Energy-saving device for switching test detection of distribution transformer on-load tap-changer

Abstract

The utility model discloses an energy-saving device for switching test detection of an on-load tap-changer of a distribution transformer. The energy-saving device comprises a 10kV power supply; according to the utility model, the 10kV power supply, the customized test transformer, the adjustable load and the current control device are arranged, so that high price and high economical efficiency of the on-load tap-changer switching test detection for the distribution transformer are realized, the high-voltage part of the customized test transformer is a conventional 10kV winding, and the low-voltage part of the customized test transformer respectively leads out 250V, 500V, 750V and 1000V voltage taps, so that the test efficiency is improved. The requirements of the types of existing tap switch products can be met; the adjustable load can be adjusted according to test parameter requirements; the current control device can instantly control power-on and power-off of the load before and after the tap switches are switched, the power-on time of the load is effectively shortened, the purpose of saving energy is achieved, in addition, the PLC can conduct programming according to the tap switches of different models, automatic control is achieved, and the test efficiency and precision are further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power electronics, and in particular relates to an energy-saving device for switching test and detection of on-load tap changers of distribution transformers. Background Art

[0002] In recent years, with the rapid development of China's smart grid, the off-circuit tap-changers used in distribution transformers have been gradually replaced by on-load tap-changers. On-load tap-changers offer advantages such as low current, small size, compact structure, intelligence, and maintenance-free operation. However, their quality and stability directly impact the safe operation of distribution transformers and the quality of power supply, necessitating rigorous switching testing and inspection.

[0003] The existing on-load tap-changer switching test detection methods for distribution transformers are mainly divided into transformer method, resistance method, compensation method and resonance method. Among them, the transformer method completely simulates the actual use of the tap-changer, so it has the best equivalence. However, since it is in a long-term energized state, the current is generally 50A and the voltage is about 500V. If the test is 300,000 times, the line loss will be high and the test cost will be too high. The resistance method uses a principle similar to the transformer method, using resistance to replace the coil part of the transformer. It is second only to the transformer method in equivalence, but it is also in a long-term energized state, and the test cost is too high. The compensation method uses a three-phase power supply for direct power supply, and ab and ac are matched with suitable capacitors to make the line reach a balance. The state method places the tap changer in a simulated environment. Although the step voltage test current at both ends of the tap changer can be matched to the required test parameters as much as possible, the external environment it is subjected to is completely different. This cannot fully simulate the actual use scenario of the tap changer, resulting in poor equivalence. However, its circuit is in a balanced state, and a reactor is used as the load, so its economy is better. The resonance method uses LC resonance to simulate the actual use of the tap changer. When the tap changer current is small, it is difficult to achieve the required balanced state for the entire test circuit through LC resonance, resulting in poor equivalence. These methods cannot simultaneously meet the requirements of test equivalence and economy. Utility Model Content

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide an energy-saving device for on-load tap changer switching test detection of distribution transformers, so as to solve the problem that the transformer method, resistance method, compensation method and resonance method in the existing on-load tap changer switching test detection methods for distribution transformers proposed in the above background technology cannot simultaneously meet the requirements of test equivalence and economy.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an energy-saving device for testing and detecting on-load tap changers of distribution transformers, comprising:

[0006] 10kV power supply;

[0007] The test transformer has a conventional 10kV high-voltage winding and low-voltage taps of 250V, 500V, 750V, and 1000V.

[0008] Load, which can be an adjustable reactor or an adjustable resistor;

[0009] A current control device comprising:

[0010] Solid-state relay, connected between the low-voltage side of the test transformer and the load;

[0011] PLC, connected between the controller and the solid-state relay;

[0012] Controller, connected between the tap changer controller and PLC;

[0013] The current control device can control the power on and off of the load instantly before and after the tap changer is switched, effectively reducing the load power on time, thereby achieving the purpose of energy saving.

[0014] Preferably, the current control device is used to control the power on and off of the load immediately before and after the tap changer is switched.

[0015] Preferably, the load is an adjustable reactor or an adjustable resistor.

[0016] Preferably, the PLC performs logical judgment based on the passive signal of the tap changer controller and the external passive switch signal to control the switching state of the solid-state relay.

[0017] Preferably, the PLC can be programmed according to different models of tap changers to achieve the setting and adjustment of different test parameters.

[0018] Preferably, the controller is used to collect the passive signal of the tap changer controller and the external passive switch signal, and send them to the PLC.

[0019] Preferably, the current control device further includes: a power supply module for providing power to the PLC and the solid-state relay.

[0020] Preferably, the power supply module includes: a transformer, a rectifier bridge and a filter capacitor.

[0021] Compared with the prior art, the present invention provides an energy-saving device for testing and detecting on-load tap changers of distribution transformers, which has the following beneficial effects:

[0022] 1. The utility model realizes high equivalence and high economy of on-load tap-changer switching test detection for distribution transformers by providing a 10kV power supply, a customized test transformer, an adjustable load and a current control device. The high-voltage part of the customized test transformer is a conventional 10kV winding, and the low-voltage part leads to 250V, 500V, 750V and 1000V voltage taps respectively, which can meet the requirements of existing tap-changer product categories; the adjustable load can be adjusted according to the test parameter requirements; the current control device can control the power on and off of the load instantly before and after the tap-changer is switched, effectively reducing the load power-on time, thereby achieving the purpose of energy saving. In addition, the PLC can be programmed according to different models of tap-changers to realize automatic control, further improving the test efficiency and accuracy, and effectively avoiding the problem that the transformer method, resistance method, compensation method and resonance method in the existing on-load tap-changer switching test detection methods for distribution transformers cannot simultaneously meet the requirements of test equivalence and economy;

[0023] 2. By setting up a PLC and a solid-state relay, the utility model realizes the automation and intelligence of the on-load tap-changer switching test detection for the distribution transformer. The PLC can make logical judgments based on the passive signals of the tap-changer controller and the external passive switch signals to control the switching state of the solid-state relay, thereby realizing instantaneous power on and off of the load before and after the tap-changer is switched. This automated control method can avoid human operation errors and improve the accuracy and reliability of the test. In addition, the PLC can be programmed according to different models of tap-changers to realize the setting and adjustment of different test parameters, further improving the flexibility and applicability of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 This is the PLC logic diagram proposed by the utility model;

[0026] Figure 2 This is the connection circuit diagram of the PLC and solid-state relay proposed in this utility model;

[0027] Figure 3 This is the traditional transformer method test circuit diagram proposed by the utility model;

[0028] Figure 4 This is the traditional resistance method test circuit diagram proposed by the utility model;

[0029] Figure 5 This is the traditional compensation method test circuit diagram proposed by the utility model;

[0030] Figure 6 This is the traditional resonance method test circuit diagram proposed by the utility model;

[0031] Figure 7 This is the energy-saving circuit diagram for the on-load tap-changer switching test of the distribution transformer proposed in the utility model;

[0032] In the figure: T, test transformer; C, compensation capacitor; L, adjustable reactor; W, Z, main on-off contacts; X, Y, transition contacts; R, transition resistor; S1, passive signal of tap changer controller;

[0033] S2, external passive switch; the relationship between I1, I2 and S1, S2 is: I1, I2 are PLC logical representations, S1, S2 are physical components; Solid-state relay. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] See also Figure 1-7 The utility model provides a technical solution: an energy-saving device for testing and detecting the on-load tap changer switching of a distribution transformer, comprising:

[0036] 10kV power supply provides stable high voltage power input for the entire test device.

[0037] The high-voltage part of the test transformer is a conventional 10kV winding, which is used to step down the 10kV power supply to a voltage range suitable for tap-changer testing. The low-voltage part leads to 250V, 500V, 750V, and 1000V voltage taps, which can meet the testing requirements of different types of tap-changers and provide flexible voltage selection.

[0038] The load, which can be an adjustable reactor or an adjustable resistor, is used to simulate the load conditions of the distribution transformer in actual operation and is adjusted according to the test parameter requirements, such as short-circuit impedance, load power, etc., to realize switching tests under different operating conditions of the tap changer.

[0039] A current control device comprising:

[0040] The solid-state relay is connected between the low-voltage side of the test transformer and the load, and is responsible for controlling the power on and off of the load to achieve fast and reliable switching control.

[0041] The PLC is connected between the controller and the solid-state relay. It is responsible for receiving controller signals and controlling the switching state of the solid-state relay according to the preset program to achieve precise control of the tap changer switching process.

[0042] The controller is connected between the tap changer controller and the PLC. It is responsible for collecting the passive signals of the tap changer controller and the external passive switch signals, and sending them to the PLC to achieve real-time monitoring and control of the tap changer switching status.

[0043] The power module provides stable power input for the PLC and solid-state relay to ensure the normal operation of the current control device.

[0044] In the present invention, preferably, the current control device is used to control the power on and off of the load instantly before and after the tap changer is switched, effectively reducing the load power on time, thereby achieving the purpose of energy saving.

[0045] In the present invention, preferably, the load is an adjustable reactor or an adjustable resistor. The adjustable reactor can simulate the inductive load of the distribution transformer, and the adjustable resistor can simulate the resistive load of the distribution transformer. The combination of the two loads can more realistically simulate the load conditions of the distribution transformer in actual operation.

[0046] In the present invention, preferably, the PLC performs logical judgment based on the passive signal of the tap changer controller and the external passive switch signal to control the switching state of the solid-state relay. The passive signal of the tap changer controller can reflect the switching state of the tap changer, and the external passive switch signal can be used to manually control the switching of the tap changer. The PLC performs logical judgment based on these signals to achieve precise control of the solid-state relay and ensure the smooth operation of the tap changer switching process.

[0047] In the present invention, preferably, the PLC can be programmed according to different models of tap changers to achieve the setting and adjustment of different test parameters. By programming the PLC, different test parameters can be set, such as the number of switching times, switching time intervals, load parameters, etc., to meet the test requirements of different models of tap changers.

[0048] In the present invention, the controller is preferably used to collect passive signals from the tap changer controller and external passive switch signals and send them to the PLC. The controller can monitor the switching status of the tap changer in real time and send this information to the PLC. The PLC can then perform logical judgment and control based on this information, achieving precise control of the tap changer switching process.

[0049] In the present invention, preferably, the current control device further comprises: a power supply module for providing power to the PLC and the solid-state relay. The power supply module can provide stable power input, ensure the normal operation of the current control device, and improve the reliability of the entire test device.

[0050] In the present invention, the power module preferably includes a transformer, a rectifier bridge, and a filter capacitor. The transformer is used to step down the 10kV power supply to a voltage range suitable for use by the PLC and solid-state relays. The rectifier bridge is used to convert AC power to DC power. The filter capacitor is used to filter out ripple in the DC power, thereby providing a stable DC power input for the PLC and solid-state relays.

[0051] The working principle and use process of this utility model: Step 1: Test preparation:

[0052] Connect the 10kV power supply, test transformer, load, current control device and power module.

[0053] Select appropriate test transformer low-voltage tap and load parameters according to the model and test parameters of the tap changer to be tested.

[0054] Program the PLC and set test parameters, such as switching times, switching time interval, load parameters, etc.

[0055] Connect the tap-changer to the test device and ensure it is in the initial state.

[0056] Step 2: Test process:

[0057] Start the 10kV power supply to provide high voltage power input for the test device.

[0058] According to preset parameters, the PLC controls the solid-state relay to close and open instantly before and after the tap changer is switched, thereby energizing and de-energizing the load.

[0059] The tap changer controller controls the tap changer to perform switching operations.

[0060] The controller collects the passive signals of the tap changer controller and the external passive switch signals and sends them to the PLC.

[0061] The PLC makes logical judgments based on the received signals and controls the switching status of the solid-state relay to ensure the smooth switching process of the tap changer.

[0062] During the test, the switching status of the tap changer and parameters such as load current and voltage can be monitored in real time, recorded and analyzed.

[0063] Step 3: End of the experiment:

[0064] After completing the preset number of switching tests, stop the test device.

[0065] Organize and analyze the test data to evaluate the performance and reliability of the tap changer.

[0066] Based on the test results, the tap changer is maintained or replaced to ensure its normal operation.

[0067] Step 4: Energy saving advantages:

[0068] Through the current control device, the load is energized and de-energized only at the moment before and after the tap changer is switched, effectively reducing the load energization time, thereby reducing the power consumption during the test and achieving the purpose of energy saving.

[0069] Compared with the traditional transformer method and resistance method, the utility model has higher economy and can effectively reduce the test cost.

[0070] Step 5: Scope of application:

[0071] The utility model is suitable for switching test detection of on-load tap changers for distribution transformers of various models, can meet the requirements of different test parameters, and achieve the purpose of energy saving and consumption reduction.

[0072] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An energy-saving device for testing and detecting on-load tap-changers of distribution transformers, characterized by: include: 10kV power supply; The test transformer has a conventional 10kV high-voltage winding and low-voltage taps of 250V, 500V, 750V, and 1000V. Load, which can be an adjustable reactor or an adjustable resistor; A current control device comprising: Solid-state relay, connected between the low-voltage side of the test transformer and the load; PLC, connected between the controller and the solid-state relay; Controller, connected between the tap changer controller and PLC; The current control device can control the power on and off of the load instantly before and after the tap changer is switched, effectively reducing the load power on time, thereby achieving the purpose of energy saving.

2. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 1, characterized in that: The current control device is used to control the power on and off of the load instantly before and after the tap changer is switched.

3. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 1, characterized in that: The load is an adjustable reactor or an adjustable resistor.

4. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 1, characterized in that: The PLC performs logic judgment based on the passive signal of the tap changer controller and the external passive switch signal to control the switching state of the solid-state relay.

5. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 1, characterized in that: The PLC can be programmed according to different models of tap changers to achieve the setting and adjustment of different test parameters.

6. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 1, characterized in that: The controller is used to collect the passive signal of the tap changer controller and the external passive switch signal, and send them to the PLC.

7. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 1, characterized in that: The current control device further includes: a power supply module, which is used to provide power to the PLC and the solid-state relay.

8. The energy-saving device for switching test and detection of on-load tap changers of distribution transformers according to claim 7, characterized in that: The power supply module includes: a transformer, a rectifier bridge and a filter capacitor.

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