DRIVE SYSTEM AND METHOD FOR CONTROLLING A SYNCHRONOUS MOTOR HAVING SEVERAL PHASES

Abstract

A drive system and method for controlling a synchronous motor having several phases, in which a method for controlling a drive system includes a synchronous motor having several phases comprises the steps: providing appropriate operating parameters for the synchronous motor by processing an input of the drive system; in case of a determination of a fault of one of the phases, calculating a zero sequence voltage for a neutral conductor based on motor parameters estimated by a parameter estimation algorithm based on detected operating parameters; and applying the calculated zero sequence voltage to the neutral conductor.

Claims

1-8. (canceled)

9. A drive system, comprising: a synchronous motor having several phases; an input interface to input operating parameters; a first device to execute a control algorithm for controlling the synchronous motor during operation without a fault of one of the phases; a second device to execute a control algorithm for controlling the synchronous motor during operation in case of a determination of a fault of one of the phases; a switch to switch between the first device and the second device depending on the determination of a fault of one of the phases; a driver device to provide appropriate operating parameters for the synchronous motor; sensors to detect a position and a current of the synchronous motor; and a parameter estimator to execute a parameter estimation algorithm to estimate motor parameters based on the detected position and current of the synchronous motor; wherein the drive system is configured to provide a zero sequence voltage calculated based on the estimated motor parameters for a neutral connector of the synchronous motor.

10. A method for controlling a drive system, including a synchronous motor having several phases, the method comprising providing appropriate operating parameters for the synchronous motor by processing input of the drive system; calculating, for a determination of a fault of one of the phases, a zero sequence voltage for a neutral conductor based on motor parameters estimated by a parameter estimation algorithm based on detected operating parameters; and applying the calculated zero sequence voltage to the neutral conductor.

11. The method of claim 10, wherein the motor parameters include an inductance and a phase resistance.

12. The method of claim 10, wherein the parameter estimation algorithm is based on a Model-Reference-Adaptive-Control (MRCA) model.

13. The method of anyone of claim 10, wherein there is a control algorithm for an operation without a fault of one of the phases, wherein there is a control algorithm including the parameter estimation algorithm for an operation for the determination of a fault of one of the phases, and wherein for the determination of a fault of one of the phases, the synchronous motor is controlled by the control algorithm for an operation in case of the determination of a fault of one of the phases.

14. The method of claim 10, wherein the zero sequence voltage is calculated based on a feedforward method.

15. The method of claim 10, wherein the operating parameters include at least one of a voltage, a current, and a frequency.

16. A non-transitory computer readable medium having a computer program, which is executable by a processor, comprising: a program code arrangement having program code for controlling a drive system, including a synchronous motor having several phases, by performing the following: providing appropriate operating parameters for the synchronous motor by processing input of the drive system; calculating, for a determination of a fault of one of the phases, a zero sequence voltage for a neutral conductor based on motor parameters estimated by a parameter estimation algorithm based on detected operating parameters; and applying the calculated zero sequence voltage to the neutral conductor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 shows a block diagram of a drive system for providing a method according to the invention.

[0023] FIG. 2 shows a flow chart of the method according to the invention.

DETAILED DESCRIPTION

[0024] FIG. 1 shows a block diagram of a drive system 1 for providing a method according to the invention.

[0025] The drive system 1 comprises a synchronous motor 3 having several phases and an input interface 2 for inputting operating parameters for the synchronous motor 3. In this embodiment, the synchronous motor has three phases. Alternative, another quantity of phases larger than 1 is provided. The operating parameters comprise a voltage U.sub.d,q, a current i.sub.d,q, and an electric speed ω.sub.e. Alternatively, not all of these operating parameters are input.

[0026] Further, the drive system 1 further comprises a first device 4 configured to execute a control algorithm for controlling the synchronous motor 3 during operation without a fault of one of the phases and a second device 5 configured to execute a control algorithm for controlling the synchronous motor 3 during operation in case of the determination of a fault of one of the phases. Alternatively, one control algorithm covering both operation conditions or one device comprising both control algorithms is provided.

[0027] Moreover, the drive system 1 comprises a switch 6 for switching between the first device 4 and the second device 5 depending on the determination of a fault of one of the phases.

[0028] The drive system 1 further comprises a driver 7 providing appropriate operating parameters for the synchronous motor 3.

[0029] Sensors 8, in this embodiment a position sensor and a current sensor, are provided in the drive system 1 for detecting a position and a current of the synchronous motor 3.

[0030] Finally, the drive system 1 comprises a parameter estimator 9. The parameter estimator 9 executes a parameter estimation algorithm in order to estimate an inductance L and phase resistance R. Alternatively, other operating parameters, such as a permanent magnet flux linkage Ψ.sub.PM is estimated. The parameter estimator 9 executes the parameter estimation algorithm based on a Model-Reference-Adaptive-Control (MRAC)—model. Alternatively, another parameter estimation algorithm, e.g. based on an “Extended-Kalman-Filter”, is executed.

[0031] In use, in the drive system 1, the appropriate operating parameters, i.e. the voltage u.sub.d,q, the current i.sub.d,q, and the electric speed ω.sub.e, are provided for the synchronous motor 3 in step S1.

[0032] In case of a determination of a fault of one of the phases, in step 2, a zero sequence voltage for a neutral conductor is calculated based on motor parameters, i.e., the inductance L and the phase resistance R, estimated by the parameter estimation algorithm based on the detected operating parameters u.sub.d,q, i.sub.d,q, ω.sub.e. The parameter estimation algorithm is based on the Model-Reference-Adaptive-Control MRCA model. Alternatively, another parameter estimation algorithm, e.g., an Extended-Kalman-Filter is used.

[0033] In case of no determination of a fault of one of the phases, the control algorithm for an operation without a fault of one of the phases is used.

[0034] In step S3, the zero sequence voltage calculated based on a feedforward method is applied to the neutral conductor. Alternatively, other motor parameters, e.g. the permanent magnet flux linkage Ψ.sub.PM or not all of the operating parameters or other operating parameters are used or the zero sequence voltage is calculated based on another method, e.g., by a proportional-integral controller.

[0035] An input from the input interface 2 is forwarded to the control algorithm for an operation without a fault of one of the phases and to the control algorithm for an operation in case of the determination of a fault of one of the phases. Depending on a detection if a fault of one of the phases is present, the input is processed by anyone of the first device 4 and the second device 5. Depending on this detection, further, via the switch 6, the output of the first device 4 or of the second device 5 are forwarded to the driver 7 which provides appropriate operating parameters to the synchronous motor 3. The sensors 8 provide the operating parameters of the position and the current for the driver 7 and for the first and second devices 4 and 5. The parameter estimator 9 provides the estimated operating parameters L and R for the driver 7 and the devices 4 and 5.

[0036] The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. Such modifications may involve other features, which are already known in the art and may be used instead of or in addition to features already described herein. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

THE LIST OF REFERENCE SIGNS IS AS FOLLOWS

[0037] 1 drive system [0038] 2 input interface [0039] 3 synchronous motor [0040] 4 first device [0041] 5 second device [0042] 6 switch [0043] 7 driver [0044] 8 sensors (position sensor and current sensor) [0045] 9 parameter estimator [0046] MRCA model reference adaptive control