Offline detection system for series thyristors

Abstract

The utility model discloses a series thyristor off-line detection system, which comprises a series thyristor detection module and a series thyristor circuit to be detected, and is characterized in that the series thyristor detection module comprises a main circuit and a control unit; a main circuit of the series thyristor detection module comprises a switch Ks, a load resistor Rs, a direct current power supply Us and a voltmeter Vs. The on-off action of the switch Ks is controlled by the control unit, and the series thyristor circuit to be tested comprises thyristors S1 and S2, resistors R1 and R2, and capacitors C1 and C2; the on-off actions of the thyristors S1 and S2 are controlled by the control unit; according to the series thyristor detection system provided by the utility model, the detection system is directly connected to the two ends of the uncharged series thyristor, and the test process is relatively safe because the test voltage is low voltage; and the states of the series thyristors can be detected at the same time, fault detection of the series thyristors is realized, and the method is simple and efficient.

Description

Technical Field

[0001] The utility model belongs to the field of power electronics applications, and particularly relates to a series thyristor off-line detection system. Background Art

[0002] With the continuous development of power electronics technology in the power system, thyristors are widely used. Limited by the electrical characteristics of single devices, thyristor series and parallel connections are relatively common technical means to achieve larger current and voltage outputs. In many devices containing thyristors, the number of thyristors is large, and thyristor detection technology also needs to be continuously improved and perfected.

[0003] The patent with the publication number CN108828421A discloses a thyristor fault detection system and method, which mainly focuses on the fault identification of a single thyristor. The detection circuit is complex and the cost is relatively high.

[0004] The patent with the publication number CN109901039A discloses an invention related to a commutation valve thyristor voltage equalizing element test device and method, which requires designing a detection circuit and a signal source to collect loop voltage and current signals. The cost is high and the test process is complex; and it mainly focuses on the fault identification of a single thyristor, with low efficiency. Summary of the Invention

[0005] The purpose of the utility model is to provide a series thyristor off-line detection system to solve the problem of off-line rapid detection of series thyristors, so as to achieve simple and efficient rapid detection of series thyristor faults.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] A series thyristor off-line detection system includes a series thyristor detection module and a series thyristor circuit to be tested. The series thyristor detection module includes a main circuit and a control unit; the main circuit of the series thyristor detection module includes a switch Ks, a load resistor Rs, a DC power supply Us, and a voltmeter Vs. The switching action of the switch Ks is controlled by the control unit. The series thyristor circuit to be tested includes thyristors S1, S2, resistors R1, R2, and capacitors C1, C2; the turn-on and turn-off actions of the thyristors S1, S2 are controlled by the control unit.

[0008] Further, the main circuit includes that the positive pole of the DC power supply Us is connected in series with the switch Ks and the load resistor Rs, and the other end of the load resistor Rs forms a connection point 1; the negative pole of the DC power supply Us is connected to the negative pole of the voltmeter Vs to form a connection point 3; the positive pole of the voltmeter Vs is connected to form a connection point 2.

[0009] Further, the series thyristor circuit to be measured includes a thyristor S1 in parallel with a resistor R1 and a capacitor C1. The anode of the thyristor S1 is connected to the junction point 1, and the cathode of the thyristor S1 is connected to the junction point 2. The thyristor S2 is in parallel with a resistor R2 and a capacitor C2. The anode of the thyristor S2 is connected to the junction point 2, and the cathode of the thyristor S2 is connected to the junction point 3.

[0010] Further, the resistance value of the load resistor Rs is much smaller than the resistance values of the resistors R1 and R2.

[0011] Further, the thyristors S1 and S2 can be regarded as two groups of series thyristor circuits to be measured in series with n thyristors (n≥1), and screening is carried out according to the fast approximation algorithm.

[0012] Further, the series thyristor detection system controls the opening and closing of the switch Ks and the thyristors S1 and S2 through the control unit, detects the value of the voltmeter Vs, and judges whether the working state of the series thyristor is normal by looking up the table.

[0013] The following beneficial effects can be obtained through the above technical solutions:

[0014] The series thyristor detection system provided by the present invention is directly connected to both ends of the series thyristor in a non-powered state. Since the test voltage is a low voltage, the test process is relatively safe; and it can detect the state of the series thyristor at the same time, realizing the fault detection of the series thyristor, and has the characteristics of simplicity and high efficiency. Description of the Drawings

[0015] Figure 1 is the schematic diagram of the series thyristor detection system of the present invention;

[0016] Figure 2 is the fault judgment logic diagram of the series thyristor of the present invention. Detailed Embodiments

[0017] The following embodiments are combined with the attached Figure 1 and 2 to further illustrate the present invention:

[0018] The schematic diagram of the series thyristor detection system of the present invention is as Figure 1 shown, and includes a series thyristor detection module and a series thyristor circuit to be measured. The series thyristor detection module includes a main circuit and a control unit; the main circuit of the series thyristor detection device includes a switch Ks, a load resistor Rs, a DC power supply Us, and a voltmeter Vs. The series thyristor circuit to be measured includes thyristors S1 and S2, resistors R1 and R2, and capacitors C1 and C2; the switching action of the switch Ks is controlled by the control unit.

[0019] The present invention is specifically applied as follows:

[0020] The main circuit of the series thyristor detection module includes the positive pole of the DC power supply Us and the switch Ks, and the load resistor Rs is connected end to end. The other end of the load resistor Rs forms a connection point 1; the negative pole of the DC power supply Us is connected to the negative pole of the voltmeter Vs to form a connection point 3; the positive pole of the voltmeter Vs is connected to form a connection point 2;

[0021] The series thyristor circuit to be tested includes the thyristor S1 and the resistor R1, and the capacitor C1 is connected in parallel. The anode of the thyristor S1 is connected to the connection point 1, and the cathode of the thyristor S1 is connected to the connection point 2; the thyristor S2 and the resistor R2, and the capacitor C2 are connected in parallel. The anode of the thyristor S2 is connected to the connection point 2, and the cathode of the thyristor S2 is connected to the connection point 3; the on-off actions of the thyristors S1 and S2 are controlled by the control unit; the resistance value of the load resistor Rs is much smaller than the resistance values of the resistors R1 and R2.

[0022] In the specific detection: the series thyristor detection system controls the on-off of the switch Ks and the thyristors S1 and S2 through the control unit, detects the value of the voltmeter Vs, and judges whether the working state of the series thyristor is normal by looking up the table. For the specific value of the detected Vs, please refer to Figure 2 The shown series thyristor fault judgment logic diagram.

[0023] In the above specific application, the thyristors S1 and S2 can be regarded as two groups of series thyristor circuits to be tested with n thyristors connected in series. (n≥1), and screening is carried out according to the fast approximation algorithm.

[0024] All of the above are the preferred embodiments of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, the modifications of various equivalent forms of the present invention all fall within the protection scope of the appended claims of this application.

Claims

1. A series thyristor offline detection system, characterized in that: The offline detection system comprises a series thyristor detection module and a series thyristor circuit to be tested. The series thyristor detection module comprises a control unit and a main circuit. The main circuit comprises a switch (Ks), a load resistor (Rs), a DC power supply (Us) and a voltmeter (Vs). One end of the load resistor (Rs) forms a connection point (1). The negative pole of the DC power supply (Us) is connected to the negative pole of the voltmeter (Vs) to form a connection point (3). The positive end of the voltmeter (Vs) forms a connection point (2). The control unit controls the switch (Ks) on and off. The on and off actions of the thyristors in the series thyristor circuit to be tested are controlled by the control unit.

2. A series thyristor offline detection system according to claim 1, characterized in that: The series thyristor circuit to be tested comprises a thyristor (S1), a thyristor (S2), a resistor (R1), a resistor (R2), a capacitor (C1), and a capacitor (C2).

3. A series thyristor offline detection system according to claim 1 or 2, characterized in that: The series thyristor circuit to be tested includes a thyristor (S1) connected in parallel with a resistor (R1) and a capacitor (C1), wherein the anode of the thyristor (S1) is connected to a connection point (1), and the cathode of the thyristor (S1) is connected to a connection point (2); and a thyristor (S2) connected in parallel with a resistor (R2) and a capacitor (C2), wherein the anode of the thyristor (S2) is connected to a connection point (2), and the cathode of the thyristor (S2) is connected to a connection point (3).

4. The off-line detection system for series thyristors according to claim 1, characterized in that: The positive pole of the DC power supply (Us) of the main circuit is connected to the switch (Ks) and the load resistor (Rs) end to end, and one end of the load resistor (Rs) forms a connection point (1); the negative pole of the DC power supply (Us) is connected to the negative pole of the voltmeter (Vs) to form a connection point (3); and the positive end of the voltmeter (Vs) forms a connection point (2).

5. A series thyristor offline detection system according to claim 1 or 2, characterized in that: The resistance of the load resistor (Rs) is much smaller than the resistance of the resistor (R1) and the resistor (R2).

6. The off-line detection system for series thyristors according to claim 2, characterized in that: The thyristor (S1) and the thyristor (S2) can be regarded as two groups of series thyristor circuits to be tested in which a plurality of thyristors are connected in series.

7. The off-line detection system for series thyristors according to claim 2, characterized in that: The control unit controls the on and off of the switch (Ks) and the thyristor (S1) and the thyristor (S2), detects the value of the voltmeter (Vs), and determines whether the working state of the series thyristor is normal by looking up the table.

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