A DC power supply controller

• US 5,656,923 A
• Filed: 04/10/1995
• Issued: 08/12/1997
• Est. Priority Date: 04/10/1995
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology, The Whitaker Corporation (Meggitt PLC)
• Original Assignee: The Whitaker Corporation (Meggitt PLC)
• Inventors: Schultz, Aaron M., Varghese, George C., Leeb, Steven B., Mitwalli, Ahmed
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Berhane, Adolf
• Application Number:
  US08/419,271
• Time in Patent Office: 855 Days
• Field of Search: 363/79, 363/80, 363/81, 363/89, 363/126, 363/127, 323/207, 323/222, 320/20, 320/21, 320/32, 320/23, 320/35, 320/39, 320/40, 320/52
• US Class Current: 323/207
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A large signal, linear, digital, unity power-factor controller for controlling a power supply is disclosed. The power supply controller includes a voltage controller and a current controller. The voltage controller is a feed forward and proportional-integral type of controller. By determining the control command of the voltage controller as a function of the feed forward load power, the power term in the state equations for the voltage controller is eliminated. As such, the current controller operates in time domain in such a way that the voltage controller appears as a unit time delay to the current controller. The load is a battery incorporated within an electrically-powered vehicle. The controller operates to charge the battery. The connection between the battery and the power supply being controlled is an inductive coupling.

Claims

1. A large signal substantially unity power-factor controller for controlling a power supply, the power supply supplying a load thereto, comprising:

a large-signal feedforward digital voltage controller operating in a discrete time frame of units of n for controlling voltage output to the load which is resistive and at least one of inductive and capacitive, the voltage controller converging in Q*n cycles, where Q is an integer and Q≧

2; and

a current controller, operatively connected to the voltage controller, for controlling current output to the load operating in a discrete-time frame of units of N, where N=Q*n.

a feedforward parameter of the voltage controller being a function of scaled power to the load.

2. A power supply controller as in claim 1 wherein;

the voltage controller operates as a unit delay for the current controller.

3. A power supply controller as in claim 1 wherein:

the load includes a battery; and

the power supply controller functions to recharge the battery.

4. A power supply controller as in claim 3, wherein:

the battery is integrated within an electrically-powered car; and

the connection between the power supply and the battery is an inductive coupling.

5. A power supply controller as in claim 1, wherein:

the large-signal voltage controller is a feedforward and a proportional-integral controller.

6. A power supply controller as in claim 1, wherein:

the current controller includes;

a multiplying digital to analog converter.

7. A power supply controller as in claim 1, further comprising:

a load temperature sensor outputting a load temperature;

at least one of the large-signal voltage controller and the current controller controlling one of voltage and current, respectively, to the load also as a function of the load temperature.

8. A large signal substantially unity power-factor controller for controlling a power supply, the power supply supplying a load thereto, comprising:

a large-signal feedforward digital voltage controller for controlling voltage output to the load which is resistive and at least one of inductive and capacitive; and

a current controller, operatively connected to the voltage controller, for controlling current output to the load operating in a discrete-time frame of units of N, where N=Q*n whereby;

the load draws a large signal range from the power supply controller; and

the voltage controller includes;

a resolution mapping means, responsive to the large signal range drawn by the load, for selectively digitizing a small range of the large signal range; and

a programmed microprocessor for selectively using one of an output of the resolution mapping means and a predetermined saturation value to determine a voltage control command.

9. A large signal substantially unity power-factor controller for controlling a power supply, the power supply supplying a load thereto, comprising:

a large-signal feedforward digital voltage controller for controlling voltage output to the load which is resistive and at least one of inductive and capacitive the voltage controller including;

a first squarer for squaring voltage on the load to form V² ;

a squarer for squaring a reference voltage to form V² ;

difference means for forming a difference Δ

v between V² and v² ;

first scaling means for scaling the difference Δ

v to form a scaled difference;

integrator means for integrating the difference Δ

v to form an integrated difference; and

an adder for adding the scaled difference and the integrated difference to form the first control command; and

a current controller, operatively connected to the voltage controller, for controlling current output to the load operating in a discrete-time frame of units of N, where N=Q*n.

10. A power supply controller as in claim 9, wherein:

the voltage controller forms a control command k_-- tilde[n] according to ##EQU9##

11. A large signal voltage controller for controlling a power supply, the power supply supplying a load voltage and load current to a load being resistive and at least one of inductive and capacitive comprising:

feedback means for determining an error Δ

s between a first feedback parameter s from the load and a reference value S corresponding to the first feedback parameter s the error Δ

s being determined as a function of a square v² of the load voltage and a square V² of a reference voltage; and

final command means for determining a control command as a function of the error Δ

s and at least one feedforward parameter which includes scaled power to the load.

12. A large signal voltage controller as in claim 11, further comprising:

a load temperature sensor for sensing load temperature;

the final control means determining the control command as a function of the error Δ

s and the feedforward load power and load temperature.

13. A large signal voltage controller as in claim 11, wherein the feedback means includes:

a first squarer for squaring the load voltage to form v² ;

a squarer for squaring of the reference voltage V² ;

difference means for forming a difference Δ

v between V² and v² ;

first scaling means for scaling the difference Δ

v to form a scaled difference;

integrator means for integrating the difference Δ

v to form an integrated difference; and

an adder for adding the scaled difference and the integrated difference to form the first control command.

14. A large signal voltage controller as in claim 13, wherein:

the feedback means forms the control command k_-- tilde[n] according to ##EQU10##

15. A large-signal voltage controller as in claim 11, wherein:

the load includes a battery; and

the controller functions to recharge the battery.

16. A large-signal voltage controller as in claim 15, wherein:

the battery is integrated within an electrically-powered car; and

the connection between the power supply and the battery is an inductively coupling.