A test circuit for generating asymmetric current in LC oscillation discharge circuit

Abstract

The invention discloses a test circuit for generating an asymmetric current in an LC oscillation discharge circuit. One end of a DC charging device is connected to one end of a charging isolation switch, the other end of the charging isolation switch is connected to one end of a discharge isolation switch, one end of a first closing switch, one end of a second closing switch and one end of a main capacitor, the other end of the discharge isolation switch is connected to one end of a discharge resistor, the other end of the first closing switch is connected to one end of a first inductor, the other end of the second closing switch is connected to one end of a second inductor, the other end of the DC charging device, the other end of the main capacitor, the other end of the discharge resistor, the other end of the first inductor and the other end of the second inductor are all grounded. The test circuit can realize an asymmetric current.

Description

Technical Field

[0001] The invention relates to a test circuit, in particular to a test circuit used for an LC oscillation discharge circuit to generate an asymmetric current. Background Art

[0002] Asymmetric current is generally generated when the power system is short-circuited at different initial phase angles α of the power supply voltage. For inductive circuits, by adjusting the initial phase angle α, asymmetric currents with different DC components can be obtained. Figure 1 In the field of high-voltage electrical testing, the asymmetrical short-circuit current that needs to be generated is generally between 20kA and 63kA. Using the power system to generate such a large short-circuit current for high-voltage electrical testing, the investment in the general test circuit is tens of millions of yuan, which is a large investment. The investment in the LC oscillation circuit is lower, generally around several million, but the general LC oscillation circuit can only generate symmetrical current, not asymmetrical current. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a test circuit for generating an asymmetric current in an LC oscillation discharge circuit, wherein the test circuit can realize the asymmetric current.

[0004] To achieve the above-mentioned object, the test circuit for generating asymmetric current in an LC oscillation discharge circuit of the present invention comprises a DC charging device, a charging isolating switch, a main capacitor, a discharge isolating switch, a discharge resistor, a first closing switch, a first inductor, a second closing switch and a second inductor;

[0005] One end of the DC charging device is connected to one end of the charging isolation switch, the other end of the charging isolation switch is connected to one end of the discharging isolation switch, one end of the first closing switch, one end of the second closing switch and one end of the main capacitor, the other end of the discharging isolation switch is connected to one end of the discharging resistor, the other end of the first closing switch is connected to one end of the first inductor, the other end of the second closing switch is connected to one end of the second inductor, and the other end of the DC charging device, the other end of the main capacitor, the other end of the discharging resistor, the other end of the first inductor and the other end of the second inductor are all grounded.

[0006] The charging voltage of the DC charging device can be adjusted.

[0007] The capacitance value and charging level of the main capacitor are adjusted according to the size of the generated current.

[0008] When there is residual charge in the main capacitor, the discharge isolation switch is closed to discharge the main capacitor through the discharge resistor to ensure the safety of the circuit.

[0009] The inductance values ​​of the first inductor and the second inductor are adjusted according to the magnitude and the DC component of the generated asymmetric current.

[0010] The control accuracy of the first closing switch and the second closing switch is within ±0.5ms.

[0011] The required asymmetric current is generated by controlling the sequence of the first closing switch and the second closing switch.

[0012] The present invention has the following beneficial effects:

[0013] In the specific operation of the test circuit for generating asymmetric current in the LC oscillation discharge circuit described in the present invention, the main capacitor is charged by a DC charging device. After the main capacitor is charged, the charging isolation switch is separated, and then the first closing switch is closed. After a few ms, the second closing switch is closed, and the circuit generates an asymmetric current. By changing the charging voltage, the capacitance of the main capacitor, the size of the first inductor, the size of the second inductor, and the time coordination relationship between the first closing switch and the second closing switch, the asymmetric current with the required amplitude and DC component is obtained, and the cost investment is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the prior art;

[0015] Figure 2 It is a structural schematic diagram of the present invention;

[0016] Figure 3 This is a 40kA symmetrical current waveform diagram generated by the prior art;

[0017] Figure 4 This is a 40kA asymmetric current waveform diagram generated by the present invention.

[0018] Among them, 1 is a DC charging device, 2 is a charging isolating switch, 3 is a main capacitor, 4 is a discharging isolating switch, 5 is a discharging resistor, 6 is a first closing switch, 7 is a first inductor, 8 is a second closing switch, and 9 is a second inductor. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0020] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0021] refer to Figure 2 The test circuit for generating asymmetric current in an LC oscillation discharge circuit of the present invention comprises a DC charging device 1, a charging isolating switch 2, a main capacitor 3, a discharge isolating switch 4, a discharge resistor 5, a first closing switch 6, a first inductor 7, a second closing switch 8 and a second inductor 9;

[0022] One end of the DC charging device 1 is connected to one end of the charging isolation switch 2, the other end of the charging isolation switch 2 is connected to one end of the discharge isolation switch 4, one end of the first closing switch 6, one end of the second closing switch 8 and one end of the main capacitor 3, the other end of the discharge isolation switch 4 is connected to one end of the discharge resistor 5, the other end of the first closing switch 6 is connected to one end of the first inductor 7, the other end of the second closing switch 8 is connected to one end of the second inductor 9, and the other end of the DC charging device 1, the other end of the main capacitor 3, the other end of the discharge resistor 5, the other end of the first inductor 7 and the other end of the second inductor 9 are all grounded.

[0023] It should be noted that the DC charging device 1 in the present invention is a charging element, and the charging voltage of the DC charging device 1 can be adjusted; the main capacitor 3 is charged by closing the charging isolation switch 2; the main capacitor 3 is an energy storage element, and the capacitance value and charging level of the main capacitor 3 are adjusted according to the size of the generated current to provide energy for the generation of asymmetric current in this circuit; when there is residual charge in the main capacitor 3, the discharge isolation switch 4 is closed, and the main capacitor 3 is discharged through the discharge resistor 5 to ensure the safety of the circuit; the first inductor 7 and the second inductor 9 are regulating elements of this circuit, and the inductance values ​​of the first inductor 7 and the second inductor 9 are adjusted according to the size of the generated asymmetric current and the DC component; the first closing switch 6 and the second closing switch 8 are actuators, and the control accuracy is required to be within ±0.5ms, and the required asymmetric current is generated by controlling the sequence of the first closing switch 6 and the second closing switch 8.

[0024] The specific operation process of the present invention is:

[0025] The charging isolating switch 2 is closed to allow the DC charging device 1 to charge the main capacitor 3. After the main capacitor 3 is charged, the charging isolating switch 2 is separated, the first closing switch 6 is closed, and the second closing switch 8 is closed after a few ms. An asymmetric current is generated in the circuit. By changing the charging voltage, the capacitance of the main capacitor 3, the size of the first inductor 7, the size of the second inductor 9, and the time coordination relationship between the first closing switch 6 and the second closing switch 8, an asymmetric current with a required amplitude and DC component is obtained.

Claims

1. A test circuit for generating an asymmetric current in an LC oscillation discharge circuit, characterized in that: It comprises a DC charging device (1), a charging isolating switch (2), a main capacitor (3), a discharging isolating switch (4), a discharging resistor (5), a first closing switch (6), a first inductor (7), a second closing switch (8) and a second inductor (9); One end of the DC charging device (1) is connected to one end of the charging isolation switch (2); the other end of the charging isolation switch (2) is connected to one end of the discharging isolation switch (4), one end of the first closing switch (6), one end of the second closing switch (8) and one end of the main capacitor (3); the other end of the discharging isolation switch (4) is connected to one end of the discharging resistor (5); the other end of the first closing switch (6) is connected to one end of the first inductor (7); the other end of the second closing switch (8) is connected to one end of the second inductor (9); the other end of the DC charging device (1), the other end of the main capacitor (3), the other end of the discharging resistor (5), the other end of the first inductor (7) and the other end of the second inductor (9) are all grounded; The inductance values ​​of the first inductor (7) and the second inductor (9) are adjusted according to the magnitude and DC component of the generated asymmetrical current; The required asymmetric current is generated by controlling the sequence of the first closing switch (6) and the second closing switch (8).

2. The test circuit for generating asymmetric current in an LC oscillation discharge circuit according to claim 1, characterized in that: The charging voltage of the DC charging device (1) can be adjusted.

3. The test circuit for generating asymmetric current in an LC oscillation discharge circuit according to claim 1, characterized in that: The capacitance value and charging level of the main capacitor (3) are adjusted according to the magnitude of the generated current.

4. The test circuit for generating asymmetric current in an LC oscillation discharge circuit according to claim 1, characterized in that: When there is residual charge in the main capacitor (3), the discharge isolating switch (4) is closed, and the main capacitor (3) is discharged through the discharge resistor (5) to ensure the safety of the circuit.

5. The test circuit for generating asymmetric current in an LC oscillation discharge circuit according to claim 1, characterized in that: The control accuracy of the first closing switch (6) and the second closing switch (8) is within ±0.5 ms.

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