Thyristor module detection circuit of three-phase alternating current and detection method thereof

Abstract

The invention discloses a three-phase alternating current thyristor module detection circuit and a detection method thereof, and relates to the field of detection circuits, the three-phase alternating current thyristor module detection circuit comprises an input voltage detection circuit, a thyristor two-end voltage detection circuit and a DSP processing unit, and input voltage detection and two-end voltage detection can be carried out on each thyristor module of the three-phase alternating current. Therefore, whether the thyristor module is normal or not is judged, automatic detection of the thyristor module is realized, the detection is accurate, the cost is low, and the device can be assembled on a power supply cabinet. The system also comprises a trigger signal detection circuit, and the trigger signal detection circuit can reflect the fault condition of a trigger signal in an acousto-optic combined alarm mode, thereby further improving the function of the detection circuit, and further improving and guaranteeing the accuracy of subsequent detection.

Description

Technical Field

[0001] The present invention relates to the field of detection circuits, and in particular to a three-phase alternating current thyristor module detection circuit and a detection method thereof. Background Art

[0002] Thyristor modules are widely used in power supply cabinets. Their functions mainly include power switch control, current regulation and conversion, AC-DC conversion, voltage control, power stability improvement, and intelligent voltage regulation systems. In the control of three-phase AC power, each phase voltage line requires a thyristor module and synchronized control. A failure of a thyristor module in one phase will affect the normal power supply of the power supply cabinet. However, current power supply cabinets do not have their own thyristor module detection circuit, which is inconvenient and time-consuming to repair. Therefore, it is necessary to design a reliable and low-cost thyristor module detection circuit and detection method that can be installed in the power supply cabinet. Summary of the Invention

[0003] The purpose of the present invention is to provide a three-phase alternating current thyristor module detection circuit and a detection method thereof, which aims to overcome the above-mentioned problems existing in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solutions: A thyristor module detection circuit for three-phase alternating current includes a first thyristor module, a second thyristor module, and a third thyristor module to be detected, wherein the first thyristor module, the second thyristor module, and the third thyristor module are respectively connected to different phases of the three-phase alternating current, and is characterized in that it also includes an input voltage detection circuit, a thyristor two-terminal voltage detection circuit, and a DSP processing unit; The voltage input terminals of the first thyristor module, the second thyristor module and the third thyristor module are connected to the collection terminal of the input voltage detection circuit, and the output terminal of the input voltage detection circuit is connected to the DSP processing unit for detecting whether the input voltage of each thyristor module is normal; The voltage detection circuit at both ends of the thyristor includes a third voltage acquisition module, a comparator U3A, a comparator U3B, a comparator U8A, a comparator U8B, a comparator U11A, a comparator U11B, a fourth reference voltage module and a fifth reference voltage module. The input divided voltage VA_IN and the output divided voltage VA_OUT of the first thyristor module are raised and proportionally amplified by the third voltage acquisition module and are simultaneously connected to the negative input terminal of the comparator U3A and the positive input terminal of the comparator U3B; the input divided voltage VB_IN and the output divided voltage VB_OUT of the second thyristor module are raised and proportionally amplified by the third voltage acquisition module and are simultaneously connected to the negative input terminal of the comparator U8A and the positive input terminal of the comparator U8B; the input divided voltage VC_IN and the output divided voltage VC_OUT of the third thyristor module are raised and proportionally amplified by the third voltage acquisition module and are simultaneously connected to the negative input terminal of the comparator U11A and the positive input terminal of the comparator U11B; The fourth reference voltage module is simultaneously connected to the positive input terminals of comparator U3A, comparator U8A and comparator U11A, and the fifth reference voltage module is simultaneously connected to the negative input terminals of comparator U3B, comparator U8B and comparator U11B; the output terminals of comparator U3A, comparator U3B, comparator U8A, comparator U8B, comparator U11A and comparator U11B are respectively connected to optical coupler U4, optical coupler U5, optical coupler U6, optical coupler U7, optical coupler U9 and optical coupler U10 The diode anode of the optocoupler U4, optocoupler U5, optocoupler U6, optocoupler U7, optocoupler U9 and optocoupler U10 are grounded. The output ends of the optocoupler U4, optocoupler U6 and optocoupler U9 are connected in series, one end of which is connected to the DSP processing unit and the light-emitting diode LED3, and the other end is grounded. The output ends of the optocoupler U5, optocoupler U7 and optocoupler U10 are connected in series, one end of which is connected to the DSP processing unit and the light-emitting diode LED4, and the other end is grounded.

[0005] Furthermore, it also includes a trigger signal detection circuit, which includes a first voltage acquisition module, a comparator U104A, a light-emitting diode LED1, a comparator U104B, a light-emitting diode LED2 and a first reference voltage module. One trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is proportionally amplified by the first voltage acquisition module and connected to the positive input end of the comparator U104A; another trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is proportionally amplified by the first voltage acquisition module and connected to the positive input end of the comparator U104A; the first reference voltage module is simultaneously connected to the negative input ends of the comparator U104A and the comparator U104B; the output ends of the comparator U104A and the comparator U104B are respectively connected to the light-emitting diode LED1 and the light-emitting diode LED2, and are also connected to the DSP processing unit.

[0006] Furthermore, the trigger signal detection circuit also includes a line sequence detection unit, including an optocoupler U101, a buzzer B1, an optocoupler U102 and a buzzer B2. One trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the diode anode and the diode cathode of the optocoupler U101, and the output end of the optocoupler U101 is connected to the buzzer B1; another trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the diode anode and the diode cathode of the optocoupler U102, and the output end of the optocoupler U102 is connected to the buzzer B2.

[0007] Furthermore, the input voltage detection circuit includes a second voltage acquisition module, a comparator U203A, a comparator U203B, a comparator U205A, a comparator U205B, a comparator U207A, a comparator U207B, a second reference voltage module, and a third reference voltage module. The input terminal divided voltage VA_IN and the input terminal divided voltage VB_IN are amplified and taken as absolute values ​​by the second voltage acquisition module, and are then simultaneously connected to the positive input terminal of the comparator U203A and the negative input terminal of the comparator U203B; the input terminal divided voltage VB_IN and the input terminal divided voltage VC_IN are amplified and taken as absolute values ​​by the second voltage acquisition module, and are then simultaneously connected to the positive input terminal of the comparator U205A and the negative input terminal of the comparator U205B; the input terminal divided voltage VC_IN and the input terminal divided voltage VA_IN are amplified and taken as absolute values ​​by the second voltage acquisition module, and are then simultaneously connected to the positive input terminal of the comparator U207A and the negative input terminal of the comparator U207B; The second reference voltage module is connected to the negative input terminal of comparator U203A, comparator U205A and comparator U207A, and the third reference voltage module is connected to the positive input terminal of comparator U203B, comparator U205B and comparator U207B; the output terminals of comparator U203A, comparator U203B, comparator U205A, comparator U205B, comparator U207A and comparator U207B are respectively connected to the DSP processing unit.

[0008] Furthermore, the first voltage acquisition module includes a proportional amplifier U103A and a proportional amplifier U103B. The negative input terminal of the proportional amplifier U103A is grounded via a capacitor C102 and a resistor R106 connected in parallel, and the output terminal is connected to the positive input terminal via a capacitor C3 and a resistor R107 connected in parallel; the negative input terminal of the proportional amplifier U103B is grounded via a capacitor C105 and a resistor R1116 connected in parallel, and the output terminal is connected to the positive input terminal via a capacitor C106 and a resistor R117 connected in parallel; One trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the positive and negative input terminals of the proportional amplifier U103A, and the output terminal of the proportional amplifier U103A is connected to the positive input terminal of the comparator U104A; the other trigger signal lines of the first thyristor module, the second thyristor module and the third thyristor module are connected to the positive and negative input terminals of the proportional amplifier U103B, and the output terminals of the proportional amplifier U103B are respectively connected to the positive input terminal of the comparator U104B.

[0009] Further, the first thyristor module includes a thyristor D3, a thyristor D6, a resistor R121, a resistor R122, a resistor R123, a resistor R124, a resistor R125 and a resistor R126; The thyristor D3 and the thyristor D6 are connected in parallel and in opposite directions, with the positive electrode of the thyristor D6 serving as the voltage input terminal VIN1 and the other terminal serving as the voltage output terminal VOUT1. The cathode of the thyristor D6 serves as the signal line K1, and the control electrode of the thyristor D6 serves as the signal line G1, serving as one trigger signal line. The cathode of the thyristor D3 serves as the signal line K2, and the control electrode of the thyristor D3 serves as the signal line G2, serving as another trigger signal line. The voltage input terminal VIN1 is grounded after passing through the series-connected resistors R123 and R122, and the connection node of the resistors R123 and R122 is connected through the resistor R121 to serve as the input voltage divider VA_IN; the voltage input terminal VOUT1 is grounded after passing through the series-connected resistors R124 and R125, and the connection node of the resistors R124 and R125 is connected through the resistor R126 to serve as the output voltage divider VA_OUT.

[0010] Furthermore, the third voltage acquisition module includes a proportional amplifier U1A, a capacitor C1, a resistor R23, a resistor R24 ​​and a capacitor C4; the output voltage divider VA_OUT and the input voltage divider VA_IN are respectively connected to the positive and negative input terminals of the proportional amplifier U1A; The negative input terminal of the proportional amplifier U1A is connected to the voltage Va via the capacitor C1 and the resistor R23 connected in parallel, and the output terminal of the proportional amplifier U1A is connected to the positive output terminal via the resistor R24 ​​and the capacitor C4 connected in parallel; the output terminal of the proportional amplifier U1A is simultaneously connected to the negative input terminal of the comparator U3A and the positive input terminal of the comparator U3B.

[0011] Furthermore, the second voltage acquisition module includes a proportional amplifier U201A, a proportional amplifier U202D and a proportional amplifier U202A; The input voltage divider VB_IN and the input voltage divider VA_IN are connected to the positive and negative input terminals of the proportional amplifier U201A respectively; The negative input terminal of the proportional amplifier U201A is grounded via a capacitor C201 and a resistor R201 connected in parallel, and the output terminal is connected to the negative input terminal via a capacitor C202 and a resistor R202 connected in parallel, and the output terminal is connected to the positive input terminal of the proportional amplifier U202D; the negative input terminal of the proportional amplifier U202D is grounded, and the output terminal is connected to the positive input terminal of the proportional amplifier U202A via a diode D201, and the output terminal is connected to the negative input terminal of the proportional amplifier U202A via a diode D202; The output of the proportional amplifier U202A is connected to the positive input of the comparator U203A and the negative input of the comparator U203B.

[0012] A thyristor detection method uses a detection circuit with a structure as described above to perform the following detection on a thyristor module of three-phase alternating current: (1) When the three-phase AC power inputted by the three thyristor modules is detected to be normal, the DSP processing unit repeats the thyristor input voltage detection process through the input voltage detection circuit; until the DSP processing unit detects that the input three-phase AC power is abnormal, it enters step (2); (2) The DSP processing unit issues a cut-off instruction. There is no signal output between the signal line K1 and the signal line G1, and between the signal line K2 and the signal line G2. At this time, the three thyristor modules should be in the cut-off state; proceed to step (3); (3) The DSP processing unit detects through the voltage detection circuit at both ends of the thyristor. If any one of the output voltage Va_in, output voltage Vb_in, and output voltage Vc_in is less than the reference voltage V2 for a long time, the connection terminal DSP-H and the connection terminal DSP-G are at a high level, and the light-emitting diodes LED3 and LED4 are off, indicating that the corresponding thyristor module whose output voltage is less than the reference voltage V2 is abnormal. At this time, the DSP processing unit determines that the thyristor module may be faulty. If the output voltage Va_in, output voltage Vb_in, and connection terminal Vc_in are all greater than the reference voltage V2 during the detection, the connection terminal DSP-H is grounded, the light-emitting diode LED4 lights up, the connection terminal DSP-G is at a high level, and the light-emitting diode LED3 is off. This indicates that the voltage difference between the two ends of the three thyristor modules is large and they are all in the cut-off state. At this time, the DSP processing unit determines that the three thyristor modules are all in the cut-off state and enters step (4). (4) The DSP processing unit repeats the thyristor input voltage detection process through the input voltage detection circuit until the DSP processing unit detects that the input three-phase AC power is normal, and then enters step (5); (5) The DSP processing unit issues a conduction instruction, and the signal lines K1 and G1, as well as the signal lines K2 and G2, have signal outputs. At this time, the three thyristor modules should be in the conduction state; proceed to step (6); (6) The DSP processing unit detects through the voltage detection circuit at both ends of the thyristor. If any one of the output voltage Va_in, output voltage vb_in, and output voltage vc_in is greater than the reference voltage V1 for a long time, the connection terminal DSP-H and the connection terminal DSP-G are at a high level, and the light-emitting diodes LED3 and LED4 are both off, indicating that the corresponding thyristor module whose output voltage is greater than the reference voltage V1 is abnormal. At this time, the DSP processing unit determines that the thyristor module may be faulty. If the output voltage Va_in, output voltage Vb_in, and output voltage Vc_in are all less than the reference voltage V1, the connection terminal DSP-G is grounded, the connection terminal DSP-H is at a high level, the light-emitting diode LED3 is on, and the light-emitting diode LED4 is off, indicating that the voltage difference between the two ends of the three thyristor modules is small and they are all in the on state. At this time, the DSP processing unit determines that the three-phase thyristor module is in the on state and jumps to step (1).

[0013] Furthermore, in step (1) and step (4), the DSP processing unit performs a thyristor input voltage detection process through an input voltage detection circuit, specifically: When the reference voltage Vmax>output voltage Va_in1, output voltage Vb_in1, output voltage Vc_in1>reference voltage Vmin, connection terminals DSP_A, DSP_B, DSP_C, DSP_D, DSP_E, and DSP_F are at a high level. At this time, the DSP processing unit determines that the three-phase AC power input by the three thyristor modules is normal; otherwise, the DSP processing unit determines that the three-phase AC power is abnormal.

[0014] Furthermore, before step (1), the DSP processing unit also includes performing a trigger signal detection process through a trigger signal detection circuit, which is specifically as follows: When the DSP processing unit issues a cut-off instruction, if LED1 and LED2 light up and buzzer B1 and buzzer B2 do not make a sound; when the DSP processing unit issues a turn-on instruction, if LED1 and LED2 go out and buzzer B1 and buzzer B2 do not make a sound, then it is determined that the two trigger signal lines are normal and the process goes to step (1); otherwise, there is an abnormality in the two trigger signal lines.

[0015] Compared with the prior art, the present invention has the following beneficial effects: First, the present invention includes an input voltage detection circuit, a thyristor two-end voltage detection circuit and a DSP processing unit, which can perform input voltage detection and two-end voltage detection on each thyristor module of three-phase AC power, thereby judging whether the thyristor module is normal, realizing automatic detection of the thyristor module, with accurate detection, low cost, and can be assembled in the power supply cabinet.

[0016] Secondly, the present invention also includes a trigger signal detection circuit, which can reflect the fault condition of the trigger signal in an alarm manner combining sound and light, further improving the function of the detection circuit and further enhancing the accuracy of subsequent detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a structural block diagram of a thyristor module detection circuit for three-phase alternating current in the present invention, in which only the thyristor module and its detection circuit for one phase are shown.

[0018] Figure 2 This is a circuit diagram of three transistor modules in the present invention. From top to bottom, they are the first transistor module, the second transistor module, and the third transistor module.

[0019] Figure 3 In the present invention, the structure of the voltage detection circuit at both ends of the thyristor is Figure 1 .

[0020] Figure 4 In the present invention, the structure of the voltage detection circuit at both ends of the thyristor is Figure 2 .

[0021] Figure 5 In the present invention, the structure of the input voltage detection circuit is Figure 1 .in, Figure 5 The left edge of Figure 6 The right edge of the splice.

[0022] Figure 6 In the present invention, the structure of the input voltage detection circuit is Figure 2 .

[0023] Figure 7 This is a structural diagram of the trigger signal detection circuit in the present invention.

[0024] Figure 8 This is a flow chart of a detection method for a three-phase alternating current thyristor module in the present invention. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described below with reference to the accompanying drawings. In order to fully understand the present invention, many details are described below, but for those skilled in the art, the present invention can be implemented without these details.

[0026] (1) Detection circuit framework like Figure 1 As shown, a thyristor module detection circuit for three-phase alternating current includes an input voltage detection circuit, a thyristor voltage detection circuit, a DSP processing unit, a trigger signal detection circuit, and three thyristor modules to be detected, and the three thyristor modules are respectively connected to different phases of the three-phase alternating current.

[0027] The connection method of the input voltage detection circuit, the voltage detection circuit across the thyristor, the DSP processing unit and the three thyristor modules is the same. Take one of the thyristor modules as an example: The voltage at both ends of the thyristor module is connected to the collection end of the voltage detection circuit at both ends of the thyristor. The output end of the voltage detection circuit at both ends of the thyristor is connected to the DSP processing unit for detecting whether the voltage at both ends of the thyristor module is normal.

[0028] The voltage input end of the thyristor module is connected to the acquisition end of the input voltage detection circuit, and the output end of the input voltage detection circuit is connected to the DSP processing unit for detecting whether the input voltage of the thyristor module is normal.

[0029] The DSP processing unit is connected to the thyristor module and provides a trigger signal for the thyristor module.

[0030] The trigger signal end of the thyristor module is connected to the acquisition end of the trigger signal detection circuit, and the output end of the trigger signal detection circuit is connected to the DSP processing unit for detecting whether the trigger signal of the thyristor module is normal.

[0031] (2) Thyristor module like Figure 1 and Figure 2 As shown, the three thyristor modules are a first thyristor module, a second thyristor module, and a third thyristor module, wherein the first thyristor module includes thyristor D3, thyristor D6, resistor R121, resistor R122, resistor R123, resistor R124, resistor R125, and resistor R126.

[0032] Thyristor D3 and thyristor D6 are connected in parallel and in opposite directions. The positive electrode of thyristor D6 serves as the voltage input terminal VIN1, and the other terminal serves as the voltage output terminal VOUT1. The cathode of thyristor D6 serves as signal line K1, and the control electrode of thyristor D6 serves as signal line G1, which serves as one trigger signal line. The cathode of thyristor D3 serves as signal line K2, and the control electrode of thyristor D3 serves as signal line G2, which serves as another trigger signal line.

[0033] The voltage input terminal VIN1 is grounded after passing through resistors R123 and R122 connected in series, and the connection node of resistors R123 and R122 is connected through resistor R121 to serve as the input voltage divider VA_IN. The voltage input terminal VOUT1 is grounded after passing through resistors R124 and R125 connected in series, and the connection node of resistors R124 and R125 is connected through resistor R126 to serve as the output voltage divider VA_OUT.

[0034] The voltage input terminal VIN1 is used to connect to the A-phase power supply line of the three-phase AC power supply and is also used to connect to the acquisition terminal of the input voltage detection circuit. The input voltage divider VA_IN and the output voltage divider VA_OUT are used to connect to the acquisition terminal of the two-terminal voltage of the thyristor module. Signal line K1 and signal line G1 form one trigger signal line, and signal line K2 and signal line G2 form another trigger signal line. These two trigger signal lines are synchronized and are used to connect to the trigger signal output terminal of the DSP processing module and the acquisition terminal of the trigger signal detection circuit.

[0035] like Figure 2 As shown, preferably, the first thyristor module further includes a filter circuit consisting of a capacitor C110, a capacitor C111, a resistor R139 and a resistor R140, and two ends of the filter circuit are respectively connected to the voltage input terminal VIN1 and the voltage output terminal VOUT1.

[0036] like Figure 2 As shown, the second thyristor module is connected to the B-phase power supply line of the three-phase AC power, and the third thyristor module is connected to the C-phase power supply line of the three-phase AC power. In addition, the structures of the second and third thyristor modules are the same as those of the first thyristor module, and their specific structures are not repeated here.

[0037] (3) Voltage detection circuit across thyristor like Figure 3 and Figure 4 As shown, the voltage detection circuit across the thyristor mainly includes a third voltage acquisition module, comparator U3A, comparator U3B, comparator U8A, comparator U8B, comparator U11A, comparator U11B, a fourth reference voltage module and a fifth reference voltage module.

[0038] The input voltage VA_IN and output voltage VA_OUT of the first thyristor module are boosted and amplified by the third voltage acquisition module and then connected to the negative input of comparator U3A and the positive input of comparator U3B. The input voltage VB_IN and output voltage VB_OUT of the second thyristor module are boosted and amplified by the third voltage acquisition module and then connected to the negative input of comparator U8A and the positive input of comparator U8B. The input voltage VC_IN and output voltage VC_OUT of the third thyristor module are boosted and amplified by the third voltage acquisition module and then connected to the negative input of comparator U11A and the positive input of comparator U11B.

[0039] The fourth reference voltage module is simultaneously connected to the positive input terminals of comparators U3A, U8A, and U11A. The fifth reference voltage module is simultaneously connected to the negative input terminals of comparators U3B, U8B, and U11B. The output terminals of comparators U3A, U3B, U8A, U8B, U11A, and U11B are respectively connected to the anodes of the diodes of optocouplers U4, U5, U6, U7, U9, and U10. The cathodes of the diodes of optocouplers U4, U5, U6, U7, U9, and U10 are grounded. The output terminals of optocouplers U4, U6, and U9 are connected in series, with one end connected to the DSP processing unit and light-emitting diode LED3, and the other end connected to ground. The output ends of the optical coupler U5 , the optical coupler U7 and the optical coupler U10 are connected in series, one end of which is connected to the DSP processing unit and the light emitting diode LED4 , and the other end is grounded.

[0040] The reference voltage V1 provided by the fourth reference voltage module is the turn-on threshold voltage of the thyristor, and the reference voltage V2 provided by the fifth reference voltage module is the turn-off threshold voltage of the thyristor. Specifically, the fourth reference voltage module is composed of a power supply, resistors R19 and R20, and capacitor C2. The fifth reference voltage module is composed of a power supply, resistors R21 and R22, and capacitor C3.

[0041] like Figure 3 and Figure 4As shown, taking the branch where the first thyristor module is located as an example, the specific structure of one branch of the third voltage acquisition module is further described: The third voltage acquisition module includes a proportional amplifier U1A, a capacitor C1, resistors R23, R24, and a capacitor C4. The output voltage divider VA_OUT and the input voltage divider VA_IN are connected to the positive and negative input terminals of proportional amplifier U1A, respectively. The negative input terminal of proportional amplifier U1A is connected to voltage Va via capacitor C1 and resistor R23 connected in parallel. The output terminal of proportional amplifier U1A is connected to the positive output terminal via resistor R24 ​​and capacitor C4 connected in parallel. The output terminal of proportional amplifier U1A is simultaneously connected to the negative input terminal of comparator U3A and the positive input terminal of comparator U3B. Voltage Va is provided by a reference voltage module formed by connecting a power supply, resistors R51, R52, and capacitor C14.

[0042] like Figure 3 and Figure 4 As shown, the specific structure of the third voltage acquisition module in the branch where the second thyristor module and the third thyristor module are located is the same as the above specific structure and will not be repeated here.

[0043] (4) Trigger signal detection circuit like Figure 7 As shown, the trigger signal detection circuit includes a line sequence detection unit, a first voltage acquisition module, a comparator U104A, a light emitting diode LED1, a comparator U104B, a light emitting diode LED2 and a first reference voltage module.

[0044] The line sequence detection unit includes an optocoupler U101, a buzzer B1, an optocoupler U102, and a buzzer B2. One trigger signal line for each of the first, second, and third thyristor modules is connected to the anode and cathode of the diode in optocoupler U101, and the output of optocoupler U101 is connected to buzzer B1. Another trigger signal line for each of the first, second, and third thyristor modules is connected to the anode and cathode of the diode in optocoupler U102, and the output of optocoupler U102 is connected to buzzer B2.

[0045] One trigger signal line from each of the first, second, and third thyristor modules is amplified by the first voltage acquisition module and then connected to the positive input of comparator U104A. Another trigger signal line from each of the first, second, and third thyristor modules is amplified by the first voltage acquisition module and then connected to the positive input of comparator U104A. A first reference voltage module is connected to the negative inputs of both comparators U104A and U104B. The outputs of comparators U104A and U104B are connected to light-emitting diodes LED1 and LED2, respectively, and are also connected to the DSP processing unit. The reference voltage Vref provided by the first reference voltage module serves as the voltage threshold for the thyristor trigger signal. The first reference voltage module consists of a power supply, resistors R108 and R109 connected in series, and then grounded.

[0046] Specifically, the first voltage acquisition module includes a proportional amplifier U103A and a proportional amplifier U103B. The negative input of proportional amplifier U103A is connected to ground via a capacitor C102 and a resistor R106 connected in parallel, and the output is connected to the positive input via a capacitor C3 and a resistor R107 connected in parallel. The negative input of proportional amplifier U103B is connected to ground via a capacitor C105 and a resistor R1116 connected in parallel, and the output is connected to the positive input via a capacitor C106 and a resistor R117 connected in parallel. The trigger signal lines (i.e., signal line G1 and signal line K1) of the first, second, and third thyristor modules are each connected to the positive and negative inputs of proportional amplifier U103A, and the output of proportional amplifier U103A is connected to the positive input of comparator U104A. The other trigger signal lines (i.e., signal line G2 and signal line K3) of the first thyristor module, the second thyristor module, and the third thyristor module are all connected to the positive and negative input terminals of the proportional amplifier U103B, and the output terminals of the proportional amplifier U103B are respectively connected to the positive input terminal of the comparator U104B.

[0047] (5) Input voltage detection circuit like Figure 5 and Figure 6 As shown, the input voltage detection circuit includes a second voltage acquisition module, a comparator U203A, a comparator U203B, a comparator U205A, a comparator U205B, a comparator U207A, a comparator U207B, a second reference voltage module and a third reference voltage module.

[0048] The input voltages VA_IN and VB_IN of the first transistor module are amplified and their absolute values ​​are taken by the second voltage acquisition module, and then connected to the positive input of comparator U203A and the negative input of comparator U203B. The input voltages VB_IN and VC_IN of the second transistor module are amplified and their absolute values ​​are taken by the second voltage acquisition module, and then connected to the positive input of comparator U205A and the negative input of comparator U205B. The input voltages VC_IN and VA_IN of the third transistor module are amplified and their absolute values ​​are taken by the second voltage acquisition module, and then connected to the positive input of comparator U207A and the negative input of comparator U207B.

[0049] The second reference voltage module is connected to the negative input terminals of comparators U203A, U205A, and U207A. The third reference voltage module is connected to the positive input terminals of comparators U203B, U205B, and U207B. The output terminals of comparators U203A, U203B, U205A, U205B, U207A, and U207B are connected to the DSP processing unit's connectors DSP_A, DSP_B, DSP_C, DSP_D, DSP_E, and DSP_F, respectively. The reference voltage Vmax provided by the second reference voltage module is the input voltage overvoltage point, and the reference voltage Vmin provided by the third reference voltage module is the input voltage undervoltage point.

[0050] like Figure 5 and Figure 6 As shown, taking the branch where the first thyristor module is located as an example, the specific structure of one branch of the second voltage acquisition module is further described: The second voltage acquisition module includes a proportional amplifier U201A, a proportional amplifier U202D, and a proportional amplifier U202A. The input voltage divider VB_IN and the input voltage divider VA_IN are connected to the positive and negative inputs of proportional amplifier U201A, respectively. The negative input of proportional amplifier U201A is connected to ground via a capacitor C201 and a resistor R201 connected in parallel. The output is connected to the negative input via a capacitor C202 and a resistor R202 connected in parallel. The output is also connected to the positive input of proportional amplifier U202D. The negative input of proportional amplifier U202D is grounded, and the output is connected to the positive input of proportional amplifier U202A via a diode D201. The output is also connected to the negative input of proportional amplifier U202A via a diode D202. The output of proportional amplifier U202A is simultaneously connected to the positive input of comparator U203A and the negative input of comparator U203B.

[0051] like Figure 5 and Figure 6 As shown, the specific structure of the second voltage acquisition module in the branch where the second thyristor module and the third thyristor module are located is the same as the above specific structure and will not be repeated here.

[0052] (6) Detection methods like Figures 1 to 8 As shown, a thyristor detection method uses the detection circuit with the above structure to perform the following detection on three thyristor modules (i.e., the first thyristor module, the second thyristor module, and the third thyristor module) of three-phase alternating current: (1) When the three-phase AC power input by the three thyristor modules is detected to be normal, the DSP processing unit repeats the thyristor input voltage detection process through the input voltage detection circuit. Until the DSP processing unit detects that the input three-phase AC power is abnormal, it enters step (2).

[0053] (2) The DSP processing unit issues a cutoff instruction. There is no signal output between signal line K1 and signal line G1, and between signal line K2 and signal line G2. At this time, the three thyristor modules should be in the cutoff state. Go to step (3).

[0054] (3) The DSP processing unit detects the voltage at both ends of the thyristor through the voltage detection circuit. If any one of the output voltage Va_in, output voltage Vb_in, and output voltage Vc_in is less than the reference voltage V2 for a long time, the connection terminal DSP-H and the connection terminal DSP-G are at a high level, and the light-emitting diodes LED3 and LED4 are both off, indicating that the corresponding thyristor module whose output voltage is less than the reference voltage V2 is abnormal. At this time, the DSP processing unit determines that the thyristor module may be faulty. If the output voltage Va_in, output voltage Vb_in, and connection terminal Vc_in are all greater than the reference voltage V2 during the detection, the connection terminal DSP-H is grounded, the light-emitting diode LED4 lights up, the connection terminal DSP-G is at a high level, and the light-emitting diode LED3 is off, indicating that the voltage difference between the two ends of the three thyristor modules is large and they are all in the cut-off state. At this time, the DSP processing unit determines that the three thyristor modules are all in the cut-off state and enters step (4).

[0055] (4) The DSP processing unit repeats the thyristor input voltage detection process through the input voltage detection circuit until the DSP processing unit detects that the input three-phase AC power is normal, and then enters step (5).

[0056] (5) The DSP processing unit issues a conduction instruction, and signal lines K1 and G1, as well as signal lines K2 and G2, have signal outputs. At this time, the three thyristor modules should be in the conduction state. Go to step (6).

[0057] (6) The DSP processing unit detects the voltage at both ends of the thyristor through the voltage detection circuit. If any one of the output voltage Va_in, output voltage vb_in, and output voltage vc_in is greater than the reference voltage V1 for a long time, the connection terminal DSP-H and the connection terminal DSP-G are at a high level, and the light-emitting diodes LED3 and LED4 are both off, indicating that the corresponding thyristor module whose output voltage is greater than the reference voltage V1 is abnormal. At this time, the DSP processing unit determines that the thyristor module may be faulty. If the output voltage Va_in, output voltage Vb_in, and output voltage Vc_in are all less than the reference voltage V1, the connection terminal DSP-G is grounded, the connection terminal DSP-H is at a high level, the light-emitting diode LED3 is on, and the light-emitting diode LED4 is off, indicating that the voltage difference between the two ends of the three thyristor modules is small and they are all in the on state. At this time, the DSP processing unit determines that the three-phase thyristor module is in the on state and jumps to step (1).

[0058] Furthermore, in step (1) and step (4), the DSP processing unit performs a thyristor input voltage detection process through an input voltage detection circuit, specifically: When the reference voltage Vmax > the output voltage Va_in1, the output voltage Vb_in1, and the output voltage Vc_in1 > the reference voltage Vmin, the connection terminals DSP_A, DSP_B, DSP_C, DSP_D, DSP_E, and DSP_F are at a high level, and the DSP processing unit determines that the three-phase AC power input by the three thyristor modules is normal. Otherwise, the DSP processing unit determines that the three-phase AC power is abnormal.

[0059] Furthermore, thyristor input voltage detection is specifically divided into the following situations: When the reference voltage Vmax > the output voltage Va_in1 > the reference voltage Vmin, the connection terminals DSP_A and DSP_B of the input voltage detection circuit are high. When the reference voltage Vmax > the output voltage Vb_in1 > the reference voltage Vmin, the connection terminals DSP_C and DSP_D of the input voltage detection circuit are high. When the reference voltage Vmax > the output voltage Vc_in1 > the reference voltage Vmin, the connection terminals DSP_E and DSP_F of the input voltage detection circuit are high.

[0060] When the output voltage Va_in1 is less than the reference voltage Vmin, it indicates that the line voltage VAB is undervoltage, and the connection terminal DSP_A is at a low level. When Va_in1 is greater than the reference voltage Vmax, it indicates that the line voltage VAB is overvoltage, and the connection terminal DSP_B is at a low level.

[0061] When the output voltage Vb_in1 is less than the reference voltage Vmin, it indicates that the line voltage VBC is undervoltage, and the connection terminal DSP_C is at a low level. When the output voltage Vb_in1 is greater than the reference voltage Vmax, it indicates that the line voltage VBC is overvoltage, and the connection terminal DSP_D is at a low level.

[0062] When the output voltage Vc_in1 is less than the reference voltage Vmin, it indicates that the line voltage VCA is undervoltage, and the connection terminal DSP_E is at a low level. When the output voltage Vc_in1 is greater than the reference voltage Vmax, it indicates that the line voltage VCA is overvoltage, and the connection terminal DSP_F is at a low level.

[0063] Therefore, the DSP processing unit can further determine and give the specific abnormal conditions of the input voltage according to the feedback signals of the above-mentioned several conditions.

[0064] Furthermore, before step (1), the DSP processing unit also includes performing a trigger signal detection process through a trigger signal detection circuit, which is as follows: When the DSP processing unit issues a cut-off instruction, if LED1 and LED2 light up and buzzer B1 and buzzer B2 do not make a sound; when the DSP processing unit issues a turn-on instruction, if LED1 and LED2 go out and buzzer B1 and buzzer B2 do not make a sound, then it is determined that the two trigger signal lines are normal and the process goes to step (1); otherwise, there is an abnormality in the two trigger signal lines.

[0065] Furthermore, trigger signal detection is specifically divided into the following situations: When the line sequence of the two trigger signal lines is normal and there is a trigger signal, the connection terminals DSP_I and DSP_J are at a high level, and the light-emitting diodes LED1 and LED2 are off. When the line sequence of the two trigger signal lines is normal and there is no trigger signal, the connection terminals DSP_I and DSP_J are at a low level, and the light-emitting diodes LED1 and LED2 are on.

[0066] When the signal line is open, such as signal line G1 is broken, buzzers B1 and B2 will not sound; when the connection terminal DSP_I is low, LED1 will light up; when the connection terminal DSP_J is high, LED2 will go out.

[0067] When the signal lines are out of sequence, such as G1 signal and K1 signal are connected reversely, buzzer B1 will sound, terminal DSP_I will be at a low level, LED1 will light up, buzzer B2 will not sound, terminal DSP_J will be at a high level, LED2 will be off.

[0068] Therefore, the operator can further identify the specific abnormal situation of the trigger signal based on the sound and light alarms in the above-mentioned situations.

[0069] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited to this. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A thyristor module detection circuit for three-phase alternating current, comprising a first thyristor module, a second thyristor module and a third thyristor module to be detected, wherein the first thyristor module, the second thyristor module and the third thyristor module are respectively connected to different phases of the three-phase alternating current, characterized in that: It also includes an input voltage detection circuit, a voltage detection circuit at both ends of the thyristor, and a DSP processing unit; The voltage input terminals of the first thyristor module, the second thyristor module and the third thyristor module are connected to the collection terminal of the input voltage detection circuit, and the output terminal of the input voltage detection circuit is connected to the DSP processing unit to detect whether the input voltage of each thyristor module is normal; The voltage detection circuit at both ends of the thyristor includes a third voltage acquisition module, a comparator U3A, a comparator U3B, a comparator U8A, a comparator U8B, a comparator U11A, a comparator U11B, a fourth reference voltage module and a fifth reference voltage module. The input voltage VA_IN and the output voltage VA_OUT of the first thyristor module are connected to the negative input of the comparator U3A and the positive input of the comparator U3B after being lifted and proportionally amplified by the third voltage acquisition module; the input voltage VB_IN and the output voltage VB_OUT of the second thyristor module are connected to the negative input of the comparator U8A and the positive input of the comparator U8B after being lifted and proportionally amplified by the third voltage acquisition module; the input voltage VC_IN and the output voltage VC_OUT of the third thyristor module are connected to the negative input of the comparator U11A and the positive input of the comparator U11B after being lifted and proportionally amplified by the third voltage acquisition module; The fourth reference voltage module is simultaneously connected to the positive input terminals of the comparator U3A, the comparator U8A and the comparator U11A, and the fifth reference voltage module is simultaneously connected to the negative input terminals of the comparator U3B, the comparator U8B and the comparator U11B; the output terminals of the comparator U3A, the comparator U3B, the comparator U8A, the comparator U8B, the comparator U11A and the comparator U11B are respectively connected to the optical coupler U4, the optical coupler U5, the optical coupler U6, the optical coupler U7, the optical coupler U9 and the optical coupler U10 The diode anode of the optical coupler U4, the optical coupler U5, the optical coupler U6, the optical coupler U7, the optical coupler U9 and the optical coupler U10 are grounded; after the output ends of the optical coupler U4, the optical coupler U6 and the optical coupler U9 are connected in series, one end is connected to the DSP processing unit and the light-emitting diode LED3, and the other end is grounded; after the output ends of the optical coupler U5, the optical coupler U7 and the optical coupler U10 are connected in series, one end is connected to the DSP processing unit and the light-emitting diode LED4, and the other end is grounded.

2. The three-phase alternating current thyristor module detection circuit according to claim 1, characterized in that: It also includes a trigger signal detection circuit, which includes a first voltage acquisition module, a comparator U104A, a light-emitting diode LED1, a comparator U104B, a light-emitting diode LED2 and a first reference voltage module. One trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is proportionally amplified by the first voltage acquisition module and connected to the positive input end of the comparator U104A; another trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is proportionally amplified by the first voltage acquisition module and connected to the positive input end of the comparator U104A; the first reference voltage module is simultaneously connected to the negative input ends of the comparator U104A and the comparator U104B; the output ends of the comparator U104A and the comparator U104B are respectively connected to the light-emitting diode LED1 and the light-emitting diode LED2, and are simultaneously connected to the DSP processing unit.

3. The three-phase alternating current thyristor module detection circuit according to claim 2, characterized in that: The trigger signal detection circuit also includes a line sequence detection unit, including an optical coupler U101, a buzzer B1, an optical coupler U102 and a buzzer B2. One trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the diode anode and the diode cathode of the optical coupler U101, and the output end of the optical coupler U101 is connected to the buzzer B1; another trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the diode anode and the diode cathode of the optical coupler U102, and the output end of the optical coupler U102 is connected to the buzzer B2.

4. A three-phase alternating current thyristor module detection circuit according to claim 1, 2 or 3, characterized in that: The input voltage detection circuit includes a second voltage acquisition module, a comparator U203A, a comparator U203B, a comparator U205A, a comparator U205B, a comparator U207A, a comparator U207B, a second reference voltage module and a third reference voltage module. After the input voltage divided VA_IN and the input voltage divided VB_IN are amplified and taken as absolute values ​​by the second voltage acquisition module, they are simultaneously connected to the positive input terminal of the comparator U203A and the negative input terminal of the comparator U203B; after the input voltage divided VB_IN and the input voltage divided VC_IN are amplified and taken as absolute values ​​by the second voltage acquisition module, they are simultaneously connected to the positive input terminal of the comparator U205A and the negative input terminal of the comparator U205B; after the input voltage divided VC_IN and the input voltage divided VA_IN are amplified and taken as absolute values ​​by the second voltage acquisition module, they are simultaneously connected to the positive input terminal of the comparator U207A and the negative input terminal of the comparator U207B; The second reference voltage module is connected to the negative input terminal of comparator U203A, comparator U205A and comparator U207A, and the third reference voltage module is connected to the positive input terminal of comparator U203B, comparator U205B and comparator U207B; the output terminals of comparator U203A, comparator U203B, comparator U205A, comparator U205B, comparator U207A and comparator U207B are respectively connected to the DSP processing unit.

5. The three-phase alternating current thyristor module detection circuit according to claim 2, characterized in that: The first voltage acquisition module includes a proportional amplifier U103A and a proportional amplifier U103B, wherein the negative input terminal of the proportional amplifier U103A is grounded via a capacitor C102 and a resistor R106 connected in parallel, and the output terminal is connected to the positive input terminal via a capacitor C3 and a resistor R107 connected in parallel; the negative input terminal of the proportional amplifier U103B is grounded via a capacitor C105 and a resistor R1116 connected in parallel, and the output terminal is connected to the positive input terminal via a capacitor C106 and a resistor R117 connected in parallel; One trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the positive and negative input terminals of the proportional amplifier U103A, and the output terminal of the proportional amplifier U103A is connected to the positive input terminal of the comparator U104A; another trigger signal line of the first thyristor module, the second thyristor module and the third thyristor module is connected to the positive and negative input terminals of the proportional amplifier U103B, and the output terminal of the proportional amplifier U103B is respectively connected to the positive input terminal of the comparator U104B.

6. The three-phase alternating current thyristor module detection circuit according to claim 1, characterized in that: The first thyristor module includes a thyristor D3, a thyristor D6, a resistor R121, a resistor R122, a resistor R123, a resistor R124, a resistor R125 and a resistor R126; The thyristor D3 and the thyristor D6 are connected in parallel and in opposite directions, with the positive electrode of the thyristor D6 being the voltage input terminal VIN1 and the other end being the voltage output terminal VOUT1; the cathode of the thyristor D6 being the signal line K1, and the control electrode of the thyristor D6 being the signal line G1, serving as a trigger signal line; The cathode of the thyristor D3 is the signal line K2, and the control pole of the thyristor D3 is the signal line G2, which serves as another trigger signal line; The voltage input terminal VIN1 is grounded after being connected in series with resistors R123 and R122, and the connection node between resistors R123 and R122 is connected via resistor R121 to serve as an input voltage divider VA_IN; the voltage input terminal VOUT1 is grounded after being connected in series with resistors R124 and R125, and the connection node between resistors R124 and R125 is connected via resistor R126 to serve as an output voltage divider VA_OUT.

7. The three-phase alternating current thyristor module detection circuit according to claim 6, characterized in that: The third voltage acquisition module includes a proportional amplifier U1A, a capacitor C1, a resistor R23, a resistor R24 ​​and a capacitor C4; the output voltage division VA_OUT and the input voltage division VA_IN are respectively connected to the positive and negative input terminals of the proportional amplifier U1A; The negative input terminal of the proportional amplifier U1A is connected to the voltage Va via the capacitor C1 and the resistor R23 connected in parallel, and the output terminal of the proportional amplifier U1A is connected to the positive output terminal via the resistor R24 ​​and the capacitor C4 connected in parallel; the output terminal of the proportional amplifier U1A is simultaneously connected to the negative input terminal of the comparator U3A and the positive input terminal of the comparator U3B.

8. The three-phase alternating current thyristor module detection circuit according to claim 4, characterized in that: The second voltage acquisition module includes a proportional amplifier U201A, a proportional amplifier U202D and a proportional amplifier U202A; The input voltage divider VB_IN and the input voltage divider VA_IN are respectively connected to the positive and negative input terminals of the proportional amplifier U201A; The negative input terminal of the proportional amplifier U201A is grounded via a capacitor C201 and a resistor R201 connected in parallel, and the output terminal is connected to the negative input terminal via a capacitor C202 and a resistor R202 connected in parallel, and the output terminal is connected to the positive input terminal of the proportional amplifier U202D; the negative input terminal of the proportional amplifier U202D is grounded, and the output terminal is connected to the positive input terminal of the proportional amplifier U202A via a diode D201, and the output terminal is connected to the negative input terminal of the proportional amplifier U202A via a diode D202; The output of the proportional amplifier U202A is simultaneously connected to the positive input of the comparator U203A and the negative input of the comparator U203B.

9. A thyristor detection method, characterized in that: The detection circuit according to any one of claims 1 to 8 is used to detect the thyristor module of three-phase alternating current as follows: (1) When the three-phase AC power input by the three thyristor modules is detected to be normal, the DSP processing unit repeats the thyristor input voltage detection process through the input voltage detection circuit; until the DSP processing unit detects that the input three-phase AC power is abnormal, it enters step (2); (2) The DSP processing unit issues a cut-off instruction, and there is no signal output between the signal line K1 and the signal line G1, and between the signal line K2 and the signal line G2. At this time, the three thyristor modules should be in the cut-off state; proceed to step (3); (3) The DSP processing unit detects through the voltage detection circuit at both ends of the thyristor. If any one of the output voltage Va_in, output voltage Vb_in, and output voltage Vc_in is less than the reference voltage V2 for a long time, the connection terminal DSP-H and the connection terminal DSP-G are at a high level, and the light-emitting diodes LED3 and LED4 are off, indicating that the corresponding thyristor module whose output voltage is less than the reference voltage V2 is abnormal. At this time, the DSP processing unit determines that the thyristor module may be faulty; if the output voltage Va_in, output voltage Vb_in, and connection terminal Vc_in are all greater than the reference voltage V2 during the detection, the connection terminal DSP-H is grounded, the light-emitting diode LED4 is on, the connection terminal DSP-G is at a high level, and the light-emitting diode LED3 is off, indicating that the voltage difference between the two ends of the three thyristor modules is large and they are all in the cut-off state. At this time, the DSP processing unit determines that the three thyristor modules are all in the cut-off state and enters step (4); (4) The DSP processing unit repeats the thyristor input voltage detection process through the input voltage detection circuit until the DSP processing unit detects that the input three-phase AC power is normal, and then enters step (5); (5) The DSP processing unit issues a conduction instruction, and the signal line K1 and the signal line G1, and the signal line K2 and the signal line G2 have signal outputs. At this time, the three thyristor modules should be in the conduction state; proceed to step (6); (6) The DSP processing unit detects through the voltage detection circuit at both ends of the thyristor. If any one of the output voltage Va_in, the output voltage vb_in, and the output voltage vc_in is greater than the reference voltage V1 for a long time, the connection terminals DSP-H and DSP-G are at a high level, and the light-emitting diodes LED3 and LED4 are both off, indicating that the corresponding thyristor module whose output voltage is greater than the reference voltage V1 is abnormal. At this time, the DSP processing unit determines that the thyristor module may be faulty; if the output voltage Va_in, the output voltage Vb_in, and the output voltage Vc_in are all less than the reference voltage V1, the connection terminal DSP-G is grounded, the connection terminal DSP-H is at a high level, the light-emitting diode LED3 is on, and the light-emitting diode LED4 is off, indicating that the voltage difference between the two ends of the three thyristor modules is small and they are all in the on state. At this time, the DSP processing unit determines that the three-phase thyristor module is in the on state and jumps to step (1).

10. The method for detecting a thyristor according to claim 9, characterized in that: In the steps (1) and (4), the DSP processing unit performs a thyristor input voltage detection process through an input voltage detection circuit, specifically: When the reference voltage Vmax>output voltage Va_in1, output voltage Vb_in1, output voltage Vc_in1>reference voltage Vmin, connection terminals DSP_A, DSP_B, DSP_C, DSP_D, DSP_E, and DSP_F are at high levels. At this time, the DSP processing unit determines that the three-phase AC power input by the three thyristor modules is normal; otherwise, the DSP processing unit determines that the three-phase AC power is abnormal.

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