstand voltage test control circuit.

10. The AC voltage withstand test device of claim 9, wherein, The alternating current withstand voltage test device further comprises a terminal post arranged on a side of the alternating current withstand voltage test device close to a stator winding of a to-be-tested generator, and the terminal post is used for connecting the high-voltage wire with the stator winding of the to-be-tested generator.

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