Power phase-loss protection device and method, motor controller, frequency converter and motor

Abstract

The application belongs to the technical field of electric machines, and discloses a power supply open-phase protection device and method, an electric machine controller, a frequency converter and an electric machine. The device comprises a sampling unit and a control unit. The sampling unit is used to acquire the voltage value of each phase of a three-phase input power supply when the electric machine is running, to obtain the voltage value of the three-phase input power supply, and to acquire an open-phase false triggering protection value of the three-phase input power supply. The control unit is used to determine whether the three-phase input power supply is open-phase according to the voltage value of the three-phase input power supply and the open-phase false triggering protection value of the three-phase input power supply, to execute a preset power supply open-phase protection strategy when it is determined that the three-phase input power supply is open-phase, and to continue to control the electric machine to run when it is determined that the three-phase input power supply is not open-phase. The scheme increases the open-phase false triggering protection function for preventing false triggering of the open-phase protection in the case of power failure, avoids false triggering of the open-phase protection in the case of power failure, and improves the reliability of the electric machine running.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric machines, and particularly relates to a power phase-loss protection device and method, an electric machine controller, a frequency converter and an electric machine, in particular to a three-phase input power phase-loss protection control device and method for an electric machine, an electric machine controller, a frequency converter and an electric machine. BACKGROUND

[0002] In the field of industrial fans, EC electric machines (i.e. electronic commutated electric machines) are widely used, and the energy efficiency of the EC electric machines is higher than that of the alternating current electric machines in the energy efficiency ratio related scheme. In the case of power supply of the electric machine by a three-phase input power, three-phase input power phase-loss protection needs to be performed.

[0003] In the related scheme, whether the three-phase input power is phase-loss is determined by collecting the voltage value of the three-phase input power of the electric machine, but in the case of power failure, the three-phase input power is misjudged as phase-loss and the phase-loss protection is mis-triggered.

[0004] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as prior art. SUMMARY

[0005] The present application aims to provide a power phase-loss protection device and method, an electric machine controller, a frequency converter and an electric machine, to solve the problem of mis-triggering of phase-loss protection in the case of power failure in the related scheme by collecting the voltage value of the three-phase input power of the electric machine to determine whether the three-phase input power is phase-loss, to achieve the effect of increasing the phase-loss mis-trigger protection function in the control algorithm to prevent mis-triggering of phase-loss protection in the case of power failure by collecting the voltage value of each phase power in the three-phase input power of the electric machine, to accurately determine the phase-loss of the three-phase input power of the electric machine, to avoid mis-triggering of phase-loss protection in the case of power failure, and to be beneficial to improving the reliability of the operation of the electric machine.

[0006] The application provides a power phase loss protection device applied to phase loss protection of three-phase input power of a motor.

[0007] In some embodiments, the sampling unit comprises three sampling modules, each of which is used for sampling the voltage value of a corresponding phase of the three-phase input power; each sampling module comprises a voltage dividing module, a voltage reducing module and a clamping module; each phase of the three-phase input power is connected to the voltage reducing module through the voltage dividing module and the clamping module, and the voltage value of the phase is output from the common end of the voltage reducing module and the clamping module.

[0008] In some embodiments, the voltage dividing module comprises at least two resistance modules connected in series, the voltage reducing module comprises a voltage reducing diode module, and the clamping module comprises a clamping diode module; each phase of the three-phase input power is connected to the anode of the voltage reducing diode module through the at least two resistance modules, the cathode of the voltage reducing diode module is connected to the clamping end of the clamping module, the anode of the clamping diode module is grounded, the cathode of the clamping diode module is connected to a preset voltage source, the common end of the cathode of the voltage reducing diode module and the clamping end of the clamping diode module is the common end of the voltage reducing module and the clamping module, the cathode of the voltage reducing diode module is the output end of the voltage reducing module, and the clamping end of the clamping diode module is the output end of the clamping module.

[0009] In some embodiments, each of the sampling modules further comprises a first filtering module and / or a second filtering module; the first filtering module is arranged between the output of the voltage reduction module and the ground; and the second filtering module is arranged between the output of the clamping module and the ground.

[0010] In some embodiments, the first filtering module comprises a first resistance module and a first capacitance module; the first resistance module and the first capacitance module are connected in parallel between the output of the voltage reduction module and the ground; and / or the second filtering module comprises a second resistance module and a second capacitance module; the second resistance module and the second capacitance module are connected in series between the output of the clamping module and the ground; and the common terminal of the second resistance module and the second capacitance module is the output of the sampling module.

[0011] In some embodiments, the control unit determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply, comprising: determining the maximum value in the voltage values of the three-phase input power supply as the maximum voltage value of the three-phase input power supply; and determining the voltage values of the two-phase input power supply other than the maximum voltage value of the three-phase input power supply in the voltage values of the three-phase input power supply as the two-phase smaller voltage values of the three-phase input power supply; determining whether the voltage value of each phase input power supply in the voltage values of the three-phase input power supply is greater than or equal to the out-of-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple are simultaneously satisfied: if yes, it is determined that the three-phase input power supply is out of phase, so as to execute the preset power supply out-of-phase protection strategy; otherwise, it is determined that the three-phase input power supply is not out of phase, so as to control the motor to continue running; and / or the control unit executes the preset power supply out-of-phase protection strategy, comprising: controlling the motor to slow down or controlling the motor to shut down.

[0012] In some embodiments, the control unit determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply, comprising: determining the maximum value in the voltage values of the three-phase input power supply as the maximum voltage value of the three-phase input power supply; and determining the voltage values of the two-phase input power supply other than the maximum voltage value of the three-phase input power supply in the voltage values of the three-phase input power supply as the two-phase smaller voltage values of the three-phase input power supply; determining whether the voltage value of each phase input power supply in the voltage values of the three-phase input power supply is greater than or equal to the out-of-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple are simultaneously satisfied: if yes, it is determined that the three-phase input power supply is out of phase, so as to execute the preset power supply out-of-phase protection strategy; otherwise, it is determined that the three-phase input power supply is not out of phase, so as to control the motor to continue running; and / or the control unit executes the preset power supply out-of-phase protection strategy, comprising: controlling the motor to slow down or controlling the motor to shut down.

[0013] In some embodiments, the control unit determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply, comprising: determining the maximum value in the voltage values of the three-phase input power supply as the maximum voltage value of the three-phase input power supply; and determining the voltage values of the two-phase input power supply other than the maximum voltage value of the three-phase input power supply in the voltage values of the three-phase input power supply as the two-phase smaller voltage values of the three-phase input power supply; determining whether the voltage value of each phase input power supply in the voltage values of the three-phase input power supply is greater than or equal to the out-of-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple are simultaneously satisfied: if yes, it is determined that the three-phase input power supply is out of phase, so as to execute the preset power supply out-of-phase protection strategy; otherwise, it is determined that the three-phase input power supply is not out of phase, so as to control the motor to continue running; and / or the control unit executes the preset power supply out-of-phase protection strategy, comprising: controlling the motor to slow down or controlling the motor to shut down.

[0014] In some embodiments, the control unit determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply, comprising: determining the maximum value in the voltage values of the three-phase input power supply as the maximum voltage value of the three-phase input power supply; and determining the voltage values of the two-phase input power supply other than the maximum voltage value of the three-phase input power supply in the voltage values of the three-phase input power supply as the two-phase smaller voltage values of the three-phase input power supply; determining whether the voltage value of each phase input power supply in the voltage values of the three-phase input power supply is greater than or equal to the out-of-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple are simultaneously satisfied: if yes, it is determined that the three-phase input power supply is out of phase, so as to execute the preset power supply out-of-phase protection strategy; otherwise, it is determined that the three-phase input power supply is not out of phase, so as to control the motor to continue running; and / or the control unit executes the preset power supply out-of-phase protection strategy, comprising: controlling the motor to slow down or controlling the motor to shut down.

[0015] According to the device, the application further provides a power phase loss protection method, comprising: obtaining voltage values of each phase of the three-phase input power by the sampling unit under the operation of the motor, to obtain voltage values of the three-phase input power; and obtaining a phase loss false triggering protection value of the three-phase input power; determining whether the three-phase input power is in phase loss according to the voltage values of the three-phase input power and the phase loss false triggering protection value of the three-phase input power; increasing a phase loss false triggering protection function for preventing false triggering of the phase loss protection under the condition of power failure in the control algorithm by collecting voltage values of each phase of the three-phase input power of the motor, to accurately determine the phase loss of the three-phase input power of the motor; and executing a preset power phase loss protection strategy under the condition that the three-phase input power is determined to be in phase loss; and continuing to control the operation of the motor under the condition that the three-phase input power is determined not to be in phase loss.

[0016] In some embodiments, the determination of whether the three-phase input power is in phase loss according to the voltage values of the three-phase input power and the phase loss false triggering protection value of the three-phase input power comprises: determining a maximum value of the voltage values of the three-phase input power as a maximum voltage value of the three-phase input power; determining voltage values of two phases of the three-phase input power other than the maximum voltage value of the three-phase input power as two-phase smaller voltage values of the three-phase input power; determining whether each voltage value of the voltage values of the three-phase input power is greater than or equal to the phase loss false triggering protection value of the three-phase input power and an absolute value of a difference between the two-phase smaller voltage values of the three-phase input power is greater than a set multiple of the maximum voltage value of the three-phase input power; if yes, determining that the three-phase input power is in phase loss to execute the preset power phase loss protection strategy; otherwise, determining that the three-phase input power is not in phase loss to control the motor to continue to operate; and / or the execution of the preset power phase loss protection strategy comprises: controlling the motor to slow down or stopping the motor.

[0017] Therefore, the scheme of the application, for the three-phase input power supply of the motor, sets the acquisition module of the hardware circuit part and the control algorithm of the software control part, acquires the voltage value of each phase power supply in the three-phase input power supply of the motor by the acquisition module, and obtains the voltage value of the three-phase; sets the open-phase false triggering protection value (such as voltage Vz), and determines that the three-phase input power supply of the motor is open-phase to trigger the open-phase protection in the case that the voltage value of the three-phase acquired is greater than or equal to the open-phase false triggering protection value, and the absolute value of the voltage value difference of the smaller two phases in the voltage value of the three-phase is greater than the maximum voltage value of the three-phase in the set multiple (such as 0.5); thereby, by acquiring the voltage value of each phase power supply in the three-phase input power supply of the motor, the open-phase false triggering protection function of preventing false triggering of the open-phase protection under the power-off condition is added in the control algorithm, the open-phase of the three-phase input power supply of the motor can be accurately determined, false triggering of the open-phase protection under the power-off condition is avoided, and the reliability of the motor operation is improved.

[0018] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application.

[0019] The technical scheme of the present application will be further described in detail below with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of an embodiment of the power supply open-phase protection device of the present application.

[0021] Figure 2 It is a structural schematic diagram of another embodiment of the power supply open-phase protection device of the present application.

[0022] Figure 3 It is a structural schematic diagram of another embodiment of the power supply open-phase protection device of the present application.

[0023] Figure 4 It is a structural schematic diagram of an embodiment of the acquisition module of the hardware circuit part.

[0024] Figure 5 It is a flow schematic diagram of an embodiment of the three-phase input power supply open-phase protection control method of the motor of the present application.

[0025] Figure 6 It is a flow schematic diagram of an embodiment of the power supply open-phase protection method of the present application.

[0026] Figure 7 It is a flow schematic diagram of an embodiment of determining whether the three-phase input power supply is open-phase in the power supply open-phase protection method of the present application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0028] It is considered that the power supply mode of the motor has single-phase power supply and three-phase power supply. In single-phase power supply, the rectifier module of the hardware circuit cannot work when one phase of the input power supply is missing, that is, the circuit cannot run after rectification by the controller, so the single-phase motor does not consider the missing phase protection design of the power supply. In three-phase power supply, the rectifier module of the hardware circuit can still be rectified by the other two phases when one phase of the input power supply is missing, and the subsequent circuit can continue to run, but the missing phase operation will cause the input current to abnormally increase, the motor temperature to rise, and the motor controller to burn out. Therefore, the three-phase motor needs to add power supply missing phase protection to prevent the harm caused by the missing phase of the power supply.

[0029] In the related scheme, the missing phase protection of the three-phase motor is to collect the voltage value of the three-phase input power supply by the acquisition module of the hardware circuit part, and judge whether the three-phase input power supply is missing according to the voltage value of the three-phase input power supply. For example, the voltage value of the three-phase input power supply is determined by a corresponding judgment formula to determine whether the three-phase input power supply is missing. However, this scheme has a disadvantage: when the motor suddenly loses power, the three-phase input power supply is disconnected, and the main control logic module of the motor drive circuit also recognizes that the power supply is missing, thereby triggering the missing phase protection by mistake. That is, in the moment when the motor suddenly loses power, the main control logic module will recognize that the power supply is missing and trigger the missing phase protection by mistake. The missing phase protection triggered by mistake causes interference to the entire control system of the motor, which needs to be manually checked for failure and is time-consuming and laborious.

[0030] Therefore, the present application provides a power supply missing phase protection method for a motor, specifically a three-phase input power supply missing phase protection control method for a motor. The acquisition module of the hardware circuit part and the control algorithm of the software control part are set, the voltage value of each phase of the three-phase input power supply of the motor is collected by the acquisition module, and the accuracy of the collection can be guaranteed. Then, the control algorithm is used to judge whether the three-phase input power supply is missing according to the collected voltage values of the three-phase input power supply. Specifically, in the case where the collected voltage values of the three-phase input power supply are all greater than the missing phase protection triggering value (such as voltage Vz), if the absolute value of the difference between the voltage values of the smaller two phases of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple (such as 0.5), it can be accurately determined that the three-phase input power supply of the motor is missing, the missing phase protection is avoided from being triggered by mistake in the power failure, and the reliability of the motor operation is improved.

[0031] According to an embodiment of the present application, a power phase-loss protection device is provided. Figure 1 Figure 1 is a structural schematic diagram of an embodiment of the power phase-loss protection device of the present application. Figure 1 Figure 1 is a structural schematic diagram of an embodiment of the power phase-loss protection device of the present application. Figure 1 Figure 1 is a structural schematic diagram of an embodiment of the power phase-loss protection device of the present application. Figure 4 Figure 1 is a structural schematic diagram of an embodiment of the power phase-loss protection device of the present application.

[0032] The sampling unit is configured to acquire voltage values of each phase of the three-phase input power supply when the motor is running, to obtain voltage values of the three-phase input power supply, such as voltage values of the three-phase input power supply being respectively V a, V b and V c. V l1 、 V l2 、 V l3 The phase-loss false-trigger protection value of the three-phase input power supply can be pre-determined and stored in the control side of the motor, such as the control unit.

[0033] The control unit is configured to determine whether the three-phase input power supply is phase-loss based on the voltage values of the three-phase input power supply and the phase-loss false-trigger protection value of the three-phase input power supply.

[0034] The control unit is further configured to execute a preset power phase-loss protection strategy to adjust the running condition of the motor when it is determined that the three-phase input power supply is phase-loss, and continue to control the motor to run to maintain the running condition of the motor when it is determined that the three-phase input power supply is not phase-loss.

[0035] The present application provides a three-phase input power supply phase-loss protection control scheme for a motor, which combines the acquisition module of the hardware circuit part and the control algorithm of the software control part, increases the phase-loss false-trigger protection function in the control algorithm to prevent false triggering of the phase-loss protection under the condition of power failure, eliminates the problem of false triggering of the power phase-loss protection due to sudden power failure of the motor, and realizes the function of timely protection when the power is phase-loss. Thus, the problem of phase-loss protection of the motor supplied by the three-phase input power supply is solved, and the abnormal phenomenon of false triggering of the power phase-loss protection due to sudden power failure of the motor is also solved.

[0036] In some embodiments, the sampling unit comprises three sampling modules, each of the three sampling modules is configured to sample a voltage value of a corresponding one of the three-phase input power supply, and the three sampling modules have the same structure.

[0037] Figure 2 FIG. 2 is a structural schematic diagram of another embodiment of the power supply open-phase protection device according to the present application. As shown in FIG. 2, each of the sampling modules comprises a voltage dividing module, a voltage reducing module and a clamping module. Figure 2 The voltage dividing module can be, for example, four resistors with large resistance values, the voltage reducing module can be, for example, a voltage reducing diode, and the clamping module can be, for example, a clamping diode.

[0038] In the present application, the voltage value of each phase of the three-phase input power supply is collected by the sampling module of the hardware circuit part, and the accuracy of the collected voltage value can be guaranteed, thereby improving the accuracy of the open-phase determination.

[0039] In some embodiments, the voltage dividing module comprises at least two resistor modules connected in series, the voltage reducing module comprises a voltage reducing diode module, and the clamping module comprises a clamping diode module. For example, the at least two resistor modules can be resistors R1, R2, R3 and R4, the voltage reducing diode module can be diode D1, and the clamping diode module can be clamping diode D4.

[0040] In the present application, the voltage value of each phase of the three-phase input power supply is collected by the sampling module of the hardware circuit part, and the accuracy of the collected voltage value can be guaranteed, thereby improving the accuracy of the open-phase determination.

[0041] In the present application, the voltage value of each phase of the three-phase input power supply is collected by the sampling module of the hardware circuit part, and the accuracy of the collected voltage value can be guaranteed, thereby improving the accuracy of the open-phase determination.

[0042] In the present application, the voltage value of each phase of the three-phase input power supply is collected by the sampling module of the hardware circuit part, and the accuracy of the collected voltage value can be guaranteed, thereby improving the accuracy of the open-phase determination.Figure 4 Structure diagram of an embodiment of the acquisition module which is a hardware circuit part. Figure 4 In the example shown, four high-resistance resistors are used for each phase of the L1 phase, L2 phase and L3 phase of the three-phase input power supply to divide the input voltage of the three-phase input power supply, such as the resistors R1, R2, R3 and R4 used in the L1 phase, the resistors R7, R8, R9 and R10 used in the L2 phase, and the resistors R13, R14, R15 and R16 used in the L3 phase. After the input voltage of the three-phase input power supply is divided by the voltage-dividing resistors, the L1 phase passes through the diode D1, the L2 phase passes through the diode D2, and the L3 phase passes through the diode D3. The diodes D1, D2 and D3 serve as voltage reduction devices, and at the same time, the voltage reduction diodes (i.e., the diodes D1, D2 and D3) can be used as overvoltage protection to prevent damage to other components caused by excessively high input voltage of the three-phase input power supply. The acquisition module mainly acquires voltage, which can improve the quality of the acquired signal and eliminate high-frequency noise.

[0043] After the input voltage of the three-phase input power supply is divided by the voltage-dividing resistors and reduced by the voltage reduction diodes and overvoltage protection, the clamping diodes D4, D5 and D6 are used. The negative poles of the clamping diodes D4, D5 and D6 are clamped by the maximum level allowed by the master control chip in the master logic module (CLAMPING), and the positive poles are grounded, so that the sampled voltage is maintained between 0 and the maximum voltage allowed by the master control chip in the master logic module. This design ensures the fluctuation range of the input voltage and prevents the possibility of damage to the control chip caused by a sharp voltage impact.

[0044] In some embodiments, each of the sampling modules further comprises a first filter module and / or a second filter module, which can be specifically referred to in Figure 3 The example shown; wherein, taking the L1 phase as an example, the first filter module is, for example, the resistor R6 and the capacitor C3; and the second filter module is, for example, the resistor R5 and the capacitor C6. Figure 3 Structure diagram of another embodiment of the power supply open-phase protection device of the application.

[0045] The first filter module is arranged between the output end of the voltage reduction module and the ground; the output end of the voltage reduction module is, for example, the cathode of the voltage reduction diode.

[0046] The second filter module is arranged between the output end of the clamping module and the ground; the output end of the clamping module is, for example, the clamping end of the clamping diode.

[0047] In Figure 4In the shown example, the input voltage of the three-phase input power supply is divided by the voltage dividing resistor, is reduced by the voltage reduction diode, is protected by the overvoltage protection, is clamped by the clamping diode D5 and the clamping diode D6, is filtered by the RC filter circuit composed of the resistor R5, the resistor R11, the resistor R17 and the capacitor C4, the capacitor C5 and the capacitor C6, so that the voltage value detected by the main control logic module is more accurate.

[0048] In addition, in Figure 4 In the shown example, the input voltage of the three-phase input power supply is divided by the voltage dividing resistor, is reduced by the voltage reduction diode, is protected by the overvoltage protection, is clamped by the clamping diode D5 and the clamping diode D6, is filtered by the RC filter circuit composed of the resistor R5, the resistor R11, the resistor R17 and the capacitor C4, the capacitor C5 and the capacitor C6, so that the voltage value detected by the main control logic module is more accurate.

[0049] In some embodiments, the first filter module comprises a first resistor module and a first capacitor module; the first resistor module and the first capacitor module are connected in parallel between the output end of the voltage reduction module and the ground; wherein, taking the L1 phase as an example, the first resistor module is, for example, the resistor R6, and the first capacitor module is, for example, the capacitor C3.

[0050] And / or, the second filter module comprises a second resistor module and a second capacitor module; the second resistor module and the second capacitor module are connected in series between the output end of the clamping module and the ground; the common end of the second resistor module and the second capacitor module serves as the output end of the sampling module. Wherein, taking the L1 phase as an example, the second filter module, the second resistor module is, for example, the resistor R5, and the second capacitor module is, for example, the capacitor C6.

[0051] As Figure 4As shown, the acquisition module of the hardware circuit part comprises resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, capacitors C1, C2, C3, C4, C5, C6, diodes D1, D2, D3, clamping diodes D4, D5, D6. The resistors R1, R2, R3, R4, R7, R8, R9, R10, R13, R14, R15, R16 are high-value resistors; the diodes D1, D2, D3 are voltage reduction diodes. The high-value resistors are mainly used to collect the voltage value of the 380V fire line into a voltage value within 3.3V, such as four 200kΩ resistors.

[0052] The input end of the L1 phase of the three-phase input power supply is connected to the anode of the diode D1 in sequence through the resistors R1, R2, R3 and R4; the cathode of the diode D1 is grounded through the resistor R5 and the capacitor C6, and the common end of the resistor R5 and the capacitor C6 is connected to the output end of the voltage value V l1 of the three-phase input power supply. The cathode of the diode D1 is also connected to the midpoint of the clamping diode D4; the anode of the clamping diode D4 is grounded, and the cathode of the clamping diode D4 is connected to the CLAMPING end. The CLAMPING voltage provided by the CLAMPING end represents the maximum voltage that can be borne by the power pin of the master control chip in the master control logic module. The clamping diode D4 is composed of two diodes (such as a first diode and a second diode). The anode of the first diode is grounded, the cathode of the first diode is connected to the anode of the second diode and constitutes the midpoint of the clamping diode D4, and the cathode of the second diode is connected to the CLAMPING end. The cathode of the diode D1 is also grounded through the parallel-connected capacitor C3 and resistor R6.

[0053] The input end of the L2 phase of the three-phase input power supply is connected to the anode of the diode D2 in sequence through the resistors R7, R8, R9 and R10; the cathode of the diode D2 is grounded through the resistor R11 and the capacitor C5, and the common end of the resistor R11 and the capacitor C5 is connected to the output end of the voltage value V l2The cathode of the diode D2 is also connected to the midpoint of the clamping diode D5, the anode of the clamping diode D5 is grounded, and the cathode of the clamping diode D5 is connected to the CLAMPING terminal, which provides a CLAMPING voltage representing the maximum voltage that the power pin of the master chip in the master logic module can withstand. The clamping diode D5 is composed of two diodes (e.g., a first diode and a second diode), the anode of the first diode is grounded, the cathode of the first diode is connected to the anode of the second diode and constitutes the midpoint of the clamping diode D5, and the cathode of the second diode is connected to the CLAMPING terminal. The cathode of the diode D2 is also connected to the ground through the parallel capacitor C2 and resistor R12.

[0054] The input terminal of the L3 phase of the three-phase input power supply is connected to the anode of the diode D3 in sequence through the resistors R13, R14, R15, and R16. The cathode of the diode D3 is connected to the ground through the resistor R17 and the capacitor C4, and the common terminal of the resistor R17 and the capacitor C4 is connected to the voltage value V l3 The cathode of the diode D3 is also connected to the midpoint of the clamping diode D6, the anode of the clamping diode D6 is grounded, and the cathode of the clamping diode D6 is connected to the CLAMPING terminal, which provides a CLAMPING voltage representing the maximum voltage that the power pin of the master chip in the master logic module can withstand. The clamping diode D6 is composed of two diodes (e.g., a first diode and a second diode), the anode of the first diode is grounded, the cathode of the first diode is connected to the anode of the second diode and constitutes the midpoint of the clamping diode D6, and the cathode of the second diode is connected to the CLAMPING terminal. The cathode of the diode D3 is also connected to the ground through the parallel capacitor C1 and resistor R18.

[0055] In the scheme of the present application, the cost is low and the reliability is high through resistance sampling. The voltage values of each phase power supply are collected by the acquisition module of the hardware circuit part. The judgment threshold value (e.g., the open-phase false triggering protection value) is added in the control algorithm to avoid false triggering of the open-phase protection in the power-off condition, which is beneficial to improve the reliability of motor operation.

[0056] In some embodiments, the control unit determines whether the three-phase input power supply is open-phase according to the voltage values of the three-phase input power supply and the open-phase false triggering protection value of the three-phase input power supply, including:

[0057] The control unit specifically further determines the maximum value in the voltage values of the three-phase input power supply, which is recorded as the maximum voltage value of the three-phase input power supply. The voltage values of the two-phase input power supply other than the maximum voltage value of the three-phase input power supply are recorded as the two-phase smaller voltage values of the three-phase input power supply.

[0058] The control unit is further configured to determine whether the voltage value of each phase of the three-phase input power supply is greater than or equal to the phase loss false trigger protection value of the three-phase input power supply, and the absolute value of the difference between the two smaller voltage values ​​of the three-phase input power supply is greater than a set multiple of the maximum voltage value of the three-phase input power supply. If so, the control unit determines that the three-phase input power supply is in a phase loss state and executes a preset phase loss protection strategy. Otherwise, the control unit determines that the three-phase input power supply is not in a phase loss state and controls the motor to continue running.

[0059] This invention proposes a three-phase input power supply phase loss protection control scheme for a motor, applicable to the motor controller described in this invention. The motor controller mainly consists of a data acquisition module, a main control logic module, and an execution power switch module. The main control logic module is divided into a main control logic module discrimination function area, a main control speed reduction command function area, and a stop command function area. This invention employs a hardware circuit + software control scheme. The data acquisition module in the hardware circuit detects the voltage value of each phase of the three-phase input power supply and feeds it back to the main control logic module. The main control logic module performs logic processing to determine if a phase is missing. If a phase is missing, the main control logic module issues a speed reduction or stop command, simultaneously displaying a "power phase loss" fault message. The software control method: Let the collected three-phase input power supply voltage values ​​be... V l1 , V l2 , V l3 Take the maximum value as V max Then, based on the absolute value of the difference between two phases, such as | V l1 - V l2 Greater than 0.5 times V max This is used as a criterion to determine if a phase is missing. To ensure synchronization in the event of a sudden power outage, phase loss detection is only performed if the voltage of each phase is higher than Vz, preventing false triggering during power outages and improving reliability and applicability. Here, we assume the voltage values ​​of the three-phase input power supply are... V l1 , V l2 , V l3 The maximum value is the voltage value of phase L3. V l3 The smaller of the two phase values ​​is the voltage value of phase L1. V l1 Voltage value of L2 phase V l2The voltage value of the three-phase input power supply V l1 、 V l2 、 V l3 The absolute value of the difference between the two smaller voltage values is compared with 0.5 times the maximum value, and it can be determined whether the phase is missing.

[0060] In the scheme of the application, in the case of sudden power failure, the phase missing recognition is performed only when the voltage of each phase is higher than Vz, which can be: first, the acquisition module of the hardware circuit part acquires the voltage of the three-phase input power supply V l1 、 V l2 、 V l3 Then, according to the formula such as formula (1), it is determined whether the phase is missing: if the absolute value of the difference between the two smallest voltage values of the three-phase input power supply V l1 、 V l2 、 V l3 is greater than 0.5 times the maximum voltage value of the three-phase input power supply V l1 、 V l2 、 V l3 , it is considered that the three-phase input power supply is missing; if the three-phase input power supply is missing, protection is performed, and the protection mode can be shutdown or speed reduction. Wherein, formula (1) is as follows:

[0061] | V l1 - V l2 |>0.5* V max (1).

[0062] In the scheme of the application, when the motor is missing, the phenomenon of motor overcurrent, overheating and controller damage caused by sudden current surge can be avoided; in the scheme of the application, protection is performed through judgment when the motor is powered off, so that artificial and cost loss caused by power failure can be avoided. Compared with related schemes, the scheme of the application is simple to configure, the software response time is shorter, and it is more suitable for EC industrial motor.

[0063] In some embodiments, the preset power phase missing protection strategy includes: a strategy of controlling the motor to reduce speed or a strategy of controlling the motor to stop; the control unit executes the preset power phase missing protection strategy, including: the control unit is specifically further used for controlling the motor to reduce speed or controlling the motor to stop.

[0064] Figure 5 Flow chart of an embodiment of a three-phase input power phase loss protection control method for a motor. Figure 5 As shown in the figure, the three-phase input power phase loss protection control method for a motor proposed by the present application comprises:

[0065] Step 1, first, the voltage value of the three-phase input power of the motor is collected by the collection module V l1 , V l2 , V l3 , and then step 2 is performed.

[0066] In step 1, the sampling method uses resistance sampling, and four large resistance resistors are used for voltage division in each phase, such as resistors R1, R2, R3, and R4 for the L1 phase, resistors R7, R8, R9, and R10 for the L2 phase, and resistors R13, R14, R15, and R16 for the L3 phase. After the input voltage of the three-phase input power is divided by the voltage division resistors, it passes through diodes D1, D2, and D3, which function as voltage reduction. The voltage reduction diodes (i.e., diodes D1, D2, and D3) can also be used for overvoltage protection to prevent damage to other components caused by excessively high input voltage of the three-phase input power. Next, clamping diodes D4, D5, and D6 are used, and the negative poles of the clamping diodes D4, D5, and D6 are clamped at the maximum level allowed by the master control chip in the master logic module (CLAMPING), and the positive poles are grounded, so that the sampled voltage is maintained between 0 and the maximum voltage allowed by the master control chip in the master logic module. This design ensures the fluctuation range of the input voltage and prevents the possibility of damage to the control chip caused by a sharp voltage surge. Then, the voltage value detected by the master logic module is more accurate after being filtered by the RC filter circuit composed of resistors R5, R11, and R17 and capacitors C4, C5, and C6. In addition, after the input voltage of the three-phase input power is divided by the voltage division resistors and reduced by the voltage reduction diodes and overvoltage protection, it is filtered by the RC filter circuit composed of resistors R18, R12, and R6 and capacitors C1, C2, and C3 before being clamped by clamping diodes D5 and D6, which can filter out noise to improve the quality of the output voltage.

[0067] Step 2, second, the voltage of the three-phase input power collected by the collection module in the hardware circuit part V l1 , V l2 , Vl3 , take the largest value of the three as the voltage V max , set the missing phase false trigger protection value as voltage Vz. The value of voltage Vz is greater than or equal to V l1 , V l2 , V l3 ; can take 0~0.5, specific to determine their own scheme. When the voltage of three-phase input power V l1 , V l2 , V l3 is greater than or equal to the voltage Vz, determine whether formula (2) is true: if yes, execute step 3, otherwise execute step 4.

[0068] | V l（1、2、3） - V l（1、2、3） |>0.5* V max (2).

[0069] Step 3, when the voltage of three-phase input power V l1 , V l2 , V l3 is greater than or equal to the voltage Vz, if formula (2) is true; that is, the voltage of three-phase input power V l1 , V l2 , V l3 all meet the above two conditions, that is, meet the voltage of three-phase input power V l1 , V l2 , V l3 is greater than or equal to the voltage Vz, and formula (2) is met, it is determined that the three-phase input power of the motor is in the missing phase state, and the motor is implemented stop or speed down instruction, and the three-phase input power of the motor is prompted "missing phase" abnormal.

[0070] Step 4, when the voltage of three-phase input power V l1 , V l2 , V l3If the three-phase input power supply of the motor is determined to be not missing phase under the condition that the three-phase voltage of the motor is sampled, the absolute value of the difference between the two smallest voltage values of the sampled three-phase voltage is greater than 0.5 times the maximum voltage value of the sampled three-phase voltage, and the three-phase voltage of the motor is greater than or equal to the voltage Vz, and / or the formula (2) is not satisfied, the motor is determined to continue stable operation.

[0071] In the scheme of the present application, the three-phase voltage of the motor is sampled, and the missing phase protection is implemented under the condition that the absolute value of the difference between the two smallest voltage values of the sampled three-phase voltage is greater than 0.5 times the maximum voltage value of the sampled three-phase voltage, and the three-phase voltage of the motor is greater than or equal to the missing phase false triggering protection value (such as the voltage Vz). The power-off condition detection function is provided to prevent the false triggering of the missing phase protection.

[0072] The software and hardware control scheme of the present application can effectively avoid the problems caused by the significant increase of the current of the remaining two phases when the phase is missing, such as overheating, unbalanced motor operation, additional mechanical stress, increased noise and vibration, etc. That is, if the three-phase input power supply of the motor is detected to be missing phase, the protection is triggered, such as speed reduction or shutdown, to effectively avoid the problems caused by the significant increase of the current of the remaining two phases when the phase is missing.

[0073] The technical scheme of the present application sets the acquisition module of the hardware circuit part and the control algorithm of the software control part for the three-phase input power supply of the motor, acquires the voltage value of each phase power supply in the three-phase input power supply of the motor by using the acquisition module, obtains the three-phase voltage value, sets the missing phase false triggering protection value (such as the voltage Vz), and determines that the three-phase input power supply of the motor is missing phase under the condition that the three-phase voltage value acquired is greater than or equal to the missing phase false triggering protection value, and the absolute value of the difference between the two smallest voltage values of the three-phase voltage is greater than 0.5 times the maximum voltage value of the three-phase voltage, to trigger the missing phase protection. Thus, by acquiring the voltage value of each phase power supply in the three-phase input power supply of the motor, the missing phase false triggering protection function of preventing the false triggering of the missing phase protection under the power-off condition is added in the control algorithm, the missing phase of the three-phase input power supply of the motor can be accurately determined, the false triggering of the missing phase protection under the power-off condition is avoided, and the reliability of the motor operation is improved.

[0074] According to the embodiments of the present application, a motor controller corresponding to the power supply missing phase protection device is also provided. The motor controller can include the power supply missing phase protection device described above.

[0075] Since the processing and functions realized by the motor controller of the present embodiment are basically corresponding to the embodiments, principles and examples of the foregoing device, the description of the present embodiment will not be described in detail, and the relevant description in the foregoing embodiments can be referred to, which will not be described herein.

[0076] According to an embodiment of the present application, a frequency converter corresponding to the power phase-loss protection device is also provided. The frequency converter can comprise the power phase-loss protection device as described above.

[0077] Since the processing and functions realized by the frequency converter of the present embodiment are basically corresponding to the embodiments, principles and examples of the aforementioned device, the description of the present embodiment will not be elaborated on the related descriptions in the aforementioned embodiments.

[0078] According to an embodiment of the present application, a motor corresponding to the power phase-loss protection device is also provided. The motor can comprise the power phase-loss protection device as described above, or the motor controller as described above, or the frequency converter as described above.

[0079] Since the processing and functions realized by the motor of the present embodiment are basically corresponding to the embodiments, principles and examples of the aforementioned device, the description of the present embodiment will not be elaborated on the related descriptions in the aforementioned embodiments.

[0080] According to an embodiment of the present application, a power phase-loss protection method corresponding to the power phase-loss protection device is also provided. Figure 6 A flowchart of an embodiment of the power phase-loss protection method of the present application is shown in FIG. 11. The power phase-loss protection method can comprise steps S110-S130. Figure 6 A flowchart of an embodiment of the power phase-loss protection method of the present application is shown in FIG. 11. The power phase-loss protection method can comprise steps S110-S130.

[0081] At step S110, the voltage value of each phase of the three-phase input power is obtained by the sampling unit under the operation of the motor, to obtain the voltage value of the three-phase input power, such as the voltage values of the three-phase input power are respectively V l1 、 V l2 、 V l3 ; and the phase-loss false triggering protection value of the three-phase input power is obtained. The phase-loss false triggering protection value of the three-phase input power can be determined in advance and stored in the control side of the motor, such as the control unit.

[0082] At step S120, whether the three-phase input power is phase-loss is determined according to the voltage value of the three-phase input power and the phase-loss false triggering protection value of the three-phase input power. By collecting the voltage value of each phase of the three-phase input power of the motor, the phase-loss false triggering protection function of preventing false triggering of the phase-loss protection under the power-off condition is added in the control algorithm, to accurately determine the phase-loss of the three-phase input power of the motor, and

[0083] At step S130, in a case where it is determined that the three-phase input power supply is open-phase, a preset open-phase protection strategy of the power supply is executed to adjust the operation of the motor; in a case where it is determined that the three-phase input power supply is not open-phase, the motor continues to be controlled to maintain the operation of the motor.

[0084] The scheme of the application, in combination with the acquisition module of the hardware circuit part and the control algorithm of the software control part, adds the open-phase false triggering protection function in the control algorithm to prevent false triggering of the open-phase protection in the case of power failure, eliminates the problem of false triggering of the open-phase protection of the power supply in the case of sudden power failure of the motor, and realizes the function of timely protection in the case of open-phase of the power supply; thereby, the open-phase protection problem of the motor supplied by the three-phase input power supply is solved, and the abnormal phenomenon of false triggering of the open-phase protection of the power supply in the case of sudden power failure of the motor is also solved.

[0085] In some embodiments, the specific process of determining whether the three-phase input power supply is open-phase in step S120 according to the voltage value of the three-phase input power supply and the open-phase false triggering protection value of the three-phase input power supply is described in the following example.

[0086] The following will be described in combination with Figure 7 The following will be described in combination with

[0087] Step S210, determining the maximum value in the voltage value of the three-phase input power supply, denoted as the maximum voltage value of the three-phase input power supply; and the voltage values of the two-phase input power supply other than the maximum voltage value of the three-phase input power supply in the voltage value of the three-phase input power supply, denoted as the two-phase smaller voltage values of the three-phase input power supply.

[0088] Step S220, determining whether the voltage value of each phase of the three-phase input power supply is greater than or equal to the open-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple: if yes, it is determined that the three-phase input power supply is open-phase, and the preset open-phase protection strategy of the power supply is executed; otherwise, it is determined that the three-phase input power supply is not open-phase, and the motor continues to be controlled to operate.

[0089] The solution of this invention can be applied to the motor controller described in this invention. The motor controller mainly consists of a data acquisition module, a main control logic module, and an execution power switch module. The main control logic module is divided into a main control logic module discrimination function area, a main control speed reduction command function area, and a stop command function area. This invention employs a hardware circuit + software control scheme. The data acquisition module in the hardware circuit detects the voltage value of each phase of the three-phase input power supply and feeds it back to the main control logic module. The main control logic module performs logic processing to determine if a phase is missing. If a phase is missing, the main control logic module issues a speed reduction or stop command, simultaneously displaying a "power phase missing" fault message. The software control method: Let the voltage values ​​of the three-phase input power supply be respectively... V l1 , V l2 , V l3 Take the maximum value as V max Then, based on the absolute value of the difference between two phases, such as | V l1 - V l2 Greater than 0.5 times V max This is used as a criterion to determine if a phase is missing. To ensure synchronization in the event of a sudden power outage, phase loss detection is only performed if the voltage of each phase is higher than Vz, preventing false triggering during power outages and improving reliability and applicability. Here, we assume the voltage values ​​of the three-phase input power supply are... V l1 , V l2 , V l3 The maximum value is the voltage value of phase L3. V l3 The smaller of the two values ​​is the voltage value of phase L1. V l1 Voltage value of L2 phase V l2 The voltage value of the three-phase input power supply V l1 , V l2 , V l3 By comparing the absolute value of the difference between the two smaller values ​​of the two phases with 0.5 times the maximum value, it can be determined whether a phase is missing.

[0090] In the solution of this invention, in the event of a sudden power outage, phase loss identification is performed only when the voltage of each phase is higher than Vz. This can be achieved by: firstly, the acquisition module of the hardware circuit acquiring the voltage of the three-phase input power supply. V l1 ,V l2 , V l3 Then, determine whether a phase is missing according to the formula (1): If the voltage of the three-phase input power supply is... V l1 , V l2 , V l3 The absolute value of the difference between the two smallest phase voltages is greater than the voltage of the three-phase input power supply. V l1 , V l2 , V l3 If the voltage is 0.5 times the maximum voltage value, it is considered that a phase of the three-phase input power supply is missing; if a phase of the three-phase input power supply is missing, protection is activated, and the protection method can be shutdown or speed reduction. Among them, formula (1) is as follows:

[0091] | V l1 - V l2 |>0.5* V max (1).

[0092] The solution of this invention can avoid motor overcurrent, overheating, and controller damage caused by sudden current surges when a phase is lost in the motor. Furthermore, by determining when the motor is powered off, this solution provides protection, avoiding labor and cost losses caused by power outages. Compared to related solutions, the solution of this invention is simpler to configure, has a shorter software response time, and is more suitable for EC industrial motors.

[0093] In some implementations, the preset power phase loss protection strategy includes: a strategy to control the speed reduction of the motor or a strategy to control the shutdown of the motor.

[0094] In step S130, a preset power phase loss protection strategy is executed, including: controlling the motor to slow down or controlling the motor to stop.

[0095] like Figure 5 As shown, the present invention proposes a three-phase input power supply phase loss protection control method for a motor, comprising:

[0096] Step 1: First, the acquisition module acquires the voltage values ​​of the three-phase input power supply to the motor. V l1 , V l2 , V l3 Then proceed to step 2.

[0097] In step 1, the sampling method uses resistance sampling, each phase uses four large resistance resistors as voltage dividing resistors, such as resistors R1, R2, R3, R4 for L1 phase, resistors R7, R8, R9, R10 for L2 phase, and resistors R13, R14, R15, R16 for L3 phase. After the input voltage of the three-phase input power is divided by the voltage dividing resistors, it passes through diodes D1, D2, D3, which act as voltage reduction. The voltage reduction diodes (i.e. diodes D1, D2, D3) can be used as overvoltage protection to prevent damage to other components caused by excessively high input voltage of the three-phase input power. Next, use clamping diodes D4, D5, and D6, the negative terminals of which are clamped to the maximum level allowed by the main control chip in the main control logic module (CLAMPING), and the positive terminals are grounded, so that the sampled voltage is maintained between 0 and the maximum allowed voltage of the main control chip in the main control logic module. This design ensures the fluctuation range of the input voltage and prevents the possibility of damage to the control chip caused by a sharp voltage spike. Then, the voltage is filtered by the RC filter circuit composed of resistors R5, R11, R17 and capacitors C4, C5, C6, so that the voltage value detected by the main control logic module is more accurate. In addition, after the input voltage of the three-phase input power is divided by the voltage dividing resistors and is reduced by the voltage reduction diodes and overvoltage protection, it is filtered by the RC filter circuit composed of resistors R18, R12, R6 and capacitors C1, C2, C3 before being clamped by clamping diodes D5 and D6, which can filter out noise to improve the quality of the output voltage.

[0098] Step 2, secondly, according to the voltage of the three-phase input power collected by the collection module of the hardware circuit part V l1 、 V l2 、 V l3 , take the maximum value of the three as the voltage V max , and set the open-phase false trigger protection value as voltage Vz. When the voltages of the three-phase input power V l1 、 V l2 、 V l3 are all greater than or equal to voltage Vz, determine whether formula (2) is true: if yes, execute step 3, otherwise execute step 4.

[0099] | V l（1、2、3） - Vl（1、2、3） |>0.5* V max (2).

[0100] Step 3, in the case that the voltages of the three-phase input power supply are all greater than or equal to the voltage Vz, if formula (2) is established; that is, the voltages of the three-phase input power supply are all greater than or equal to the voltage Vz, and formula (2) is established. V l1 、 V l2 、 V l3 V l1 、 V l2 、 V l3 V l1 、 V l2 、 V l3

[0101] Step 4, in the case that the voltages of the three-phase input power supply are all not greater than or equal to the voltage Vz, and / or formula (2) is not established, it is determined that the three-phase input power supply of the motor is not found to be in the open-phase state, and the motor is controlled to continue stable operation. V l1 、 V l2 、 V l3

[0102] In the scheme of the present application, by sampling the three-phase voltages of the three-phase input power supply of the motor, it is determined that the three-phase input power supply of the motor is in the open-phase state according to the fact that the absolute value of the difference between the minimum two-phase voltage values of the sampled three-phase voltages is greater than 0.5 times the maximum voltage value of the sampled three-phase voltages, and the sampled three-phase voltages are all greater than or equal to the open-phase false triggering protection value (such as the voltage Vz), and the above conditions are satisfied to implement open-phase protection; and the power-off condition detection function is provided to prevent triggering of the open-phase protection.

[0103] By using the software and hardware control scheme of the present application, the problems caused by the fact that the current of the remaining two phases will significantly increase when the open-phase occurs can be effectively avoided, such as the overheating phenomenon, unbalanced motor operation, generation of additional mechanical stress, increase of noise and vibration, etc. That is, if it is detected that the three-phase input power supply of the motor is in the open-phase state, protection is triggered, such as speed reduction or shutdown, to effectively avoid the problems caused by the fact that the current of the remaining two phases will significantly increase when the open-phase occurs.

[0104] ​​​​Since the processing and functions realized by the method of the embodiment are basically corresponding to the foregoing embodiments, principles and examples of the motor controller, the frequency converter and the motor, the description of the embodiment which is not elaborated can be seen in the foregoing related description of the embodiments, and will not be described here.

[0105] In summary, the person skilled in the art can easily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0106] The above only describes the embodiments of the present application and is not used to limit the present application. The present application can have various modifications and changes for the person skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A power phase-loss protection device, characterized by, The application is applied to three-phase input power supply of motor for phase loss protection; the power supply phase loss protection device comprises a sampling unit and a control unit; wherein, The sampling unit is used for obtaining voltage values of each phase input power supply in the three-phase input power supply when the motor is running, obtaining voltage values of the three-phase input power supply, and obtaining a phase loss false trigger protection value of the three-phase input power supply; The control unit is used for determining whether the three-phase input power supply is phase loss according to the voltage values of the three-phase input power supply and the phase loss false trigger protection value of the three-phase input power supply; and In the case of determining that the three-phase input power supply is phase loss, a preset power supply phase loss protection strategy is executed; in the case of determining that the three-phase input power supply is not phase loss, the motor continues to run; Wherein, the phase loss false trigger protection value is set, in the case of meeting that the collected voltage values of the three phases are all greater than or equal to the phase loss false trigger protection value, and the absolute value of the voltage value difference of the smaller two phases in the three-phase voltage values is greater than the maximum voltage value of the three-phase voltage values multiplied by a set multiple, it is determined that the three-phase input power supply of the motor is phase loss, so as to trigger the phase loss protection; Adopt the hardware circuit + software control scheme to realize, the collection module of hardware circuit part detects each phase power supply voltage value of three phase input power supply, the control method of software part: set the voltage value of three phase input power supply collected respectively V l1 、 V l2 、 V l3 , take the maximum value as V max , compare the absolute value of the difference of the smaller value of two phases of three phase input power supply voltage value V l1 、 V l2 、 V l3 With 0.5 times the maximum value, judge whether the phase is missing. The set open-phase false trigger protection value is greater than or equal to V l1 、 V l2 、 V l3 , take 0~0.

5.

2. The power phase loss protection device of claim 1, wherein, The sampling unit comprises a sampling module, and the number of the sampling module is three; each sampling module in the three sampling modules is used for sampling the voltage value of the corresponding phase input power supply in the three-phase input power supply; Each sampling module comprises a voltage dividing module, a voltage reducing module and a clamping module; wherein, Each phase input power supply in the three-phase input power supply is output from the common end of the voltage reducing module and the clamping module after passing through the voltage dividing module, the voltage reducing module and the clamping module in the corresponding one of the three sampling modules.

3. The power phase loss protection device of claim 2, wherein, The voltage dividing module comprises at least two resistance modules connected in series; the voltage reducing module comprises a voltage reducing diode module; the clamping module comprises a clamping diode module; wherein, Each phase input power supply in the three-phase input power supply is connected to the anode of the voltage reducing diode module after passing through the at least two resistance modules; the cathode of the voltage reducing diode module is connected to the clamping end of the clamping module; the anode of the clamping diode module is grounded, and the cathode of the clamping diode module is connected to a preset voltage source; The common end of the cathode of the voltage reducing diode module and the clamping end of the clamping diode module is the common end of the voltage reducing module and the clamping module; the cathode of the voltage reducing diode module is the output end of the voltage reducing module; and the clamping end of the clamping diode module is the output end of the clamping module.

4. The power phase loss protection device of claim 2, wherein, Each sampling module further comprises a first filter module and / or a second filter module; wherein, The first filter module is arranged between the output end of the voltage reducing module and the ground; The second filter module is arranged between the output end of the clamping module and the ground.

5. The power phase loss protection device of claim 4, wherein, Wherein, The first filter module comprises a first resistance module and a first capacitor module; the first resistance module and the first capacitor module are connected in parallel between the output end of the voltage reducing module and the ground; And / or, The second filter module comprises a second resistance module and a second capacitance module; the second resistance module and the second capacitance module are connected in series between the output end of the clamping module and the ground; the common end of the second resistance module and the second capacitance module serves as the output end of the sampling module.

6. The phase loss protection device of any one of claims 1 to 5, wherein, Wherein, The control unit determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply, and comprises: determining the maximum value in the voltage values of the three-phase input power supply as the maximum voltage value of the three-phase input power supply; and determining the voltage values of the two-phase input power supply in the voltage values of the three-phase input power supply except for the maximum voltage value of the three-phase input power supply as the two-phase smaller voltage values of the three-phase input power supply; determining whether the voltage value of each phase input power supply in the voltage values of the three-phase input power supply is greater than or equal to the out-of-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple: if yes, it is determined that the three-phase input power supply is out of phase, so as to execute the preset power supply out-of-phase protection strategy; otherwise, it is determined that the three-phase input power supply is not out of phase, so as to control the motor to continue running; And / or, The control unit executes the preset power supply out-of-phase protection strategy, and comprises: controlling the motor to slow down or stop.

7. An electric machine controller characterized by Comprise: The power supply out-of-phase protection device according to any one of claims 1 to 6.

8. A frequency converter, characterized in that Comprise: The power supply out-of-phase protection device according to any one of claims 1 to 6.

9. An electric machine characterized by Comprise: The power supply out-of-phase protection device according to any one of claims 1 to 6, the motor controller according to claim 7, or the frequency converter according to claim 8.

10. A power phase failure protection method for implementing power phase failure protection using the power phase failure protection device according to any one of claims 1 to 6, characterized by, Comprise: The sampling unit acquires the voltage value of each phase input power supply in the three-phase input power supply to obtain the voltage values of the three-phase input power supply under the condition that the motor is running; and acquires the out-of-phase false triggering protection value of the three-phase input power supply; determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply; and in the case of determining that the three-phase input power supply is out of phase, executes the preset power supply out-of-phase protection strategy; in the case of determining that the three-phase input power supply is not out of phase, continues to control the motor to run.

11. The power phase failure protection method of claim 10, wherein, Wherein, The control unit determines whether the three-phase input power supply is out of phase according to the voltage values of the three-phase input power supply and the out-of-phase false triggering protection value of the three-phase input power supply, and comprises: determining the maximum value in the voltage values of the three-phase input power supply as the maximum voltage value of the three-phase input power supply; and determining the voltage values of the two-phase input power supply in the voltage values of the three-phase input power supply except for the maximum voltage value of the three-phase input power supply as the two-phase smaller voltage values of the three-phase input power supply; determining whether the voltage value of each phase input power supply in the voltage values of the three-phase input power supply is greater than or equal to the out-of-phase false triggering protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the maximum voltage value of the three-phase input power supply by a set multiple: if yes, it is determined that the three-phase input power supply is out of phase, so as to execute the preset power supply out-of-phase protection strategy; otherwise, it is determined that the three-phase input power supply is not out of phase, so as to control the motor to continue running; determining whether each of the voltage values of the three-phase input power supply meets the condition that the voltage value of each phase input power supply is greater than or equal to the open-phase false trigger protection value of the three-phase input power supply, and the absolute value of the difference between the two-phase smaller voltage values of the three-phase input power supply is greater than the set multiple of the maximum voltage value of the three-phase input power supply: if yes, it is determined that the three-phase input power supply is open-phase, and a preset power supply open-phase protection strategy is executed; otherwise, it is determined that the three-phase input power supply is not open-phase, and the motor continues to run. and / or, executing the preset power supply open-phase protection strategy, including: controlling the motor to slow down or controlling the motor to stop.

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