KR-20260067812-A - MOTOR DRIVING SYSTEM AND FAULT DIAGNOSING METHOD THEREFOR

Abstract

A motor driving system and a method for diagnosing a fault thereof are introduced, comprising: a driving unit including a motor, a first inverter and a second inverter respectively connected to both ends of the plurality of windings; and a control unit that controls the outputs of the first inverter and the second inverter based on a zero-sequence current command and diagnoses a fault in the driving unit based on the phase current flowing through each of the plurality of windings as a result of the control.

Inventors

• 고영수
• 안준모
• 백현우

Assignees

• 현대자동차주식회사
• 기아 주식회사

Dates

Publication Date

20260513

Application Date

20241106

Claims (20)

1. A driving unit comprising a motor having a plurality of windings corresponding to a plurality of phases, a first inverter connected to one end of the plurality of windings, and a second inverter connected to the other end of the plurality of windings; and A motor driving system comprising a control unit that controls the outputs of the first inverter and the second inverter based on a zero-sequence current command to cause phase currents having the same magnitude and phase to flow in each of the plurality of windings, and diagnoses a fault in the driving unit based on the phase currents flowing in each of the plurality of windings as a result of the control.
2. In claim 1, The above control unit is, A motor driving system characterized by maintaining the values of the d-axis current command and the q-axis current command at '0' while controlling the outputs of the first inverter and the second inverter based on the above-mentioned image component current command.
3. In claim 1, The above image component current command is, A motor drive system characterized by having a sinusoidal wave.
4. In claim 1, The above control unit is, A motor driving system characterized by controlling the outputs of the first inverter and the second inverter based on the zero-sequence current command when the rotational speed of the motor exceeds '0'.
5. In claim 1, The above control unit is, A motor driving system characterized by controlling the outputs of the first inverter and the second inverter based on the zero-sequence current command when the driving of the motor is initiated.
6. In claim 1, The above control unit is, A motor drive system characterized by determining that a fault has occurred in the drive unit when the error between the value of the phase current flowing in at least one of the plurality of phases and the value of the zero-sequence current command exceeds a preset allowable error.
7. In claim 6, The above control unit is, A motor drive system characterized by determining that a fault has occurred in the phase corresponding to the winding through which the phase current flows, where the above error exceeds a preset allowable error.
8. In claim 1, The above driving unit is, It further includes a plurality of switching switches, each having one end connected to the other end of each of the plurality of windings, and each having the other ends interconnected to form a node. The above control unit is, A motor drive system characterized by controlling the switching state of the plurality of switching switches to electrically connect or disconnect the motor and the second inverter.
9. In claim 8, The above control unit is, A motor driving system characterized by controlling the outputs of the first inverter and the second inverter based on the zero-sequence current command while the plurality of switching switches are turned off and the second inverter is electrically connected to the plurality of windings.
10. In claim 1, The above control unit is, A motor drive system characterized by stopping the operation of the motor when it is determined that a failure has occurred in the drive unit.
11. A method for diagnosing a fault in a drive unit comprising a motor having a plurality of windings each corresponding to a plurality of phases, a first inverter connected to one end of the plurality of windings, and a second inverter connected to the other end of the plurality of windings. A step of controlling the outputs of the first inverter and the second inverter based on a zero-sequence current command that causes a phase current having the same magnitude and phase to flow in each of the plurality of windings; and A method for diagnosing a fault in a motor drive system, comprising the step of diagnosing a fault in the drive unit based on the phase current flowing through each of the plurality of windings as a result of the above control.
12. In claim 11, The step of controlling the above output is, A method for diagnosing a fault in a motor drive system, characterized by including the step of maintaining the values of the d-axis current command and the q-axis current command at '0' while controlling the outputs of the first inverter and the second inverter based on the above-mentioned image component current command.
13. In claim 11, The above image component current command is, A method for diagnosing a fault in a motor drive system, characterized in that the phase current flowing through each of the plurality of windings has a sinusoidal shape.
14. In claim 11, The step of controlling the above output is, A method for diagnosing a fault in a motor drive system, characterized by including the step of controlling the outputs of the first inverter and the second inverter based on the zero-sequence current command while the rotational speed of the motor exceeds '0'.
15. In claim 11, The step of controlling the above output is, A method for diagnosing a fault in a motor drive system, characterized by including the step of controlling the outputs of the first inverter and the second inverter based on the zero-sequence current command before the driving of the motor is initiated.
16. In claim 11, The step of determining the above fault is, A method for diagnosing a fault in a motor drive system, characterized by including a step of determining that a fault has occurred in the drive unit when the error between the value of the phase current flowing in at least one of the plurality of phases and the value of the zero-sequence current command exceeds a preset allowable error.
17. In claim 16, The step of determining the above fault is, A method for diagnosing a fault in a motor drive system, characterized by including a step of determining that a fault has occurred in a phase corresponding to a winding through which a phase current flows in which the above error exceeds a preset allowable error.
18. In claim 11, The above driving unit is, It further includes a plurality of switching switches, each having one end connected to the other end of each of the plurality of windings, and each having the other ends interconnected to form a node. A method for diagnosing a fault in a motor drive system, characterized by further including the step of controlling the switching state of the plurality of switching switches to electrically connect or disconnect the motor and the second inverter.
19. In claim 18, The step of controlling the above output is, A method for diagnosing a fault in a motor drive system, characterized by including the step of controlling the outputs of the first inverter and the second inverter based on the zero-sequence current command while the second inverter is electrically connected to the plurality of windings.
20. In claim 11, A method for diagnosing a fault in a motor drive system, further comprising the step of stopping the operation of the motor when it is determined that a fault has occurred in the drive unit.

Description

Motor Driving System and Falution Diagnosis Method Therefor The present invention relates to a motor drive system that diagnoses a fault through a zero-sequence current command and a fault diagnosis method thereof. Generally, one end of each phase winding included in the motor is connected to a single inverter, and the other ends are connected to each other to form a Y-connection. When driving the motor, the switching element in the inverter is turned on/off by pulse width modulation control, and torque is generated by applying line voltage to the windings of the Y-connected motor to generate alternating current. In addition, instead of having the other end of the motor form a Y-connection, two inverters may be connected to both ends of the motor, and the motor output may be increased by driving the motor through the two inverters. Meanwhile, fault diagnosis of a motor drive system including such a motor and inverter can be performed by applying a fault diagnosis current command and checking the value of the phase current actually flowing through each winding in accordance with the application of the current command. The matters described above as background technology are intended only to enhance understanding of the background of the present invention and should not be construed as an acknowledgment that they constitute prior art already known to those skilled in the art. FIGS. 1 and FIGS. 2 are drawings showing the configuration of a motor drive system according to embodiments of the present invention. FIG. 3 is a diagram showing the configuration of a control unit according to one embodiment of the present invention. Figure 4 is a diagram showing the phase current and torque according to the fault diagnosis of a motor drive system according to one embodiment of the present invention. FIG. 5 is a flowchart illustrating a fault diagnosis method for a motor drive system according to an embodiment of the present invention. Specific structural or functional descriptions of the embodiments of the present invention disclosed in this specification or application are merely illustrative for the purpose of explaining embodiments according to the present invention, and embodiments according to the present invention may be implemented in various forms and should not be interpreted as being limited to the embodiments described in this specification or application. Since embodiments according to the present invention may be subject to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit embodiments according to the concept of the present invention to specific disclosed forms, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification. Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted. In the description of the following embodiments, the term "pre-set" means that the numerical value of a parameter is predetermined when the parameter is used in a process or algorithm. Depending on the embodiment, the numerical value of the parameter may be set when the process or algorithm starts or during the period in which the process or algorithm is executed. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification, and do not inherently possess distinct meanings or roles. In describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art may obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted. Furthermore, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the present invention. Terms including ordinal numbers, such as first, second, etc., may be