Tuning compensation-based main transformer through-flow simulation on-load test system

Abstract

The utility model discloses a main transformer through-current simulation on-load test system based on tuning compensation, and the system comprises a through-current device which comprises a DC module which is used for converting an AC power supply into DC and outputting the DC to an inversion module; the inversion module is used for converting the direct current output by the direct current module into an alternating current signal and outputting the alternating current signal to the high-voltage module; the high-voltage module is used for amplifying the alternating current signal output by the inversion module through a power amplification unit; the compensation module is used for performing tuning compensation on reactive power generated by the alternating current signal amplified by the high-voltage module in a transformer load based on a variable capacitor to realize large-current output; the acquisition module is used for acquiring output signals of the high-voltage module and the compensation module and feeding back the output signals to the main control module; and the main control module is used for outputting control signals to the direct current module, the inversion module, the high-voltage module and the compensation module based on a preset instruction and / or the signals acquired by the acquisition module, and the control signals at least comprise capacitance value adjusting signals output to the compensation module.

Description

Technical Field

[0001] This utility model relates to the field of power system testing technology, specifically to a load test system based on tuning compensation with main transformer current simulation. Background Technology

[0002] According to the "Inspection Procedures for Relay Protection and Power Grid Safety Automatic Devices" (DL / T 995-2006), before a substation is put into operation, in order to verify the safety and reliability of primary and secondary equipment, a relay protection vector check is performed by simultaneously applying working voltage and load current.

[0003] When a load current is applied, the test current is applied to the primary current system of the substation. Through the current transformer (CT) and the complete secondary circuit, the current is introduced into the relay protection device to verify the correctness of the phase, phase type, polarity, etc., of the secondary circuit wiring of the relay protection device within the substation, thus completing the relay protection vector check before project commissioning. However, the current-carrying test requires a large current, and the power supply capacity of the substation is limited, which may not meet the test requirements. Furthermore, the current-carrying devices used in existing testing methods are large and heavy, making on-site testing inconvenient. Utility Model Content

[0004] Based on the above background, the purpose of this utility model is to provide a load test system with main variable current based on tuning compensation, so as to solve the problem that existing test methods are not convenient for conducting field tests.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A tuned compensation-based system for simulating load testing with main transformer current flow includes at least a current flow device, wherein the current flow device comprises:

[0007] The DC module has its input coupled to a 380V AC power supply and its output coupled to an inverter module, which is used to convert the 380V AC power supply into DC power and output it to the inverter module.

[0008] The inverter module, whose output is coupled to the high-voltage module, is used to convert the DC power output from the DC module into an AC signal and output it to the high-voltage module.

[0009] The high-voltage module, whose output is coupled to a compensation module, is used to amplify the AC signal output by the inverter module through a power amplifier unit.

[0010] The compensation module is used to perform tuned compensation on the reactive power generated by the AC signal amplified by the high-voltage module in the transformer load based on the variable capacitor, so as to achieve high current output.

[0011] The acquisition module has its input coupled to the output of the high-voltage module and the compensation module, and its output coupled to the main control module. It is used to acquire the output signals of the high-voltage module and the compensation module and feed them back to the main control module.

[0012] The main control module, which is communicatively connected to the DC module, inverter module, high voltage module and compensation module, is used to output control signals to the DC module, inverter module and high voltage module and compensation module based on preset instructions and / or signals acquired by the acquisition module. The control signals include at least a capacitor value adjustment signal output to the compensation module.

[0013] Furthermore, the DC module includes a bridge rectifier circuit composed of rectifier diodes and filter capacitors, which converts the input 380V three-phase AC power into 540V DC power.

[0014] Furthermore, the inverter module includes an inverter circuit composed of field-effect transistors, which converts the 540V DC power output from the DC module into 300V AC power.

[0015] Furthermore, the high-voltage module includes at least a transformer and a power amplifier unit, which convert the 300V AC output from the inverter module into 1500V AC.

[0016] Furthermore, the acquisition module includes a current acquisition unit and a voltage acquisition unit. The current acquisition unit includes a current transformer for acquiring current signals and a first operational amplifier coupled to the current transformer. The voltage acquisition unit includes a voltage transformer for acquiring voltage signals and a second operational amplifier coupled to the voltage transformer. The output terminals of the first operational amplifier and the second operational amplifier are coupled to the main control module.

[0017] Furthermore, the main control module includes a DSP unit, as well as a signal acquisition circuit, a keyboard control input circuit, a power supply circuit, a PWM output circuit, an IO control output circuit, and a wireless communication circuit coupled to the DSP unit.

[0018] Furthermore, the compensation module includes multiple parallel capacitor banks of different capacities and a switching unit for connecting different capacitors to the circuit. The parallel capacitor banks are coupled between the secondary winding of the transformer of the high-voltage module and the test current output terminal. The switching unit is coupled to the main control module and controls the connection of different capacitors to the circuit according to the control signal of the main control module, thereby realizing the adjustment of the total compensation capacitance.

[0019] Furthermore, the system also includes a voltage supply device for providing a reference voltage phase to the relay protection device under test.

[0020] Furthermore, the system also includes a handheld terminal, which is communicatively connected to the current-passing device and the voltage-passing device, and is used to provide a reference signal to realize phase adjustment and synchronization of the output current and voltage signals of the current-passing device and the voltage-passing device.

[0021] The beneficial effects of this utility model are as follows:

[0022] This utility model discloses a tuned compensation-based simulated load test system for main transformer current carrying capacity. Through a compensation module using a variable capacitor for tuned compensation, it achieves high current output, thereby providing a large current for testing and verifying the main transformer. This overcomes the shortcomings of similar devices, which are large in size and weight, and inconvenient for on-site testing. Simultaneously, it enables communication synchronization between the handheld controller and the main control module, achieving phase synchronization of secondary current and voltage without the need for conversion. Furthermore, the test operation requires only one person, eliminating the need for multiple people to coordinate, saving labor costs and reducing the occurrence of test errors. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the module composition and connection relationship of the flow device in the simulated load test system with main variable flow of this utility model.

[0024] Figure 2 This is a circuit diagram of the compensation module in an embodiment of the current-carrying device in the simulated load test system with main variable current of this utility model.

[0025] Figure 3 This is a schematic diagram of the DC module circuit of an embodiment of the current-carrying device in the simulated load test system with main transformer current carrying capacity of this utility model.

[0026] Figure 4 This is a schematic diagram of the inverter module circuit in an embodiment of the current-carrying device in the simulated load test system with main transformer current carrying capacity according to this utility model.

[0027] Figure 5 This is a schematic diagram of the acquisition module circuit of an embodiment of the current-carrying device in the simulated load test system with main variable current of this utility model, wherein... Figure 5 (a) is a schematic diagram of the current acquisition unit circuit, where Figure 5 (b) is a schematic diagram of the voltage acquisition unit circuit.

[0028] Figure 6 This is a schematic diagram of the main control module circuit of the current-carrying device in the simulated load test system with main variable current of this utility model. Detailed Implementation

[0029] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] A single resistor in the circuit diagram can be equivalently replaced by multiple resistors connected in series or parallel in the actual circuit, and this invention is not limited to this. Similarly, a high-voltage capacitor can also be equivalently replaced by multiple high-voltage capacitors connected in series or parallel.

[0032] The term "coupled" in the specification and claims of this utility model includes both direct and indirect connections, such as connections via an electrical conduction medium, like a conductor, which may contain parasitic inductance or capacitance. It may also include connections via other active or passive devices that achieve the same or similar functional purpose, such as connections via switches, follower circuits, or other circuits or components.

[0033] See Figure 1 This utility model embodiment provides a load-bearing simulation test system with main variable current based on tuning compensation, which includes at least a current-passing device, the current-passing device including:

[0034] The DC module has its input coupled to a 380V AC power supply and its output coupled to an inverter module, which is used to convert the 380V AC power supply into DC power and output it to the inverter module.

[0035] The inverter module, whose output is coupled to the high-voltage module, is used to convert the DC power output from the DC module into an AC signal and output it to the high-voltage module.

[0036] The high-voltage module, whose output is coupled to a compensation module, is used to amplify the AC signal output by the inverter module through a power amplifier unit.

[0037] The compensation module is used to tune and compensate the reactive power generated by the amplified AC signal from the high-voltage module in the transformer load based on the variable capacitor, so as to achieve high current output.

[0038] The acquisition module has its input coupled to the output of the high-voltage module and the compensation module, and its output coupled to the main control module. It is used to acquire the output signals of the high-voltage module and the compensation module and feed them back to the main control module.

[0039] The main control module, which is communicatively connected to the DC module, inverter module, high voltage module and compensation module, is used to output control signals to the DC module, inverter module and high voltage module and compensation module based on preset instructions and / or signals acquired by the acquisition module. The control signals include at least a capacitor value adjustment signal output to the compensation module.

[0040] See Figure 2 In a preferred embodiment, the compensation module includes multiple parallel capacitor banks 100 of different capacities and a switching unit 101 for connecting different capacitors to the circuit. The parallel capacitor banks are coupled between the high-voltage module and the test current output terminal. The switching unit is coupled to the main control module and controls the connection of different capacitors to the circuit according to the control signal from the main control module, thereby adjusting the total compensation capacitance.

[0041] See Figure 3 As a preferred embodiment, in this embodiment, the DC module includes a bridge rectifier circuit composed of rectifier diodes VD1-VD6 and filter capacitor C, which converts the input 380V three-phase AC power into 540V DC power.

[0042] See Figure 4 As a preferred embodiment, in this embodiment, the inverter module includes an inverter circuit composed of field-effect transistors P1, P2, P3, and P4, which converts the 540V DC power output from the DC module into 300V AC power.

[0043] As a preferred embodiment, in this embodiment, the high-voltage module includes at least a transformer and a power amplification unit, which convert the 300V AC output from the inverter module into 1500V AC.

[0044] See Figure 5 As a preferred embodiment, in this example, the acquisition module includes a current acquisition unit and a voltage acquisition unit. Wherein, for example... Figure 5 As shown in (a), the current acquisition unit includes a current transformer for acquiring current signals and a first operational amplifier coupled to the current transformer, as follows: Figure 5 As shown in (b), the voltage acquisition unit includes a voltage transformer for acquiring voltage signals and a second operational amplifier coupled to the voltage transformer. The output terminals of the first operational amplifier and the second operational amplifier are coupled to the main control module.

[0045] See Figure 6As a preferred embodiment, in this example, the main control module includes a DSP unit, and signal acquisition circuit, keyboard control circuit, power supply circuit, PWM output circuit, IO control output circuit, wireless synchronization circuit, and wireless communication circuit coupled to the DSP unit. The signal acquisition circuit includes an AD chip for converting analog signals output from the first and second operational amplifiers into digital signals and outputting them to the DSP unit; the keyboard control circuit receives keyboard input commands; the PWM output circuit outputs modulation signals to the high-voltage module; the IO control output circuit outputs control signals to the switching unit of the compensation module; the wireless synchronization circuit receives synchronization signals from the handheld controller; and the wireless communication circuit establishes wireless communication connections with external devices.

[0046] The current-carrying device in this embodiment achieves high current output based on capacitor tuning compensation. The specific working principle is as follows:

[0047] In AC circuits, capacitors generate capacitive reactive current, which cancels out the inductive reactive current required by inductive loads (such as motors and transformers), thereby improving the power factor, reducing reactive power flow in the system, and lowering the total power of the current-carrying device. When tuning compensation makes the power factor 1, it means that the reactive power in the system is completely compensated. In some cases, if the compensation is excessive or the system parameters happen to meet the resonance condition, resonance may occur. In circuits containing inductors and capacitors, when the inductive reactance (X... L =ωL, where ω is the angular frequency and L is the inductance value) and capacitive reactance (X C When the capacitance (ωC) is equal to 1 / ωC, resonance occurs. At this time, the total impedance of the circuit is at its minimum, and the current reaches its maximum value. In the resonant state, the current in the circuit increases sharply. The current-carrying device of this invention utilizes this characteristic to achieve high current flow. Due to the resistance in the circuit, the resonant current is controllable. Therefore, the compensating current-carrying device of this invention can maintain the balance of the resonant current with a relatively small output energy.

[0048] During the specific test, before performing reactive power capacitor compensation, one side of the transformer under test can be short-circuited, and current can be passed through the winding on the other side to calculate the impedance of the transformer winding and estimate the required capacity of the parallel capacitor. The measured power factor before compensation is cosθ, and the impedance modulus is |Z|. The calculated compensation capacitor is... Furthermore, the number of parallel capacitor banks can be calculated based on the calculated compensation capacitors. The rated operating voltage of the parallel capacitors is the output voltage of the current-carrying device; a single capacitor only needs to meet the required withstand voltage rating. After calculating the number of capacitor banks that need to be connected in parallel, the main control module sends the corresponding control command to the compensation module. The switching unit of the compensation module executes the command, connecting the corresponding capacitors into the circuit, thereby achieving tuning compensation.

[0049] As a further preferred embodiment, the simulated load test system with main transformer current in this utility model also includes a voltage supply device, which is used to provide a reference voltage phase to the relay protection device under test to ensure the stability of the vector diagram.

[0050] As a further preferred embodiment, the current-carrying simulation load test system with main transformer in this utility model also includes a handheld terminal, which is wirelessly connected to the current-carrying device and the voltage-carrying device to provide a reference signal to realize the phase adjustment and synchronization of the output current and voltage signals of the current-carrying device and the voltage-carrying device.

[0051] The embodiments of this utility model are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this utility model should be included within the protection scope of this utility model.

Claims

1. A system for simulating a load test of a power transformer with a power transformer bypass based on tuning compensation, characterized by At least comprising a through-flow device, the through-flow device comprising: a direct current module, an input of which is coupled with a 380V alternating current power supply, and an output of which is coupled with an inverter module, for converting the 380V alternating current power supply into direct current and outputting to the inverter module; the inverter module, an output of which is coupled with a high-voltage module, for converting the direct current outputted by the direct current module into an alternating current signal and outputting to the high-voltage module; the high-voltage module, an output of which is coupled with a compensation module, for amplifying the alternating current signal outputted by the inverter module through a power amplification unit; the compensation module, for tuning and compensating the reactive power generated in the transformer load based on the variable capacitance to the amplified alternating current signal of the high-voltage module, to realize large current output; a collection module, an input of which is coupled with the outputs of the high-voltage module and the compensation module, and an output of which is coupled with a master control module, for collecting the output signals of the high-voltage module and the compensation module and feeding back to the master control module; the master control module, which is communicatively connected with the direct current module, the inverter module, the high-voltage module and the compensation module, for outputting control signals to the direct current module, the inverter module, the high-voltage module and the compensation module based on preset instructions and / or the signals collected by the collection module, the control signals at least comprising a capacitance value adjustment signal outputted to the compensation module.

2. The tuned compensation based band main pass analog loading test system of claim 1, wherein, The direct current module comprises a bridge rectifier circuit composed of rectifier diodes and filter capacitors, which converts the input 380V three-phase alternating current into 540V direct current.

3. The tuned compensation based band main pass analog loading test system of claim 2, wherein, The inverter module comprises an inverter circuit composed of field effect tubes, which converts the 540V direct current outputted by the direct current module into 300V alternating current.

4. The tuned compensation based band main pass analog loading test system of claim 3, wherein, The high-voltage module at least comprises a transformer and a power amplification unit, which convert the 300V alternating current outputted by the inverter module into 1500V alternating current.

5. The tuned compensation based band main pass analog loading test system of claim 1, wherein, The collection module comprises a current collection unit and a voltage collection unit, the current collection unit comprising a current transformer for collecting current signals and a first operational amplifier coupled with the current transformer, the voltage collection unit comprising a voltage transformer for collecting voltage signals and a second operational amplifier coupled with the voltage transformer, the outputs of the first and second operational amplifiers being coupled with the master control module.

6. The tuned compensation based band main pass analog loading test system of claim 1, wherein, The master control module comprises a DSP unit, a signal collection circuit, a keyboard control input circuit, a power supply circuit, a PWM output circuit, an IO control output circuit and a wireless communication circuit coupled with the DSP unit.

7. The tuned compensation based on-load test system with main transformer through-flow simulation system according to any one of claims 1-6, characterized in that, The compensation module comprises a plurality of parallel capacitor groups with different capacitance sizes and a switching unit for connecting the different capacitors into the circuit, the parallel capacitor groups being coupled between the secondary side winding of the transformer of the high-voltage module and a test current output terminal, the switching unit being coupled with the master control module and controlling the connection of different capacitors into the circuit according to the control signals of the master control module, to realize the adjustment of the total compensation capacitance.

8. The tuned compensation based band main pass analog loading test system of claim 7, wherein, Further comprising a through-voltage device, the through-voltage device being used to provide a reference voltage phase to the relay protection device to be tested.

9. The tuned compensation based band main pass analog loading test system of claim 8, wherein, Further comprising a handheld terminal, the handheld terminal being wirelessly communicatively connected with the through-flow device and the through-voltage device, for providing a reference signal to realize the phase adjustment and synchronization of the current and voltage signals outputted by the through-flow device and the through-voltage device.

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