A control method for a dual-winding motor

Abstract

The present invention relates to a control method for a dual-winding motor, comprising the following steps: Step 1, two sets of controllers are adopted, each operating in a speed control mode, each calculating and outputting torque, and a torque balance algorithm is added to one of the controllers; Step 2, for the controller without the torque balance algorithm, the output torque in Step 1 is directly used to control the operation of the winding; for the controller with the torque balance algorithm, the three-phase currents of the two sets of windings are simultaneously collected, the current difference is calculated, and the current difference, the speed command data, and the motor speed signal are subjected to the operation of the torque balance algorithm to dynamically adjust the output torque of the controller and control the operation of the winding, so that the output torques of the two sets of controllers are finally equal; the present invention enables the two sets of controllers and the motor windings to have the same load and a relatively high system life; it can also avoid the low-efficiency operation condition where one winding is in the electric state and the other winding is in the generating state.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and more specifically, to a control method for a dual-winding motor. Background Art

[0002] With the continuous increase in the power demand of motors and the continuous improvement of the reliability requirements for motor systems, in the fields of marine drive motors and vehicle drive motors, the use of dual-winding or six-phase motors has gradually become a trend. The two sets of windings arranged in the same motor will affect each other, and when one set of windings has a short-circuit fault, a large amount of heat will be generated in this winding, causing the temperature inside the motor to rise. When the temperature inside the motor is too high, it may also burn out the other set of windings, reducing the reliability of the dual-winding motor.

[0003] At the same time, dual-winding motors generally use two controllers to independently control the two windings. The two controllers generally have a master-slave relationship. If the master controller is damaged, the slave controller cannot be used either, affecting stability; moreover, there will be a problem of uneven torque distribution between the two windings. It is possible that one winding and its controller operate under a large load for a long time, while the other winding operates without load, reducing the service life of the entire system; in extreme cases, it is possible that one winding rotates with positive torque and the other winding generates electricity with negative torque, resulting in serious problems such as low system efficiency and wasted electricity. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a control method for a dual-winding motor, which enables the dual-winding motor to have high operating efficiency, a relatively high system service life, and low cost.

[0005] In order to achieve the above invention purpose, the present invention adopts the following technical solutions:

[0006] A control method for a dual-winding motor includes the following steps:

[0007] Step 1: Use two sets of controllers, each operating in a speed control mode, each calculating and outputting torque, and adding a torque balance algorithm to one of the controllers;

[0008] Step 2: For the controller without the torque balance algorithm, directly control the operation of the winding with the output torque in Step 1; for the controller with the torque balance algorithm, collect the three-phase currents of the two sets of windings at the same time, calculate the current difference, and perform an operation of the torque balance algorithm on the current difference, speed command data, and motor speed signal, dynamically adjust the output torque of this controller, and control the operation of the winding, ultimately making the output torques of the two sets of controllers equal;

[0009] Step 3: When the controller without the torque balance algorithm detects a fault, the corresponding winding stops operating; the torque balance algorithm of the other controller continues to operate, and the other controller will control the corresponding winding to operate and finally control the motor to operate at a speed lower than the target speed.

[0010] When the controller with the torque balance algorithm detects a fault, the corresponding winding stops operating; the other controller continues to operate normally and controls the motor to operate at a speed lower than the target speed.

[0011] As a preferred solution: In step 2, the controller with the torque balance algorithm simultaneously collects the three-phase currents of itself and the three-phase currents of the other controller. After Clarke / Park transformation, the d-axis components Id1 and Id2 of the currents in the rotating coordinate system and the q-axis components Iq1 and Iq2 are obtained respectively.

[0012] The torque balance algorithm calculates the difference between Iq1 and Iq2 to obtain the difference value Iq_Delta; the amplitude of Iq_Delta is limited. If Iq_Delta is less than the limit value Iq_Delta_Limit, Iq_Delta is sent to the speed PI controller; if Iq_Delta is greater than the limit value Iq_Delta_Limit, then Iq_Delta_Limit is sent to the speed PI controller.

[0013] The controller with the torque balance algorithm collects the motor speed signal and calculates the difference from the speed command to obtain the speed difference Spd_Delta; Spd_Delta is multiplied by the proportional coefficient P to obtain the proportional term, Spd_Delta is multiplied by the integral coefficient I and accumulated with Iq_Delta and the previous integral term to obtain the current integral term, and the integral term and the proportional term are summed to obtain the output torque command TqReq. The reference formula is: TqReq = Spd_Delta * P + ∑(Spd_Delta * I + Iq_Delta).

[0014] As a preferred solution: The Clarke transformation formula is

[0015]

[0016] The Park transformation formula is

[0017]

[0018] As a preferred solution: In the controller with a torque balance algorithm in step 2, the process of dynamically adjusting the output torque of the controller includes collecting the three-phase current signals of the motor multiple times and calculating the current difference Iq_Delta between two windings. At the same time, the motor speed signal is collected multiple times, and the above data is subjected to the torque balance algorithm operation multiple times, finally making the output torques TqReq of the two controllers the same.

[0019] As a preferred solution: The process of driving the dual windings with the output torque in step 2 is as follows: The output torque TqReq is calculated through MTPA to obtain the current commands Id* and Iq*. After taking the difference between the current commands and the collected currents Id and Iq, they are sent to the current loop controller to obtain the voltage command. The voltage command is modulated by SVPWM to generate the mosfet drive signal and finally drive the motor to rotate.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The dual-winding motor of the present invention adopts two sets of controllers, and there is no master-slave relationship between the two sets of controllers. They operate independently, with high safety. At the same time, a torque balance algorithm is added to one set of controllers, making the loads of the two sets of controllers and the motor windings the same, and the system has a relatively long lifespan. It can also avoid the low-efficiency operation situation where one winding generates electricity while the other winding operates as a motor. In addition, the added torque balance algorithm is relatively simple, with low requirements for the computing performance of the main chip and low cost. Since only a single winding needs to be balanced for torque, there is no need for digital signal communication between the two, and the anti-interference ability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute a limitation to this application.

[0023] Figure 1 It is a schematic diagram of the principle of the control method of the present invention;

[0024] Figure 2 It is a schematic diagram of the principle of the torque balance algorithm of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0026] It should be noted that the terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and / or combinations thereof.

[0027] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

[0029] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0032] As Figure 1 and Figure 2 shown, a control method for a dual-winding motor includes the following steps:

[0033] Step 1: Use two sets of controllers, each operating in a speed control mode, each calculating and outputting torque, and adding a torque balance algorithm to one of the controllers.

[0034] For the controller without the torque balance algorithm, use the output torque in Step 1 to directly control the operation of the winding; for the controller with the torque balance algorithm, simultaneously collect the three-phase currents of the two sets of windings, and after Clarke / Park transformation, obtain the d-axis components Id1, Id2 and the q-axis components Iq1, Iq2 of the currents in the rotating coordinate system respectively;

[0035] The Clarke transformation formula is

[0036]

[0037] The Park transformation formula is

[0038]

[0039] The torque balance algorithm calculates the difference between Iq1 and Iq2 to obtain the difference value Iq_Delta; limit the amplitude of Iq_Delta. If Iq_Delta is less than the limit value Iq_Delta_Limit, send Iq_Delta to the speed PI controller; if Iq_Delta is greater than the limit value Iq_Delta_Limit, then send Iq_Delta_Limit to the speed PI controller;

[0040] The controller with the torque balance algorithm collects the motor speed signal, calculates the difference with the speed command to obtain the speed difference Spd_Delta; multiply Spd_Delta by the proportional coefficient P to obtain the proportional term, multiply Spd_Delta by the integral coefficient I and accumulate Iq_Delta and the previous integral term to obtain the current integral term, and sum the integral term and the proportional term to obtain the output torque command TqReq. The reference formula is: TqReq = Spd_Delta * P + ∑(Spd_Delta * I + Iq_Delta).

[0041] Since the amplitude of Tq_Delta is limited in this embodiment, the output torques obtained after the first torque balance algorithm are not necessarily the same. It is necessary to repeatedly collect the three-phase current signals of the motor and calculate the current difference Iq_Delta between the two windings. At the same time, the motor speed signal is collected multiple times, and the above data is subjected to the torque balance algorithm operation multiple times, so that the output torques TqReq of the two controllers are finally the same.

[0042] The process of driving the dual winding by the output torque in step 2 is as follows: The output torque TqReq is calculated through MTPA to obtain the current commands Id* and Iq*. After the current commands are subtracted from the collected currents Id and Iq, they are sent to the current loop controller to obtain the voltage command. The voltage command is modulated by SVPWM to generate the mosfet drive signal, and finally drives the motor to rotate.

[0043] Step 3, when the controller without the torque balance algorithm detects a fault, the corresponding winding stops running; the torque balance algorithm of the other controller continues to run, and the other controller will control the corresponding winding to run, and finally control the motor to run at a speed lower than the target speed; when the controller with the torque balance algorithm detects a fault, the corresponding winding stops running; the other controller continues to run normally and controls the motor to run at a speed lower than the target speed.

[0044] In summary, the two sets of controller algorithms of the present invention operate independently in the speed control mode. One set of controllers collects the three-phase currents of the two windings, and a torque balance algorithm is added to this controller to achieve power balance.

[0045] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0046] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solutions of the present invention.

Claims

1. A control method for a dual-winding motor, characterized in that, It includes the following steps: Step 1: Adopt two sets of controllers, each operating in the speed control mode, each calculating and outputting torque, and adding a torque balance algorithm to one of the controllers; Step 2: For the controller without the torque balance algorithm, directly control the operation of the winding with the output torque in Step 1; for the controller with the torque balance algorithm, simultaneously collect the three-phase currents of the two sets of windings, calculate the current difference, and perform the operation of the torque balance algorithm on the current difference, speed command data, and motor speed signal, dynamically adjust the output torque of this controller, and control the operation of the winding, ultimately making the output torques of the two controllers equal; Step 3: When the controller without the torque balance algorithm detects a fault, the corresponding winding stops operating; the torque balance algorithm of the other controller continues to operate, and the other controller will control the corresponding winding to operate, and ultimately control the motor to operate at a state lower than the target speed; When the controller with the torque balance algorithm detects a fault, the corresponding winding stops operating; the other controller continues to operate normally and controls the motor to operate at a state lower than the target speed; In Step 2, the controller with the torque balance algorithm simultaneously collects its own three-phase current and the three-phase current of the other controller. After Clarke / Park transformation, the d-axis components Id1, Id2 and q-axis components Iq1, Iq2 of the current in the rotating coordinate system are obtained respectively; The torque balance algorithm calculates the difference between Iq1 and Iq2 to obtain the difference Iq_Delta between them; limit the amplitude of Iq_Delta. If Iq_Delta is less than the limit value Iq_Delta_Limit, send Iq_Delta to the speed PI controller; if Iq_Delta is greater than the limit value Iq_Delta_Limit, then send Iq_Delta_Limit to the speed PI controller; The controller with the torque balance algorithm collects the motor speed signal, calculates the difference from the speed command to obtain the speed difference Spd_Delta; multiply Spd_Delta by the proportional coefficient P to obtain the proportional term, multiply Spd_Delta by the integral coefficient I and accumulate Iq_Delta and the previous integral term to obtain the current integral term, sum the integral term and the proportional term to obtain the output torque command TqReq. The reference formula is: TqReq = Spd_Delta * P + ∑(Spd_Delta * I + Iq_Delta).

2. The control method of a dual-winding motor according to claim 1, characterized in that: The Clarke transformation formula is The Park transformation formula is 3. The control method of a dual-winding motor according to claim 1, characterized in that: In Step 2, for the controller with the torque balance algorithm, the process of dynamically adjusting the output torque of this controller includes collecting the motor three-phase current signal multiple times and calculating the current difference Iq_Delta between the two windings, simultaneously collecting the motor speed signal multiple times, and performing the operation of the torque balance algorithm on the above data multiple times, ultimately making the output torques TqReq of the two controllers the same.

4. A control method for a dual-winding motor according to claim 1, characterized in that: The process of driving the dual-winding operation with the output torque in Step 2 is as follows: The output torque TqReq is calculated through MTPA to obtain the current commands Id* and Iq*. After the difference between the current commands and the measured currents Id and Iq is obtained, it is sent to the current-loop controller to obtain the voltage command. The voltage command is modulated by SVPWM to generate the mosfet drive signal, which ultimately drives the motor to rotate.

Images