Method for controlling voltage of DC link for electric vehicle

• US 7,528,566 B2
• Filed: 12/13/2005
• Issued: 05/05/2009
• Est. Priority Date: 11/17/2005
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), Pohang University of Science and Technology (Posco Holdings Incorporated)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group), Pohang University of Science and Technology Foundation
• Inventors: Nam, Kwang Hee, Song, Hong Seok, Kim, Sung Young, Oh, Doo Yong
• Primary Examiner(s): Ro; Bentsu
• Application Number:
  US11/300,161
• Publication Number:
  US 20070296357A1
• Time in Patent Office: 1,239 Days
• Field of Search: 318/461, 318/478, 318/153, 318/689, 318/799, 318/800, 318/801, 318/139, 318/621, 318/632, 318/700
• US Class Current: 318/632
• CPC Class Codes: H02P 23/07 Polyphase or monophase asynchronous induction motors

Abstract

Disclosed is a method for controlling a voltage of a DC link for an electric vehicle, which can reduce a capacitance of the DC link interposed between an inverter and a DC/DC converter.

The method for controlling the voltage of the DC link in a power system of a vehicle including a battery, a DC/DC converter, the DC link, an inverter, a motor, and a control part controlling the DC/DC converter and the inverter includes the steps of installing a compensator in a control loop of the control part such that a DC link current of the DC/DC converter follows a DC link current of the inverter, calculating a predetermined compensation term based on information of the motor inputted into the compensator, and applying the compensation term to a voltage node in the control loop of the control part in the compensator.

Claims

1. A method for controlling a voltage of a DC link in a power system of a vehicle including a battery, a DC/DC converter, the DC link, an inverter, a motor, and a control part controlling the DC/DC converter and the inverter, the method comprising:

installing a compensator in a control loop of the control part such that a DC link current of the DC/DC converter follows a DC link current of the inverter;

calculating a compensation term based on information of the motor inputted into the compensator; and

applying the compensation term to a voltage node in the control loop of the control part.

2. The method as claimed in claim 1, wherein the information about the motor includes a current, a voltage, and a speed of the motor.

3. The method as claimed in claim 1, wherein the compensation term is determined through an equation,

4. The method as claimed in claim 3, wherein the average i_inv of the inverter current is obtained through a voltage equation, a phase current equation, and a phase voltage equation of the motor.

5. The method as claimed in claim 3, wherein, when the motor is a permanent magnetic synchronization motor, the equation,

6. The method as claimed in claim 3, wherein the compensation term

7. A power system for a vehicle, comprising:

a battery;

a DC/DC converter coupled to the battery;

a motor;

an inverter coupled to the motor;

a DC link interposed between the DC/DC converter and the inverter; and

a control part for controlling a voltage of the DC link, the control part including a control loop that includes a compensator to generate a compensation term such that a DC link current of the DC/DC converter follows a DC link current of the inverter,

wherein the compensator receives motor information as an input and determines the compensation term based on the motor information, and

wherein the motor information includes a current, a voltage, and a speed of the motor.

8. The system of claim 7, wherein the compensation term is supplied to a voltage node in the control loop of the control part instead of being supplied to a current node in the control loop.

9. A power system for a vehicle, comprising:

a battery;

a DC/DC converter coupled to the battery;

a motor;

an inverter coupled to the motor;

a DC link interposed between the DC/DC converter and the inverter; and

a control part for controlling a voltage of the DC link, the control part including a control loop that includes a compensator to generate a compensation term such that a DC link current of the DC/DC converter follows a DC link current of the inverter,

wherein the compensation term is determined through an equation,

10. The system of claim 9, wherein the inverter current is obtained through a voltage equation, a phase current equation, and a phase voltage equation of the motor.

11. The system of claim 9, wherein, when the motor is a permanent magnetic synchronization motor, the equation,

12. The system of claim 9, wherein the compensation term is supplied to a voltage node in the control loop of the control part instead of being supplied to a current node in the control loop.