A conduction angle detection device and method for thyristor used in textile electronic control system

Abstract

The present invention relates to the technical field of thyristors for textile electronic control systems, and specifically to a conduction angle detection device and method for thyristors for textile electronic control systems. A conduction angle detection device for thyristors for textile electronic control systems comprises a detection device body, including an optocoupler, which operates in a saturation region or a cutoff region; a first resistor, whose first end is connected to the positive electrode of the positive side of the optocoupler; a first power supply, connected to the second end of the first resistor; a second resistor, whose first end is connected to the first interface end of the secondary side of the optocoupler; a third resistor, whose first end is connected to the second interface end of the secondary side of the optocoupler; a first connection interface, connected to the second end of the second resistor, and used to connect to the first anode of the thyristor to be detected; a second connection interface, connected to the second end of the third resistor, and used to connect to the second anode of the thyristor to be detected. The conduction angle detection device and method of the present application can very easily realize the conduction angle detection of bidirectional thyristors.

Description

Technical Field

[0001] The present invention relates to the technical field of thyristors for textile electronic control systems, and in particular to a conduction angle detection device and method for thyristors for textile electronic control systems. Background Art

[0002] A thyristor (SCR), also known as a silicon controlled device (Cycler), is a semi-controlled device. It is fed with alternating current (AC), which has a 360-degree cycle: a positive half-cycle of 180 degrees and a negative half-cycle of 180 degrees. When AC current passes through the SCR, it allows the positive half-cycle (a positive voltage is applied to the SCR's anode during the positive half-cycle) to pass, while blocking the negative half-cycle. However, the SCR does not allow the entire positive half-cycle to pass. Starting from the moment the positive half-cycle is applied to the SCR's anode, a trigger pulse must be applied to the SCR's control electrode at some point within the 180-degree angle. This is when the SCR begins to conduct until it shuts off at the end of the positive half-cycle. The electrical angle corresponding to the non-conducting portion is called the control angle, while the electrical angle corresponding to the conducting portion is called the conduction angle. For example, if a pulse is applied at 30 degrees, the SCR will only allow the remaining 150 degrees to pass. Therefore, its control angle is 30 degrees, and its conduction angle is 150 degrees.

[0003] Bidirectional thyristors (TRIACs) operate in a similar manner, except that they can pass both positive and negative 180°C current (a trigger pulse is also required for negative 180°C current). Bidirectional thyristors are used in textile electronic control systems, and their conduction angle is a key parameter. If the conduction angle of a thyristor does not meet the requirements, it will directly affect the performance of the system. Therefore, it is best to test the conduction angle of the TRIAC before use to determine whether it meets the requirements.

[0004] However, the prior art does not have a device or method capable of detecting the conduction angle of a single bidirectional thyristor. The prior art can usually only detect a circuit system connected to the bidirectional thyristor, and the detection operation is very inconvenient. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention proposes a conduction angle detection device and method for thyristors used in a textile electric control system, which can detect the conduction angle of a single bidirectional thyristor and the detection operation is very convenient.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a conduction angle detection device for thyristor used in textile electric control system, comprising

[0007] The detection equipment body includes

[0008] Optocoupler, which operates in the saturation region or cutoff region;

[0009] a first resistor, a first end of which is connected to the positive electrode of the positive side of the optical coupler;

[0010] a first power supply connected to the second end of the first resistor;

[0011] a second resistor, a first end of which is connected to the first interface end of the secondary side of the optocoupler;

[0012] a third resistor, a first end of which is connected to the second interface end of the secondary side of the optocoupler;

[0013] a first connection interface connected to the second end of the second resistor and used to be connected to the first anode of the thyristor to be tested;

[0014] a second connection interface connected to the second end of the third resistor and used to be connected to the second anode of the thyristor to be detected;

[0015] A third connection interface is connected to the first interface end of the secondary side of the optocoupler and is used to connect to the control electrode of the thyristor to be detected;

[0016] a load detachably connected to the detection device body, wherein the detection device body further comprises a load interface connected to the second end of the second resistor;

[0017] a second power supply detachably connected to the detection device body and configured to provide an AC power supply, the detection device body further comprising a power interface connected to the second end of the third resistor, and the second power supply being connected to the load;

[0018] A PWM wave generator is detachably connected to the detection device body and is used to generate a PWM waveform with a required duty cycle, and the detection device body also includes a waveform generator interface connected to the positive and negative electrodes of the optocoupler;

[0019] A waveform display is detachably connected to the detection device body, and is used to obtain and display the voltage waveform between the first anode of the thyristor to be detected and the second anode of the thyristor to be detected, and the detection device body also includes a display interface 1 connected to the second end of the second resistor and used to be connected to the first detection terminal of the waveform display, and a display interface 2 connected to the second end of the third resistor and used to be connected to the second detection terminal of the waveform display.

[0020] Preferably, the conduction angle detection device further includes a controller connected to the PWM wave generator, the controller including

[0021] The conduction angle detection value input unit is used to input the conduction angle detection value of the thyristor to be detected;

[0022] a duty cycle calculation unit connected to the conduction angle detection value input unit, and calculating the required duty cycle of the PWM wave according to the conduction angle detection value;

[0023] The duty cycle adjustment unit is connected to the duty cycle calculation unit and adjusts the PWM wave generator according to the required duty cycle of the PWM wave so as to generate a PWM wave with a corresponding duty cycle.

[0024] Preferably, the controller is further connected to the second power supply, and the controller further includes

[0025] The period adjustment unit is used to adjust the PWM wave so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply.

[0026] Preferably, the load is a motor.

[0027] Preferably, the detection device body further includes

[0028] a fourth resistor, a first end of which is connected to the second end of the second resistor;

[0029] A capacitor, a positive electrode of which is connected to the second end of the fourth resistor, and a negative electrode of which is connected to the second end of the third resistor.

[0030] A method for detecting the conduction angle of a thyristor for a textile electronic control system, using the above-mentioned conduction angle detection device, includes the following steps:

[0031] L1 connects the first anode of the thyristor to be tested to the first connection interface, connects the second anode of the thyristor to be tested to the second connection interface, and connects the control electrode of the thyristor to be tested to the third connection interface;

[0032] L2 turns on the PWM wave generator to generate a PWM wave, turns on the second power supply to generate an AC power supply, and adjusts the PWM wave so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply;

[0033] L3 determines the conduction angle detection value of the thyristor to be detected, determines the required duty cycle of the PWM wave according to the conduction angle detection value, and adjusts the PWM wave generator according to the required duty cycle of the PWM wave to generate a PWM wave with a corresponding duty cycle;

[0034] L4 waveform display obtains and displays the voltage waveform between the first anode of the thyristor to be tested and the second anode of the thyristor to be tested, and determines the conduction angle of the thyristor to be tested through the voltage waveform;

[0035] L5 determines whether the conduction angle detection of the thyristor to be detected is completed. If yes, the conduction angle detection ends; if not, it returns to L3.

[0036] Preferably, L2 specifically adjusts the PWM wave through a period adjustment unit so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply.

[0037] Preferably, the L3 specifically includes:

[0038] L31 inputs the conduction angle detection value of the thyristor to be detected through the conduction angle detection value input unit;

[0039] L32 calculates the required duty cycle of the PWM wave according to the conduction angle detection value through the duty cycle calculation unit;

[0040] L33 adjusts the PWM wave generator according to the required duty cycle of the PWM wave through the duty cycle adjustment unit to generate a PWM wave with a corresponding duty cycle.

[0041] Preferably, the L4 specifically includes

[0042] L41: When the voltage amplitude in the voltage waveform is 0 or the voltage amplitude fluctuates significantly, the conduction angle is determined to be abnormal and the process goes to L5; otherwise, the process goes to L42;

[0043] L42 calculates the actual conduction angle value of the thyristor to be tested based on the voltage waveform, and calculates the conduction angle delay value based on the actual conduction angle value and the conduction angle detection value. When the conduction angle delay value is within the allowable range, the conduction angle is judged to be normal; otherwise, the conduction angle is judged to be abnormal.

[0044] Preferably, a maximum voltage amplitude reference line and a minimum voltage amplitude reference line are provided in the voltage waveform diagram for assisting in determining whether the voltage amplitude fluctuation is obvious.

[0045] Beneficial effects

[0046] The conduction angle detection device and method of the present application can simulate the formation of a trigger signal for triggering the conduction of the thyristor to be detected through a first power supply, a first resistor, an optocoupler and a PWM wave generator, can form a detection circuit that allows the thyristor to be detected to be bidirectionally conductive through a second resistor, a third resistor, a load and a second power supply, can obtain a voltage waveform through a waveform display to determine whether the conduction angle currently detected by the thyristor to be detected is normal or abnormal, and thus can very easily realize the conduction angle detection of a single bidirectional thyristor. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a circuit connection diagram of the conduction angle detection device of the thyristor used in the textile electronic control system of the present invention. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0049] Example 1: Figure 1 As shown, a conduction angle detection device for a thyristor used in a textile electric control system includes a detection device body, a load 6, a second power supply 8, a PWM wave generator 4 and a waveform display.

[0050] The detection device body includes an outer shell, a circuit board is arranged inside the outer shell, and a first connection interface, a second connection interface, a third connection interface, a load interface, a power supply interface, a waveform generator interface, a display interface 1 and a display interface 2 are arranged on the outer shell.

[0051] The circuit board includes an optocoupler 1, a first resistor 2, a first power supply 3, a second resistor 5 and a third resistor 7. The optocoupler 1 operates in a saturation region or a cutoff region and acts as a switch. The first end of the first resistor 2 is connected to the positive electrode of the positive side of the optocoupler 1, and its resistance can be 330Ω. The first power supply 3 is connected to the second end of the first resistor 2, and its resistance can be 3.3V. The first end of the second resistor 5 is connected to the first interface end of the secondary side of the optocoupler 1, and its resistance can be 100Ω. The first end of the third resistor 7 is connected to the second interface end of the secondary side of the optocoupler 1, and its resistance can be 100Ω.

[0052] The first connection interface is connected to the second end of the second resistor 5 and is used to connect to the first anode of the thyristor 9 to be tested. The second connection interface is connected to the second end of the third resistor 7 and is used to connect to the second anode of the thyristor 9 to be tested. The third connection interface is connected to the first interface terminal of the secondary side of the optocoupler 1 and is used to connect to the control electrode of the thyristor 9 to be tested.

[0053] The load 6 is detachably connected to the detection device body. The detection device body is provided with a load interface connected to the second end of the second resistor 5. The load 6 is connected to the detection device body via the load interface. In this embodiment, the load 6 is a motor, which can be a torque motor or a roller motor. Once the load 6 is connected to the load interface of the detection device body, it can remain in use for a long time.

[0054] The second power supply 8 is detachably connected to the detection device body to provide AC power. The second power supply 8 can be 110V AC. The detection device body is provided with a power interface connected to the second end of the third resistor 7. The second power supply 8 is connected to the detection device body through the power interface, and the second power supply 8 is also connected to the load 6. After the second power supply 8 is connected to the power interface of the detection device body and the load 6, it does not need to be removed for a long time.

[0055] The PWM wave generator 4 is detachably connected to the detection device body and is used to generate a PWM waveform with the required duty cycle. The detection device body is provided with a waveform generator interface connected to the positive and negative electrodes of the optocoupler 1. The PWM wave generator 4 is connected to the detection device body via the waveform generator interface. Once connected to the detection device body, the PWM wave generator 4 can be left in place for a long period of time. In this embodiment, when the PWM wave is at a high level, the light-emitting diode on the positive side of the optocoupler 1 is not conducting, and therefore the secondary side of the optocoupler 1 is also not conducting. When the PWM wave is at a low level, the light-emitting diode on the positive side of the optocoupler 1 is conducting, causing the secondary side of the optocoupler 1 to also conduct. In this embodiment, during one cycle of the PWM wave, the front portion is set to a high level and the rear portion is set to a low level. At the moment of transition from high level to low level, the circuit between the second resistor 5 and the third resistor 7 is turned on due to the conduction of the secondary side of the optocoupler 1, thereby causing the control electrode of the control silicon 9 to be detected to have a trigger current. In one cycle, the proportion of the high level in the entire cycle is the duty cycle of the PWM wave. By adjusting the duty cycle, it is possible to control when the secondary side of the optocoupler 1 is turned on, and thus control when the trigger current is provided to the control electrode of the control silicon 9 to be detected.

[0056] The waveform display is detachably connected to the detection device body and is used to obtain and display a voltage waveform between the first anode and the second anode of the thyristor 9 to be detected. The detection device body is provided with a display interface 1 connected to the second end of the second resistor 5 and used to be connected to the first detection terminal of the waveform display, and a display interface 2 connected to the second end of the third resistor 7 and used to be connected to the second detection terminal of the waveform display. The first detection terminal of the waveform display is connected to the detection device body via the display interface 1, and the second detection terminal of the waveform display is connected to the detection device body via the display interface 2. Once connected, the two terminals do not need to be disassembled for a long time.

[0057] Before specifically testing the conduction angle of the thyristor (SCR) to be tested (9), it is necessary to first determine the conduction angle (i.e., the conduction angle detection value) that the thyristor (9) to be tested will use in the textile electronic control system (assuming the conduction angle detection value is 135 degrees in this case, although multiple values are possible). The corresponding control angle should be 45 degrees, so a trigger current should be supplied to the thyristor (9) to be tested at 45 degrees of the positive or negative half-cycle of the AC power supply. Furthermore, the PWM wave cycle coincides with the positive or negative half-cycle of the AC power supply: the PWM wave cycle begins at the beginning of the positive half-cycle (or negative half-cycle) and ends at the end of the positive half-cycle (or negative half-cycle). When the control angle of the thyristor (9) to be tested is 45 degrees, the control angle accounts for 25% of the positive half-cycle (or negative half-cycle) of the AC power supply. Therefore, the PWM wave needs to undergo a high-low level transition at the 25% position, thus determining that the duty cycle of the PWM wave needs to be 25%.

[0058] The specific detection process of the conduction angle of the thyristor 9 to be tested is as follows: first turn on the PWM wave generator 4 and adjust the PWM wave generator 4 so that it generates a PWM wave with a high level in the first half and a low level in the second half and a duty cycle of 25%, and at the same time turn on the second power supply 8. When the second power supply 8 is in the positive half cycle, the second anode of the thyristor 9 to be tested is a positive voltage and the first anode is a negative voltage. When the PWM wave is converted from a high level to a low level, the secondary side of the optocoupler 1 is turned on. At this time, the circuit of the second resistor 5 and the third resistor 7 is turned on, providing a trigger current to the control electrode of the thyristor 9 to be tested, thereby causing the second anode of the thyristor 9 to be tested to be turned on with the first anode, so that the load 6 works. When the second power supply 8 is in the negative half cycle, the first anode of the thyristor 9 to be tested is a positive voltage and the second anode is a negative voltage. When the PWM wave is converted from a high level to a low level, the secondary side of the optocoupler 1 is turned on. At this time, the circuit of the second resistor 5 and the third resistor 7 is turned on, providing a trigger current to the control electrode of the thyristor 9 to be tested, thereby turning on the first anode and the second anode of the thyristor 9 to be tested, so that the load 6 works.

[0059] Then, check the voltage waveform between the first anode of the thyristor 9 to be tested and the second anode of the thyristor 9 to be tested through the waveform display. If the voltage amplitude of the voltage waveform is 0, it means that the first anode and the second anode of the thyristor 9 to be tested are not conducting, and the conduction angle corresponding to the thyristor 9 to be tested is problematic and abnormal. If the voltage waveform has a voltage amplitude, but the voltage amplitude fluctuates greatly, it means that the conduction angle corresponding to the thyristor 9 to be tested is still problematic and abnormal. If the voltage waveform has a voltage amplitude and the voltage amplitude fluctuates slightly, it is necessary to further determine the conduction delay of the conduction angle.

[0060] The conduction delay situation can be determined in the following way: first determine the proportion of the voltage waveform with a voltage amplitude not equal to 0 in the voltage waveform diagram, and multiply it by 180 degrees to obtain the actual value of the conduction angle. Subtract the actual value of the conduction angle from the conduction angle detection value to obtain the conduction angle delay difference. Then divide the conduction angle delay difference by 180 and multiply it by the time value of half a cycle to obtain the final conduction angle delay value. If the conduction angle delay value exceeds the allowable range, it means that the conduction angle corresponding to the detection of the thyristor 9 to be detected is problematic and abnormal. If the conduction angle delay value is within the allowable range, it means that the conduction angle corresponding to the detection of the thyristor 9 to be detected is normal.

[0061] After the current conduction angle of the thyristor 9 to be tested is detected, it can be determined whether other conduction angles need to be tested. If so, the duty cycle of the PWM wave is determined and adjusted based on the new conduction angle detection value. If not, the thyristor 9 to be tested is removed from the first connection interface, the second connection interface, and the third connection interface, and then another thyristor 9 to be tested is replaced.

[0062] Furthermore, the conduction angle detection device further includes a controller connected to the PWM wave generator 4, and the controller includes a conduction angle detection value input unit, a duty cycle calculation unit and a duty cycle adjustment unit.

[0063] The conduction angle detection value input unit is used to input the conduction angle detection value of the thyristor 9 to be tested. After determining the conduction angle detection value of the thyristor 9 to be tested (determined based on the use requirements of the textile electronic control system), the staff inputs this conduction angle detection value into the controller through the conduction angle detection value input unit. For example, the conduction angle detection value can be 90 degrees.

[0064] The duty cycle calculation unit is connected to the conduction angle detection value input unit and calculates the required duty cycle of the PWM wave according to the conduction angle detection value. When the conduction angle detection value is 90 degrees, the calculated required duty cycle of the PWM wave is 50%.

[0065] The duty cycle adjustment unit is connected to the duty cycle calculation unit and adjusts the PWM wave generator 4 according to the desired duty cycle of the PWM wave to generate a PWM wave with a corresponding duty cycle. When the desired duty cycle of the PWM wave is 50%, the duty cycle adjustment unit automatically controls the output waveform of the PWM wave generator 4 to output a PWM waveform with a duty cycle of 50%.

[0066] The setting of the conduction angle detection value input unit, the duty cycle calculation unit and the duty cycle adjustment unit, on the one hand, allows the staff to only input the conduction angle detection value, without the need to manually calculate the duty cycle, nor to manually adjust the PWM wave generator 4, making the thyristor conduction angle detection operation simpler; on the other hand, compared with manual calculation of the duty cycle and manual adjustment of the duty cycle, the duty cycle is calculated by the duty cycle calculation unit and adjusted by the duty cycle adjustment unit, so that the output PWM wave is more accurate, thereby making the conduction angle detection more accurate.

[0067] Furthermore, the controller is also connected to the second power source 8 and includes a period adjustment unit. During conduction angle detection, the PWM wave period must be synchronized with the positive or negative half-cycle of the AC power source. However, manually adjusting the PWM wave period to synchronize with the positive / negative half-cycle of the AC power source is difficult. This embodiment uses the period adjustment unit to automatically adjust the PWM wave period to synchronize with the positive / negative half-cycle of the AC power source, further improving the convenience of thyristor conduction angle detection and achieving higher adjustment accuracy, thereby further enhancing the accuracy of conduction angle detection.

[0068] Further, such as Figure 1As shown, the detection device body also includes a fourth resistor 10 and a capacitor 11. The first end of the fourth resistor 10 is connected to the second end of the second resistor 5, wherein the resistance of the fourth resistor 10 is 100Ω. The positive pole of the capacitor 11 is connected to the second end of the fourth resistor 10, and the negative pole of the capacitor 11 is connected to the second end of the third resistor 7, and the value of the capacitor 11 is 100nF. In this embodiment, an RC resistor and a capacitor are connected in parallel at both ends of the thyristor 9 to be detected, and the characteristic that the voltage at both ends of the capacitor cannot change suddenly is used to limit the voltage rise rate at both ends of the thyristor 9 to be detected, thereby protecting the thyristor 9 to be detected.

[0069] The conduction angle detection device of this embodiment can first simulate the formation of a trigger signal for triggering the conduction of the thyristor 9 to be detected through the first power supply 3, the first resistor 2, the optocoupler 1 and the PWM wave generator 4, and the generation time of the trigger signal can be adaptively adjusted by changing the duty cycle of the PWM wave, thereby being able to detect any conduction angle of the thyristor that needs to be detected.

[0070] Secondly, a detection circuit that allows the thyristor to be tested 9 to be bidirectionally conductive can be formed by the second resistor 5, the third resistor 7, the load 6, and the second power supply 8, thereby eliminating the zero-crossing detection circuit that is essential when the thyristor is unidirectionally conductive. When detecting the conduction angle of the bidirectional thyristor, it is also possible to only detect a single conduction direction. However, in that case, there will be no periodic alternation of positive and negative voltages across the thyristor to be tested 9, and thus the automatic shutdown of the thyristor to be tested 9 cannot be achieved (i.e., the zero-crossing detection circuit must detect the end of half a cycle before the thyristor to be tested 9 can be turned off). The provision of a zero-crossing detection circuit makes the entire detection circuit very complicated.

[0071] Finally, the voltage waveform between the first anode of the thyristor to be tested and the second anode of the thyristor to be tested can be obtained and displayed through the waveform display. Through the voltage waveform, it is very easy to determine whether the conduction angle currently detected by the thyristor to be tested is normal or abnormal.

[0072] Example 2: Figure 1 As shown, a method for detecting the conduction angle of a thyristor for a textile electric control system adopts the conduction angle detection device in Example 1, specifically comprising the following steps:

[0073] L1 connects the first anode of the thyristor to be tested to the first connection interface, connects the second anode of the thyristor to be tested to the second connection interface, and connects the control electrode of the thyristor to be tested to the third connection interface.

[0074] L2 turns on the PWM wave generator 4 to generate a PWM wave, turns on the second power supply 8 to generate an AC power supply, and adjusts the PWM wave so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply.

[0075] Specifically, L2 adjusts the PWM wave via a period adjustment unit to synchronize the PWM wave period with the positive / negative half-cycle of the AC power source. During conduction angle detection, the PWM wave period must be synchronized with either the positive or negative half-cycle of the AC power source. However, manually adjusting the PWM wave period to synchronize with the positive / negative half-cycle of the AC power source is difficult. This embodiment automatically adjusts the PWM wave period via the period adjustment unit to synchronize the PWM wave period with the positive / negative half-cycle of the AC power source, further enhancing the convenience of thyristor conduction angle detection and improving the accuracy of the adjustment, thereby further improving the accuracy of conduction angle detection.

[0076] L3 determines the conduction angle detection value of the thyristor 9 to be detected, determines the required duty cycle of the PWM wave according to the conduction angle detection value, and adjusts the PWM wave generator 4 according to the required duty cycle of the PWM wave to generate a PWM wave with a corresponding duty cycle.

[0077] Specifically, L3 includes: L31 inputting the conduction angle detection value of the thyristor (SCR) 9 to be tested via a conduction angle detection value input unit. After determining the conduction angle detection value of the thyristor 9 to be tested (based on the requirements of the textile electronic control system), the operator inputs the conduction angle detection value into the controller via the conduction angle detection value input unit. For example, the conduction angle detection value can be 90 degrees. L32 calculates the required duty cycle of the PWM wave based on the conduction angle detection value via a duty cycle calculation unit. When the conduction angle detection value is 90 degrees, the calculated required duty cycle of the PWM wave is 50%. L33 adjusts the PWM wave generator 4 based on the required duty cycle of the PWM wave via a duty cycle adjustment unit to generate a PWM wave with a corresponding duty cycle. When the required duty cycle of the PWM wave is 50%, the duty cycle adjustment unit automatically controls the output waveform of the PWM wave generator 4 to output a PWM waveform with a 50% duty cycle.

[0078] The setting of the conduction angle detection value input unit, the duty cycle calculation unit and the duty cycle adjustment unit, on the one hand, allows the staff to only input the conduction angle detection value, without the need to manually calculate the duty cycle, nor to manually adjust the PWM wave generator 4, making the thyristor conduction angle detection operation simpler; on the other hand, compared with manual calculation of the duty cycle and manual adjustment of the duty cycle, the duty cycle is calculated by the duty cycle calculation unit and adjusted by the duty cycle adjustment unit, so that the output PWM wave is more accurate, thereby making the conduction angle detection more accurate.

[0079] The L4 waveform display obtains and displays the voltage waveform between the first anode of the thyristor to be detected 9 and the second anode of the thyristor to be detected 9, and determines the conduction angle of the thyristor to be detected through the voltage waveform.

[0080] When the second power supply 8 is in the positive half cycle, the second anode of the thyristor 9 to be detected is a positive voltage and the first anode is a negative voltage. When the PWM wave is converted from a high level to a low level, the secondary side of the optocoupler 1 is turned on. At this time, the circuit of the second resistor 5 and the third resistor 7 is turned on, providing a trigger current to the control electrode of the thyristor 9 to be detected, thereby causing the second anode of the thyristor 9 to be detected to be turned on with the first anode, so that the load 6 works. When the second power supply 8 is in the negative half cycle, the first anode of the thyristor 9 to be detected is a positive voltage and the second anode is a negative voltage. When the PWM wave is converted from a high level to a low level, the secondary side of the optocoupler 1 is turned on. At this time, the circuit of the second resistor 5 and the third resistor 7 is turned on, providing a trigger current to the control electrode of the thyristor 9 to be detected, thereby causing the first anode of the thyristor 9 to be detected to be turned on with the second anode, so that the load 6 works.

[0081] The L4 specifically includes L41. When the voltage amplitude in the voltage waveform is 0 or the voltage amplitude fluctuates significantly, the conduction angle is determined to be abnormal and the process goes to L5; otherwise, the process goes to L42. If the voltage amplitude in the voltage waveform is 0, it means that the first anode and the second anode of the thyristor 9 to be tested are not conducting, and the conduction angle corresponding to the thyristor 9 to be tested is problematic and abnormal. If the voltage waveform has a voltage amplitude, but the voltage amplitude fluctuates greatly, it means that the conduction angle corresponding to the thyristor 9 to be tested is still problematic and abnormal. In addition, in this embodiment, a maximum voltage amplitude reference line and a minimum voltage amplitude reference line can be set in the voltage waveform to assist in determining whether the voltage amplitude fluctuation is obvious. When the sum of the number of times the voltage waveform is higher than the maximum voltage amplitude reference line and the number of times it is lower than the minimum voltage amplitude reference line is greater than the set number, it indicates that the voltage amplitude fluctuation is obvious.

[0082] L42 calculates the actual conduction angle of the thyristor 9 under test based on the voltage waveform. It also calculates the conduction angle delay value based on the actual conduction angle value and the conduction angle detection value. If the conduction angle delay value is within the allowable range, the conduction angle is determined to be normal; otherwise, the conduction angle is determined to be abnormal. If the voltage waveform shows a voltage amplitude and the voltage amplitude fluctuation is not significant, further determination of the conduction angle delay is required. The conduction delay situation can be determined in the following way: first determine the proportion of the voltage waveform with a voltage amplitude not equal to 0 in the voltage waveform diagram, and multiply it by 180 degrees to obtain the actual value of the conduction angle. Subtract the actual value of the conduction angle from the conduction angle detection value to obtain the conduction angle delay difference. Then divide the conduction angle delay difference by 180 and multiply it by the time value of half a cycle to obtain the final conduction angle delay value. If the conduction angle delay value exceeds the allowable range, it means that the conduction angle corresponding to the detection of the thyristor 9 to be detected is problematic and abnormal. If the conduction angle delay value is within the allowable range, it means that the conduction angle corresponding to the detection of the thyristor 9 to be detected is normal.

[0083] L5 determines whether the conduction angle detection of the current thyristor 9 to be tested has been completed. If so, the conduction angle detection ends; if not, the process returns to L3. After the conduction angle detection of the current thyristor 9 to be tested is completed, it is determined whether additional conduction angles need to be tested. If so, the process returns to L3 to determine and adjust the PWM duty cycle based on the new conduction angle detection value. If not, the thyristor 9 to be tested is removed from the first, second, and third connection interfaces, and then replaced with another thyristor 9 to be tested.

[0084] The conduction angle detection method of this embodiment can first simulate the formation of a trigger signal for triggering the conduction of the thyristor 9 to be detected through the first power supply 3, the first resistor 2, the optocoupler 1 and the PWM wave generator 4, and the generation time of the trigger signal can be adaptively adjusted by changing the duty cycle of the PWM wave, thereby being able to detect any conduction angle of the thyristor that needs to be detected.

[0085] Secondly, a detection circuit that allows the thyristor to be tested 9 to be bidirectionally conductive can be formed by the second resistor 5, the third resistor 7, the load 6, and the second power supply 8, thereby eliminating the zero-crossing detection circuit that is essential when the thyristor is unidirectionally conductive. When detecting the conduction angle of the bidirectional thyristor, it is also possible to only detect a single conduction direction. However, in that case, there will be no periodic alternation of positive and negative voltages across the thyristor to be tested 9, and thus the automatic shutdown of the thyristor to be tested 9 cannot be achieved (i.e., the zero-crossing detection circuit must detect the end of half a cycle before the thyristor to be tested 9 can be turned off). The provision of a zero-crossing detection circuit makes the entire detection circuit very complicated.

[0086] Finally, the voltage waveform between the first anode of the thyristor to be tested and the second anode of the thyristor to be tested can be obtained and displayed through the waveform display. Through the voltage waveform, it is very easy to determine whether the conduction angle currently detected by the thyristor to be tested is normal or abnormal.

[0087] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Any modifications and improvements to the technical solution of the present invention made by a person of ordinary skill in the art without departing from the design concept of the present invention shall fall within the scope of protection of the present invention. The technical content for which protection is sought in the present invention is fully set forth in the claims.

Claims

1. A conduction angle detection device for thyristors used in textile electronic control systems, characterized by: include The detection equipment body includes Optocoupler (1), which operates in a saturation region or a cutoff region; A first resistor (2), a first end of which is connected to the positive electrode of the positive side of the optical coupler (1); A first power supply (3) connected to the second end of the first resistor (2); A second resistor (5), a first end of which is connected to the first interface end of the secondary side of the optical coupler (1); A third resistor (7), a first end of which is connected to the second interface end of the secondary side of the optical coupler (1); A first connection interface connected to the second end of the second resistor (5) and used to connect to the first anode of the thyristor (9) to be detected; A second connection interface connected to the second end of the third resistor (7) and used to connect to the second anode of the thyristor (9) to be detected; A third connection interface is connected to the first interface end of the secondary side of the optical coupler (1) and is used to connect to the control electrode of the thyristor (9) to be detected; A load (6) is detachably connected to the detection device body, and the detection device body further comprises a load interface connected to the second end of the second resistor (5); a second power supply (8) detachably connected to the detection device body and used to provide an AC power supply, the detection device body further comprising a power supply interface connected to the second end of the third resistor (7), and the second power supply (8) is connected to the load (6); A PWM wave generator (4) is detachably connected to the detection device body and is used to generate a PWM waveform with a required duty cycle, and the detection device body also includes a waveform generator interface connected to the positive and negative electrodes of the optical coupler (1); A waveform display is detachably connected to the detection device body and is used to obtain and display a voltage waveform diagram between the first anode of the thyristor (9) to be detected and the second anode of the thyristor (9) to be detected, and the detection device body also includes a display interface 1 connected to the second end of the second resistor (5) and used to be connected to the first detection terminal of the waveform display, and a display interface 2 connected to the second end of the third resistor (7) and used to be connected to the second detection terminal of the waveform display.

2. The conduction angle detection device for a thyristor used in a textile electronic control system according to claim 1, characterized in that: The conduction angle detection device further comprises a controller connected to the PWM wave generator (4), the controller comprising A conduction angle detection value input unit, used for inputting the conduction angle detection value of the thyristor (9) to be detected; a duty cycle calculation unit connected to the conduction angle detection value input unit, and calculating the required duty cycle of the PWM wave according to the conduction angle detection value; A duty cycle adjustment unit is connected to the duty cycle calculation unit and adjusts the PWM wave generator (4) according to the required duty cycle of the PWM wave so as to generate a PWM wave with a corresponding duty cycle.

3. The conduction angle detection device for a thyristor used in a textile electronic control system according to claim 2, characterized in that: The controller is also connected to the second power supply (8), and the controller also includes The period adjustment unit is used to adjust the PWM wave so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply.

4. The conduction angle detection device for a thyristor used in a textile electronic control system according to claim 1, characterized in that: The load (6) is a motor.

5. The conduction angle detection device for a thyristor used in a textile electronic control system according to claim 1, characterized in that: The detection device body also includes a fourth resistor (10), a first end of which is connected to the second end of the second resistor (5); A capacitor (11), a positive electrode of which is connected to the second end of the fourth resistor (10), and a negative electrode of which is connected to the second end of the third resistor (7).

6. A method for detecting the conduction angle of a thyristor for a textile electronic control system, using the conduction angle detection device according to any one of claims 1 to 5, characterized in that: The following steps are included L1 connects the first anode of the thyristor to be tested to the first connection interface, connects the second anode of the thyristor to be tested to the second connection interface, and connects the control electrode of the thyristor to be tested to the third connection interface; L2 turns on the PWM wave generator (4) to generate a PWM wave, turns on the second power supply (8) to generate an AC power supply, and adjusts the PWM wave so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply; L3 determines the conduction angle detection value of the thyristor (9) to be detected, determines the required duty cycle of the PWM wave according to the conduction angle detection value, and adjusts the PWM wave generator (4) according to the required duty cycle of the PWM wave to generate a PWM wave with a corresponding duty cycle; The L4 waveform display obtains and displays a voltage waveform diagram between the first anode of the thyristor (9) to be detected and the second anode of the thyristor (9) to be detected, and determines the conduction angle of the thyristor to be detected through the voltage waveform diagram; L5 determines whether the conduction angle detection of the current thyristor (9) to be detected has been completed. If yes, the conduction angle detection ends; if not, it returns to L3.

7. The method for detecting the conduction angle of a thyristor for a textile electronic control system according to claim 6, characterized in that: Specifically, L2 adjusts the PWM wave through a period adjustment unit so that the period of the PWM wave is synchronized with the positive / negative half period of the AC power supply.

8. The method for detecting the conduction angle of a thyristor for a textile electronic control system according to claim 6, wherein: The L3 specifically includes: L31 inputs the conduction angle detection value of the thyristor (9) to be detected through the conduction angle detection value input unit; L32 calculates the required duty cycle of the PWM wave according to the conduction angle detection value through the duty cycle calculation unit; L33 adjusts the PWM wave generator (4) through the duty cycle adjustment unit according to the required duty cycle of the PWM wave so as to generate a PWM wave with a corresponding duty cycle.

9. The method for detecting the conduction angle of a thyristor for a textile electronic control system according to claim 6, wherein: The L4 specifically includes L41: When the voltage amplitude in the voltage waveform is 0 or the voltage amplitude fluctuates significantly, the conduction angle is determined to be abnormal and the process goes to L5; Otherwise, proceed to L42; L42 calculates the actual conduction angle value of the thyristor (9) to be detected based on the voltage waveform diagram, and calculates the conduction angle delay value based on the actual conduction angle value and the conduction angle detection value. When the conduction angle delay value is within the allowable range, it is determined that the conduction angle is normal; otherwise, it is determined that the conduction angle is abnormal.

10. The method for detecting the conduction angle of a thyristor for a textile electronic control system according to claim 9, characterized in that: A maximum voltage amplitude reference line and a minimum voltage amplitude reference line are set in the voltage waveform diagram for assisting in determining whether the voltage amplitude fluctuation is obvious.

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