A simulation measurement device for low-temperature resistance of the insulation film of a dry-type air-core reactor winding

Abstract

A device for simulating and measuring the low-temperature resistance of the insulation film of a dry-type hollow reactor winding relates to a device for simulating and measuring the winding of a reactor, and is intended to solve the problem of unreliable insulation status assessment results of existing reactor windings in a low-temperature environment. The test model of the present invention is used to simulate the reactor winding; a low-temperature environment chamber is used to simulate a low-temperature environment; the test model is arranged in the low-temperature environment chamber; one end of the high-voltage bushing is inserted into the low-temperature environment chamber; an industrial frequency AC power supply is electrically connected to the test model, and the negative pole of the industrial frequency AC power supply is grounded; a voltage divider is electrically connected to the test model, and the negative pole of the voltage divider is grounded; the acquisition signal output end of the voltage divider is connected to the acquisition signal input end of a partial discharge acquisition system; the other end of the test model passes through the side wall of the low-temperature environment chamber and is electrically connected to the partial discharge acquisition system and a detection impedance at the same time, and the other end of the detection impedance is grounded. The beneficial effect is that the reliability of the evaluation results of the insulation status of the reactor winding is improved.

Description

Technical Field

[0001] The invention relates to a winding simulation measurement device for a reactor. Background Art

[0002] The windings of dry-type air-core reactors are typically made of multiple strands of insulated cable with internally transposed positions. Each strand is wrapped in multiple layers of insulating film, which ensures mutual insulation between the strands. The strands are then transposed and wrapped with external insulation consisting of multiple layers of insulating film. These films ensure that the reactor will not short-circuit. The external insulation prevents short circuits between turns, and the interstrand insulation prevents the effects of contact between different strands. However, the insulation level of these films may be affected in low-temperature environments. The main detection method for existing dry-type air-core reactor windings is to perform interturn overvoltage tests during power outages, using the same detection and evaluation methods as in normal operating environments. Therefore, the insulation status of the reactor windings in low-temperature environments cannot be timely evaluated, and the evaluation results are not very reliable. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem that the insulation status evaluation results of the existing reactor windings are unreliable in a low temperature environment, and proposes a low temperature resistance simulation measurement device for the insulation film of a dry-type hollow reactor winding.

[0004] The present invention provides a dry-type air-core reactor winding insulation film low-temperature resistance simulation measurement device, which includes a high-voltage bushing, a low-temperature environment box, a test model, an industrial frequency AC power supply, a partial discharge acquisition system, a voltage divider, and a detection impedance;

[0005] The test model is used to simulate the reactor winding;

[0006] The low temperature environment box is used to simulate a low temperature environment; and the test model is arranged inside the low temperature environment box;

[0007] One end of the high-voltage bushing is passed through the side wall of the low-temperature environment box into the interior of the low-temperature environment box;

[0008] The positive electrode of the industrial frequency AC power supply is electrically connected to one end of the test model through the high-voltage bushing, and the negative electrode of the industrial frequency AC power supply is grounded;

[0009] The positive electrode of the voltage divider is electrically connected to one end of the test model through the high-voltage bushing, and the negative electrode of the voltage divider is grounded; and the acquisition signal output end of the voltage divider is connected to the acquisition signal input end of the partial discharge acquisition system;

[0010] The other end of the test model passes through the side wall of the low-temperature environment box and is electrically connected to the acquisition signal input end of the partial discharge acquisition system and one end of the detection impedance, and the other end of the detection impedance is grounded.

[0011] Furthermore, the test model includes a transposition line, a polyimide film and a polyester film;

[0012] Among them, the transposition line consists of two rows, upper and lower, with 8 monofilament aluminum wires in each row, and each monofilament aluminum wire is wrapped with polyester film; the outside of the transposition line is wrapped with two layers of polyester film with a layer of polyimide film sandwiched in between.

[0013] Furthermore, the outer diameter of each monofilament aluminum wire is 2.54 mm;

[0014] The thickness of the polyester film wrapped around each monofilament aluminum wire is: 0.01mm;

[0015] The width of the transposition line is 21.7 mm, and the height of the transposition line is 5.8 mm;

[0016] The thickness of the polyester film outside the transposed line is 25 μm; the thickness of each layer of polyimide film is 25 μm.

[0017] Furthermore, the low-temperature environment box is a cube structure, and a refrigerator is provided inside the low-temperature environment box. The temperature range of the refrigerator is -60°C to 100°C; the temperature control accuracy is ±0.3°C.

[0018] Furthermore, the industrial frequency AC power supply is a voltage-adjustable industrial frequency AC power supply, and the voltage output by the industrial frequency AC power supply passes through the transformer T and is electrically connected to one end of the test model.

[0019] Furthermore, the voltage divider is a resistor-capacitor voltage divider, which includes a resistor R2, a resistor R3, a capacitor C1 and a capacitor C2;

[0020] Among them, one end of the resistor R2 is connected to one end of the capacitor C1 and one end of the test model 3 at the same time; the other end of the resistor R2 is connected to the other end of the capacitor C1, one end of the resistor R3 and one end of the capacitor C2 at the same time, and the common connection end is the acquisition signal output end of the voltage divider; the other end of the resistor R3 is connected to the other end of the capacitor C2 and is grounded.

[0021] The working principle of the simulation measurement device described in the present invention is as follows: first, a test model is used to simulate the reactor winding, and the test model is placed in a low-temperature environmental chamber. The low-temperature environmental chamber simulates different low-temperature environments. At the same time, different voltages are passed through the test model using an industrial frequency AC power supply, and voltage data is obtained using a voltage divider; then the insulation state of the dry-type air-core reactor is evaluated.

[0022] The beneficial effects of the present invention are as follows: the simulation measurement device uses a test model to simulate the reactor winding, and places the test model in a low-temperature environment box to simulate a low-temperature environment, and uses an industrial frequency AC power supply to simulate the power-on state of the reactor winding. It can evaluate its insulation state when the test model is powered on and in a low-temperature environment. Therefore, the simulation measurement device can timely evaluate the insulation state of the reactor winding in a low-temperature environment, thereby improving the reliability of the insulation state evaluation results of the reactor winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the circuit principle of a device for simulating and measuring the low-temperature resistance of the insulation film of a dry-type air-core reactor winding according to the first embodiment;

[0024] Figure 2 This is the wiring schematic diagram of the AC withstand voltage test of the test model in the first specific implementation method. DETAILED DESCRIPTION

[0025] Combine Figures 1 to 2 This embodiment describes a dry-type air-core reactor winding insulation film low-temperature resistance simulation measurement device, which includes a high-voltage bushing 1, a low-temperature environment chamber 2, a test model 3, an industrial frequency AC power supply 4, a partial discharge acquisition system 5, a voltage divider 6, and a detection impedance 7;

[0026] The test model 3 is used to simulate the reactor winding;

[0027] The low temperature environment box 2 is used to simulate a low temperature environment; and the test model 3 is set inside the low temperature environment box 2;

[0028] One end of the high-voltage bushing 1 is inserted into the low-temperature environment box 2 through the side wall of the low-temperature environment box 2;

[0029] The positive electrode of the power frequency AC power supply 4 passes through the high voltage bushing 1 and is electrically connected to one end of the test model 3, and the negative electrode of the power frequency AC power supply 4 is grounded;

[0030] The positive electrode of the voltage divider 6 passes through the high-voltage bushing 1 and is electrically connected to one end of the test model 3, and the negative electrode of the voltage divider 6 is grounded; and the acquisition signal output end of the voltage divider 6 is connected to the acquisition signal input end of the partial discharge acquisition system 5;

[0031] The other end of test model 3 passes through the side wall of low-temperature environmental chamber 2 and is electrically connected to the signal input terminal of partial discharge acquisition system 5 and one end of detection impedance 7. The other end of detection impedance 7 is grounded. Detection impedance 7 is used to prevent excessive current in the circuit and provides protection. Detection impedance 7 also acts as a pull-up resistor, collecting the output signal through detection impedance 7.

[0032] In this embodiment, a test model 3 is used to simulate the reactor winding and is placed in a low-temperature environment chamber 2. Different low-temperature environments are simulated by the low-temperature environment chamber 2. At the same time, different voltages are applied to the test model 3 using an industrial frequency AC power supply 4, and voltage data is obtained using a voltage divider 6. The insulation condition of the dry-type air-core reactor is then evaluated.

[0033] In a preferred embodiment, the test model 3 includes a transposed wire, a polyimide film, and a polyester film;

[0034] Among them, the transposition line consists of two rows, upper and lower, with 8 monofilament aluminum wires in each row, and each monofilament aluminum wire is wrapped with polyester film; the outside of the transposition line is wrapped with 2 layers of polyester film and 1 layer of polyimide film in the middle, and 1 / 3 of each layer of polyester film is overlapped and wrapped.

[0035] In a preferred embodiment, the outer diameter of each monofilament aluminum wire is 2.54 mm;

[0036] The thickness of the polyester film wrapped around each monofilament aluminum wire is: 0.01mm;

[0037] The width of the transposition line is 21.7 mm, and the height of the transposition line is 5.8 mm;

[0038] The thickness of the polyester film outside the transposed line is 25 μm; the thickness of each layer of polyimide film is 25 μm.

[0039] In a preferred embodiment, the low-temperature environment box 2 is a cube structure, and a refrigerator is provided inside the low-temperature environment box 2 . The temperature range of the refrigerator is -60°C to 100°C, and the temperature control accuracy is ±0.3°C.

[0040] In this embodiment, the dimensions of the low-temperature environment box 2 are 5m×5m×5m; the low-temperature environment box 2 has the function of automatic temperature control and maintenance.

[0041] In a preferred embodiment, the industrial frequency AC power source 4 is a voltage-adjustable industrial frequency AC power source, and the voltage output by the industrial frequency AC power source 4 passes through a transformer T and is electrically connected to one end of the test model 3 .

[0042] In this embodiment, the two ends of the primary coil of the transformer T are respectively connected to the positive output terminal and the negative output terminal of the industrial frequency AC power supply 4; one end of the secondary coil of the transformer T is connected to one end of the test model 3 through the resistor R1; the other end of the secondary coil of the transformer T is grounded; the resistor R1 is a protective resistor; wherein, the voltage regulation range of the industrial frequency AC power supply 4 is: 220V to 10kV.

[0043] In a preferred embodiment, the voltage divider 6 is a resistor-capacitor voltage divider, and the voltage divider 6 includes a resistor R2, a resistor R3, a capacitor C1, and a capacitor C2;

[0044] Among them, one end of the resistor R2 is connected to one end of the capacitor C1 and one end of the test model 3 at the same time; the other end of the resistor R2 is connected to the other end of the capacitor C1, one end of the resistor R3 and one end of the capacitor C2 at the same time, and the common connection end is the acquisition signal output end of the voltage divider 6; the other end of the resistor R3 is connected to the other end of the capacitor C2 and is grounded.

[0045] In this embodiment, the AC withstand voltage test is performed at temperatures of 30°C, -25°C, and -40°C in the low-temperature environmental chamber 2. At these three temperatures, a certain interval is left between each test to ensure that no moisture enters the low-temperature environmental chamber 2. In each test, the voltage of the industrial frequency AC power supply 4 is gradually increased until the polyester film surrounding the monofilament aluminum wire breaks down.

[0046] Table 1 Pressure resistance of polyester film at different temperatures

[0047]

[0048] Table 2 Pressure resistance of polyimide films at different temperatures

[0049]

[0050] From the above test results, it can be seen that low temperature will not reduce the tolerance level of the insulating film. At -25℃, the tolerance level of the polyester film is slightly improved compared with room temperature. At -40℃, the tolerance levels of the polyester film and polyimide film are about 20% higher than those at 30℃. The drop in temperature increases the insulation level of the insulating film. Based on this phenomenon, the evaluation result is: the insulating film alone will not produce any defects in the insulation level in a low temperature environment.

[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A dry-type air-core reactor winding insulation film low-temperature resistance simulation measurement device, characterized in that: The simulation measurement device includes a high-voltage bushing (1), a low-temperature environment box (2), a test model (3), an industrial frequency AC power supply (4), a partial discharge acquisition system (5), a voltage divider (6), and a detection impedance (7); The test model (3) is used to simulate the reactor winding; The low-temperature environment box (2) is used to simulate a low-temperature environment; and the test model (3) is arranged inside the low-temperature environment box (2); One end of the high-voltage bushing (1) penetrates into the interior of the low-temperature environment box (2) through the side wall of the low-temperature environment box (2); The positive electrode of the industrial frequency AC power supply (4) passes through the high-voltage bushing (1) and is electrically connected to one end of the test model (3), and the negative electrode of the industrial frequency AC power supply (4) is grounded; The positive electrode of the voltage divider (6) passes through the high-voltage bushing (1) and is electrically connected to one end of the test model (3), and the negative electrode of the voltage divider (6) is grounded; and the acquisition signal output end of the voltage divider (6) is connected to the acquisition signal input end of the partial discharge acquisition system (5); The other end of the test model (3) passes through the side wall of the low-temperature environment box (2) and is electrically connected to the acquisition signal input end of the partial discharge acquisition system (5) and one end of the detection impedance (7), and the other end of the detection impedance (7) is grounded.

2. The device for simulating and measuring the low temperature resistance of the winding insulation film of a dry-type air-core reactor according to claim 1, characterized in that: The test model (3) includes a transposition line, a polyimide film and a polyester film; Among them, the transposition line consists of two rows, upper and lower, with 8 monofilament aluminum wires in each row, and each monofilament aluminum wire is wrapped with polyester film; the outside of the transposition line is wrapped with two layers of polyester film with a layer of polyimide film in the middle.

3. The device for simulating and measuring the low temperature resistance of the winding insulation film of a dry-type air-core reactor according to claim 2, characterized in that: The outer diameter of each monofilament aluminum wire is 2.54mm; The thickness of the polyester film wrapped around each monofilament aluminum wire is: 0.01mm; The width of the transposition line is 21.7 mm, and the height of the transposition line is 5.8 mm; The thickness of the polyester film outside the transposed line is 25 μm; the thickness of each layer of polyimide film is 25 μm.

4. The device for simulating and measuring the low temperature resistance of the winding insulation film of a dry-type air-core reactor according to claim 1, characterized in that: The low-temperature environment box (2) is a cube structure, and a refrigerator is provided inside the low-temperature environment box (2). The temperature range of the refrigerator is -60°C to 100°C; the temperature control accuracy is ±0.3°C.

5. The device for simulating and measuring the low temperature resistance of the winding insulation film of a dry-type air-core reactor according to claim 1, characterized in that: The industrial frequency AC power supply (4) is a voltage-adjustable industrial frequency AC power supply, and the voltage output by the industrial frequency AC power supply (4) is electrically connected to one end of the test model (3) after passing through a transformer T.

6. The device for simulating and measuring the low temperature resistance of the winding insulation film of a dry-type air-core reactor according to claim 1, characterized in that: The voltage divider (6) is a resistor-capacitor voltage divider, and the voltage divider (6) includes a resistor R2, a resistor R3, a capacitor C1, and a capacitor C2; One end of the resistor R2 is connected to one end of the capacitor C1 and one end of the test model (3) at the same time; the other end of the resistor R2 is connected to the other end of the capacitor C1, one end of the resistor R3 and one end of the capacitor C2 at the same time, and the other end of the resistor R2 is the acquisition signal output end of the voltage divider (6); the other end of the resistor R3 is connected to the other end of the capacitor C2 and is grounded.

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