A detection method, a processor and a motor soft starter of a motor soft starter

Abstract

The application relates to a detection method, a processor and a motor soft starter of a motor soft starter. In the application, the connection detection result of a voltage detection cable between a line between a power input terminal and a silicon controlled assembly and a voltage detection circuit, the connection detection result of a trigger cable between the silicon controlled assembly and a trigger circuit, and the connection detection result of a current sampling cable between a current sensor and a current sampling circuit can be effectively obtained, manual troubleshooting is not needed, the position of the cable connection anomaly can be quickly located, the troubleshooting efficiency can be effectively improved, and the labor cost of the cable connection detection can be effectively reduced.

Description

Technical Field

[0001] This application belongs to the field of motor soft starter testing technology, and in particular relates to a testing method, processor and motor soft starter for a motor soft starter. Background Technology

[0002] Three-phase AC asynchronous motors are widely used in many industries due to their simple structure, low price, and reliable operation. However, when starting directly, they generate excessive inrush current (5 to 10 times the rated current of the motor). This not only reduces the life of the motor and generates greater mechanical stress, but also harms the power quality of the power supply and affects the normal operation of other equipment. Currently, a motor soft starter is generally installed between the power supply and the motor to suppress the starting current of the motor.

[0003] Many critical components inside a motor soft starter are directly connected via cables. For example, the circuit between the power input terminal and the thyristor assembly is connected to the voltage detection circuit via a voltage detection cable; the thyristor assembly is connected to the trigger circuit via a trigger cable; and the current sensor is connected to the current sampling circuit via a current sampling cable. During transportation or long-term operation, abnormalities such as poor contact between cables and components or disconnection between cables and components may occur. Currently, the usual method for handling such abnormalities is to manually check whether there are abnormal connections in the cables inside the motor soft starter. However, since manual inspection relies heavily on experience, it is often difficult to quickly locate the location of the abnormal cable connection, and multiple checks may be required, resulting in very low efficiency and high labor costs for cable connection inspection. Summary of the Invention

[0004] The purpose of this application is to provide a detection method, processor, and motor soft starter for a motor. The detection method, processor, and motor soft starter provided by this application can quickly locate the location of abnormal cable connections without relying on manual inspection, effectively improving the efficiency of inspection and thus effectively reducing the labor cost of cable connection inspection.

[0005] The technical solution provided in this application is as follows:

[0006] A detection method for a motor soft starter, applied to a processor, wherein the motor soft starter includes a voltage detection circuit, a silicon controlled rectifier (SCR) assembly, the processor, a trigger circuit, a current sensor, and a current sampling circuit, and the detection method includes:

[0007] After the three-phase power supply supplies power to the motor soft starter through the power input terminal, the voltage detection circuit obtains the three-phase voltage value of the three-phase voltage input from the power input terminal.

[0008] Based on the three-phase voltage values, the connection detection result of the voltage detection cable is obtained, wherein the first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end of the voltage detection cable is connected to the voltage detection circuit.

[0009] The trigger circuit is controlled to send trigger pulses to each thyristor in the thyristor assembly, so that each thyristor is turned on. The three-phase analog current output by the thyristor assembly is acquired by the current sensor and the three-phase current value is sampled by the current sampling circuit. Based on the three-phase current value, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained.

[0010] Optionally, the motor soft starter further includes a fan drive circuit and a cooling fan, and the detection method further includes:

[0011] A fan start signal is sent to the fan drive circuit so that the fan drive circuit drives the cooling fan to start.

[0012] Based on whether a speed feedback signal from the cooling fan is received within a preset time after the fan start signal is sent, the connection detection result of the fan cable between the fan drive circuit and the cooling fan is obtained.

[0013] Optionally, the three-phase voltage values ​​include a first-phase voltage value, a second-phase voltage value, and a third-phase voltage value; the power input terminals include a first-phase power input terminal, a second-phase power input terminal, and a third-phase power input terminal; the thyristor assembly includes a first thyristor assembly, a second thyristor assembly, and a third thyristor assembly; the voltage detection cable includes a first voltage detection cable, a second voltage acquisition cable, and a third voltage acquisition cable; the connection detection result of the voltage detection cable is obtained based on the three-phase voltage values; wherein, the first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end of the voltage detection cable is connected to the voltage detection circuit, including:

[0014] If the voltage value of the first phase is less than the preset voltage value, it is determined that the connection of the first voltage detection cable is abnormal. The first end of the first voltage detection cable is connected to the line between the power input terminal of the first phase and the first thyristor component, and the second end of the first voltage detection cable is connected to the voltage detection circuit.

[0015] If the voltage value of the second phase is less than the preset voltage value, it is determined that the connection of the second voltage detection cable is abnormal. The first end of the second voltage detection cable is connected to the line between the second phase power input terminal and the second thyristor component, and the second end of the second voltage detection cable is connected to the voltage detection circuit.

[0016] If the third phase voltage value is less than the preset voltage value, the connection of the third voltage detection cable is determined to be abnormal. The first end of the third voltage detection cable is connected to the line between the third phase power input terminal and the third thyristor assembly, and the second end of the third voltage detection cable is connected to the voltage detection circuit.

[0017] Optionally, the control circuit sends trigger pulses to each thyristor in the thyristor assembly to turn on each thyristor, acquires the three-phase analog current output by the thyristor assembly collected by the current sensor, and samples the three-phase current value through the current sampling circuit. Based on the three-phase current value, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained, including:

[0018] The trigger circuit is controlled to send trigger pulses to each of the thyristors in the thyristor assembly, so that each of the thyristors is turned on, so that the output voltage of the motor soft starter is a first voltage value;

[0019] The three-phase analog current output by the thyristor component is acquired by the current sensor and the three-phase current value is sampled by the current sampling circuit.

[0020] If one or more of the three-phase current values ​​are greater than zero, the trigger circuit is controlled to stop sending trigger pulses, and the connection detection result of the trigger cable between the thyristor component and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained based on the three-phase current values.

[0021] If all phase current values ​​in the three-phase current values ​​are zero, the trigger circuit is controlled to adjust the trigger pulse to increase the conduction angle of each thyristor, thereby increasing the output voltage of the motor soft starter to a second voltage value. The increased three-phase analog current output by the thyristor assembly is acquired by the current sensor and the increased three-phase current value is sampled by the current sampling circuit. If one or more phase current values ​​in the increased three-phase current values ​​are greater than zero, the trigger circuit is controlled to stop sending trigger pulses. Based on the increased three-phase current values, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained.

[0022] If all phase current values ​​in the increased three-phase current values ​​are zero, the trigger circuit is controlled to continue adjusting the trigger pulses so that the conduction angle of each thyristor continues to increase until the output voltage of the motor soft starter increases to a third voltage value. The increased three-phase analog current output by the thyristor assembly is acquired by the current sensor and the increased three-phase current value is sampled by the current sampling circuit. The trigger circuit is then controlled to stop sending trigger pulses. Based on the increased three-phase current values, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, as well as the connection detection result of the current sampling cable between the current sensor and the current sampling circuit, are obtained.

[0023] Optionally, the three-phase current values ​​include a first-phase current value, a second-phase current value, and a third-phase current value; the trigger circuit includes a first trigger circuit, a second trigger circuit, and a third trigger circuit; the trigger cable includes a first trigger cable, a second trigger cable, and a third trigger cable; the current sensor includes a first current sensor, a second current sensor, and a third current sensor; and the current sampling cable includes a first current sampling cable, a second current sampling cable, and a third current sampling cable. If one or more of the three-phase current values ​​are greater than zero, the trigger circuit is controlled to stop sending trigger pulses, and based on the three-phase current values, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained, including:

[0024] If the first phase current value, the second phase current value, and the third phase current value are all greater than zero, and the effective value of the first phase current value is equal to the effective values ​​of the second phase current value and the third phase current value, then it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is normal, the second trigger cable connection between the second thyristor component and the second trigger circuit is normal, the third trigger cable connection between the third thyristor component and the third trigger circuit is normal, and the first current sampling cable connection between the first current sensor and the current sampling circuit is normal, the second current sampling cable connection between the second current sensor and the current sampling circuit is normal, and the third current sampling cable connection between the third current sensor and the current sampling circuit is normal.

[0025] If the first phase current value is zero and the second phase current value and the third phase current value are greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal.

[0026] If the second phase current value is zero and the first phase current value and the third phase current value are greater than zero, it is determined that the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal.

[0027] If the third phase current value is zero and the first phase current value and the second phase current value are greater than zero, it is determined that the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

[0028] If the first phase current value and the second phase current value are zero and the third phase current value is greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal, and the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal.

[0029] If the first phase current value and the third phase current value are zero and the second phase current value is greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal, and the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

[0030] If the second phase current value and the third phase current value are zero and the first phase current value is greater than zero, it is determined that the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal, and the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

[0031] This application also provides a processor, including:

[0032] The acquisition module is used to acquire the three-phase voltage value of the three-phase voltage input from the power input terminal after the three-phase power supply supplies power to the motor soft starter through the power input terminal;

[0033] The first detection module is used to obtain the connection detection result of the voltage detection cable based on the three-phase voltage value, wherein the first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end of the voltage detection cable is connected to the voltage detection circuit.

[0034] The second detection module is used to control the trigger circuit to send trigger pulses to each thyristor in the thyristor assembly, so that each thyristor is turned on, to acquire the three-phase analog current output by the thyristor assembly collected by the current sensor and the three-phase current value sampled by the current sampling circuit, and to obtain the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit based on the three-phase current value.

[0035] Optionally, it also includes:

[0036] A control module is used to send a fan start signal to the fan drive circuit so that the fan drive circuit drives the cooling fan to start.

[0037] The third detection module is used to obtain the connection detection result of the fan cable between the fan drive circuit and the cooling fan based on whether a speed feedback signal sent by the cooling fan is received within a preset time after the fan start signal is sent.

[0038] This application also provides a motor soft starter, including the processor, voltage detection circuit, thyristor assembly, trigger circuit, current sensor and current sampling circuit described above;

[0039] The voltage detection circuit is used to detect the three-phase voltage value of the three-phase voltage input from the power input terminal, and send the detected three-phase voltage value to the processor;

[0040] The trigger circuit is used to send trigger pulses to each thyristor in the thyristor assembly according to the control of the processor, so as to turn on each of the thyristors;

[0041] The thyristor component is used to turn on when it receives a phase voltage input from the power input terminal and a trigger pulse sent by the trigger circuit, and to output the received phase voltage after stepping down according to the trigger pulse;

[0042] A current sensor is used to collect the three-phase analog current output by the thyristor component and send the collected three-phase analog current to the current sampling circuit.

[0043] The current sampling circuit is used to receive the three-phase analog current, sample the received three-phase analog current, and output the sampled three-phase current value to the processor.

[0044] Optionally, it also includes: a fan drive circuit and a cooling fan;

[0045] The fan drive circuit is used to drive the cooling fan to start according to the fan start signal sent by the processor;

[0046] The cooling fan is used to start according to the drive of the fan drive circuit, and after starting, sends a speed feedback signal to the processor.

[0047] Compared with existing technologies, this application provides a detection method, processor, and motor soft starter for a motor. After a three-phase power supply is supplied to the motor soft starter through the power input terminal, a voltage detection circuit detects the three-phase voltage values ​​input from the power input terminal. Based on these three-phase voltage values, the connection detection result of the voltage detection cable is obtained. The first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end is connected to the voltage detection circuit. A trigger circuit is then controlled to send trigger pulses to each thyristor in the thyristor assembly, causing each thyristor to conduct. The three-phase analog current output by the thyristor assembly is acquired by a current sensor and then processed through a current sensor. The three-phase current values ​​sampled by the sampling circuit are used to obtain the connection detection results of the trigger cable between the thyristor component and the trigger circuit, as well as the connection detection results of the current sampling cable between the current sensor and the current sampling circuit. In this application, the connection detection results of the voltage detection cable between the power input terminal and the thyristor component and the voltage detection circuit, the connection detection results of the trigger cable between the thyristor component and the trigger circuit, and the connection detection results of the current sampling cable between the current sensor and the current sampling circuit can be obtained effectively without relying on manual inspection. It can quickly locate the location of cable connection abnormalities, effectively improve the efficiency of inspection, and thus effectively reduce the labor cost of cable connection inspection. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a flowchart of a detection method for a motor soft starter disclosed in an embodiment of this application;

[0050] Figure 2 This is a schematic diagram of the structure of a processor disclosed in an embodiment of this application;

[0051] Figure 3 This is a schematic diagram of another processor disclosed in an embodiment of this application;

[0052] Figure 4 This is a schematic diagram of the structure of a motor soft starter disclosed in an embodiment of this application. Detailed Implementation

[0053] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0054] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0055] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0057] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0058] like Figure 1 As shown in the embodiment of this application, a detection method for a motor soft starter is provided, applied to a processor. The motor soft starter includes a voltage detection circuit, a thyristor assembly, a processor, a trigger circuit, a current sensor, and a current sampling circuit. The detection method includes:

[0059] S1. After the three-phase power supply supplies power to the motor soft starter through the power input terminal, the voltage detection circuit detects the three-phase voltage value of the three-phase voltage input from the power input terminal.

[0060] In this embodiment, the three-phase power supply can be a three-phase industrial frequency power supply. The processor can be a CPU (Central Processing Unit / Processor), or a microcontroller, DSP (Digital Signal Processor), CPLD (Complex Programmable Logic Device), or FPGA (Field-Programmable Gate Array), etc. The three-phase power supply can include a first-phase power supply, a second-phase power supply, and a third-phase power supply. The motor soft starter is provided with power input terminals, which can include a first-phase power input terminal (e.g., R terminal), a second-phase power input terminal (e.g., S terminal), and a third-phase power input terminal (e.g., T terminal). The first-phase power input terminal is used to connect to the first phase of the three-phase power supply, the second-phase power input terminal is used to connect to the second phase of the three-phase power supply, and the third-phase power input terminal is used to connect to the third phase of the three-phase power supply. The three-phase voltage can include the first-phase voltage, the second-phase voltage, and the third-phase voltage. The phase voltage value can include the first phase voltage value, the second phase voltage value, and the third phase voltage value. After the three-phase power supply supplies power to the motor soft starter through the first phase power input terminal to the third phase power input terminal, the voltage detection circuit detects the first phase voltage value of the first phase voltage input from the first phase power input terminal, the second phase voltage value of the second phase voltage input from the second phase power input terminal, and the third phase voltage value of the third phase voltage input from the third phase power input terminal, and sends the detected first phase voltage value, second phase voltage value, and third phase voltage value input from the first phase power input terminal to the processor.

[0061] S2. Based on the three-phase voltage values, obtain the connection test results of the voltage detection cable. The first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end of the voltage detection cable is connected to the voltage detection circuit.

[0062] In this embodiment, the thyristor assembly may include a first thyristor assembly, a second thyristor assembly, and a third thyristor assembly. The voltage detection cable may include a first voltage detection cable, a second voltage detection cable, and a third voltage detection cable. The first end of the first voltage detection cable is connected to the line between the first phase power input terminal and the first thyristor assembly, and the second end of the first voltage detection cable is connected to the voltage detection circuit. The first end of the second voltage detection cable is connected to the line between the second phase power input terminal and the second thyristor assembly, and the second end of the second voltage detection cable is connected to the voltage detection circuit. The first end of the third voltage detection cable is connected to the line between the third phase power input terminal and the third thyristor assembly, and the second end of the third voltage detection cable is connected to the voltage detection circuit. The processor can obtain the connection detection result of the first voltage detection cable based on the first phase voltage value input from the first phase power input terminal, the connection detection result of the second voltage detection cable based on the second phase voltage value input from the second phase power input terminal, and the connection detection result of the third voltage detection cable based on the third phase voltage value input from the third phase power input terminal.

[0063] S3. The control trigger circuit sends trigger pulses to each thyristor in the thyristor assembly to turn on each thyristor, acquire the three-phase analog current output by the thyristor assembly collected by the current sensor and the three-phase current value sampled by the current sampling circuit, and obtain the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, as well as the connection detection result of the current sampling cable between the current sensor and the current sampling circuit based on the three-phase current value.

[0064] In this embodiment, the triggering circuit may include a first triggering circuit, a second triggering circuit, and a third triggering circuit. The triggering cable may include a first triggering cable, a second triggering cable, and a third triggering cable. A first end of the first triggering cable is connected to the control electrode of the thyristor in the first thyristor assembly, and a second end of the first triggering cable is connected to the first triggering circuit. A first end of the second triggering cable is connected to the control electrode of the thyristor in the second thyristor assembly, and a second end of the second triggering cable is connected to the second triggering circuit. A first end of the third triggering cable is connected to the control electrode of the thyristor in the third thyristor assembly, and a second end of the third triggering cable is connected to the third triggering circuit. The current sensor may include a first current sensor, a second current sensor, and a third current sensor. The device includes a three-phase simulated current, which may include a first-phase simulated current, a second-phase simulated current, and a third-phase simulated current. The three-phase current values ​​may include the first-phase current value, the second-phase current value, and the third-phase current value. The current sampling cables may include a first-phase current sampling cable, a second-phase current sampling cable, and a third-phase current sampling cable. The motor soft starter is equipped with power output terminals, which may include a first-phase power output terminal (e.g., U terminal), a second-phase power output terminal (e.g., V terminal), and a third-phase power output terminal (e.g., W terminal). These terminals are used to connect to a three-phase motor, which can be a three-phase power frequency motor. The first current sensor is located at the first thyristor. On the line between the component and the first phase power output terminal, the first end of the first current sampling cable is connected to the first current sensor, and the second end of the first current sampling cable is connected to the current sampling circuit. The second current sensor is located on the line between the second thyristor component and the second phase power output terminal, with the first end of the second current sampling cable connected to the second current sensor and the second end of the second current sampling cable connected to the current sampling circuit. The third current sensor is located on the line between the third thyristor component and the third phase power output terminal, with the first end of the third current sampling cable connected to the third current sensor and the second end of the third current sampling cable connected to the current sampling circuit. A self-test button can be provided on the motor soft starter, which can be pressed for self-test. The self-test button sends a self-test command to the processor. Upon receiving the self-test command, the processor controls the first trigger circuit to send trigger pulses to the thyristors in the first thyristor assembly, the second trigger circuit to send trigger pulses to the thyristors in the second thyristor assembly, and the third trigger circuit to send trigger pulses to the thyristors in the third thyristor assembly, ensuring that all thyristors in the first to third thyristor assemblies are turned on. The first current sensor collects the first-phase analog current output by the first thyristor assembly and sends the collected first-phase analog current to the current sampling circuit. The current sampling circuit receives the first-phase analog current, samples the received first-phase analog current, and outputs the sampled first-phase current value to the processor.The second current sensor collects the second-phase simulated current output by the second thyristor assembly and sends the collected second-phase simulated current to the current sampling circuit. The current sampling circuit receives the second-phase simulated current, samples the received second-phase simulated current, and outputs the sampled second-phase current value to the processor. The third current sensor collects the third-phase simulated current output by the third thyristor assembly and sends the collected third-phase simulated current to the current sampling circuit. The current sampling circuit receives the third-phase simulated current, samples the received third-phase simulated current, and outputs the sampled third-phase current value to the processor. Based on the first-phase current value, the processor can obtain the connection detection results of the first trigger cable between the first thyristor assembly and the first trigger circuit, as well as the connection detection results of the first current sampling cable between the first current sensor and the current sampling circuit. Based on the second-phase current value, it can obtain the connection detection results of the second trigger cable between the second thyristor assembly and the second trigger circuit, as well as the connection detection results of the second current sampling cable between the second current sensor and the current sampling circuit. Based on the third-phase current value, it can obtain the connection detection results of the third trigger cable between the third thyristor assembly and the third trigger circuit, as well as the connection detection results of the third current sampling cable between the third current sensor and the current sampling circuit.

[0065] Compared with existing technologies, this application provides a detection method, processor, and motor soft starter for a motor. After a three-phase power supply is supplied to the motor soft starter through the power input terminal, a voltage detection circuit detects the three-phase voltage values ​​input from the power input terminal. Based on these three-phase voltage values, the connection detection result of the voltage detection cable is obtained. The first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end is connected to the voltage detection circuit. A trigger circuit is then controlled to send trigger pulses to each thyristor in the thyristor assembly, causing each thyristor to conduct. The three-phase analog current output by the thyristor assembly is acquired by a current sensor and then processed through a current sensor. The three-phase current values ​​sampled by the sampling circuit are used to obtain the connection detection results of the trigger cable between the thyristor component and the trigger circuit, as well as the connection detection results of the current sampling cable between the current sensor and the current sampling circuit. In this application, the connection detection results of the voltage detection cable between the power input terminal and the thyristor component and the voltage detection circuit, the connection detection results of the trigger cable between the thyristor component and the trigger circuit, and the connection detection results of the current sampling cable between the current sensor and the current sampling circuit can be obtained effectively without relying on manual inspection. It can quickly locate the location of cable connection abnormalities, effectively improve the efficiency of inspection, and thus effectively reduce the labor cost of cable connection inspection.

[0066] In one embodiment of this application, the motor soft starter further includes a fan drive circuit and a cooling fan, and the detection method further includes:

[0067] S4. Send a fan start signal to the fan drive circuit so that the fan drive circuit drives the cooling fan to start.

[0068] In this embodiment, the processor can send a fan start signal to the fan drive circuit. After receiving the fan start signal, the fan drive circuit drives the cooling fan to start working.

[0069] S5. Based on whether a speed feedback signal sent by the cooling fan is received within a preset time after the fan start signal is sent, the connection detection result of the fan cable between the fan drive circuit and the cooling fan is obtained.

[0070] In this embodiment, the preset time in the processor is a pre-set time. After the cooling fan starts working, the cooling fan will send a speed feedback signal to the processor. If the processor receives the speed feedback signal sent by the cooling fan within the preset time after sending the fan start signal, it is determined that the connection of the fan cable between the fan drive circuit and the cooling fan is normal. If the processor does not receive the speed feedback signal sent by the cooling fan within the preset time after sending the fan start signal, it is determined that the connection of the fan cable between the fan drive circuit and the cooling fan is abnormal.

[0071] In one embodiment of this application, the three-phase voltage values ​​include a first-phase voltage value, a second-phase voltage value, and a third-phase voltage value; the power input terminals include a first-phase power input terminal, a second-phase power input terminal, and a third-phase power input terminal; the thyristor components include a first thyristor component, a second thyristor component, and a third thyristor component; the voltage detection cable includes a first voltage detection cable, a second voltage acquisition cable, and a third voltage acquisition cable; step S2 includes:

[0072] S21. If the voltage value of the first phase is less than the preset voltage value, it is determined that the connection of the first voltage detection cable is abnormal. The first end of the first voltage detection cable is connected to the line between the first phase power input terminal and the first thyristor component, and the second end of the first voltage detection cable is connected to the voltage detection circuit.

[0073] In this embodiment, a preset voltage value can be set in the processor according to the voltage value of the three-phase power supply output voltage. If the first phase voltage value of the first phase voltage input from the first phase power supply input terminal is less than the preset voltage value, or the first phase voltage value is equal to zero, i.e., the first phase is missing, the processor determines that the connection between the line between the first phase power supply input terminal and the first thyristor component and the first voltage detection cable between the voltage detection circuit is abnormal.

[0074] S22. If the second phase voltage value is less than the preset voltage value, it is determined that the second voltage detection cable is abnormally connected. The first end of the second voltage detection cable is connected to the line between the second phase power input terminal and the second thyristor assembly, and the second end of the second voltage detection cable is connected to the voltage detection circuit.

[0075] In this embodiment, if the second phase voltage value of the second phase voltage input from the second phase power input terminal is less than the preset voltage value, or the second phase voltage value is equal to zero, i.e., the second phase is missing, the processor determines that the connection between the second phase power input terminal and the second thyristor component and the second voltage detection cable between the voltage detection circuit is abnormal.

[0076] S23. If the third phase voltage value is less than the preset voltage value, it is determined that the third voltage detection cable is abnormally connected. The first end of the third voltage detection cable is connected to the line between the third phase power input terminal and the third thyristor component, and the second end of the third voltage detection cable is connected to the voltage detection circuit.

[0077] In this embodiment, if the third phase voltage value of the third phase voltage input from the third phase power input terminal is less than the preset voltage value, or the third phase voltage value is equal to zero, i.e., the third phase is missing, the processor determines that the connection between the line between the third phase power input terminal and the third thyristor component and the third voltage detection cable between the voltage detection circuit is abnormal.

[0078] As one implementation method, in this embodiment of the application, step S3 includes:

[0079] S31. The control trigger circuit sends trigger pulses to each thyristor in the thyristor assembly so that each thyristor is turned on so that the output voltage of the motor soft starter is the first voltage value.

[0080] In this embodiment, the first voltage value can be 10% of the rated voltage of the three-phase motor. The processor controls the first trigger circuit to send trigger pulses to the thyristors in the first thyristor assembly, controls the second trigger circuit to send trigger pulses to the thyristors in the second thyristor assembly, and controls the third trigger circuit to send trigger pulses to the thyristors in the third thyristor assembly, so that each thyristor in the first to third thyristor assemblies is turned on, and the voltage value of the motor soft starter outputting the voltage through the power output terminal is the first voltage value.

[0081] S32. Obtain the three-phase analog current output by the thyristor component collected by the current sensor and the three-phase current value sampled by the current sampling circuit.

[0082] In this embodiment, a first current sensor collects the first-phase simulated current output by a first thyristor component and sends the collected first-phase simulated current to a current sampling circuit. The current sampling circuit receives the first-phase simulated current, samples the received first-phase simulated current, and outputs the sampled first-phase current value to a processor. A second current sensor collects the second-phase simulated current output by a second thyristor component and sends the collected second-phase simulated current to a current sampling circuit. The current sampling circuit receives the second-phase simulated current, samples the received second-phase simulated current, and outputs the sampled second-phase current value to a processor. A third current sensor collects the third-phase simulated current output by a third thyristor component and sends the collected third-phase simulated current to a current sampling circuit. The current sampling circuit receives the third-phase simulated current, samples the received third-phase simulated current, and outputs the sampled third-phase current value to a processor.

[0083] S33. If one or more phase current values ​​in the three phases are greater than zero, the control trigger circuit stops sending trigger pulses and obtains the connection detection results of the trigger cable between the thyristor component and the trigger circuit, as well as the connection detection results of the current sampling cable between the current sensor and the current sampling circuit, based on the three phase current values.

[0084] In this embodiment, if one of the three phase current values ​​received by the processor is greater than zero, or two of the phase current values ​​are greater than zero, or all three phase current values ​​are greater than zero, the processor controls the first to third trigger circuits to stop sending trigger pulses. Based on the first phase current value, the processor obtains the connection detection result of the first trigger cable between the first thyristor assembly and the first trigger circuit, and the connection detection result of the first current sampling cable between the first current sensor and the current sampling circuit. Based on the second phase current value, the processor obtains the connection detection result of the second trigger cable between the second thyristor assembly and the second trigger circuit, and the connection detection result of the second current sampling cable between the second current sensor and the current sampling circuit. Based on the third phase current value, the processor obtains the connection detection result of the third trigger cable between the third thyristor assembly and the third trigger circuit, and the connection detection result of the third current sampling cable between the third current sensor and the current sampling circuit.

[0085] S34. If all phase current values ​​in the three-phase current values ​​are zero, the control trigger circuit adjusts the trigger pulse to increase the conduction angle of each thyristor, thereby increasing the output voltage of the motor soft starter to the second voltage value. The increased three-phase analog current output by the thyristor component is acquired by the current sensor and the increased three-phase current value is sampled by the current sampling circuit. If one or more phase current values ​​in the increased three-phase current values ​​are greater than zero, the control trigger circuit stops sending trigger pulses. Based on the increased three-phase current values, the connection detection result of the trigger cable between the thyristor component and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained.

[0086] In this embodiment, if all phase current values ​​received by the processor are zero (i.e., the first, second, and third phase current values ​​are all zero), the processor controls the first to third trigger circuits to adjust the trigger pulses, thereby increasing the conduction angle of each thyristor. This increases the output voltage of the motor soft starter to a second voltage value, which can be 30% of the rated voltage of the three-phase motor. The processor also acquires the increased three-phase analog current output by the thyristor assembly from the current sensor and the increased three-phase current value sampled by the current sampling circuit. If one phase current value is greater than zero, or two phase current values ​​are greater than zero, or... If all three phase current values ​​are greater than zero, the processor controls the first to third trigger circuits to stop sending trigger pulses. When the increased first, second, and third phase current values ​​are all greater than zero, and the effective value of the increased first phase current is equal to the effective values ​​of the increased second and third phase currents, the processor determines that the first, second, and third trigger cable connections are normal, as are the first, second, and third current sampling cable connections. If the increased first phase current value is zero and the effective values ​​of the increased second and third phase currents are equal, the processor determines that the first, second, and third trigger cable connections are normal. When the third-phase current value is greater than zero, the connection of the first trigger cable or the first current sampling cable is determined to be abnormal. When the increased second-phase current value is zero and both the increased first-phase and third-phase current values ​​are greater than zero, the connection of the second trigger cable or the second current sampling cable is determined to be abnormal. When the increased third-phase current value is zero and both the increased first-phase and second-phase current values ​​are greater than zero, the connection of the third trigger cable or the third current sampling cable is determined to be abnormal. When both the increased first-phase and second-phase current values ​​are zero and both the increased third-phase current value is greater than zero, the connection of the first trigger cable or the first current sampling cable is determined to be abnormal. If the connection of the first current sampling cable is abnormal, or the connection of the second trigger cable is abnormal, or the connection of the third trigger cable is abnormal, or the connection of the third current sampling cable is abnormal; if the increased first phase current value and the increased third phase current value are zero and the increased second phase current value is greater than zero, then the connection of the second trigger cable is abnormal, or the connection of the second current sampling cable is abnormal, or the connection of the third trigger cable is abnormal, or the connection of the third current sampling cable is abnormal.

[0087] S35. If the current values ​​of each phase in the increased three-phase current are all zero, the control trigger circuit continues to adjust the trigger pulses to increase the conduction angle of each thyristor until the output voltage of the motor soft starter increases to the third voltage value. The control trigger circuit continues to acquire the increased three-phase analog current output by the thyristor assembly from the current sensor and the increased three-phase current value sampled by the current sampling circuit. The control trigger circuit stops sending trigger pulses and obtains the connection detection results of the trigger cable between the thyristor assembly and the trigger circuit, as well as the connection detection results of the current sampling cable between the current sensor and the current sampling circuit, based on the increased three-phase current values.

[0088] In this embodiment, if the processor receives an increased three-phase current value in which each phase current value is zero, the trigger circuit continues to adjust the trigger pulses to increase the conduction angle of each thyristor until the output voltage of the motor soft starter increases to a third voltage value, which can be 50% of the rated voltage of the three-phase motor. The processor then continues to acquire the increased three-phase analog current output from the thyristor components via the current sensor and the increased three-phase current value sampled by the current sampling circuit. Finally, the processor controls the first to third trigger circuits to stop sending trigger pulses. A determination is made when the increased three-phase current value in each phase current value is zero. If the first trigger cable connection is abnormal, or the first current sampling cable connection is abnormal, and the second trigger cable connection is abnormal, or the second current sampling cable connection is abnormal, and the third trigger cable connection is abnormal, or the third current sampling cable connection is abnormal; and when the increased first phase current value, the increased second phase current value, and the increased third phase current value are all greater than zero, and the effective value of the increased first phase current value is equal to the effective values ​​of the increased second phase current value and the increased third phase current value, then the first trigger cable connection is determined to be normal, the second trigger cable connection is normal, the third trigger cable connection is normal, and the first current sampling cable connection is normal. If the first phase current is normally connected, the second phase current sampling cable is normally connected, and the third phase current sampling cable is normally connected; if the first phase current value after the second increase is zero, and the second and third phase current values ​​after the second increase are greater than zero, then the first trigger cable connection is determined to be abnormal, or the first current sampling cable connection is abnormal; if the second phase current value after the second increase is zero, and the first and third phase current values ​​after the second increase are greater than zero, then the second trigger cable connection is determined to be abnormal, or the second current sampling cable connection is abnormal; if the third phase current value after the second increase is zero, and the first and second phase current values ​​after the second increase are greater than zero, then the first trigger cable connection is determined to be abnormal, or the second current sampling cable connection is abnormal. If the first phase current value and the second phase current value are both zero after a further increase, and the third phase current value is greater than zero, then the first trigger cable connection is determined to be abnormal, or the first current sampling cable connection is abnormal, and the second trigger cable connection is also abnormal, or the second current sampling cable connection is also abnormal.If the increased second-phase current value and the increased third-phase current value are both zero, and the increased first-phase current value is greater than zero, then the connection of either the second trigger cable or the second current sampling cable is determined to be abnormal, as is the connection of either the third trigger cable or the third current sampling cable.

[0089] In one embodiment of this application, the three-phase current values ​​include a first-phase current value, a second-phase current value, and a third-phase current value; the trigger circuit includes a first trigger circuit, a second trigger circuit, and a third trigger circuit; the trigger cable includes a first trigger cable, a second trigger cable, and a third trigger cable; the current sensor includes a first current sensor, a second current sensor, and a third current sensor; the current sampling cable includes a first current sampling cable, a second current sampling cable, and a third current sampling cable; and step S33 includes:

[0090] S331. If the first phase current value, the second phase current value, and the third phase current value are all greater than zero, and the effective value of the first phase current value is equal to the effective values ​​of the second phase current value and the third phase current value, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is normal, the second trigger cable connection between the second thyristor component and the second trigger circuit is normal, the third trigger cable connection between the third thyristor component and the third trigger circuit is normal, and the first current sampling cable connection between the first current sensor and the current sampling circuit is normal, the second current sampling cable connection between the second current sensor and the current sampling circuit is normal, and the third current sampling cable connection between the third current sensor and the current sampling circuit is normal.

[0091] S332. If the first phase current value is zero and the second phase current value and the third phase current value are greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal.

[0092] S333. If the second phase current value is zero and the first phase current value and the third phase current value are greater than zero, it is determined that the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal.

[0093] S334. If the third phase current value is zero and the first phase current value and the second phase current value are greater than zero, it is determined that the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

[0094] S335. If the first phase current value and the second phase current value are zero and the third phase current value is greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal, and the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal.

[0095] S336. If the first phase current value and the third phase current value are zero and the second phase current value is greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal, and the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

[0096] S337. If the second phase current value and the third phase current value are zero and the first phase current value is greater than zero, it is determined that the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal, and the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

[0097] like Figure 2 As shown in the illustration, this application also provides a processor, including:

[0098] The acquisition module 110 is used to acquire the three-phase voltage value of the three-phase voltage input from the power input terminal after the three-phase power supply supplies power to the motor soft starter through the power input terminal;

[0099] The first detection module 120 is used to obtain the connection detection result of the voltage detection cable based on the three-phase voltage value. The first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor component, and the second end of the voltage detection cable is connected to the voltage detection circuit.

[0100] The second detection module 130 is used to control the trigger circuit to send trigger pulses to each thyristor in the thyristor assembly so that each thyristor is turned on, to acquire the three-phase analog current output by the thyristor assembly collected by the current sensor and the three-phase current value sampled by the current sampling circuit, and to obtain the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, as well as the connection detection result of the current sampling cable between the current sensor and the current sampling circuit, based on the three-phase current value.

[0101] like Figure 3 As shown, in one embodiment, this application also includes:

[0102] The control module 140 is used to send a fan start signal to the fan drive circuit so that the fan drive circuit drives the cooling fan to start.

[0103] The third detection module 150 is used to obtain the connection detection result of the fan cable between the fan drive circuit and the cooling fan based on whether a speed feedback signal sent by the cooling fan is received within a preset time after the fan start signal is sent.

[0104] like Figure 4 As shown in the figure, this application embodiment also provides a motor soft starter, including the processor, voltage detection circuit, thyristor assembly, trigger circuit, current sensor and current sampling circuit described above;

[0105] The voltage detection circuit is used to detect the three-phase voltage value of the three-phase voltage input from the power input terminal and send the detected three-phase voltage value to the processor.

[0106] In this embodiment, the voltage detection circuit may include a voltage sensor for acquiring analog voltage and a voltage sampling circuit for sampling the analog voltage and outputting the voltage value. Alternatively, the voltage detection circuit may include other electronic components for voltage detection. The lines between the power input terminals and the thyristor assembly are connected to the voltage detection circuit via voltage detection cables. These cables include a first voltage detection cable K11, a second voltage detection cable K12, and a third voltage detection cable K13. The power input terminals include a first-phase power input terminal (i.e., R terminal), a second-phase power input terminal (i.e., S terminal), and a third-phase power input terminal (i.e., T terminal). The R terminal is used to connect to the first phase of the three-phase power supply, the S terminal is used to connect to the second phase, and the T terminal is used to connect to the third phase. The thyristor assembly includes a first thyristor assembly 110, a second thyristor assembly 120, and a third thyristor assembly 130. The first end of the first voltage detection cable K11 is connected to the line between the R terminal and the first thyristor assembly 110, and the second end of the first voltage detection cable K11 is connected to the voltage detection circuit. The first end of the second voltage detection cable K12 is connected to the line between the S terminal and the second thyristor assembly 120, and the second end of the second voltage detection cable K12 is connected to the voltage detection circuit. The first end of the third voltage detection cable K13 is connected to the line between the T terminal and the third thyristor assembly 130, and the second end of the third voltage detection cable K13 is connected to the voltage detection circuit. The voltage detection circuit is used to detect the three-phase voltage values ​​of the three-phase voltages input from the R terminal, S terminal, and T terminal, and send the detected three-phase voltage values ​​to the processor.

[0107] The trigger circuit is used to send trigger pulses to each thyristor in the thyristor assembly according to the control of the processor, so that each thyristor is turned on.

[0108] In this embodiment, the trigger circuit and the thyristor assembly are connected via trigger cables. The trigger circuit includes a first trigger circuit, a second trigger circuit, and a third trigger circuit. The first thyristor assembly 110 includes a first thyristor Q1 and a second thyristor Q2 connected in anti-parallel. The second thyristor assembly 120 includes a third thyristor Q3 and a fourth thyristor Q4 connected in anti-parallel. The third thyristor assembly 130 includes a fifth thyristor Q5 and a sixth thyristor Q6 connected in anti-parallel. The trigger cables include a first trigger cable K21, a second trigger cable K22, and a third trigger cable K23. The first end of the first trigger cable K21 is connected to the control electrode of the first thyristor Q1 and the control electrode of the second thyristor Q2. The second end of the first trigger cable K21 is connected to the first trigger circuit. The first end of the second trigger cable K22 is connected to the control electrode of the third thyristor Q3 and the control electrode of the fourth thyristor Q4. The second trigger cable K23... The second end of cable K22 is connected to the second trigger circuit, and the first end of the third trigger cable K23 is connected to the control electrode of the fifth thyristor Q5 and the control electrode of the sixth thyristor Q6. The second end of the third trigger cable K23 is connected to the third trigger circuit. The first trigger circuit is used to send trigger pulses to the first thyristor Q1 and the second thyristor Q2 in the first thyristor assembly 110 according to the control of the processor, so that the first thyristor Q1 and the second thyristor Q2 are turned on. The second trigger circuit is used to send trigger pulses to the third thyristor Q3 and the fourth thyristor Q4 in the second thyristor assembly 120 according to the control of the processor, so that the third thyristor Q3 and the fourth thyristor Q4 are turned on. The third trigger circuit is used to send trigger pulses to the fifth thyristor Q5 and the sixth thyristor Q6 in the third thyristor assembly 130 according to the control of the processor, so that the fifth thyristor Q5 and the sixth thyristor Q6 are turned on.

[0109] The thyristor component is used to turn on when it receives a phase voltage input from the power input terminal and a trigger pulse sent by the trigger circuit, and to output the received phase voltage after stepping down according to the trigger pulse;

[0110] In this embodiment, the thyristor assembly includes a first thyristor assembly 110, a second thyristor assembly 120, and a third thyristor assembly 130. The first thyristor Q1 and the second thyristor Q2 in the first thyristor assembly 110 are turned on when they receive a first phase voltage input from the R terminal and a trigger pulse sent by the first trigger circuit, and output the received first phase voltage after stepping down according to the trigger pulse. The third thyristor Q3 and the fourth thyristor Q4 in the second thyristor assembly 120 are turned on when they receive a second phase voltage input from the S terminal and a trigger pulse sent by the second trigger circuit, and output the received second phase voltage after stepping down according to the trigger pulse. The fifth thyristor Q5 and the sixth thyristor Q6 in the third thyristor assembly 130 are turned on when they receive a third phase voltage input from the T terminal and a trigger pulse sent by the third trigger circuit, and output the received third phase voltage after stepping down according to the trigger pulse.

[0111] The current sensor is used to collect the three-phase analog current output by the thyristor component and send the collected three-phase analog current to the current sampling circuit.

[0112] In this embodiment, the current sensors include a first current sensor CT1, a second current sensor CT2, and a third current sensor CT3. The motor soft starter is provided with power output terminals for connecting to a three-phase motor. The power output terminals may include a first-phase power output terminal (i.e., U terminal), a second-phase power output terminal (i.e., V terminal), and a third-phase power output terminal (i.e., W terminal). The first current sensor CT1 is disposed on the line between the first thyristor assembly 110 and the U terminal. The second current sensor CT2 is disposed on the line between the second thyristor assembly 120 and the V terminal. The third current sensor CT3 is disposed on the line between the third thyristor assembly 130 and the W terminal. The first current sensor CT1 is used to collect the first-phase analog current output by the first thyristor assembly 110 and send the collected first-phase analog current to the current sampling circuit. The second current sensor CT2 is used to collect the second-phase analog current output by the second thyristor assembly 120 and send the collected second-phase analog current to the current sampling circuit. The third current sensor CT3 is used to collect the third-phase analog current output by the third thyristor assembly 130 and send the collected third-phase analog current to the current sampling circuit.

[0113] The current sampling circuit is used to receive three-phase analog current, sample the received three-phase analog current, and output the sampled three-phase current value to the processor.

[0114] In this embodiment, the current sensor and the current sampling circuit are connected via a current sampling cable. The current sampling cable includes a first current sampling cable K31, a second current sampling cable K32, and a third current sampling cable K33. The first end of the first current sampling cable K31 is connected to the first current sensor CT1, and the second end of the first current sampling cable K31 is connected to the current sampling circuit. The first end of the second current sampling cable K32 is connected to the second current sensor CT2, and the second end of the second current sampling cable K32 is connected to the current sampling circuit. The first end of the third current sampling cable K33 is connected to the third current sensor CT3, and the second end of the third current sampling cable K33 is connected to the current sampling circuit. The current sampling circuit receives the first-phase analog current output by the first current sensor CT1 through the first current sampling cable K31, the second-phase analog current output by the second current sensor CT2 through the second current sampling cable K32, and the third-phase analog current output by the third current sensor CT3 through the third current sampling cable K33. It then samples the received first-phase analog current, second-phase analog current, and third-phase analog current and outputs the sampled first-phase current value, second-phase current value, and third-phase current value to the processor.

[0115] like Figure 4 As shown, in one embodiment, this application also includes: a fan drive circuit and a cooling fan 200;

[0116] A fan drive circuit is used to drive the cooling fan 200 to start according to the fan start signal sent by the processor.

[0117] Cooling fan 200 is used to start according to the drive circuit of fan drive, and sends speed feedback signal to processor after starting.

[0118] In this embodiment, the fan drive circuit and the cooling fan 200 are connected by a fan cable K41.

[0119] It should be understood that the use of terms such as "system," "device," "unit," and / or "module" in this application is merely one method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0120] The embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0121] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting a motor soft starter, characterized in that, Applied to a processor, the motor soft starter includes a voltage detection circuit, a thyristor assembly, the processor, a trigger circuit, a current sensor, and a current sampling circuit. The detection method includes: After the three-phase power supply supplies power to the motor soft starter through the power input terminal, the voltage detection circuit obtains the three-phase voltage value of the three-phase voltage input from the power input terminal. Based on the three-phase voltage values, the connection detection result of the voltage detection cable is obtained, wherein the first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end of the voltage detection cable is connected to the voltage detection circuit. The trigger circuit is controlled to send trigger pulses to each thyristor in the thyristor assembly, so that each thyristor is turned on. The three-phase analog current output by the thyristor assembly is acquired by the current sensor and the three-phase current value is sampled by the current sampling circuit. Based on the three-phase current value, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained.

2. The detection method according to claim 1, characterized in that, The motor soft starter also includes a fan drive circuit and a cooling fan, and the detection method further includes: A fan start signal is sent to the fan drive circuit so that the fan drive circuit drives the cooling fan to start. Based on whether a speed feedback signal from the cooling fan is received within a preset time after the fan start signal is sent, the connection detection result of the fan cable between the fan drive circuit and the cooling fan is obtained.

3. The detection method according to claim 1, characterized in that, The three-phase voltage values ​​include a first-phase voltage value, a second-phase voltage value, and a third-phase voltage value. The power input terminals include a first-phase power input terminal, a second-phase power input terminal, and a third-phase power input terminal. The thyristor assembly includes a first thyristor assembly, a second thyristor assembly, and a third thyristor assembly. The voltage detection cable includes a first voltage detection cable, a second voltage acquisition cable, and a third voltage acquisition cable. The connection detection result of the voltage detection cable is obtained based on the three-phase voltage values. The first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor assembly, and the second end of the voltage detection cable is connected to the voltage detection circuit, including: If the voltage value of the first phase is less than the preset voltage value, it is determined that the connection of the first voltage detection cable is abnormal. The first end of the first voltage detection cable is connected to the line between the power input terminal of the first phase and the first thyristor component, and the second end of the first voltage detection cable is connected to the voltage detection circuit. If the voltage value of the second phase is less than the preset voltage value, it is determined that the connection of the second voltage detection cable is abnormal. The first end of the second voltage detection cable is connected to the line between the second phase power input terminal and the second thyristor component, and the second end of the second voltage detection cable is connected to the voltage detection circuit. If the third phase voltage value is less than the preset voltage value, the connection of the third voltage detection cable is determined to be abnormal. The first end of the third voltage detection cable is connected to the line between the third phase power input terminal and the third thyristor assembly, and the second end of the third voltage detection cable is connected to the voltage detection circuit.

4. The detection method according to claim 3, characterized in that, The control circuit sends trigger pulses to each thyristor in the thyristor assembly to turn on each thyristor, acquires the three-phase analog current output by the thyristor assembly collected by the current sensor, and samples the three-phase current value through the current sampling circuit. Based on the three-phase current value, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained, including: The trigger circuit is controlled to send trigger pulses to each of the thyristors in the thyristor assembly, so that each of the thyristors is turned on, so that the output voltage of the motor soft starter is a first voltage value; The three-phase analog current output by the thyristor component is acquired by the current sensor and the three-phase current value is sampled by the current sampling circuit. If one or more of the three-phase current values ​​are greater than zero, the trigger circuit is controlled to stop sending trigger pulses, and the connection detection result of the trigger cable between the thyristor component and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained based on the three-phase current values. If all phase current values ​​in the three-phase current values ​​are zero, the trigger circuit is controlled to adjust the trigger pulse to increase the conduction angle of each thyristor, thereby increasing the output voltage of the motor soft starter to a second voltage value. The increased three-phase analog current output by the thyristor assembly is acquired by the current sensor and the increased three-phase current value is sampled by the current sampling circuit. If one or more phase current values ​​in the increased three-phase current values ​​are greater than zero, the trigger circuit is controlled to stop sending trigger pulses. Based on the increased three-phase current values, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained. If all phase current values ​​in the increased three-phase current values ​​are zero, the trigger circuit is controlled to continue adjusting the trigger pulses so that the conduction angle of each thyristor continues to increase until the output voltage of the motor soft starter increases to a third voltage value. The increased three-phase analog current output by the thyristor assembly is acquired by the current sensor and the increased three-phase current value is sampled by the current sampling circuit. The trigger circuit is then controlled to stop sending trigger pulses. Based on the increased three-phase current values, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, as well as the connection detection result of the current sampling cable between the current sensor and the current sampling circuit, are obtained.

5. The detection method according to claim 4, characterized in that, The three-phase current values ​​include a first-phase current value, a second-phase current value, and a third-phase current value. The trigger circuit includes a first trigger circuit, a second trigger circuit, and a third trigger circuit. The trigger cable includes a first trigger cable, a second trigger cable, and a third trigger cable. The current sensor includes a first current sensor, a second current sensor, and a third current sensor. The current sampling cable includes a first current sampling cable, a second current sampling cable, and a third current sampling cable. If one or more of the three-phase current values ​​are greater than zero, the trigger circuit is controlled to stop sending trigger pulses. Based on the three-phase current values, the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit are obtained, including: If the first phase current value, the second phase current value, and the third phase current value are all greater than zero, and the effective value of the first phase current value is equal to the effective values ​​of the second phase current value and the third phase current value, then it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is normal, the second trigger cable connection between the second thyristor component and the second trigger circuit is normal, the third trigger cable connection between the third thyristor component and the third trigger circuit is normal, and the first current sampling cable connection between the first current sensor and the current sampling circuit is normal, the second current sampling cable connection between the second current sensor and the current sampling circuit is normal, and the third current sampling cable connection between the third current sensor and the current sampling circuit is normal. If the first phase current value is zero and the second phase current value and the third phase current value are greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal. If the second phase current value is zero and the first phase current value and the third phase current value are greater than zero, it is determined that the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal. If the third phase current value is zero and the first phase current value and the second phase current value are greater than zero, it is determined that the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal. If the first phase current value and the second phase current value are zero and the third phase current value is greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal, and the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal. If the first phase current value and the third phase current value are zero and the second phase current value is greater than zero, it is determined that the first trigger cable connection between the first thyristor component and the first trigger circuit is abnormal, or the first current sampling cable connection between the first current sensor and the current sampling circuit is abnormal, and the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal. If the second phase current value and the third phase current value are zero and the first phase current value is greater than zero, it is determined that the second trigger cable connection between the second thyristor component and the second trigger circuit is abnormal, or the second current sampling cable connection between the second current sensor and the current sampling circuit is abnormal, and the third trigger cable connection between the third thyristor component and the third trigger circuit is abnormal, or the third current sampling cable connection between the third current sensor and the current sampling circuit is abnormal.

6. A processor, characterized in that, include: The acquisition module is used to acquire the three-phase voltage value of the three-phase voltage input from the power input terminal after the three-phase power supply supplies power to the motor soft starter through the power input terminal; The first detection module is used to obtain the connection detection result of the voltage detection cable based on the three-phase voltage value, wherein the first end of the voltage detection cable is connected to the line between the power input terminal and the thyristor component of the motor soft starter, and the second end of the voltage detection cable is connected to the voltage detection circuit. The second detection module is used to control the trigger circuit to send trigger pulses to each thyristor in the thyristor assembly, so that each thyristor is turned on, to acquire the three-phase analog current output by the thyristor assembly collected by the current sensor and the three-phase current value sampled by the current sampling circuit, and to obtain the connection detection result of the trigger cable between the thyristor assembly and the trigger circuit, and the connection detection result of the current sampling cable between the current sensor and the current sampling circuit based on the three-phase current value.

7. The processor according to claim 6, characterized in that, Also includes: The control module is used to send a fan start signal to the fan drive circuit of the motor soft starter, so that the fan drive circuit drives the cooling fan of the motor soft starter to start. The third detection module is used to obtain the connection detection result of the fan cable between the fan drive circuit and the cooling fan based on whether a speed feedback signal sent by the cooling fan is received within a preset time after the fan start signal is sent.

8. A motor soft starter, characterized in that, Includes the processor, voltage detection circuit, thyristor assembly, trigger circuit, current sensor, and current sampling circuit as described in claim 6 or 7; The voltage detection circuit is used to detect the three-phase voltage value of the three-phase voltage input from the power input terminal, and send the detected three-phase voltage value to the processor; The trigger circuit is used to send trigger pulses to each thyristor in the thyristor assembly according to the control of the processor, so as to turn on each of the thyristors; The thyristor component is used to turn on when it receives a phase voltage input from the power input terminal and a trigger pulse sent by the trigger circuit, and to output the received phase voltage after stepping down according to the trigger pulse; A current sensor is used to collect the three-phase analog current output by the thyristor component and send the collected three-phase analog current to the current sampling circuit. The current sampling circuit is used to receive the three-phase analog current, sample the received three-phase analog current, and output the sampled three-phase current value to the processor.

9. The motor soft starter according to claim 8, characterized in that, Also includes: Fan drive circuit and cooling fan; The fan drive circuit is used to drive the cooling fan to start according to the fan start signal sent by the processor; The cooling fan is used to start according to the drive of the fan drive circuit, and after starting, sends a speed feedback signal to the processor.

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