Synchronous motor control system for electric vehicle

• US 5,583,411 A
• Filed: 08/04/1993
• Issued: 12/10/1996
• Est. Priority Date: 08/04/1992
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Kanai, Yasushi, Takeuchi, Akishiro, Saito, Yuji, Kusano, Katsuyuki
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US08/103,492
• Time in Patent Office: 1,224 Days
• Field of Search: 318/376, 318/378, 318/798-817, 318/432, 318/437, 318/300, 318/716-719, 318/490, 318/560, 318/254, 318/138, 318/626, 318/629, 318/632, 318/616, 318/139, 363/34, 363/39, 363/40, 363/44, 363/55, 363/56, 363/27, 180/170, 180/171, 180/242, 180/244, 180/65.1, 180/65.3, 180/65.8
• US Class Current: 318/719
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A synchronous motor control system controls a synchronous motor on an electric vehicle for propelling the electric vehicle in a propulsive mode or regenerating electric energy in a regenerative model. The synchronous motor control system has a rotational speed sensor for detecting a rotational speed of the synchronous motor, an accelerator for producing a torque command signal, and a driver connected between a battery on the electric vehicle and the synchronous motor for operating the synchronous motor in either the propulsive mode or the regenerative mode. A controller is responsive to the rotational speed detected by the rotational speed sensor and the torque command signal produced by the accelerator for controlling the driver to operate the synchronous motor in either the propulsive mode or the regenerative mode. The controller has maps for storing lead and lag values which are selectively readable to control the driver to operate the synchronous motor with a maximum efficiency based on two parameters of operation of the electric vehicle, namely, the rotational speed of the motor and the torque command from the accelerator.

Claims

1. A synchronous motor control system for an electric vehicle comprising:

a synchronous motor on the electric vehicle for propelling the electric vehicle in a propulsive mode or regenerating electric energy in a regenerative mode;

a battery on the electric vehicle;

a rotational speed sensor for detecting a rotational speed of said synchronous motor;

an accelerator for producing a torque command signal;

a driver connected between said battery and said synchronous motor for operating said synchronous motor in either said propulsive mode or said regenerative mode; and

control means responsive to the rotational speed detected by said rotational speed sensor and the torque command signal produced by said accelerator for controlling said driver to operate said synchronous motor in either said propulsive mode or said regenerative mode, said control means comprising a single control loop between the rotational speed sensor and said driver, and having map means for storing lead and lag phase values corresponding to rotational speeds of the motor and torque command signals from the accelerator which are selectively readable to control said driver to operate said synchronous motor of the electric vehicle.

2. A synchronous motor control system according to claim 1, wherein said control means comprises means for controlling said driver to operate said synchronous motor in said propulsive mode with phase currents leading in phase by one of said lead values read from said map means.

3. A synchronous motor control system according to claim 1, wherein said control means comprises means for controlling said driver to operate said synchronous motor in said regenerative mode with phase currents lagging in phase by one of said lag values read from said map means.

4. A synchronous motor control system according to claim 1, wherein said driver comprises a plurality of switching elements connected between said battery and said synchronous motor, said control means comprising means for generating and applying pulse-width-modulated signals to said switching elements and means for supplying data to control said pulse-width-modulated signals in timing based on one of said lead and lag values read from said map means.

5. A synchronous motor control system for a synchronous motor in an electric vehicle for moving the electric vehicle by electric energy supplied by a battery on the electric vehicle in response to an accelerator pedal, comprising:

means for detecting a rotational speed of the synchronous motor;

means for detecting a torque command signal from the accelerator pedal;

driver means connected between said battery and said synchronous motor for operating said synchronous motor in either a propulsive mode or a regenerative mode; and

map means for storing electrical current lead phase values and lag phase values corresponding to rotational speeds of the motor and torque command signals from the accelerator pedal;

controls means for reading a phase value from said map means in response to said detected rotational speed and detected torque command signal for controlling said driver means, said control means comprising a single control loop from the means for detecting a rotational speed to the driver means, to operate the synchronous motor in either said propulsive mode or said regenerative mode with said read phase value.

6. A synchronous motor control system according to claim 5, wherein said map means comprises a pair of maps containing said electrical current lead and lag phase values, respectively.

7. A synchronous motor control system according to claim 5, wherein said control means includes means for controlling said driver to operate said synchronous motor in said propulsive mode with phase currents leading in phase by one of said lead phase values read from said map means.

8. A synchronous motor control system according to claim 5, wherein said control means includes means for controlling said driver to operate said synchronous motor in said regenerative mode with phase currents lagging in phase by one of said lag phase values read from said map means.

9. A synchronous motor control system according to claim 5, wherein said driver comprises a plurality of switching elements connected between said battery and said synchronous motor, said control means comprising means for generating and applying pulse-width-modulated signals to said switching elements and means for supplying dam to control said pulse-width-modulated signals in timing based on one of said lead and lag phase values read from said map means.

10. In a synchronous motor control system for a synchronous motor propelling an electric vehicle having a battery for supplying electric current to the synchronous motor and an accelerator pedal for controlling speed of the electric vehicle, the improvement comprising:

means for detecting a rotational speed of the synchronous motor;

means for detecting for the position of the accelerator pedal;

map means for storing electrical current lead phase values and lag phase values corresponding to rotational speeds of the motor and torque command signals from the accelerator pedal; and

control means responsive to said detected rotational speed and the detected position of the accelerator for controlling the operation of the synchronous motor in either a propulsive mode or a regenerative mode by applying a phase leading or a phase lagging, respectively, electric current to the synchronous motor based on phase values from the map means corresponding to said detected rotational speed and accelerator pedal position with said control means comprising a single control loop between the means for detecting a rotational speed and the motor.

11. A synchronous motor control system according to claim 10, wherein map means are provided for determining values of said phase leading or phase lagging electric current based on said detected speed and detected position of the accelerator pedal.

12. A synchronous motor control system according to claim 10, wherein said responsive means includes means for operating the synchronous motor in said propulsive mode with leading phase currents.

13. A synchronous motor control system according to claim 10, wherein said responsive means includes means for operating the synchronous motor in said regenerative mode with lagging phase currents.

14. A method of controlling the operation of a synchronous motor in an electric vehicle for propelling the electric vehicle by a battery in the electric vehicle and controlled by an accelerator pedal, comprising the steps of:

detecting a rotational speed of the synchronous motor;

detecting a position of the accelerator pedal;

retrieving lead or lag phase values from a map, the values corresponding to rotational speeds of the motor and positions of the accelerator pedal; and

supplying electrical currents to the synchronous motor in a phase leading mode or a phase lagging mode based only on values selected from the map depending on said detected rotational speed of the synchronous motor and said detected position of the accelerator pedal.