DOUBLE WOUND MOTOR CONTROL APPARATUS AND METHOD

Abstract

The present disclosure relates to a double wound motor and a control method therefor, and comprises: a first inverter and a second inverter for supplying phase currents respectively to a first winding unit and a second winding unit of the double wound motor; a gate driver for driving switches respectively included in the first inverter and second inverter and detecting whether there is a switch abnormality in the first inverter or second inverter and whether there is a winding abnormality in the first winding unit and second winding unit; and a motor control unit for outputting a current command to attenuate a torque ripple in response to a torque ripple pattern according to the switch or winding abnormality.

Claims

1. A control apparatus for a double wound motor, comprising: a first inverter and a second inverter for supplying phase currents respectively to a first winding unit and a second winding unit of the double wound motor; a gate driver for driving switches respectively comprised in the first inverter and second inverter and detecting whether there is a switch abnormality in the first inverter or second inverter and whether there is a winding abnormality in the first winding unit and second winding unit; and a motor control unit for outputting a current command to attenuate a torque ripple in response to a torque ripple pattern according to the switch or winding abnormality.

2. The control apparatus for a double wound motor of claim 1, wherein the motor control unit: stores different types of torque ripple information according to a position of a short-circuited switch, and when information on a switch in which a short circuit occurred is received from the gate driver, performs current control according to the information on the switch in which the short circuit occurred.

3. The control apparatus for a double wound motor of claim 1, wherein the motor control unit: stores torque ripple information when the winding of the first winding unit or the second winding unit is short-circuited to ground and when a short circuit occurs between windings, and performs current control by classifying a short circuit between a winding and ground or a short circuit between windings according to the current detected by the gate driver.

4. A control method for a double wound motor, comprising: a) storing torque ripple information according to an abnormality occurrence type and a current control command according to a form of torque ripple in the motor control unit; b) detecting whether an abnormality has occurred in an inverter or a winding unit in a gate driver; and c) executing a current control command in the motor control unit according to the type of abnormality detected in step b).

5. The control method for a double wound motor of claim 4, wherein in the step a), the abnormality occurrence type is an abnormality in an inverter or a winding unit, and the abnormality occurrence type of the inverter is a position of a switch in which a short circuit occurred among comprised switches.

6. The control method for a double wound motor of claim 4, wherein in the step a), the abnormality occurrence type is an abnormality in an inverter or a winding unit, and the abnormality occurrence type of the winding unit is a short circuit between winding and ground or short circuit between windings.

7. The control method for a double wound motor of claim 5, wherein the step b) is detecting the abnormality occurrence type by detecting phase current or counter electromotive voltage.

8. The control method for a double wound motor of claim 6, wherein the step b) is detecting the abnormality occurrence type by detecting phase current or counter electromotive voltage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other objects, features, and advantages of the present disclosure will become more apparent to those of ordinary skill in the art by describing exemplary embodiments thereof in detail with reference to the accompanying drawings, in which:

[0037] FIG. 1 is a configuration diagram of a conventional control apparatus for a double wound motor;

[0038] FIG. 2 is a configuration diagram of a control apparatus for a double wound motor of the present disclosure;

[0039] FIGS. 3 to 5 are each a flow chart of the phase current when one of the inverter switches is abnormal;

[0040] FIG. 6 is a phase current waveform diagram;

[0041] FIG. 7 is a waveform diagram of torque when one of the inverter switches is abnormal;

[0042] FIG. 8 is a waveform diagram of a phase current and a shaft current in the state of FIG. 7;

[0043] FIGS. 9 to 12 are each a flow chart of the phase current when two or more switches in one phase of inverter switches are abnormal;

[0044] FIG. 13 is a graph of a breaking torque according to a motor rotation angle when two or more switches in one phase of inverter switches are abnormal;

[0045] FIG. 14 is a waveform diagram of a phase current and a shaft current of FIG. 13;

[0046] FIG. 15 is a graph showing a breaking torque according to an angle when a winding and a ground line of the motor are short-circuited;

[0047] FIG. 16 is a graph showing a phase current and a shaft current when a winding and a ground line are short-circuited as in FIG. 15;

[0048] FIG. 17 is a graph of breaking torque according to an angle when a short circuit occurs between windings of the motor; and

[0049] FIG. 18 is a graph showing a phase current and a shaft current when a short circuit occurs between windings of the motor as in FIG. 17.

[0050]

TABLE-US-00001 <Description of Symbols> 10: first inverter 20: second inverter 30: first winding unit 40: second winding unit 50: gate driver 60: motor control unit

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] Hereinafter, a control apparatus and method for a double wound motor of the present disclosure will be described in detail with reference to the accompanying drawings.

[0052] Embodiments of the present disclosure are provided to describe the present disclosure more fully to those skilled in the art, the embodiments described below can be modified into various other forms, and the scope of the present disclosure is not limited to the following embodiments. Rather, these embodiments make the present disclosure more meaningful and complete and are provided for fully conveying the concept of the present disclosure to those skilled in the art.

[0053] The terminologies used herein are for the purpose of describing particular embodiments only and are not intended to be limiting to the present disclosure. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. In addition, the terms “comprise” and/or “comprising,” when used in this specification, specify the presence of stated shapes, integers, steps, operations, members, elements and/or a group thereof but do not preclude the presence or addition of one or more other shapes, integers, steps, operations, members, elements, and/or groups thereof. As used herein, the term “and/or” includes any one of and all combinations of one or more of the relevant listed items.

[0054] Although the terms “first,” “second,” etc. are used herein to describe various members, regions and/or parts, it is apparent that these members, components, regions, layers and/or parts are not limited by these terms. These terms do not imply any particular order, top, bottom, or superiority and are used only to distinguish one member, region, or part from another member, region, or part. Thus, the first member, the first region, or the first part described below may refer to the second member, the second region, or the second part without departing from the teachings of the present disclosure.

[0055] Hereinafter, the embodiments of the present disclosure are described with reference to the drawings schematically illustrating the embodiments of the present disclosure. In the drawings, for example, variations in the illustrated shape may be expected depending on manufacturing techniques and/or tolerances. Accordingly, the embodiments of the present disclosure should not be construed as being limited to any particular shape of the regions illustrated herein and should include, for example, variations in shape resulting from manufacturing.

[0056] FIG. 2 is a block configuration diagram of a control apparatus for a double wound motor according to a preferred embodiment of the present disclosure.

[0057] Referring to FIG. 2, the present disclosure includes a first inverter 10 for controlling a current supplied to a first winding unit 30, a second inverter 20 for controlling a current supplied to a second winding unit 40, a gate driver 50 that controls driving of switches of the first inverter 10 and the second inverter 20 and detects whether the switches are normally driven, and a motor control unit 60 that reduces torque ripple generated when a switch malfunctions by outputting a control current that cancels out a pre-stored form of torque ripple according to the detection result of the gate driver 50.

[0058] Hereinafter, the configuration and operation of the control circuit of a double wound motor according to a preferred embodiment of the present disclosure configured as above will be described in detail.

[0059] First, the present disclosure relates to a control apparatus and method applied to a double wound motor including a first winding unit 30 and a second winding unit 40 in the same motor.

[0060] The first winding unit 30 and the second winding unit 40 each include polyphase windings.

[0061] Each of the switches of the first inverter 10 and the second inverter 20 is driven by the gate driver 50 controlled by the motor control unit 60 to supply current to each winding of the first winding unit 30 and the second winding unit 40.

[0062] FIG. 2 is a diagram on the assumption that a double wound motor to be controlled is a three-phase motor.

[0063] In the first inverter 10, a pair of switches connected in series with each other is provided for each phase, and the pairs of switches of each phase are connected in parallel with each other.

[0064] That is, the first inverter 10 includes six switches SW11, SW12, SW13, SW14, SW15, and SW16.

[0065] The second inverter 20 having the same configuration also includes six switches SW21, SW22, SW23, SW24, SW25, and SW26.

[0066] Among the switches of the first inverter 10 and the second inverter 20, the same state control is performed on switches located at the same position.

[0067] FIGS. 3 to 5 are circuit diagrams illustrating the phase current flow in a state in which the switch SW11 of the first inverter 10 is short-circuited, respectively.

[0068] FIG. 3 shows a state in which the switch SW13 of the b-phase (or v-phase) is closed, and at this time, the flow of the b-phase current is shown.

[0069] Similarly, FIG. 4 shows a state in which the switch SW15 of the c-phase (or w-phase) is closed, and at this time, the flow of the c-phase current is shown.

[0070] Similarly, FIG. 5 shows the phase current flow in a state in which both the b-phase and c-phase switches SW13 and SW15 are closed.

[0071] FIG. 6 is a graph of counter electromotive voltage.

[0072] As such, when an abnormality occurs in the specific switch SW11, an abnormality occurs in the normal counter electromotive force, and a characteristic torque ripple is generated according to the position of the abnormal switch.

[0073] FIG. 7 is a graph showing the type of torque ripple when the upper switch SW11 of the a-phase is short-circuited.

[0074] It represents the breaking torque generated according to the angle of the motor rotor, and although it is constant, unstable torque is generated by the occurrence of torque ripple.

[0075] FIG. 8 is a graph of a phase current and a shaft current when the upper switch SW11 of a-phase is short-circuited.

[0076] As shown in this figure, the shaft currents Iq and Id also have a current change period corresponding to the torque ripple of FIG. 7.

[0077] FIGS. 9 to 12 are phase current flow charts when the switches SW11 and SW12 of the a-phase (or u-phase) of the first inverter 10 is short-circuited, respectively.

[0078] FIG. 9 shows the phase current flow in a state in which the upper switches SW13 and SW15 of the b-phase (or v-phase) and the c-phase (or w-phase) are all closed, and FIG. 10 shows the phase current flow in a state in which the upper switch SW13 of the b-phase and the lower switch SW16 of the c-phase are closed.

[0079] FIG. 11 shows the phase current flow in a state in which the upper switch SW15 of the c-phase and the lower switch SW14 of the b-phase are closed, and FIG. 12 shows the phase current flow in a state in which the lower switches SW14 and SW16 of the b-phase and the c-phase are closed.

[0080] As such, when both switches SW11 and SW12 of the a-phase are short-circuited, the flow of the phase current is different from the case where only one switch SW11 described with reference to FIGS. 3 to 5 is short-circuited, and thus the torque ripple also occurs in a different form.

[0081] FIG. 13 is a graph of breaking torque according to a motor rotation angle.

[0082] As shown in FIG. 13, although it has a constant torque form, a stable torque is not formed due to the occurrence of torque ripple.

[0083] Comparing the graph of FIG. 13 and the previously described graph of FIG. 7, there is a difference in the form of torque and torque ripple generated according to the failure position of the switch.

[0084] This can also be seen in the phase current graph of FIG. 14.

[0085] Comparing the phase current graph of FIG. 14 and FIG. 8 showing the phase current graph when only one switch SW11 is short-circuited, it can be seen that the peak values of the shaft currents Id and Iq do not differ much, but the period in which the peak appears is shortened.

[0086] As such, there is a difference in the form of torque ripple generated at each failure position of the inverter switch, and current control that can cancel out this difference is possible.

[0087] The inverter switch failure position can be detected in the gate driver 50 through current detection, and the motor control unit 60 that stores the form information of the torque ripple for each failure position and a control current value capable of cancelling out it may cancel out the generated torque ripple through current control according to the failure position.

[0088] Also, according to the present disclosure, it is possible to check the form of torque ripple due to abnormality in the winding of the motor by tracking the change in phase current or counter electromotive voltage, and to perform control to attenuate the torque ripple.

[0089] FIG. 15 is a graph showing a breaking torque according to an angle when a winding and a ground line of the motor are short-circuited, and FIG. 16 is a graph showing a phase current and a shaft current when a winding and a ground line are short-circuited as in FIG. 15.

[0090] As shown in these figures, the short circuit of the winding unit generates a breaking torque ripple in a different pattern from that of the switch short of the inverter, and the form of the phase current and the shaft current also shows a clear difference.

[0091] Accordingly, the motor control unit 60 may distinguish an inverter-side abnormality and a motor winding-side abnormality according to the detected current, and may perform current control according to the detected type of abnormality.

[0092] FIG. 17 is a graph of breaking torque according to an angle when a short circuit occurs between windings of the motor, and FIG. 18 a graph showing a phase current and a shaft current when a short circuit occurs between windings of the motor as in FIG. 17.

[0093] Referring to FIG. 17, when a short circuit occurs between windings, it can be seen that torque ripple is generated in a different pattern from the case where a short circuit occurs between the windings and the ground described above with reference to FIG. 15.

[0094] The current waveform of FIG. 18 also shows a clear difference from the current waveform of FIG. 16 and is distinguishable, so the motor control unit 60 can determine the type of motor winding abnormality as well as the occurrence of the motor winding abnormality, and can control the motor according to the type, thereby cancelling out the torque ripple.

[0095] As such, the present disclosure can reduce torque ripple without adding additional hardware by checking the torque ripple pattern due to abnormality in advance and programming a current command capable of cancelling out each torque ripple in the motor control unit.

[0096] In addition, according to the present disclosure, it is possible to cancel out torque ripple caused by abnormalities on the inverter-side as well as abnormalities on the motor winding-side, thereby enhancing the torque ripple removal effect.

[0097] It will be apparent to those skilled in the art that the present disclosure is not limited to the above-described embodiments and may be variously modified and changed within a range which does not depart from the technical gist of the present disclosure.

INDUSTRIAL APPLICABILITY

[0098] The present disclosure reduces the torque ripple of a double wound motor applied to an eco-friendly vehicle such as an electric vehicle by using a natural law, and has industrial applicability.