A high-voltage power grid disturbance simulation device

Abstract

The utility model relates to the test technical field of grid -connected equipment, concretely relates to a high -voltage power grid disturbance simulation device, contain first container and second container, be provided with multi -winding transformer and power grid simulation power conversion unit in first container, be provided with switch unit, isolation transformer and filter unit in second container, the input of switch unit is linked with high -voltage power grid, and the output of switch unit is linked with the primary winding of multi -winding transformer, and the secondary winding of multi -winding transformer is linked with the input of power grid simulation power conversion unit, and the output of power grid simulation power conversion unit is linked with the primary winding of isolation transformer, and the secondary winding of isolation transformer is linked with the input of filter unit, and the output of filter unit is linked with the equipment of being measured. The utility model can flexibly adjust output voltage, let high -voltage power grid disturbance simulation device can cover more extensive voltage test range, simulate high -voltage power grid voltage temporary rise, temporary drop and so on disturbance scene.

Description

Technical Field

[0001] This utility model relates to the field of grid-connected equipment testing technology, and more specifically, to a high-voltage power grid disturbance simulation device. Background Technology

[0002] With the continuous development of new energy sources, regions rich in wind and solar resources are seeing increasingly larger installed capacities for photovoltaic and wind power generation, and higher voltage levels at grid connection points. However, the stability and robustness of some basic power infrastructure, such as high-voltage power grids, remain relatively insufficient, resulting in poor power quality and frequent abnormal disturbances such as voltage dips, voltage flicker, frequency fluctuations, and high levels of low-order harmonics.

[0003] Although grid-connected converters for photovoltaic and wind power generation equipment have a certain degree of grid adaptability, when abnormal disturbances to the grid exceed the adaptability range of the grid-connected converter, the photovoltaic inverter or wind turbine will trigger its own protection mechanism, causing the power generation equipment to disconnect from the grid and stop generating electricity, resulting in a waste of power resources and idle power generation equipment.

[0004] In the prior art, grid disturbance simulation devices can be used to test the adaptability of grid-connected converters to grid disturbances, providing a reference for improving the grid disturbance adaptability of grid-connected converters. However, the grid disturbance simulation devices in the prior art are all low-voltage simulation devices with single-phase 220V or three-phase 380V. Therefore, with the continuous increase of the voltage level of the grid connection point, the low-voltage grid disturbance simulation devices in the prior art can no longer meet the disturbance simulation requirements of high-voltage grids.

[0005] Therefore, providing a high-voltage power grid disturbance simulation device to solve the problem that existing technologies cannot simulate disturbances in high-voltage power grids has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] The purpose of this invention is to provide a high-voltage power grid disturbance simulation device to solve the technical problem of how to simulate disturbances in a high-voltage power grid.

[0007] This utility model is achieved through the following technical solution: a high-voltage power grid disturbance simulation device, which adopts a container structure and includes a first container and a second container. The first container is equipped with a multi-winding transformer and a power grid simulation power conversion unit, and the second container is equipped with a switching unit, an isolation transformer and a filtering unit. The input terminal of the switching unit is connected to the high-voltage power grid, the output terminal of the switching unit is connected to the primary winding of the multi-winding transformer, the secondary winding of the multi-winding transformer is connected to the input terminal of the power grid simulation power conversion unit, the output terminal of the power grid simulation power conversion unit is connected to the primary winding of the isolation transformer, the secondary winding of the isolation transformer is connected to the input terminal of the filtering unit, and the output terminal of the filtering unit is connected to the device under test.

[0008] According to a preferred embodiment, the secondary winding of the multi-winding transformer is provided with multiple taps.

[0009] According to a preferred embodiment, the switching unit includes a disconnecting switch, a circuit breaker, and a first current transformer. The input terminal of the disconnecting switch is connected to a high-voltage power grid, the output terminal of the disconnecting switch is connected to the input terminal of the circuit breaker, the output terminal of the circuit breaker is connected to the primary winding of a multi-tap transformer, and the primary side of the first current transformer is connected in series between the circuit breaker and the multi-tap transformer.

[0010] According to a preferred embodiment, the power grid analog power conversion unit includes multiple power modules.

[0011] According to a preferred embodiment, the power module is a fundamental frequency power module.

[0012] According to a preferred embodiment, the device further includes a second current transformer and a third current transformer. The primary side of the second current transformer is connected in series between the power grid analog power conversion unit and the isolation transformer, and the primary side of the third current transformer is connected in series between the filter unit and the device under test.

[0013] According to a preferred embodiment, the filtering unit includes a filtering capacitor and a first voltage transformer. The filtering capacitor is connected in parallel to the output side of the secondary winding of the isolation transformer, and the primary side of the first voltage transformer is connected in parallel to the output side of the filtering capacitor.

[0014] According to a preferred embodiment, the second container is further provided with an auxiliary power transformer and a second voltage transformer. The primary winding of the auxiliary power transformer is connected to the high-voltage power grid. The primary side of the second voltage transformer is connected in parallel to the input side of the primary winding of the auxiliary power transformer. The secondary winding of the auxiliary power transformer is connected to the auxiliary power main circuit. The auxiliary power main circuit is connected to the first main power switch inside the second container.

[0015] According to a preferred embodiment, the system further includes a second main power switch, which is connected in parallel to the input side of the first main power switch, and the output terminal of the second main power switch is connected to the distribution box inside the first container and the second container.

[0016] According to a preferred embodiment, the electrical distribution box inside the first container is equipped with a soft start power switch, a soft start contactor, and a resistor. The input terminal of the soft start power switch is connected to the output terminal of the second main power switch, the output terminal of the soft start power switch is connected to the input terminal of the soft start contactor, the output terminal of the soft start contactor is connected to the input terminal of the resistor, and the output terminal of the resistor is connected to the auxiliary power input terminal of the multi-winding transformer.

[0017] The technical solution of the high-voltage power grid disturbance simulation device provided by this utility model has at least the following advantages and beneficial effects: (1) Through multiple taps of the secondary winding of the multi-winding transformer, the output voltage can be flexibly adjusted, so that the high-voltage power grid disturbance simulation device can cover a wider voltage test range and simulate disturbance scenarios such as voltage rise and fall in the high-voltage power grid; (2) The power grid simulation power conversion unit contains multiple fundamental power modules. Combined with the isolation transformer and the filter unit, it can simulate power grid disturbances such as voltage deviation, frequency deviation, three-phase voltage imbalance, voltage fluctuation and flicker, and harmonics, and provide a disturbance test environment related to fundamental power quality for the device under test; (3) By controlling the tap connection of the multi-winding transformer and the working state of the power module, the output voltage and frequency can be independently adjusted to meet the needs of different test scenarios; (4) The power module performs power electronic conversion based on the fundamental frequency. With the real-time monitoring and feedback of the current and voltage transformers, it can realize rapid dynamic adjustment and precise control of the disturbance output. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall wiring of the high-voltage power grid disturbance simulation device provided in Embodiment 1 of this utility model; Figure 2 A schematic diagram of the main circuit structure of the high-voltage power grid disturbance simulation device provided in Embodiment 1 of this utility model; Figure 3 This is a schematic diagram of the structure of the power grid simulation power conversion unit provided in Embodiment 1 of this utility model; Reference numerals: 100-First container, 110-Multi-winding transformer, 120-Grid simulation power conversion unit, 200-Second container, 210-Switching unit, 220-Isolation transformer, 230-Filtering unit. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Example 1 This embodiment provides a high-voltage power grid disturbance simulation device. Figure 1 This is a schematic diagram of the overall wiring of the high-voltage power grid disturbance simulation device. (See attached diagram) Figure 1 As shown, the high-voltage power grid disturbance simulation device includes a first container 100 and a second container 200. The first container 100 is equipped with a multi-winding transformer 110 and a power grid simulation power conversion unit 120. The second container 200 is equipped with a switching unit 210, an isolation transformer 220 and a filtering unit 230.

[0021] The input terminal of the switching unit 210 is connected to the high-voltage power grid, providing AC input for the entire device. The output terminal of the switching unit 210 is connected to the primary winding of the multi-winding transformer 110, receiving 35kV AC input from the switching unit 210. The secondary winding of the multi-winding transformer 110 is connected to the input terminal of the power grid simulation power conversion unit 120, providing AC input voltage for the power grid simulation power conversion unit 120. The output terminal of the power grid simulation power conversion unit 120 is connected to the primary winding of the isolation transformer 220, achieving electrical isolation between the power grid simulation power conversion unit 120 and the device under test through the isolation transformer 220, preventing mutual interference. The secondary winding of the isolation transformer 220 is connected to the input terminal of the filter unit 230 to filter the voltage, further improving the voltage waveform and making it closer to the ideal grid voltage, thereby improving the output voltage quality to meet the requirements of simulating high-voltage grid disturbances. The output terminal of the filter unit 230 is connected to the device under test, outputting a voltage value that meets the requirements of the device under test. It can simulate various grid disturbances, such as voltage deviation, frequency deviation, three-phase voltage imbalance, voltage fluctuation and flicker, harmonics, etc., to test the adaptability and stability of the device under test under different grid conditions and determine whether it meets the relevant standards and requirements.

[0022] The secondary winding of the multi-winding transformer 110 has multiple taps, which allow for flexible adjustment of the output voltage value by changing the tap connections. This adapts to different voltage requirements of the device under test and simulates various high-voltage power grid voltage disturbance scenarios, such as voltage swell and droop. This enables the high-voltage power grid disturbance simulation device to cover a wider voltage testing range, improves the comprehensiveness of testing the device under test under different voltage disturbances, enhances the device's ability to simulate complex power grid conditions, and makes the test results more consistent with actual power grid disturbances, thus helping to accurately verify the power grid adaptability of the device under test.

[0023] See Figure 2As shown, the switch unit 210, i.e., the input switch cabinet in the figure, includes a 35kV circuit breaker, as well as a disconnecting switch and a first current transformer. The input terminal of the disconnecting switch is connected to the high-voltage power grid, and the output terminal of the disconnecting switch is connected to the input terminal of the circuit breaker to achieve electrical isolation between the high-voltage power grid and the device, ensuring the safety of personnel and equipment during equipment maintenance and commissioning. The output terminal of the circuit breaker is connected to the primary winding of the multi-tap transformer, allowing the circuit breaker to quickly open and close. When it is necessary to simulate power grid disturbances, the circuit can be precisely controlled to connect and disconnect. The primary side of the first current transformer is connected in series between the circuit breaker and the multi-tap transformer to detect the current signal of this section of the circuit and provide current feedback. This current feedback can be used to monitor the circuit operating status, determine overcurrent protection, etc., and assist the device in accurately simulating power grid disturbance conditions. For example, it can be combined with the current feedback to determine whether a power grid disturbance simulation scenario caused by overcurrent is triggered.

[0024] See Figure 3 As shown, the power grid simulation power conversion unit 120 includes multiple power modules. The design of multiple power modules can be flexibly combined and expanded to increase the overall power conversion capability. This not only improves the power regulation flexibility and scalability of the device, but also ensures that the failure of a single module does not affect the operation of other modules. It also enhances the reliability and redundancy of the device, and can allocate power as needed to meet the simulation requirements of high-voltage power grids of different capacities and types. It can accurately output simulated power grid power of different power levels, allowing the device under test to undergo testing that is more in line with actual working conditions, and improving the accuracy and comprehensiveness of high-voltage power grid disturbance simulation.

[0025] The power module is a fundamental frequency power module, which focuses on the power conversion of the fundamental frequency of the power grid, reduces interference from non-fundamental components, accurately simulates the power changes of the fundamental components of the high-voltage power grid, and is used to construct disturbance scenarios of the fundamental voltage and current of the power grid, such as the amplitude, phase, and frequency disturbance simulation of the fundamental voltage, providing a disturbance test environment related to fundamental power quality for the device under test.

[0026] The device also includes a second current transformer and a third current transformer. The primary side of the second current transformer is connected in series between the power grid simulation power conversion unit 120 and the isolation transformer 220 to monitor the current between them, providing current data for operational status analysis and power control of this circuit segment. The primary side of the third current transformer is connected in series between the filter unit 230 and the device under test (DUT) to monitor the current between them, obtaining the current flowing into the DUT, which can be used to evaluate the current characteristics of the DUT during operation. By collecting current data through the second and third current transformers, the output of the power grid simulation power conversion unit 120 can be adjusted based on the current data feedback, making the simulated high-voltage power grid disturbances more closely match actual needs.

[0027] The filtering unit 230 includes a filtering capacitor and a first voltage transformer. The filtering capacitor is connected in parallel to the output side of the secondary winding of the isolation transformer 220 to filter out harmonic components in the output voltage of the isolation transformer 220, improve the voltage waveform, and make the output voltage closer to an ideal sine wave. In some preferred embodiments of this example, the filtering capacitor is a star-connected parallel compensation capacitor, which can form a low-impedance path for harmonics of specific frequencies, allowing more harmonic current to flow into the capacitor. The primary side of the first voltage transformer is connected in parallel to the output side of the filtering capacitor to monitor the voltage value at the output side of the filtering capacitor and provide voltage feedback information for determining whether the filtering unit 230 is working properly and whether the output voltage meets the requirements.

[0028] The second container 200 is also equipped with an auxiliary power transformer and a second voltage transformer. The primary winding of the auxiliary power transformer is connected to the high-voltage power grid through a fuse, receiving a 35kV AC input from the high-voltage power grid to provide the auxiliary power required for the operation of the device, such as providing a 400V auxiliary power output. The primary side of the second voltage transformer is connected in parallel to the input side of the primary winding of the auxiliary power transformer to monitor the input voltage of the auxiliary power transformer. The secondary winding of the auxiliary power transformer is connected to the main auxiliary power circuit, which is connected to the first main power switch inside the second container 200. The auxiliary power output can be turned on or off through the first main power switch.

[0029] Furthermore, it also includes a second main power switch, which is connected in parallel to the input side of the first main power switch, and the output terminal of the second main power switch is connected to the power distribution box inside the first container 100 and the second container 200. In this embodiment, the power distribution box inside the first container 100 is equipped with a soft start power switch, a soft start contactor, and a resistor. The input terminal of the soft start power switch is connected to the output terminal of the second main power switch, the output terminal of the soft start power switch is connected to the input terminal of the soft start contactor, the output terminal of the soft start contactor is connected to the input terminal of the resistor, and the output terminal of the resistor is connected to the auxiliary power input terminal of the multi-winding transformer 110. The cooperation of the soft start power switch, the soft start contactor, and the resistor can perform soft start control on the auxiliary power input terminal of the multi-winding transformer 110. After the soft start power switch is turned on, the inrush current during startup is reduced by current limiting through the resistor. The subsequent action of the soft start contactor short-circuits the resistor, allowing the multi-winding transformer 110 to smoothly enter the normal operating state, thereby effectively suppressing the surge current during the auxiliary power startup of the multi-winding transformer 110, avoiding the impact damage of large current on the multi-winding transformer 110, power supply lines, and related equipment, and extending the equipment life.

[0030] In summary, the device provided in this embodiment can flexibly adjust the output voltage through multiple taps of the secondary winding of the multi-winding transformer 110, allowing the high-voltage grid disturbance simulation device to cover a wider voltage testing range and simulate disturbance scenarios such as voltage swells and drops in the high-voltage grid. The grid simulation power conversion unit 120 includes multiple fundamental power modules, which, combined with the isolation transformer 220 and the filter unit 230, can simulate grid disturbances such as voltage deviation, frequency deviation, three-phase voltage imbalance, voltage fluctuations, flicker, and harmonics, providing a fundamental power quality-related disturbance testing environment for the device under test. By controlling the tap connections of the multi-winding transformer 110 and the operating status of the power modules, independent adjustment of the output voltage and frequency can be achieved to meet the needs of different testing scenarios. The power modules perform power electronic conversion based on the fundamental frequency, and with the real-time monitoring and feedback of the current and voltage transformers, rapid dynamic adjustment and precise control of the disturbance output can be achieved.

[0031] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-voltage power grid disturbance simulation device, adopting a container structure, characterized in that, It includes a first container (100) and a second container (200). The first container (100) is equipped with a multi-winding transformer (110) and a power grid analog power conversion unit (120). The second container (200) is equipped with a switching unit (210), an isolation transformer (220) and a filtering unit (230). The input terminal of the switching unit (210) is connected to the high-voltage power grid, the output terminal of the switching unit (210) is connected to the primary winding of the multi-winding transformer (110), the secondary winding of the multi-winding transformer (110) is connected to the input terminal of the power grid analog power conversion unit (120), the output terminal of the power grid analog power conversion unit (120) is connected to the primary winding of the isolation transformer (220), the secondary winding of the isolation transformer (220) is connected to the input terminal of the filter unit (230), and the output terminal of the filter unit (230) is connected to the device under test. The secondary winding of the multi-winding transformer (110) has multiple taps.

2. The high-voltage power grid disturbance simulation device as described in claim 1, characterized in that, The switching unit (210) includes a disconnecting switch, a circuit breaker and a first current transformer. The input terminal of the disconnecting switch is connected to the high-voltage power grid, the output terminal of the disconnecting switch is connected to the input terminal of the circuit breaker, the output terminal of the circuit breaker is connected to the primary winding of the multi-tap transformer, and the primary side of the first current transformer is connected in series between the circuit breaker and the multi-tap transformer.

3. The high-voltage power grid disturbance simulation device as described in claim 1, characterized in that, The power grid simulation power conversion unit (120) contains multiple power modules.

4. The high-voltage power grid disturbance simulation device as described in claim 3, characterized in that, The power module is a fundamental frequency power module.

5. The high-voltage power grid disturbance simulation device as described in claim 1, characterized in that, It also includes a second current transformer and a third current transformer. The primary side of the second current transformer is connected in series between the grid analog power conversion unit (120) and the isolation transformer (220), and the primary side of the third current transformer is connected in series between the filter unit (230) and the device under test.

6. The high-voltage power grid disturbance simulation device as described in claim 1, characterized in that, The filtering unit (230) includes a filtering capacitor and a first voltage transformer. The filtering capacitor is connected in parallel to the output side of the secondary winding of the isolation transformer (220), and the primary side of the first voltage transformer is connected in parallel to the output side of the filtering capacitor.

7. The high-voltage power grid disturbance simulation device as described in claim 1, characterized in that, The second container (200) is also equipped with an auxiliary power transformer and a second voltage transformer. The primary winding of the auxiliary power transformer is connected to the high-voltage power grid. The primary side of the second voltage transformer is connected in parallel to the input side of the primary winding of the auxiliary power transformer. The secondary winding of the auxiliary power transformer is connected to the auxiliary power main circuit. The auxiliary power main circuit is connected to the first main power switch inside the second container (200).

8. The high-voltage power grid disturbance simulation device as described in claim 7, characterized in that, It also includes a second main power switch, which is connected in parallel to the input side of the first main power switch, and the output end of the second main power switch is connected to the distribution box inside the first container (100) and the second container (200).

9. The high-voltage power grid disturbance simulation device as described in claim 8, characterized in that, The electrical distribution box inside the first container (100) is equipped with a soft start power switch, a soft start contactor, and a resistor. The input terminal of the soft start power switch is connected to the output terminal of the second main power switch. The output terminal of the soft start power switch is connected to the input terminal of the soft start contactor. The output terminal of the soft start contactor is connected to the input terminal of the resistor. The output terminal of the resistor is connected to the auxiliary power input terminal of the multi-winding transformer (110).

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