Voltage control apparatus and method for power supply

• US 5,892,354 A
• Filed: 09/20/1996
• Issued: 04/06/1999
• Est. Priority Date: 09/22/1995
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Takehara, Nobuyoshi, Nagao, Yoshitaka, Fukae, Kimitoshi
• Primary Examiner(s): Hecker, Stuart N.
• Application Number:
  US08/717,330
• Time in Patent Office: 928 Days
• Field of Search: 363/95, 323/220, 323/299, 323/906
• US Class Current: 323/299
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y10S 323/906 Solar cell systems

Abstract

A voltage control apparatus which is robust against disturbances such as variations in solar radiation amount around a solar cell, and has quick response, has a voltage detection unit (4) for detecting the voltage value of a battery power supply (1), a power conversion unit (2) for performing predetermined conversion of electric power supplied from the battery power supply, and supplying the converted electric power to a load or a commercial AC system (3), an output setting unit (5) for setting the output value of the power conversion unit on the basis of the voltage detection value, and a control unit (6) for controlling the power conversion unit on the basis of the output setting value. The output setting unit is constituted by a target voltage setting unit (51) for setting the target voltage value of the battery power supply, and an output calculation unit (52) for calculating the output setting value on the basis of the deviation between the voltage detection value and the target voltage value.

Claims

1. A voltage control apparatus comprising:

voltage detection means for detecting a voltage value of a battery power supply;

power conversion means for performing predetermined conversion of electric power supplied from said battery power supply, and supplying the converted electric power to a load or a commercial AC system;

output setting means for setting an output value of said power conversion means on the basis of the voltage detection value; and

control means for controlling said power conversion means on the basis of the output setting value,

wherein said output setting means comprises target voltage setting means for setting a target voltage value of said battery power supply, output calculation means for calculating the output setting value on the basis of a deviation between the voltage detection value and the target voltage value, proportional adjustment means for adjusting the output setting value in proportion to the m-th power of the deviation, and integral adjustment means for adjusting the output setting value in proportion to an integral value of the m-th power of the deviation.

2. The apparatus according to claim 1, wherein said output setting means comprises derivative adjustment means for adjusting the output setting value in proportion to a differential value of the n-th power of the deviation.

3. The apparatus according to claim 2, wherein n=2.

4. The apparatus according to claim 1, wherein m=1 or 2.

5. The apparatus according to claim 1, wherein said battery power supply comprises a solar cell.

6. The apparatus according to claim 5, wherein said solar cell comprises an amorphous solar cell.

8. The method according to claim 4, wherein n=2.

7. A battery power supply voltage control method for controlling a voltage of a battery power supply in an apparatus which comprises said battery power supply, and power conversion means for performing predetermined conversion of electric power supplied from said battery power supply, and supplying the converted electric power to a load or a commercial AC system, and controls said power conversion means on the basis of a voltage value of said battery power supply, comprising the steps of:

sampling a voltage value of said battery power supply;

setting a target voltage value of said battery power supply;

calculating a deviation between the sampled voltage value and the set target voltage value;

calculating a proportional term proportional to the m-th power of the deviation;

calculating an integral term proportional to an integral value of the m-th power of the deviation;

calculating a derivative term proportional to a differential value of the n-th power of the deviation;

calculating an output setting value of said power conversion means on the basis of a sum of the proportional, integral, and derivative terms; and

controlling a voltage of said battery power supply by controlling said power conversion means in accordance with the output setting value.

9. The method according to claim 7, wherein said battery power supply comprises a solar cell.

10. The method according to claim 9, wherein said solar cell comprises an amorphous solar cell.

11. A battery power supply voltage control method for controlling a voltage of a battery power supply in an apparatus which comprises said battery power supply, and power conversion means for performing predetermined conversion of electric power supplied from said battery power supply, and supplying the converted electric power to a load or a commercial AC system, and controls said power conversion means on the basis of a voltage value of said battery power supply, comprising the steps of:

sampling a voltage value of said battery power supply;

setting a target voltage value of said battery power supply;

calculating a deviation between the sampled voltage value and the set target voltage value;

calculating a change amount of an output setting value of said power conversion means on the basis of m-th power values and n-th power values of k deviations;

calculating a current output setting value of said power conversion means by adding a previous output setting value of said power conversion means and the change amount of the output setting value; and

controlling a voltage of said battery power supply by controlling said power conversion means in accordance with the calculated current output setting value.

12. The method according to claim 11, wherein k=3.

13. The method according to claim 12, wherein the three deviations are calculated from three successively sampled voltage values.

14. The method according to claim 11, wherein said battery power supply comprises a solar cell.

15. The method according to claim 14, wherein said solar cell comprises an amorphous solar cell.

16. The method according to claim 7 or 11, wherein m=1 or 2.

17. A voltage control apparatus comprising:

voltage detection means for detecting a voltage value of a battery power supply;

power conversion means for performing predetermined conversion of electric power supplied from said battery power supply, and supplying the converted electric power to a load or a commercial AC system;

output setting means for setting an output value of said power conversion means on the basis of the voltage detection value; and

control means for controlling said power conversion means on the basis of the output setting value,

wherein said output setting means comprises target voltage setting means for setting a target voltage value of said battery power supply, output calculation means for calculating the output setting value on the basis of a deviation between the voltage detection value and the target voltage value, and derivative adjustment means for adjusting the output setting value in proportion to a differential value of the n-th power of the deviation.

18. The apparatus according to claim 17, wherein n=2.

19. The apparatus according to claim 17, wherein said battery power supply comprises a solar cell.

20. The apparatus according to claim 19, wherein said solar cell comprises an amorphous solar cell.

21. A battery power supply voltage control method for controlling a voltage of a battery power supply in an apparatus which comprises said battery power supply, and power conversion means for performing predetermined conversion of electric power supplied from said battery power supply, and supplying the converted electric power to a load or a commercial AC system, and controls said power conversion means on the basis of a voltage value of said battery power supply, comprising the steps of:

sampling a voltage value of said battery power supply;

setting a target voltage value of said battery power supply;

calculating a deviation between the sampled voltage value and the set target voltage value;

calculating a proportional term proportional to the m-th power of the deviation;

calculating an integral term proportional to an integral value of the m-th power of the deviation;

calculating an output setting value of said power conversion means on the basis of a sum of the proportional and integral terms; and

controlling a voltage of said battery power supply by controlling said power conversion means in accordance with the output setting value.