Self-adaptive parallel compensation voltage withstanding device

Abstract

The utility model discloses a self-adaptive parallel compensation withstand voltage device which comprises a power supply control unit, a compensation unit, a self-adaptive adjusting unit and a boost unit, the power supply control unit is movably connected with the boost unit through a connecting line, and the boost unit is movably connected with the compensation unit through a connecting line. The compensation unit is used for compensating the inductance value and the capacitance value of tested equipment, the self-adaptive adjustment unit is connected with the power supply control unit and the compensation unit, and the self-adaptive adjustment unit comprises an acquisition module, a capacitor adjustment module and a reactor adjustment module. The acquisition module is used for acquiring reactance current and capacitance current of the compensation unit and sending the reactance current and the capacitance current to the power supply control unit, and the power supply control unit enables the test device to rapidly reach a resonance condition at a frequency set by a user by controlling the adjusting quantities of the capacitor adjusting module and the reactor adjusting module on a compensation reactor and a compensation capacitor of the compensation unit. And the test efficiency and the test safety are improved.

Description

Technical Field

[0001] This invention belongs to the field of power equipment maintenance and testing technology, and specifically relates to an adaptive parallel compensation withstand voltage device. Background Technology

[0002] The AC withstand voltage test is one of the most direct and effective tests for judging the insulation performance of electrical equipment. It involves applying an AC voltage higher than the rated operating voltage to the insulation of the electrical equipment for a period of time, and judging the quality of the insulation performance of the electrical equipment based on whether flashover or breakdown occurs.

[0003] Currently, AC withstand voltage tests for power equipment are mainly divided into power frequency withstand voltage and resonant withstand voltage. Among them, resonant withstand voltage mainly includes series resonant withstand voltage and parallel resonant withstand voltage. The working principle of resonant withstand voltage is to make the reactor and capacitor resonate at a specific frequency by properly matching the ratio, thereby improving the voltage output capability or current output capability of the test equipment. Power frequency withstand voltage equipment is limited by power and capacity issues and can usually only be used in some small and medium capacity transformers or cables. For some long cables and high voltage levels, resonant withstand voltage is often required.

[0004] Patent document with application number "CN206321747U" discloses a parallel differential compensation withstand voltage test device. It primarily increases the output power of the test device by adjusting the sizes of the compensation reactor and compensation capacitor in the compensation unit, causing the parallel resonant circuit, composed of the compensation reactor and compensation capacitor of the test device and the capacitor in the power cable, to resonate at a frequency of 50Hz. This achieves power frequency withstand voltage testing. Simultaneously, the unit wiring method reduces the size and weight of the device, facilitating transportation. However, during the test, to achieve resonance at 50Hz, repeated manual adjustments to the compensation reactor and compensation capacitor are required, resulting in low test efficiency. Furthermore, the adjustment process poses a safety hazard of electric shock due to insufficient discharge of the reactor or capacitor.

[0005] Therefore, this utility model proposes an adaptive parallel compensation withstand voltage device to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide an adaptive parallel compensation withstand voltage device to solve the problem in the prior art where power frequency resonance requires repeated manual adjustment of the compensation reactor and compensation capacitor to achieve resonance at 50Hz, resulting in low testing efficiency. Furthermore, the adjustment process can easily lead to electric shock hazards due to insufficient discharge of the reactor or capacitor.

[0007] To achieve the above objectives, this utility model provides an adaptive parallel compensation withstand voltage device, comprising:

[0008] The device includes a power control unit, a compensation unit, a boost unit, and an adaptive adjustment unit. The power control unit is movably connected to the boost unit via a connecting line, and the boost unit is movably connected to the compensation unit via a connecting line. The compensation unit is used to compensate for the inductance and capacitance of the device under test. The adaptive adjustment unit is connected to both the power control unit and the compensation unit, and is used to adjust the inductance and capacitance of the compensation unit.

[0009] Preferably, in the above technical solution, the compensation unit includes a compensation capacitor module and a compensation reactor module, wherein the compensation capacitor module is mainly composed of compensation capacitors and the compensation reactor module is mainly composed of compensation reactors.

[0010] Preferably, in the above technical solution, the adaptive adjustment unit includes a data acquisition module, a capacitor adjustment module, and a reactor adjustment module. The compensation capacitor module and the compensation reactor module are respectively connected to one input terminal of the data acquisition module. The output terminal of the data acquisition module is connected to the main controller of the power control unit. The capacitor adjustment module and the reactor adjustment module are respectively connected to the main controller. The capacitor adjustment module is connected to the compensation capacitor module, and the reactor adjustment module is connected to the compensation reactor module.

[0011] Preferably, in the above technical solution, the acquisition module includes a DAC module, a first comparator, a first current transformer, a second comparator, and a second current transformer. The primary side of the first current transformer is connected to the compensation capacitor module, and the secondary side is connected to one input terminal of the first comparator. The primary side of the second current transformer is connected to the compensation reactor module, and the secondary side is connected to one input terminal of the second comparator. The output terminal of the DAC module is connected to one input terminal of the first comparator and one input terminal of the second comparator.

[0012] Preferably, in the above technical solution, the capacitor adjustment module consists of multiple high-voltage switch modules, which are connected to the compensation capacitor to realize the series or parallel connection of the compensation capacitor. The reactor adjustment module consists of a motor adjustment device to adjust the air gap of the reactor.

[0013] Preferably, in the above technical solution, the power control unit includes an autotransformer and a frequency converter, the autotransformer is connected to the frequency converter, and the frequency converter is connected to the main controller.

[0014] Preferably, in the above technical solution, the voltage frequency output by the variable frequency power supply is 50Hz-300Hz.

[0015] Preferably, in the above technical solution, the step-up unit is a step-up transformer.

[0016] Preferably, in the above technical solution, the compensation reactor module is composed of two or more reactors stacked together, and the total inductance of the compensation reactor module can be changed by adjusting the air gap of the compensation reactor through the reactor adjustment module.

[0017] Compared with existing technologies, this utility model has the following beneficial effects:

[0018] 1. The adaptive adjustment unit of this utility model includes a data acquisition module, a capacitor adjustment module, and a reactor adjustment module. The capacitor adjustment module automatically adjusts the capacitance of the compensation capacitor module, and the reactor adjustment module automatically adjusts the inductance of the compensation reactor module. The data acquisition module collects the current in the circuit of the compensation reactor module and the current in the nodes of the compensation capacitor module. The main controller determines whether the two exceed the user-set threshold, thereby realizing rapid, automatic, and closed-loop adjustment of the capacitance of the compensation capacitor module and the inductance of the compensation reactor module. This enables the test device to resonate at the user-set frequency, improving test efficiency and avoiding the problem of electric shock accidents caused by manual adjustment.

[0019] 2. The frequency of the variable frequency power supply output is 30-300Hz. By adjusting the frequency of the output voltage of the variable frequency power supply, the inductance of the compensation reactor module and the capacitance of the compensation capacitor module remain unchanged, thus making the reactance of the compensation reactor module and the capacitive reactance of the compensation capacitor module in the circuit equal. This quickly achieves the resonance condition, shortens the test time, and improves the working efficiency of the device. Selecting different test frequencies according to different devices under test can optimize the voltage distribution of the device under test and avoid damage to the equipment and test personnel caused by localized excessive voltage. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the adaptive parallel compensation pressure-resistant device provided by this utility model.

[0021] Figure 2 This is a schematic diagram of the acquisition module circuit of the adaptive parallel compensation withstand voltage device provided by this utility model.

[0022] Figure 3 This is a schematic diagram of an embodiment of the adaptive parallel compensation withstand voltage device provided by this utility model.

[0023] In the diagram: 100—Power control unit, 101—Main controller, 102—Variable frequency power supply, T1—Autotransformer, 103—Boost unit, 104—Compensation unit, 105—Adaptive adjustment unit, 106—Reactor adjustment module, 107—Capacitor adjustment module, U1—First comparator, CT1—First current transformer, U2—Second comparator, CT2—Second current transformer. Detailed Implementation

[0024] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, it should be understood that the scope of protection of this utility model is not limited to the specific embodiments.

[0025] refer to Figure 1 and Figure 3 An adaptive parallel compensation withstand voltage device includes a power control unit 100, a compensation unit 104, an adaptive adjustment unit 105, and a boost unit 103. The power control unit 100 and the boost unit 103 are movably connected via connecting lines. The adaptive adjustment unit 105 is connected to both the power control unit 100 and the compensation unit 104. The compensation unit 104 and the boost unit 103 are movably connected via connecting lines. The boost unit 103 is a boost transformer T2. Specifically, the power control unit 100 includes a main controller 101, a frequency converter 102, and an autotransformer T1. The main controller 101 is connected to the frequency converter 102, the frequency converter 102 is connected to the autotransformer T1, and the autotransformer T1 is connected to the step-up transformer T2. The main controller 101 controls the output voltage and current of the frequency converter 102, which is boosted for the first time by the autotransformer T1 and then boosted for the second time by the step-up transformer T2. In this embodiment, the main controller 101 can be an ARM chip of the STM32F407 series.

[0026] refer to Figure 3 The compensation unit 104 includes a compensation capacitor module and a compensation reactor module. The compensation reactor module is composed of two or more compensation reactors L1 stacked together, and the compensation capacitor module consists of multiple compensation capacitors C1, C2...C1 ... n The compensation reactor module is composed of series or parallel connections. The total inductance of the compensation reactor module is adjusted by adjusting the air gap of the compensation reactor L1, and the compensation capacitance of the compensation capacitor module is adjusted by connecting the compensation capacitors in series and parallel.

[0027] refer to Figure 2 and Figure 3The adaptive adjustment unit 105 includes a data acquisition module, a capacitor adjustment module 107, and a reactor adjustment module 106. The compensation capacitor module 107 and the compensation reactor module 106 are respectively connected to one input terminal of the data acquisition module, and the main controller 101 is connected to one output terminal of the data acquisition module to realize the control of the reactive current I flowing through the compensation reactor L1 in the compensation reactor module 106. L and the capacitive current at node 107 of the compensation capacitor module The collection, among which The acquisition module includes a DAC module, a first comparator U1, a first current transformer CT1, a second comparator U2, and a second current transformer CT2. The primary side of the first current transformer CT1 is connected to the compensation capacitor module 107, and the secondary side is connected to one input terminal of the first comparator U1. The primary side of the second current transformer CT2 is connected to the compensation reactor module 106, and the secondary side is connected to one input terminal of the second comparator U2. The output terminal of the DAC module is connected to one input terminal of the first comparator U1 and the second comparator U2, respectively.

[0028] The capacitor adjustment module 107 consists of multiple high-voltage switch modules. When high-voltage switches K1 and K2 are closed and high-voltage switch K3 is open, compensation capacitors c1 and c2 are connected in parallel. When high-voltage switches K1 and K2 are open and high-voltage switch K3 is closed, compensation capacitors c1 and c2 are connected in series. The reactor adjustment module 106 consists of a motor adjustment device used to adjust the air gap of the compensation reactor L1. The principle of the reactor adjustment module 106 in adjusting the air gap of the compensation reactor L1 is the same as that in the patent document with application number "CN201510429568X" for a rotary adjustable parameter power grid series reactor, and will not be repeated here. The main controller 101 is connected to both the capacitor adjustment module 107 and the reactor adjustment module 106 to control the adjustment signals of the capacitor adjustment module 107 and the reactor adjustment module 106, thereby adjusting the compensation capacitance of the compensation capacitor module 107 and the compensation inductance of the compensation reactor module 106.

[0029] Continue to refer to Figure 3 The adaptive parallel compensation withstand voltage device provided by this utility model can perform power frequency or heterogeneous frequency withstand voltage tests. Taking the power frequency withstand voltage test of a power cable as an example, during the test, the capacitance value of the power cable is first calculated based on the nameplate data of the power cable. Then, the test frequency of 50Hz and the test voltage and capacitance value of the power cable are input into the device. The main controller 101 then adjusts the test frequency according to the user input. and the capacitance value of power cables And calculate the capacitive current of the power cable branch. Then the main controller 101 determines the current... Calculate the inductance of the compensation reactor module 106. After obtaining the inductance of the compensation reactor module 106, the main controller 101 drives the reactor adjustment module 106 to adjust the inductance value of the compensation reactor module, making the actual inductance L1 close to the calculated inductance L. Simultaneously, the main controller 101 drives the capacitor adjustment module 107 to adjust the capacitance value C1 of the compensation capacitor module. .

[0030] After initially determining the inductance L1 of the compensation reactor module and the capacitance C1 of the compensation capacitor module, the main controller 101 outputs a control signal to the DAC module of the adaptive adjustment unit 105, driving the DAC module to output an analog voltage U. c One input terminal of the second comparator U2 is used as the capacitor reference voltage, where When the capacitive current in the capacitor circuit formed by the compensation capacitor module and the power cable under test... When the signal is strong, the second comparator U2 outputs 0; otherwise, it outputs 1. Simultaneously, the DAC module outputs an analog voltage U. L One input of the first comparator U1 is used as the reactance reference voltage, where When the inductor current in the compensation reactor module circuit The second comparator U2 outputs 0, and vice versa. Based on the conditions for parallel resonance, the capacitive current in the capacitor circuit formed by the compensation capacitor module and the power cable under test is... With the inductor current in the compensation reactor module circuit The main controller 101 detects the outputs of the second comparator U2 and the first comparator U1 to determine whether the inductance of the compensation reactor module and the capacitance of the compensation capacitor module can make the circuit resonate at the set frequency. This enables rapid, automatic, and closed-loop adjustment of the capacitance of the compensation capacitor module and the inductance of the compensation reactor module, allowing the test device to resonate at the user-set frequency. This improves test efficiency and avoids the problem of electric shock accidents caused by manual adjustment.

[0031] On the other hand, when performing the differential frequency withstand voltage test, the operation process of this invention is the same as that of the power frequency test. The difference lies in the output voltage frequency of the frequency converter 102, which is 30-300Hz. According to industry research and the inventor's experience, in AC insulation withstand voltage tests, the voltage distribution of the tested equipment at frequencies of 30-300Hz is highly similar to that at the power frequency. Furthermore, according to relevant test regulations, unless specifically required to use the power frequency withstand voltage test, a frequency of 30Hz to 300Hz can be used for the withstand voltage test, based on one of the conditions for parallel resonance: ,in To compensate for the reactance value of the reactor module, To compensate for the total capacitance of the capacitor module and the device under test, according to , It can be seen that the main controller 101, by controlling the output frequency of the frequency converter 102, can achieve the desired output frequency without changing the inductance of the compensation reactor module and the capacitance of the compensation capacitor module. This reduces the adjustment required for the compensation reactor and capacitor modules, enabling rapid resonance, shortening test time, and improving the device's efficiency. Furthermore, selecting different test frequencies based on the specific equipment under test optimizes the voltage distribution during testing, preventing damage to equipment and personnel from localized overvoltages.

[0032] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An adaptive parallel compensation withstand voltage device, comprising a power control unit, a compensation unit, and a boost unit, characterized in that: It also includes an adaptive adjustment unit; The power control unit is movably connected to the boost unit via a connecting line, and the boost unit is movably connected to the compensation unit via a connecting line. The compensation unit is used to compensate for the inductance and capacitance of the device under test. The adaptive adjustment unit is connected to both the power control unit and the compensation unit, and is used to adjust the inductance and capacitance of the compensation unit.

2. The adaptive parallel compensation withstand voltage device according to claim 1, characterized in that, The compensation unit includes a compensation capacitor module and a compensation reactor module. The compensation capacitor module mainly consists of compensation capacitors, and the compensation reactor module mainly consists of compensation reactors.

3. The adaptive parallel compensation withstand voltage device according to claim 2, characterized in that, The adaptive adjustment unit includes a data acquisition module, a capacitor adjustment module, and a reactor adjustment module. The compensation capacitor module and the compensation reactor module are each connected to one input terminal of the data acquisition module. The output terminal of the data acquisition module is connected to the main controller of the power control unit. The capacitor adjustment module and the reactor adjustment module are each connected to the main controller. The capacitor adjustment module is connected to the compensation capacitor module, and the reactor adjustment module is connected to the compensation reactor module.

4. The adaptive parallel compensation withstand voltage device according to claim 3, characterized in that, The acquisition module includes a DAC module, a first comparator, a first current transformer, a second comparator, and a second current transformer. The primary side of the first current transformer is connected to the compensation capacitor module, and the secondary side is connected to one input terminal of the first comparator. The primary side of the second current transformer is connected to the compensation reactor module, and the secondary side is connected to one input terminal of the second comparator. The output terminal of the DAC module is connected to one input terminal of both the first and second comparators.

5. The adaptive parallel compensation withstand voltage device according to claim 3, characterized in that, The capacitor adjustment module consists of multiple high-voltage switch modules, which are connected to the compensation capacitor to realize the series or parallel connection of the compensation capacitor. The reactor adjustment module consists of a motor adjustment device to adjust the air gap of the compensation reactor.

6. The adaptive parallel compensation withstand voltage device according to claim 3, characterized in that, The power control unit includes an autotransformer and a frequency converter. The autotransformer is connected to the frequency converter, and the frequency converter is connected to the main controller.

7. The adaptive parallel compensation withstand voltage device according to claim 6, characterized in that, The frequency of the voltage output by the variable frequency power supply is 30-300Hz.

8. The adaptive parallel compensation withstand voltage device according to claim 1, characterized in that, The step-up unit is a step-up transformer.

9. The adaptive parallel compensation withstand voltage device according to claim 3, characterized in that, The compensation reactor module is composed of two or more compensation reactors stacked together, and the total inductance of the compensation reactor module can be changed by adjusting the air gap of the compensation reactor through the reactor adjustment module.

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