Control method, system and circuit of multi-winding motor

Abstract

The invention discloses a control method, system and circuit for a multi-winding motor, and the method comprises the steps: carrying out the wave sealing of each control unit after detecting that a fault occurs in a control unit, controlling a bus capacitor in the control unit with the fault to discharge through a discharge module, and after the bus capacitor is discharged, carrying out the wave sealing of each control unit; and controlling the control unit with the fault to be short-circuited from the control units connected in series through the short-circuit module, obtaining the current operation parameters of the multi-winding motor, and controlling the control units without the fault to operate based on the current operation parameters. A standby control unit does not need to be additionally arranged, the cost is reduced, only the faulted control unit needs to be short-circuited, the multi-winding motor is controlled only through the remaining control units, the downtime of the multi-winding motor is shortened, in addition, the bus capacitor is discharged before the faulted control unit is short-circuited, the safety of the bus is guaranteed, and the service life of the multi-winding motor is prolonged. And when the multi-winding motor is restarted, running parameters of the multi-winding motor during wave sealing are tracked, so that stable work of the multi-winding motor is ensured.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a control method, system and circuit for a multi-winding motor. Background Art

[0002] At present, when controlling a multi-winding motor, multiple control units are usually connected in parallel, such as Figure 1 As shown, Figure 1 The present invention is a structural schematic diagram of a control circuit of a multi-winding motor in the prior art, wherein the control circuit includes a rectifier circuit and a control unit connected to N windings in the multi-winding motor in a one-to-one correspondence, wherein N is an integer greater than 1, the input end of the rectifier circuit is connected to an AC power supply, each winding of the multi-winding motor is connected to a control unit, and each control unit is connected in series to the output end of the rectifier circuit, the rectifier circuit rectifies the AC power output by the AC power supply, and outputs DC power to each control unit connected in series, and the inverter circuit in the control unit inverts the DC power, and outputs the AC power obtained by the inversion to the corresponding winding, so that the multi-winding motor operates in the desired state. When a control unit fails, the multi-winding motor is usually shut down first, and then the fault is checked. After the fault is eliminated, each control unit is restarted, and the time required for this process cannot be determined, which will cause the multi-winding motor to be in a shutdown state for a long time, reducing work efficiency.

[0003] The existing method for solving the above technical problem is to equip an additional spare control unit (not shown in the figure). When a control unit fails, the spare control unit is switched to replace the failed control unit to control the multi-winding motor so that the multi-winding motor can keep working continuously. Figure 1 It can be seen that bus capacitors for voltage stabilization are provided in each control unit, namely C1, C2, C3 and CN connected in series between the positive bus and the negative bus in the figure. Although the method of additionally equipping a spare control unit can avoid the shutdown of a multi-winding motor in some cases, this method not only increases the cost, but also fails to consider that when switching to the spare control unit, the bus capacitor in the faulty control unit may discharge to the bus, which will cause a greater fault. Summary of the invention

[0004] The purpose of the present invention is to provide a control method, system and circuit for a multi-winding motor, which does not require an additional backup control unit, thereby reducing costs. It only requires short-circuiting the faulty control unit and controlling the multi-winding motor by relying solely on the remaining control units, thereby reducing the downtime of the multi-winding motor. In addition, before short-circuiting the faulty control unit, the bus capacitor is discharged to ensure the safety of the bus. When restarting the multi-winding motor, the operating parameters of the multi-winding motor during the wave sealing period are tracked to ensure the stable operation of the multi-winding motor.

[0005] In order to solve the above technical problems, the present invention provides a control method for a multi-winding motor, which is applied to a processor in a control circuit of a multi-winding motor, wherein the control circuit further comprises a rectifier circuit whose input end is connected to an AC power supply, and a control unit whose output end is connected to each winding of the multi-winding motor in a one-to-one correspondence, wherein the input ends of the control units are connected in series with each other and connected to the output end of the rectifier circuit after the series connection, and each of the control units comprises a bus capacitor, an inverter circuit and a short-circuit module connected in parallel with the bus capacitor, and also comprises a discharge module connected to the bus capacitor, wherein the control method comprises:

[0006] After detecting that a fault occurs in the control unit, blocking the wave of each control unit;

[0007] The bus capacitor in the control unit with control failure is discharged through the discharge module;

[0008] After the bus capacitor is discharged, the control unit with a fault is controlled by the short-circuit module to short-circuit from the control units connected in series;

[0009] The current operating parameters of the multi-winding motor are acquired, and the operation of each of the control units that is not faulty is controlled based on the current operating parameters.

[0010] Preferably, the discharge module comprises a discharge resistor and a discharge switch; the first end of the bus capacitor is connected to the first end of the discharge resistor, the second end of the discharge resistor is connected to the first end of the discharge switch, and the second end of the discharge switch is connected to the second end of the bus capacitor;

[0011] The bus capacitor in the control unit of the control failure is discharged through the discharge module, including:

[0012] The discharge switch in the faulty control unit is controlled to close, so that the bus capacitor in the faulty control unit is discharged through the discharge resistor.

[0013] Preferably, after the bus capacitor is discharged, the short-circuiting module controls the control unit in fault to be short-circuited from the control units connected in series, including:

[0014] Determine whether the voltage value across the bus capacitor is less than a preset discharge threshold;

[0015] If so, the short-circuit module controls the control unit with the fault to be short-circuited from the control units connected in series.

[0016] Preferably, the short-circuit module is a short-circuit switch;

[0017] After the bus capacitor is discharged, the control unit with a fault is controlled by the short-circuit module to short-circuit from the control units connected in series, including:

[0018] After the bus capacitor is discharged, the short-circuit switch connected in parallel with the control unit having a fault is controlled to be closed, so that the control unit having a fault is short-circuited from the control units connected in series.

[0019] Preferably, after the bus capacitor is discharged, the short-circuit module controls the control unit with a fault to be short-circuited from the control units connected in series, and further comprises:

[0020] Based on the circuit parameters of the windings connected to the control units that have not failed, the first circuit protection threshold of each of the control units is switched to the second circuit protection threshold, and the circuit protection threshold of each of the control units is negatively correlated with the number of windings connected to the control units that have not failed.

[0021] Preferably, the control circuit further comprises a first voltage sampling circuit connected to each of the control units in a one-to-one correspondence and used for sampling the voltage across the bus capacitor;

[0022] After the bus capacitor is discharged, before the short-circuit module controls the control unit with a fault to short-circuit from the control units connected in series, the method further includes:

[0023] determining whether the bus capacitor is discharged based on a voltage sampling result of the first voltage sampling circuit;

[0024] After controlling each control unit that has not failed to operate based on the current operating parameters of the multi-winding motor, the method further includes:

[0025] Based on the circuit parameters of the control units that are not faulty, each of the control units is controlled to be disconnected from the first voltage sampling circuit and connected to the second voltage sampling circuit one by one.

[0026] Preferably, obtaining the current operating parameters of the multi-winding motor, and controlling the operation of each of the control units that are not faulty based on the current operating parameters, includes:

[0027] Acquiring current operating parameters of the multi-winding motor, and calculating a current speed and a current phase of the multi-winding motor based on the current operating parameters;

[0028] A control instruction is issued to each of the control units that has not failed, so that each of the control units that has not failed controls the multi-winding motor to start running at the current speed and the current phase.

[0029] In order to solve the above technical problems, the present invention provides a control system for a multi-winding motor, a processor applied to a control circuit of a multi-winding motor, the control circuit further comprising a rectifier circuit whose input end is connected to an AC power supply, a control unit whose output end is connected to each winding of the multi-winding motor in a one-to-one correspondence, the input ends of each of the control units are connected in series with each other and connected to the output end of the rectifier circuit after the series connection, each of the control units comprises a bus capacitor, an inverter circuit and a short-circuit module connected in parallel with the bus capacitor, and also comprises a discharge module connected to the bus capacitor, the control system comprises:

[0030] A wave sealing control unit, used for sealing the waves of each of the control units after detecting that a fault occurs in the control unit;

[0031] A discharge control unit, used for controlling the bus capacitor in the faulty control unit to discharge through the discharge module;

[0032] A short-circuit control unit, used for controlling the control unit with a fault to short-circuit from the control units connected in series through the short-circuit module after the bus capacitor is discharged;

[0033] The parameter processing unit is used to obtain the current operating parameters of the multi-winding motor and control the operation of each control unit that is not faulty based on the current operating parameters.

[0034] In order to solve the above technical problems, the present invention provides a control circuit of a multi-winding motor, comprising:

[0035] A processor, configured to implement the steps of the control method for a multi-winding motor as described above;

[0036] A rectifier circuit having an input end connected to an AC power supply, and a control unit having an output end connected to each winding of the multi-winding motor in a one-to-one correspondence, wherein the input ends of each of the control units are connected in series with each other and connected to the output end of the rectifier circuit after the series connection, and each of the control units includes a bus capacitor, an inverter circuit and a short-circuit module connected in parallel with the bus capacitor, and also includes a discharge module connected to the bus capacitor.

[0037] Preferably, it further comprises: a first voltage sampling circuit connected to each of the control units in a one-to-one correspondence;

[0038] The first voltage sampling circuit comprises:

[0039] A first sampling resistor having a first end connected to the first end of the bus capacitor and a second end connected to the first positive switch, and used for sampling the voltage of the first end of the bus capacitor;

[0040] A second sampling resistor having a first end connected to the second end of the bus capacitor and a second end connected to the second positive switch, and used for sampling the voltage at the second end of the bus capacitor;

[0041] the first positive switch having a second terminal connected to the positive input terminal of the first amplifier;

[0042] a first negative switch having a second terminal connected to a negative input terminal of the first amplifier;

[0043] The first amplifier, whose output end is connected to the processor, is used to calculate the voltage difference between the first end and the second end of the bus capacitor, and amplify the voltage difference and send it to the processor, so that the processor controls the discharge module based on the voltage difference.

[0044] The present invention provides a control method, system and circuit for a multi-winding motor. After detecting that a control unit fails, each control unit is sealed, and the bus capacitor in the control unit with the failure is discharged through a discharge module. After the bus capacitor is discharged, the control unit with the failure is controlled by a short-circuit module to short-circuit from each control unit connected in series, and the current operating parameters of the multi-winding motor are obtained, and the operation of each control unit that has not failed is controlled based on the current operating parameters. There is no need to set up an additional spare control unit, which reduces the cost. Only the failed control unit needs to be short-circuited, and the multi-winding motor is controlled by the remaining control units, which reduces the downtime of the multi-winding motor. In addition, the bus capacitor is discharged before the failed control unit is short-circuited to ensure the safety of the bus. When the multi-winding motor is restarted, the operating parameters of the multi-winding motor at the time of sealing are tracked to ensure the stable operation of the multi-winding motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 It is a structural schematic diagram of a control circuit of a multi-winding motor in the prior art;

[0047] Figure 2 A schematic flow chart of a control method for a multi-winding motor provided by the present invention;

[0048] Figure 3 A schematic diagram of the structure of a control circuit of a multi-winding motor provided by the present invention;

[0049] Figure 4A schematic diagram of a busbar capacitor discharge circuit structure provided by the present invention;

[0050] Figure 5 A schematic diagram of the connection between a control unit and a voltage sampling circuit provided by the present invention;

[0051] Figure 6 The operation timing diagram provided by the present invention takes the case where the first control unit fails as an example;

[0052] Figure 7 A schematic diagram of the structure of a control system for a multi-winding motor provided by the present invention;

[0053] Figure 8 A schematic structural diagram of a control circuit for a multi-winding motor provided by the present invention. DETAILED DESCRIPTION

[0054] The core of the present invention is to provide a control method, system and circuit for a multi-winding motor, which does not require an additional backup control unit, thereby reducing costs. It only requires short-circuiting the faulty control unit and relying solely on the remaining control units to control the multi-winding motor, thereby reducing the downtime of the multi-winding motor. In addition, before short-circuiting the faulty control unit, the bus capacitor is discharged to ensure the safety of the bus. When restarting the multi-winding motor, the operating parameters of the multi-winding motor during the wave sealing period are tracked to ensure the stable operation of the multi-winding motor.

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Please refer to Figure 2 , Figure 2 A flow chart of a control method for a multi-winding motor provided by the present invention is provided. The method is applied to a processor 81 in a control circuit of the multi-winding motor. The control circuit further includes a rectifier circuit 82 whose input end is connected to an AC power supply, and a control unit 83 whose output end is connected to each winding of the multi-winding motor in a one-to-one correspondence. The input ends of each control unit 83 are connected in series with each other and connected to the output end of the rectifier circuit 82 after being connected in series. Each control unit 83 includes a bus capacitor, an inverter circuit and a short-circuit module 832 connected in parallel with the bus capacitor, and also includes a discharge module 831 connected to the bus capacitor. The control method includes:

[0057] S11: After detecting that a control unit fails, blocking the waves of each control unit;

[0058] The control of each winding of a multi-winding motor is a complex but important process that involves precise manipulation of multiple windings inside the motor to achieve specific motor performance. Multi-winding motors connect multiple windings in series or in parallel inside a motor, and use multiple power supplies or control systems to independently control the current of each winding. Since each winding has different inductance and resistance, by adjusting the current of each winding, the motor's speed, output power, torque and other parameters can be flexibly controlled.

[0059] Some problems may arise when controlling a multi-winding motor. For example, after an irreversible fault occurs in a control unit 83, the system generally shuts down first, then troubleshoots the fault, and starts the inverter after the fault is eliminated. This process takes a few minutes to a few hours. In response to this type of problem, the prior art proposes a topological structure of newly added input switching, fault switching, and output switching circuits, so that when a control unit 83 fails, a new backup unit can be switched in to continue operation. However, the solutions in the prior art have some disadvantages, such as: it is necessary to prepare an extra control unit as a backup control unit for switching, which increases the cost of the equipment; when switching the backup control unit, the discharge of the faulty voltage-stabilizing capacitor is not considered, and a direct short circuit will cause the bus capacitor to discharge to the bus terminal, which poses a risk of explosion.

[0060] like Figure 1 As shown in , if there is a faulty control unit 83 and the faulty control unit 83 is switched to a backup control unit 83, since the bus capacitor is directly connected to the bus, the bus capacitor will be discharged directly to the bus. If so, the loss will be greater.

[0061] When determining whether the control unit 83 is faulty, the output current and output voltage of the control unit 83 can be detected to determine whether the control unit 83 is faulty. When determining that the winding is operating abnormally, it can also be indirectly determined that the control unit 83 connected to the abnormally operating winding is abnormal. This application does not limit this.

[0062] After the faulty control unit 83 is detected, the control units 83 connected to the respective windings are all blocked, that is, the inverter circuit in the control unit 83 is blocked to control it to stop output.

[0063] S12: The bus capacitor in the control unit with the control failure is discharged through the discharge module;

[0064] In order to solve the above technical problems, in the present application, a discharge module 831 connected to the bus capacitor is set in each control unit 83. If a control unit 83 fails, the bus capacitor in the failed control unit 83 is discharged first, that is, discharged through the discharge module 831, to avoid the bus capacitor from discharging to the bus, thereby improving safety.

[0065] S13: After the bus capacitor is discharged, the faulty control unit is controlled by the short-circuit module to be short-circuited from the control units connected in series;

[0066] In order to ensure that the multi-winding motor can be put into use as soon as possible, after the bus capacitor is discharged, the faulty control unit 83 is short-circuited from the control units 83 connected in series, so that the healthy control units 83 can continue to control the multi-winding motor.

[0067] Since the control units 83 are connected in series, when any control unit 83 fails, its internal bus capacitor is discharged and short-circuited, and the remaining control units 83 that have not failed are still in a series structure and can still control the multi-winding motor based on the DC power output by the rectifier circuit 82.

[0068] S14: Acquire current operating parameters of the multi-winding motor, and control the operation of each control unit that is not faulty based on the current operating parameters.

[0069] After the faulty control unit 83 is short-circuited, based on the current operating parameters of the multi-winding motor, such as the current operating speed and direction of the multi-winding motor, the non-faulty control units 83 are controlled to resume operation, thereby reducing the downtime of the multi-winding motor and ensuring stable control of the multi-winding motor.

[0070] Specifically, if a multi-winding motor includes N windings, where N is an integer greater than 1, if one of the control units 83 fails, the bus capacitor in the failed control unit 83 is discharged through the discharge module 831 and short-circuited through the short-circuit module 832. Subsequently, based on the current operating parameters of the multi-winding motor, the remaining N-1 control units 83 that have not failed are controlled to restart, and the multi-winding motor also switches from N windings operation to N-1 windings operation, thereby reducing the downtime of the multi-winding motor.

[0071] It should be noted that the multi-winding motor in the present application is not limited to a four-winding motor, that is, there is no limit on the number of windings, and there is no limit on the number of control units that have faults. The specific application shall prevail.

[0072] In summary, in the present application, there is no need to additionally set up a backup control unit 83, which reduces the cost. It is only necessary to short-circuit the faulty control unit 83 and rely solely on the remaining control units 83 to control the multi-winding motor, thereby reducing the downtime of the multi-winding motor. In addition, before short-circuiting the faulty control unit 83, the bus capacitor is discharged first to ensure the safety of the bus. When restarting the multi-winding motor, the operating parameters of the multi-winding motor during the wave sealing period are tracked to ensure the stable operation of the multi-winding motor.

[0073] Based on the above embodiments:

[0074] Please refer to Figure 3 , Figure 3 A schematic structural diagram of a control circuit for a multi-winding motor provided by the present invention.

[0075] As a preferred embodiment, the discharge module 831 includes a discharge resistor and a discharge switch; the first end of the bus capacitor is connected to the first end of the discharge resistor, the second end of the discharge resistor is connected to the first end of the discharge switch, and the second end of the discharge switch is connected to the second end of the bus capacitor;

[0076] The bus capacitor in the control unit 83 of the control fault is discharged through the discharge module 831, including:

[0077] The discharge switch in the faulty control unit 83 is controlled to be closed, so that the bus capacitor in the faulty control unit 83 is discharged through the discharge resistor.

[0078] In this embodiment, the discharge module 831 specifically includes a discharge switch and a discharge resistor. If a fault occurs in the control unit 83, the discharge switch in the faulty control unit 83 is opened, and the discharge resistor and the bus capacitor form a discharge circuit. The bus capacitor is discharged through the discharge resistor to ensure the safety of the entire control circuit.

[0079] The discharge switch may be, but is not limited to, a discharge circuit breaker, and the resistance of the discharge resistor is positively correlated with the discharge time of the bus capacitor, that is, the smaller the resistance of the discharge resistor, the shorter the discharge time of the bus capacitor, and therefore, the resistance of the discharge resistor can be selected based on actual needs. However, it should be noted that the resistance of the discharge resistor must not be less than the minimum resistance, that is, it is necessary to ensure that the bus capacitor is discharged at the discharge resistor rather than discharged to the bus.

[0080] like Figure 3 Taking the control unit 83 connected to the winding 1 in the as an example, the resistor R11 is a discharge resistor, the switch S12 is a discharge switch, the capacitor C1 is a bus capacitor, the resistor R12 is a voltage-stabilizing resistor, and the circuit composed of the switch tubes IGBT11, IGBT12, IGBT13, IGBT14, IGBT15 and IGBT16 is an inverter circuit.

[0081] Correspondingly, in the control unit 83 connected to the winding 2, the resistor R21 is a discharge resistor, the switch S22 is a discharge switch, the capacitor C2 is a bus capacitor, the resistor R22 is a voltage-stabilizing resistor, and the circuit formed by the switch tubes IGBT21, IGBT22, IGBT23, IGBT24, IGBT25 and IGBT26 is an inverter circuit. In the control unit 83 connected to the winding 3, the resistor R31 is a discharge resistor, the switch S32 is a discharge switch, the capacitor C3 is a bus capacitor, the resistor R32 is a voltage-stabilizing resistor, and the circuit formed by the switch tubes IGBT31, IGBT32, IGBT33, IGBT34, IGBT35 and IGBT36 is an inverter circuit. In the control unit 83 connected to the winding N, the resistor RN1 is a discharge resistor, the switch SN2 is a discharge switch, the capacitor CN is a bus capacitor, the resistor RN2 is a voltage-stabilizing resistor, and the circuit formed by the switch tubes IGBTN1, IGBTN2, IGBTN3, IGBTN4, IGBTN5 and IGBTN6 is an inverter circuit.

[0082] It should also be noted that Figure 3 The switches between the inverter circuit and the windings are switches connected to the three phases of the windings respectively, such as switch S13_U is a switch connected to the U1 phase winding of winding 1, switch S13_V is a switch connected to the V1 phase winding of winding 1, and switch S13_W is a switch connected to the W1 phase winding of winding 1; switch S23_U is a switch connected to the U2 phase winding of winding 2, switch S23_V is a switch connected to the V2 phase winding of winding 2, and switch S23_W is a switch connected to the The switch S33_U is a switch connected to the W2 phase winding of winding 2; the switch S33_U is a switch connected to the U3 phase winding of winding 3, the switch S33_V is a switch connected to the V3 phase winding of winding 3, and the switch S33_W is a switch connected to the W3 phase winding of winding 3; the switch SN3_U is a switch connected to the UN phase winding of winding N, the switch SN3_V is a switch connected to the VN phase winding of winding N, and the switch SN3_W is a switch connected to the WN phase winding of winding N.

[0083] Please refer to Figure 4 , Figure 4 A schematic diagram of the structure of a bus capacitor discharge circuit provided by the present invention.

[0084] In the figure, the control unit 83 connected to the winding 1 is taken as an example. When the discharge switch S12 is closed, the bus capacitor C1 and the discharge resistor R11 form a closed loop, and the bus capacitor C1 is discharged through the discharge resistor R11.

[0085] As a preferred embodiment, after the bus capacitor is discharged, the short-circuit module 832 controls the control unit 83 with a fault to be short-circuited from the control units 83 connected in series, including:

[0086] Determine whether the voltage value across the bus capacitor is less than a preset discharge threshold;

[0087] If so, the short-circuit module 832 controls the control unit 83 with the fault to be short-circuited from all the control units 83 connected in series.

[0088] When the bus capacitor is discharged, in order to ensure that the bus capacitor is completely discharged, a preset discharge threshold is set in this embodiment, that is, during the process of discharging the bus capacitor, the voltage value at both ends of the bus capacitor is detected. If the voltage value is not less than the preset discharge threshold, there is still residual electricity in the bus capacitor. At this time, the bus capacitor needs to continue to discharge, and when the voltage value is less than the preset discharge threshold, it can be determined that the bus capacitor has been completely discharged. In this embodiment, the specific discharge time of the bus capacitor is related to the resistance value of the discharge resistor, and the bus capacitor discharge time is in milliseconds, that is, the bus capacitor can be discharged quickly, so that the control unit 83 that has not failed can be put into use as soon as possible, reducing the downtime of the multi-winding motor.

[0089] Among them, the preset discharge threshold is a voltage value close to 0V, such as 1V. When setting the preset discharge threshold, it is necessary to consider the safety issue when the faulty control unit is cut off. When the faulty control unit is cut off, the bus capacitor no longer discharges to the bus.

[0090] As a preferred embodiment, the short-circuit module 832 is a short-circuit switch;

[0091] After the bus capacitor is discharged, the control unit 83 with the fault is controlled by the short-circuit module 832 to short-circuit all the control units 83 connected in series, including:

[0092] After the bus capacitor is discharged, the short-circuit switch connected in parallel with the control unit 83 having a fault is controlled to be closed, so that the control unit 83 having a fault is short-circuited from the control units 83 connected in series.

[0093] The short-circuit module 832 in this embodiment is a short-circuit switch, which is connected in parallel to both ends of the bus capacitor. When the short-circuit switch is closed, the entire control unit 83 connected in parallel therewith is short-circuited, thereby achieving the removal of the control unit 83 that is about to fail from the various control units 83 connected in series, ensuring that the control unit 83 that is not failed is put into use in time.

[0094] As a preferred embodiment, after the bus capacitor is discharged, the short-circuit module 832 controls the control unit 83 with a fault to short-circuit each control unit 83 connected in series, and further includes:

[0095] Based on the circuit parameters of the windings connected to the control unit 83 without faults, the first circuit protection threshold of each control unit 83 is switched to the second circuit protection threshold, and the circuit protection threshold of each control unit 83 is negatively correlated with the number of windings connected to the control unit 83 without faults.

[0096] In this embodiment, considering that after the faulty control unit 83 is short-circuited, the voltage divided by the remaining control units 83 becomes larger, in order to ensure that the remaining control units 83 can operate normally, the circuit protection threshold of each control unit 83 is adjusted, that is, the fewer the number of control units 83, the larger the circuit protection threshold. However, it should be noted that for safety reasons, the circuit protection threshold also has an upper limit. When the first circuit protection threshold and the second circuit protection threshold are set, they are specifically set according to the parameters of the control unit and the winding put into operation. The specific settings of the first circuit protection threshold and the second circuit protection threshold of this application are not limited, and the safe operation of the control unit and the winding can be ensured. When the number of control units and windings put into operation is large, the voltage divided by each control unit and winding is small, and when a control unit fails, after some control units and windings are cut off, the voltage divided by the remaining control units and windings put into operation is large. In order to ensure that the control unit and the winding can operate normally, it is necessary to increase the size of the circuit protection threshold accordingly after the control unit and the winding are cut off.

[0097] Specifically, when a multi-winding motor includes N windings, the bus voltage is XKv, and the control units 83 respectively connected to the N windings are operating normally, the voltage shared by the bus capacitor in each control unit 83 is (X / N)Kv. However, if a control unit 83 fails and is short-circuited, the voltage shared by the bus capacitor in the remaining control units 83 is (X / (N-1))Kv. Therefore, the circuit protection thresholds of the remaining control units 83 in the control circuit need to be increased.

[0098] As a preferred embodiment, the control circuit further includes a first voltage sampling circuit connected to each control unit 83 in a one-to-one correspondence and used to sample the voltage across the bus capacitor;

[0099] After the bus capacitor is discharged, before the short-circuit module 832 controls the control unit 83 with the fault to short-circuit from the control units 83 connected in series, the method further includes:

[0100] Determining whether the bus capacitor is discharged based on a voltage sampling result of the first voltage sampling circuit;

[0101] After controlling each control unit 83 that has not failed to operate based on the current operating parameters of the multi-winding motor, the following further includes:

[0102] Based on the circuit parameters of the control units that have not failed, each control unit 83 is controlled to be disconnected from the first voltage sampling circuit, and connected to the second voltage sampling circuit in a one-to-one correspondence.

[0103] Each control unit 83 is respectively connected to a first voltage sampling circuit, which is used to collect the voltage of the bus capacitor in each control unit to determine whether the bus capacitor has completed discharging. Considering that after the faulty control units are removed, the voltage of the bus capacitor of the control unit that is not faulty increases, if the voltage sampling is still performed through the first voltage sampling circuit, the first voltage sampling circuit may be damaged due to the low withstand voltage level of the device, and the voltage sampling cannot be performed normally. In order to ensure the normal sampling of the voltage across the bus capacitor of each control unit, a second voltage sampling circuit is additionally provided in this embodiment. Specifically, the parameters of each device in the second voltage sampling circuit can be set according to the circuit parameters of the control unit that is not faulty, such as correspondingly increasing the withstand voltage level of each device in the second voltage sampling circuit, so as to collect the voltage across the bus capacitor after the voltage is raised.

[0104] Therefore, after the faulty control unit 83 is short-circuited, the voltage sampling circuits connected to each control unit 83 need to be switched to ensure accurate voltage collection, thereby ensuring accurate control of the multi-winding motor.

[0105] For example, after the N winding is switched to the (N-1) winding, the motor parameters such as the stator resistance, D-axis inductance, Q-axis inductance and rated current of the multi-winding motor need to be considered. In addition, the rated frequency and back electromotive force of the multi-winding motor do not change and are not adjusted after the number of windings is switched. Since the windings of the multi-winding motor in the present application are connected in parallel, before the control unit 83 fails, the calculation formula of the original total resistance R is: 1 / R=1 / R1+1 / R2+1 / R3+...1 / RN, where R1, R2, R3 and RN are the resistances in each winding; if the first control unit 83 fails, the calculation formula of the total resistance R is changed to: 1 / R=1 / R2+1 / R3+...1 / RN, and the calculation formula of the original total inductance L is: 1 / L =1 / L1+1 / L2+1 / L3+...1 / LN, where L1, L2, L3 and LN are the inductances in each winding; if the first control unit 83 fails, the calculation formula of the total inductance L becomes: 1 / L =1 / L2+1 / L3+...1 / LN. After switching the (N-1) winding to operate, the rated current and rated power of the multi-winding motor are changed to (N-1) / N times of the original. Therefore, the circuit protection threshold and voltage sampling circuit of the control unit 83 need to be adjusted for withstand voltage.

[0106] Please refer to Figure 5 , Figure 5A schematic diagram of a connection between a control unit and a voltage sampling circuit provided by the present invention, Figure 5 The voltage sampling circuit in the embodiment includes a sampling resistor, a switching switch and an amplifier. Taking the control unit 83 connected to the winding 1 as an example, the first voltage sampling circuit connected to the control unit 83 includes a first sampling resistor R13, a second sampling resistor R14, a first positive switching switch K11, a first negative switching switch K12 and a first amplifier Op-Anp. The first sampling resistor R13 samples the voltage of the first end of the bus capacitor C1, and the second sampling resistor R14 samples the voltage of the second end of the bus capacitor C1. When the switch K12 is closed, the positive input end of the first amplifier Op-Anp receives the voltage of the first end of the bus capacitor C1, and the negative input end receives the voltage of the second end of the bus capacitor C1. Based on this, the voltage difference between the two ends of the bus capacitor C1 can be calculated, and the voltage difference is amplified and sent to the processor. The processor determines whether the bus capacitor has been discharged based on the voltage difference. If the discharge is completed, the faulty control unit 83 can be removed through the short-circuit module 832, and the voltage of the two ends of the bus capacitor in each control unit 83 can be sampled by the second voltage sampling circuit. The second voltage sampling circuit directly uses the first sampling resistor R13 and the second sampling resistor R14 in the first voltage sampling circuit, and also includes a second positive switching switch K13, a second negative switching switch K14 and a second amplifier Op-Anp1. When the first voltage sampling circuit connected to the control unit 83 corresponding to the winding 1 is switched to the second voltage sampling circuit, it is only necessary to turn off the first positive switching switch K11 and the first negative switching switch K12, and close the second positive switching switch K13 and the second negative switching switch K14. By analogy, the circuit structures of the first voltage sampling circuit and the second voltage sampling circuit corresponding to the control unit 83 connected to the winding 2, the winding 3 and the winding N can be obtained.

[0107] Specifically, the first voltage sampling circuit connected to the control unit 83 connected to the winding 2 includes a first sampling resistor R23, a second sampling resistor R24, a first positive switching switch K21, a first negative switching switch K22 and a first amplifier Op-Anp2. The second voltage sampling circuit directly applies the first sampling resistor R23 and the second sampling resistor R24 ​​in the first voltage sampling circuit, and also includes a second positive switching switch K23, a second negative switching switch K24 and a second amplifier Op-Anp3. When the first voltage sampling circuit connected to the control unit 83 corresponding to the winding 2 is switched to the second voltage sampling circuit, it is only necessary to turn off the first positive switching switch K21 and the first negative switching switch K22, and close the second positive switching switch K23 and the second negative switching switch K24.

[0108] The first voltage sampling circuit and the second voltage sampling circuit of the control unit 83 connected to the winding 3 are both connected in parallel to the two ends of the bus capacitor C3, wherein the first voltage sampling circuit includes a first sampling resistor R33, a second sampling resistor R34, a first positive switching switch K31, a first negative switching switch K32 and a first amplifier Op-Anp5, and the second voltage sampling circuit directly applies the first sampling resistor R33 and the second sampling resistor R34 in the first voltage sampling circuit, and also includes a second positive switching switch K33, a second negative switching switch K34 and a second amplifier Op-Anp6. When the first voltage sampling circuit connected to the control unit 83 corresponding to the winding 3 is switched to the second voltage sampling circuit, it is only necessary to turn off the first positive switching switch K31 and the first negative switching switch K32, and close the second positive switching switch K33 and the second negative switching switch K34.

[0109] The first voltage sampling circuit and the second voltage sampling circuit of the control unit 83 connected to the winding N are both connected in parallel to the two ends of the bus capacitor CN, wherein the first voltage sampling circuit includes a first sampling resistor RN3, a second sampling resistor RN4, a first positive switching switch KN1, a first negative switching switch KN2 and a first amplifier Op-Anp4, and the second voltage sampling circuit directly applies the first sampling resistor RN3 and the second sampling resistor RN4 in the first voltage sampling circuit, and also includes a second positive switching switch KN3, a second negative switching switch KN4 and a second amplifier Op-Anp7. When the first voltage sampling circuit connected to the control unit 83 corresponding to the winding N is switched to the second voltage sampling circuit, it is only necessary to turn off the first positive switching switch KN1 and the first negative switching switch KN2, and close the second positive switching switch KN3 and the second negative switching switch KN4.

[0110] It can be seen that each control unit 83 is respectively provided with a first voltage sampling circuit and a second voltage sampling circuit. After the faulty control unit 83 is cut off, the control unit 83, whether faulty or not, switches from being connected to the first voltage sampling circuit to being connected to the second voltage sampling circuit. By collecting the voltage across the bus capacitor in the faulty control unit 83, it can be determined whether there is leakage in the faulty control unit 83 to ensure the safety of the equipment.

[0111] As a preferred embodiment, the current operating parameters of the multi-winding motor are obtained, and each control unit 83 that has not failed is controlled to operate based on the current operating parameters, including:

[0112] Acquire current operating parameters of the multi-winding motor, and calculate the current speed and current phase of the multi-winding motor based on the current operating parameters;

[0113] A control instruction is issued to each control unit 83 that has not failed, so that each control unit 83 that has not failed controls the multi-winding motor to start running at the current speed and the current phase.

[0114] Considering that the multi-winding motor is in a running state before shutdown, or is in a running state due to the motor's own inertia, if the multi-winding motor is directly controlled to start at zero speed, it will cause the multi-winding motor to start abnormally. Therefore, in this embodiment, when the control unit 83 without faults is restarted, the speed of the multi-winding motor is first tracked, that is, the current speed and current phase of the multi-winding motor are determined, and the multi-winding motor is controlled to start linearly.

[0115] Please refer to Figure 6 , Figure 6 The present invention provides an operation timing diagram for the case where the first control unit fails as an example. The upper curve in the figure is the motor running speed, the lower curve is the control circuit operating state, and the horizontal axis is time. During normal operation, the multi-winding motor stably runs at 100% speed, and the whole machine state is RUN. When a fault occurs, the whole machine state is switched to the ERROR state, and the processor 81 first blocks the pulse output of all control units 83, and the multi-winding motor continues to rotate and run by inertia. At this time, the discharge switch S12 in the faulty control unit 83 is closed, and the bus capacitor C1 is discharged through the discharge resistor R11. When the voltage across the bus capacitor C1 drops below the preset discharge threshold, the discharge process has ended. At this time, the discharge switch S12 is disconnected, and the short-circuit switch S11 is closed, and the faulty control unit 83 is completely bypassed. While bypassing the faulty control unit 83, the software automatically switches the protection thresholds such as the overvoltage point and the overcurrent point, that is, the circuit protection threshold. After the adjustment is completed, the operation state of the whole machine is switched to the SpdTrace speed tracking state, and the current speed and current phase of the multi-winding motor are calculated in real time based on the back electromotive force in the stator coil of the motor. The specific implementation method is: after the fault is sealed, the processor 81 uses the output voltage sampling circuit to detect the line voltages UUV and UVW of the output multi-winding motor, and the detected line voltages UUV and UVW are transformed by Clark and Park to obtain Ud and Uq in the rotating coordinate system. The operating speed, rotor position, and voltage amplitude of the multi-winding motor are calculated in real time using the phase-locked loop principle. After the control unit 83 is adjusted, the processor 81 restarts according to the calculated speed and phase of the offline motor, and the state of the whole machine jumps from the SpdTrace state to the RUN state. This process is completed in a very short time, and the motor speed remains basically stable without obvious speed drop, ensuring linear control of the multi-winding motor.

[0116] Please refer to Figure 7 , Figure 7The present invention provides a structural schematic diagram of a control system for a multi-winding motor, the system is applied to a processor 81 in a control circuit of the multi-winding motor, the control circuit also includes a rectifier circuit 82 whose input end is connected to an AC power supply, and a control unit 83 whose output end is connected to each winding of the multi-winding motor in a one-to-one correspondence, the input ends of each control unit 83 are connected in series with each other and connected to the output end of the rectifier circuit 82 after the series connection, each control unit 83 includes a bus capacitor, an inverter circuit and a short-circuit module 832 connected in parallel with the bus capacitor, and also includes a discharge module 831 connected to the bus capacitor, the control system includes:

[0117] The wave blocking 71 is used to block the waves of each control unit 83 after detecting that a control unit 83 has a fault;

[0118] A discharge control unit 72, used to control the bus capacitor in the fault control unit 83 to discharge through a discharge module 831;

[0119] The short-circuit control unit 73 is used to control the control unit 83 with a fault to be short-circuited from the control units 83 connected in series through the short-circuit module 832 after the bus capacitor is discharged;

[0120] The parameter processing unit 74 is used to obtain the current operating parameters of the multi-winding motor and control the operation of each control unit 83 that is not faulty based on the current operating parameters.

[0121] For an introduction to the control system of the multi-winding motor of the asynchronous motor provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here.

[0122] Please refer to Figure 8 , Figure 8 A schematic diagram of a control circuit for a multi-winding motor provided by the present invention, the circuit comprising:

[0123] A processor 81, configured to implement the steps of the control method for a multi-winding motor as described above;

[0124] A rectifier circuit 82 having an input end connected to an AC power supply, and a control unit 83 having an output end connected one-to-one with each winding of a multi-winding motor. The input ends of the control units 83 are connected in series with each other and connected to the output end of the rectifier circuit 82 after the series connection. Each control unit 83 includes a bus capacitor, an inverter circuit and a short-circuit module 832 connected in parallel with the bus capacitor, and also includes a discharge module 831 connected to the bus capacitor.

[0125] As a preferred embodiment, it also includes: a first voltage sampling circuit connected to each control unit in a one-to-one correspondence;

[0126] The first voltage sampling circuit comprises:

[0127] A first sampling resistor having a first end connected to the first end of the bus capacitor and a second end connected to the first positive switch, and used for sampling the voltage of the first end of the bus capacitor;

[0128] A second sampling resistor having a first end connected to the second end of the bus capacitor and a second end connected to the second positive switch, and used for sampling the voltage at the second end of the bus capacitor;

[0129] a first positive switch having a second terminal connected to the positive input terminal of the first amplifier;

[0130] a first negative switch having a second terminal connected to the negative input terminal of the first amplifier;

[0131] The first amplifier whose output end is connected to the processor is used to calculate the voltage difference between the first end and the second end of the bus capacitor, and send the voltage difference to the processor after amplification, so that the processor controls the discharge module based on the voltage difference.

[0132] For an introduction to the control circuit of the multi-winding motor of the asynchronous motor provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here.

[0133] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0134] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a multi-winding motor, It is characterized in that A processor applied to a control circuit of a multi-winding motor, the control circuit further comprising a rectifier circuit having an input end connected to an AC power supply, a control unit having an output end connected to each winding of the multi-winding motor in a one-to-one correspondence, the input ends of each of the control units being connected in series with each other and connected to the output end of the rectifier circuit after the series connection, each of the control units comprising a bus capacitor, an inverter circuit and a short-circuit module connected in parallel with the bus capacitor, and also comprising a discharge module connected to the bus capacitor, the control method comprising: After detecting that a fault occurs in the control unit, blocking the wave of each control unit; The bus capacitor in the control unit with control failure is discharged through the discharge module; After the bus capacitor is discharged, the control unit with a fault is controlled by the short-circuit module to short-circuit from the control units connected in series; The current operating parameters of the multi-winding motor are acquired, and the operation of each of the control units that is not faulty is controlled based on the current operating parameters.

2. The control method of a multi-winding motor according to claim 1, It is characterized in that The discharge module includes a discharge resistor and a discharge switch; the first end of the bus capacitor is connected to the first end of the discharge resistor, the second end of the discharge resistor is connected to the first end of the discharge switch, and the second end of the discharge switch is connected to the second end of the bus capacitor; The bus capacitor in the control unit of the control failure is discharged through the discharge module, including: The discharge switch in the faulty control unit is controlled to close, so that the bus capacitor in the faulty control unit is discharged through the discharge resistor.

3. The control method of a multi-winding motor according to claim 1, It is characterized in that After the bus capacitor is discharged, the control unit with a fault is controlled by the short-circuit module to short-circuit from the control units connected in series, including: Determine whether the voltage value across the bus capacitor is less than a preset discharge threshold; If so, the short-circuit module controls the control unit with the fault to be short-circuited from the control units connected in series.

4. The control method of a multi-winding motor according to claim 1, It is characterized in that The short-circuit module is a short-circuit switch; After the bus capacitor is discharged, the control unit with a fault is controlled by the short-circuit module to short-circuit from the control units connected in series, including: After the bus capacitor is discharged, the short-circuit switch connected in parallel with the control unit having a fault is controlled to be closed, so that the control unit having a fault is short-circuited from the control units connected in series.

5. The control method of a multi-winding motor according to claim 1, It is characterized in that After the bus capacitor is discharged, the short-circuit module controls the control unit with a fault to be short-circuited from the control units connected in series, and further includes: Based on the circuit parameters of the windings connected to the control units that have not failed, the first circuit protection threshold of each of the control units is switched to the second circuit protection threshold, and the circuit protection threshold of each of the control units is negatively correlated with the number of windings connected to the control units that have not failed.

6. The control method of a multi-winding motor according to claim 1, It is characterized in that The control circuit further includes a first voltage sampling circuit connected to each of the control units in a one-to-one correspondence and used to sample the voltage across the bus capacitor; After the bus capacitor is discharged, before the short-circuit module controls the control unit with a fault to short-circuit from the control units connected in series, the method further includes: determining whether the bus capacitor is discharged based on a voltage sampling result of the first voltage sampling circuit; After controlling each control unit that has not failed to operate based on the current operating parameters of the multi-winding motor, the method further includes: Based on the circuit parameters of the control units that are not faulty, each of the control units is controlled to be disconnected from the first voltage sampling circuit and connected to the second voltage sampling circuit one by one.

7. The control method of a multi-winding motor according to any one of claims 1 to 6, It is characterized in that Acquiring current operating parameters of the multi-winding motor, and controlling the operation of each control unit that has not failed based on the current operating parameters, including: Acquiring current operating parameters of the multi-winding motor, and calculating a current speed and a current phase of the multi-winding motor based on the current operating parameters; A control instruction is issued to each of the control units that has not failed, so that each of the control units that has not failed controls the multi-winding motor to start running at the current speed and the current phase.

8. A control system for a multi-winding motor, It is characterized in that A processor applied to a control circuit of a multi-winding motor, wherein the control circuit further comprises a rectifier circuit having an input end connected to an AC power supply, and a control unit having an output end connected to each winding of the multi-winding motor in a one-to-one correspondence, wherein the input ends of the control units are connected in series with each other and connected to the output end of the rectifier circuit after the series connection, wherein each control unit comprises a bus capacitor, an inverter circuit and a short-circuit module connected in parallel with the bus capacitor, and further comprises a discharge module connected to the bus capacitor, wherein the control system comprises: A wave sealing control unit, used for sealing the waves of each of the control units after detecting that a fault occurs in the control unit; A discharge control unit, used for controlling the bus capacitor in the faulty control unit to discharge through the discharge module; A short-circuit control unit, used for controlling the control unit with a fault to short-circuit from the control units connected in series through the short-circuit module after the bus capacitor is discharged; The parameter processing unit is used to obtain the current operating parameters of the multi-winding motor and control the operation of each control unit that is not faulty based on the current operating parameters.

9. A control circuit for a multi-winding motor, It is characterized in that include: A processor, configured to implement the steps of the method for controlling a multi-winding motor as claimed in any one of claims 1 to 7; A rectifier circuit having an input end connected to an AC power supply, and a control unit having an output end connected to each winding of the multi-winding motor in a one-to-one correspondence, wherein the input ends of each of the control units are connected in series with each other and connected to the output end of the rectifier circuit after the series connection, and each of the control units includes a bus capacitor, an inverter circuit and a short-circuit module connected in parallel with the bus capacitor, and also includes a discharge module connected to the bus capacitor.

10. The control circuit of the multi-winding motor according to claim 9, It is characterized in that Also includes: A first voltage sampling circuit connected to each of the control units in a one-to-one correspondence; The first voltage sampling circuit comprises: A first sampling resistor having a first end connected to the first end of the bus capacitor and a second end connected to the first positive switch, and used for sampling the voltage of the first end of the bus capacitor; A second sampling resistor having a first end connected to the second end of the bus capacitor and a second end connected to the second positive switch, and used for sampling the voltage at the second end of the bus capacitor; the first positive switch having a second terminal connected to the positive input terminal of the first amplifier; a first negative switch having a second terminal connected to a negative input terminal of the first amplifier; The first amplifier, whose output end is connected to the processor, is used to calculate the voltage difference between the first end and the second end of the bus capacitor, and amplify the voltage difference and send it to the processor, so that the processor controls the discharge module based on the voltage difference.

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