Charging or discharging apparatus for electrically charging or discharging a capacitor storage type power source adapted to store electric energy in electric double layer capacitors

• US 7,622,898 B2
• Filed: 02/16/2007
• Issued: 11/24/2009
• Est. Priority Date: 02/17/2006
• Status: Expired due to Fees

• Current Assignee: Power Systems Incorporated
• Original Assignee: Power Systems Incorporated
• Inventors: Tsuji, Hiroshi, Yamamoto, Shinichi, Shimizu, Masaaki, Shimizu, Masahiko, Yamagishi, Masaaki, Mitsui, Katsuji, Shinotsuka, Masahiko, Shimizu, Atsushi
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US11/707,097
• Publication Number:
  US 20070194759A1
• Time in Patent Office: 1,012 Days
• Field of Search: 320/107, 320/137, 320/139, 320/141, 320/166
• US Class Current: 320/166
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A charging apparatus for electrically charging a capacitor storage type power source comprises a switching circuit for turning on/off the charge current, a current detection circuit for detecting the charge current, a voltage detection circuit for detecting the voltage of power source, a constant current control circuit for outputting an error amplifying signal according to the current value, a power control circuit for outputting an error amplifying signal according to the current value, the voltage value-and a power reference value, a constant voltage control circuit for outputting an error amplifying signal according to the voltage value and a voltage reference value, an OR circuit for selecting one of the error amplifying signals and a control circuit for generating a pulse width modulation signal according to the error amplifying signal output from the OR circuit to turn on/off the switching circuit and control the charge current.

Claims

1. A charging apparatus for electrically charging a capacitor storage type power source adapted to store electric energy in electric double layer capacitors, said apparatus comprising:

a switching circuit for turning on/off a charge current supplied from a charge power source to the capacitor storage type power source;

a current detection circuit for detecting the charge current;

a voltage detection circuit for detecting the voltage of the capacitor storage type power source;

a constant current control circuit for outputting an error amplifying signal for controlling the charge current according to a current value detected by the current detection circuit and a current reference value;

a power control circuit for outputting an error amplifying signal for controlling the charge current according to the current value detected by the current detection circuit, a voltage value detected by the voltage detection circuit and a power reference value;

a constant voltage control circuit for outputting an error amplifying signal for controlling the charge current according to the voltage detected by the voltage detection circuit and a voltage reference value;

a logical OR circuit for selecting one of the error amplifying signals output from the constant current control circuit, the power control circuit and the constant voltage control circuit and outputting the selected error amplifying signal; and

a control circuit for generating a pulse width modulation signal according to the error amplifying signal output from the logical OR circuit to turn on/off the switching circuit and control the charge current;

the capacitor storage type power source having a plurality of electric double layer capacitors connected in series and parallel monitors for bypassing the respective charge currents of the capacitors;

the constant current control circuit selecting a smaller reference value from a plurality of reference values provided as the current reference value according to the bypassing operations of the parallel monitors.

4. The apparatus according to any of claims 1 through 3, wherein

the logical OR circuit is a diode logical OR circuit.

5. The apparatus according to claim 1 or 2, wherein

the power control circuit compares the value obtained by multiplying the current value by the voltage value and the power reference value and outputs an error amplifying signal.

6. The apparatus according to any of claims 1 through 3, wherein

the constant voltage control circuit can select the voltage reference value from a plurality of different voltage reference values.

2. A charging apparatus for electrically charging a capacitor storage type power source adapted to store electric energy in electric double layer capacitors, said apparatus comprising:

a switching circuit for turning on/off a charge current supplied from a charge power source to the capacitor storage type power source;

a current detection circuit for detecting the charge current;

a voltage detection circuit for detecting the voltage of the capacitor storage type power source;

a constant current control circuit for outputting an error amplifying signal for controlling the charge current according to a current value detected by the current detection circuit and a current reference value;

a power control circuit for outputting an error amplifying signal for controlling the charge current according to the current value detected by the current detection circuit, a voltage value detected by the voltage detection circuit and a power reference value;

a constant voltage control circuit for outputting an error amplifying signal for controlling the charge current according to the voltage value detected by the voltage detection circuit and a voltage reference value;

a logical OR circuit for selecting one of the error amplifying signals output from the constant current control circuit, the power control circuit and the constant voltage control circuit and outputting the selected error amplifying signal; and

a control circuit for generating a pulse width modulation signal according to the error amplifying signal output from the logical OR circuit to turn on/off the switching circuit and control the charge current,

the constant current control circuit having a circuit for switching, using another charging apparatus for a capacitor storage type power source as a master apparatus, the current reference value to a current value detected by the current detection circuit of the master apparatus.

3. A charging apparatus for electrically charging a capacitor storage type power source adapted to store electric energy in electric double layer capacitors, said apparatus comprising:

a switching circuit for turning on/off a charge current supplied from a charge power source to the capacitor storage type power source;

a current detection circuit for detecting the charge current;

a voltage detection circuit for detecting the voltage of the capacitor storage type power source;

a constant current control circuit for outputting an error amplifying signal for controlling the charge current according to a current value detected by the current detection circuit and a current reference value;

a power control circuit for subtracting a voltage value detected by the voltage detection circuit from a reference value, computationally comparing the difference of the subtraction and the current value detected by the current detection circuit and outputting an error amplifying signal for controlling the charge current;

a constant voltage control circuit for outputting an error amplifying signal for controlling the charge current according to the voltage value detected by the voltage detection circuit and a voltage reference value;

a logical OR circuit for selecting one of the error amplifying signals output from the constant current control circuit, the power control circuit and the constant voltage control circuit and outputting the selected error amplifying signal; and

a control circuit for generating a pulse width modulation signal according to the error amplifying signal output from the logical OR circuit to turn on/off the switching circuit and control the charge current.

7. A charging apparatus for a capacitor storage type power source adapted to store electric energy in electric double layer capacitors, the apparatus charging the power source, controlling a charge current by modulating the pulse width by a pulse width modulation means from a charge power source, said apparatus comprising:

constant current signal generation means for comparing a first reference value and the charge current and generating an error amplifying signal;

current diminishing signal generation means for inputting a detection signal of the charge voltage of the capacitor storage type power source to the inverted input terminal of an operational amplifier by way of a resistor and an offset value to the non-inverted input terminal and comparing a second reference value taken out from a subtraction circuit formed by connecting a resistor between the inverted input terminal and the output terminal and the charge current to generate an error amplifying signal; and

a logical OR circuit for inputting the error amplifying signal of the constant current signal generation means and the error amplifying signal of the current diminishing signal generation means, executing a logical OR process on the input error amplifying signals and outputting the outcome of the logical OR process to the pulse width modulation means;

the constant current charge according to the error amplifying signal of the constant current signal generation means being switched to the current diminishing charge according to the error amplifying signal of the current diminishing signal generation means in response to an increase of the charge voltage to the capacitor storage type power source.

8. The apparatus according to claim 7, further comprising:

constant voltage signal generation means for comparing the voltage reference value and the charge voltage of the capacitor storage type power source to generate an error amplifying signal;

the error amplifying signal of the constant voltage signal generation means being input to the logical OR circuit.

9. The apparatus according to claim 7, wherein

the electric double layer capacitors have respective parallel monitors for bypassing the charge current at a predetermined voltage;

the current diminishing signal generation means have a switching circuit for switching the error amplifying signal input to the logical OR circuit from effective to ineffective or vice versa;

the electric double layer capacitors are electrically charged by making the error amplifying signal of the current diminishing signal generation means ineffective; and

the switching circuit are controlled according to the bypass operation signal of any of the parallel monitors to switch the error amplifying signal of the current diminishing signal generation means to effective.

10. A charging apparatus for a capacitor storage type power source adapted to store electric energy in a plurality of electric double layer capacitors provided with respective parallel monitors for bypassing a charge current at a predetermined voltage, the apparatus charging the power source, controlling the charge current by modulating the pulse width by a pulse width modulation means from a charge power source, said apparatus comprising:

constant current signal generation means for comparing a first reference value and the charge current and generating an error amplifying signal;

current diminishing signal generation means for comparing a second reference value obtained by inverting the charge voltage of the capacitor storage type power source and turning it into a positive value by means of an offset value and the charge current to generate an error amplifying signal;

a switching circuit for switching effectiveness/ineffectiveness of the error amplifying signal of the current diminishing signal generation means;

a logical OR circuit for inputting the error amplifying signal of the constant current signal generation means and the error amplifying signal of the current diminishing signal generation means made effective by the switching circuit, executing a logical OR process on the input error amplifying signals and outputting the outcome of the logical OR process to the pulse width modulation means;

a charge process being executed by turning the error amplifying signal of the current diminishing signal generation means ineffective; and

the switching circuit being controlled according to the bypass operation signals of the parallel monitors to turn the error amplifying signal of the current diminishing signal generation means effective.

11. A charging apparatus for a capacitor storage type power source adapted to store electric energy in a plurality of electric double layer capacitors connected in series and provided with respective parallel monitors for bypassing a charge current at a predetermined voltage, the apparatus charging the power source, controlling the charge current by modulating the pulse width by a pulse width modulation means from a charge power source, said apparatus comprising:

first charge current control means for lowering the charge current in inverse proportion to the increase of the charge voltage of the capacitor storage type power source;

second charge current control means for flowing the charge current of the withstand current value of the parallel monitors;

the apparatus operating the second charge current control means to control the charge current for a predetermined time period upon detecting one of the parallel monitors bypassing the charge current and subsequently the first charge current control means to control the charge current for another predetermined time period.

12. The apparatus according to claim 11, wherein

the control operation of the second charge current control means for the predetermined time period and the control operation of the first charge current control means for the other predetermined time period are repeated alternately.

13. A charging apparatus for an capacitor storage type power source, the capacitor storage type power source having a main switching circuit to be turned on/off according to an on/off signal and a synchronous rectifier circuit to be turned on/off at phases inverse relative to the main switching circuit to store electric energy in electric double layer capacitors by accumulating energy in a choke coil at the on time of the main switching circuit and discharging the energy accumulated in the choke coil by turning on the synchronous rectifier circuit at the off time of the main switching circuit, said apparatus comprising:

a current detection circuit for detecting a charge current;

a voltage detection circuit for detecting a charge voltage of the capacitor storage type power source;

a constant current control circuit for performing an operation of comparing a current detection value detected by the current detection circuit and a current reference value to output an error amplifying signal;

a power control circuit for performing an operation of comparing the current detection value detected by the current detection circuit and a power reference value to output an error amplifying signal;

a constant voltage control circuit for performing an operation of comparing a voltage detection value detected by the voltage detection circuit and a voltage reference value to output an error amplifying signal;

a logical OR circuit for selecting one of the error amplifying signals output from the constant current control circuit, the power control circuit and the constant voltage control circuit and outputting the selected error amplifying signal;

a control circuit for generating a pulse-width-modulated on/off control signal according to the error amplifying signal output from the logical OR circuit to turn on/off the switching circuit and the synchronous rectifier circuit and control the charge current;

a pulse width detection circuit for detecting pulse width of the on part of the on/off control signal as fallen below a predetermined value;

a signal holding circuit for holding the synchronous rectifier circuit to an off state by means of the detection signal of the pulse width detection circuit regardless of the on/off control signal; and

a diode being connected to the polarity for discharging the energy accumulated in the choke coil in parallel with the synchronous rectifier circuit so as to stop the synchronous rectification under the condition of the pulse width fallen below the predetermined value.

14. The apparatus according to claim 13, wherein

the power control circuit is adapted to subtract the voltage value detected by the voltage detection circuit from the reference value and set the power reference value according to the difference obtained by the subtraction.

15. The apparatus according to claim 13, wherein

the pulse width detection circuit includes a rectifying and smoothing circuit for rectifying and smoothing the on/off control signal and a transistor circuit that is controlled so as to be turned off when the output of the rectifying and smoothing circuit gets to a predetermined value and that holds the signal for turning on/off the synchronous rectifier circuit to an off state.

16. The apparatus according to claim 13, wherein

the signal of the synchronous rectifier circuit is obtained by inverting the on/off control signal by means of an inversion circuit.

17. The apparatus according to claim 13, wherein

the main switching circuit and the synchronous rectifier circuit are supplied with an on/off signal by way of a delay circuit that delays the signal at the rising edge of a pulse.

18. The apparatus according to claim 17, wherein

the delay circuit is formed by inserting a parallel circuit of a diode showing the polarity opposite to the signal and a resistor in series and connecting a capacitor to the output side of the parallel circuit.

19. A charging apparatus for a capacitor storage type power source adapted to store electric energy in electric double layer capacitors, the apparatus charging the power source, controlling a charge current by modulating the pulse width by a pulse width modulation means from a charge power source, said apparatus at least comprising:

constant current signal generation means for comparing the charge current of the capacitor storage type power source with a current reference value and generating an error amplifying signal for holding the charge current to a constant level by limiting the charge current at the time of exceeding the current reference value;

input constant voltage signal generation means for comparing the input voltage from the charge power source with an input voltage reference value and generating an error amplifying signal for holding the input voltage to a constant level by lowering the charge current at the time of falling of the input voltage below the input voltage reference value and by raising the charge current at the time of rising of the input voltage above the input voltage reference value; and

current diminishing signal generation means for setting a current diminishing reference value according to the value obtained by subtracting the voltage of the capacitor storage type power source from an offset value, comparing the current diminishing reference value with the charge current of the capacitor storage type power source and generating an error amplifying signal for bringing the charge current to the current diminishing reference value by limiting the charge current at the time of rising of the charge current above the current diminishing reference value;

the error amplifying signals being supplied to the pulse width modulation means by way of a logical OR circuit.

20. The apparatus according to claim 19, wherein

the input constant voltage signal generation means connects with the logical OR circuit by way of a switching circuit for controlling the sending out of the error amplifying signals.

21. The apparatus according to claim 19, wherein

when solar cells are used as a charge power source, the input voltage reference value is the solar cell voltage close to the maximum power point of the solar cells.

22. The apparatus according to claim 19, wherein

the input voltage reference value changes according to the sunshine conditions.

23. The apparatus according to claim 19, wherein

the logical OR circuit compares the charge voltage of the capacitor storage type power source defined by the constant voltage signal generation means with a charge voltage reference value along with the error amplifying signals and executes a logical OR process on the error amplifying signals for limiting the charge voltage to supply the outcome of the logical OR process to the pulse width modulation means, when the charge voltage exceeds the charge voltage reference value.

24. A charging apparatus for a capacitor storage type power source, the apparatus having solar cells, a power conversion circuit and capacitors so as to convert the output power of the solar cells by means of the power conversion circuit and store the converted power in the capacitors, said apparatus comprising:

a sweep section for sweeping the input voltage of the power conversion circuit within a predetermined range; and

a current detection section for detecting the charge current to the capacitors;

the current detection section being adapted to detect the change in the charge current to the capacitors produced by the sweep of the input voltage by the sweep means;

the input voltage maximizing the charge current being defined as the maximum power point of the solar cells.

25. A charging apparatus for a capacitor storage type power source, the apparatus having solar cells, a power conversion circuit and capacitors so as to convert the output power of the solar cells by means of the power conversion circuit and store the converted power in the capacitors, said apparatus comprising:

a sweep section for sweeping the input voltage of the power conversion circuit within a predetermined range; and

a voltage detection section for detecting the charge voltage to the capacitors;

the voltage detection section being adapted to detect the change with time of the charge voltage to the capacitors produced by the sweep of the input voltage by the sweep means;

the input voltage maximizing the change with time of the charge voltage being defined as the maximum power point of the solar cells.

26. A charging apparatus for a capacitor storage type power source adapted to induce an electric current in the secondary side winding by turning on/off the DC current applied to the primary side winding of a transformer by means of a switching element, rectify and smooth the induced current and supply the current to capacitors to charge the capacitors, said apparatus comprising:

a power factor improvement circuit for generating the DC current;

a pulse width modulation control section for controlling the on/off operation of the switching element; and

a current transformer having a primary side connected to the primary side winding of the transformer in series and a secondary side connected to a current transformer circuit detection circuit section;

the current transformer circuit detection circuit section being adapted to take out a voltage proportional to the average current flowing through the primary side winding of the transformer and a voltage proportional to the peak current flowing through the primary side winding of the transformer.

27. A charge or discharging apparatus for a capacitor storage type power source, the apparatus having a main switching circuit for performing on/off operations according to on/off control signals and a choke coil and adapted to electrically charge or discharge the electric double layer capacitors of the power source, said apparatus comprising:

a signal intercept circuit inserted and connected in series to a signal line connected to the circuit for electrically charging or discharging the capacitor storage type power source for the purpose of detecting the current and the voltage at the time of charge or discharge, whichever appropriate;

the signal intercept circuit being adapted to intercept the signal of the signal line on a condition of the voltage being nil at a side opposite to the side of connecting the main switching circuit and the choke coil to the capacitor storage type power source.

28. A charging apparatus for a capacitor storage type power source, the apparatus having a main switching circuit for performing on/off operations according to on/off control signals and a choke coil and adapted to electrically charge the electric double layer capacitors of the power source, said apparatus comprising:

a current detection circuit for detecting a charge current;

a voltage detection circuit for detecting the voltage of the capacitor storage type power source;

a constant current control circuit for outputting an error amplifying signal for controlling the charge current according to a current value detected by the current detection circuit and a current reference value;

a power control circuit for outputting an error amplifying signal for controlling the charge current according to the current value detected by the current detection circuit, a voltage value detected by the voltage detection circuit and a power reference value;

a constant voltage control circuit for outputting an error amplifying signal for controlling the charge current according to the voltage value detected by the voltage detection circuit and a voltage reference value;

a logical OR circuit for selecting one of the error amplifying signals output from the constant current control circuit, the power control circuit and the constant voltage control circuit and outputting the selected error amplifying signal; and

a control circuit for generating a pulse width modulation signal according to the error amplifying signal output from the logical OR circuit to turn on/off the main switching circuit and control the charge current;

a signal intercept circuit being inserted and connected in series to the signal line for detecting the charge current of the current detection circuit and the signal line for detecting the voltage of the voltage detection circuit, the signal intercept circuit being adapted to intercept the signals of the signal lines on a condition of the voltage being nil at the side opposite to the side of connecting the main switching circuit and the choke coil to the capacitor storage type power source.

29. A discharging apparatus for a capacitor storage type power source, the apparatus having a main switching circuit for performing on/off operations according to on/off control signals and a choke coil and adapted to electrically discharge the electric double layer capacitors of the power source, said apparatus comprising:

a current detection circuit for detecting a discharge current;

a voltage detection circuit for detecting the voltage of the capacitor storage type power source;

a control circuit for inputting a detected discharge current and a detected voltage and controlling the discharge current by turning the main switching circuit on/off; and

a signal intercept circuit being connected in series to the signal line for detecting the discharge current of the current detection circuit and the voltage of the voltage detection circuit;

the signal line being disconnected by the signal intercept circuit provided that the voltage at the side opposite to the side connecting the main switching circuit and the choke coil to the capacitor storage type power source is nil.

30. A discharging apparatus for a capacitor storage type power source, the apparatus being separated from a charging apparatus for a capacitor storage type power source and adapted to discharge electric energy from the capacitor storage type power source storing electric energy in electric double layer capacitors to a load, said apparatus comprising:

a control circuit for controlling the discharge of electric energy to the load;

a main power supply circuit for supplying circuit drive power to the control circuit;

an auxiliary power supply circuit for boosting the voltage of the capacitor storage type power source to an operating voltage of the main power supply circuit and supplying circuit drive power to the main power supply circuit; and

a voltage boosting operation control circuit adapted to turn off the auxiliary power supply circuit when the voltage of the capacitor storage type power source is not lower than a predefined value to output the voltage of the capacitor storage type power source to the main power supply circuit but turn on the auxiliary power supply circuit when the voltage of the capacitor storage type power source is lower than the predefined value to output the voltage of the capacitor storage type power source after it is boosted by the auxiliary power supply circuit.

31. A discharging apparatus of a capacitor storage type power source for discharging electric energy from the capacitor storage type power source storing electric power in electric double layer capacitors to a load, said apparatus comprising:

a control circuit having a control power supply circuit and adapted to control the electric discharge;

an intercept circuit for turning on/off the power feed circuit for feeding electric power from the capacitor storage type power source to the control power supply circuit;

a bias voltage supply circuit for supplying a bias voltage to the intercept circuit;

a judge circuit for determining e a discharge condition or a suspended discharge condition and controlling the bias voltage supply circuit so as to turn off the supply of the bias voltage in the suspended discharge condition; and

a high impedance circuit for connecting the power feed circuit through a high impedance element to the judge circuit for determining the discharge condition or the suspended discharge condition and controlling the bias voltage supply circuit;

the electric current flowing in the suspended discharge condition being limited by the high impedance element.

32. The apparatus according to claim 31, wherein

the bias voltage supply circuit constitutes a circuit for supplying a constant current bias voltage.

33. The apparatus according to claim 31, wherein

the judge circuit determines a condition of the switch for suspending the electric discharge.

34. The apparatus according to claim 31, wherein

the judge circuit determines the presence or absence of a signal for controlling the electric discharge of the control circuit.

35. The apparatus according to claim 31, wherein

the judge circuit determines the presence or absence of a voltage at the load side.

36. The apparatus according to claim 31, wherein

the control power supply circuit includes a voltage boosting circuit for boosting the voltage of the electric power fed from the capacitor storage type power source and a voltage stabilizing circuit connected to the voltage boosting circuit to stabilize the output voltage.

37. The apparatus according to claim 36, wherein

the voltage boosting circuit includes a switching converter formed by connecting a choke coil and a switching circuit in series and adapted to take out a boosted voltage from the connection point of the series connection according to on/off of the switching circuit and the switching circuit is adapted to be switched from a voltage boosting mode for turning on/off the switching circuit to a voltage non-boosting mode for holding the switching circuit in an off condition and vice versa.

38. The apparatus according to claim 37, wherein

the switching converter switches to the voltage-boosting mode after determining that the voltage of the power fed from the capacitor storage type power source to be not higher than ½

of the full charge voltage thereof.

39. The apparatus according to claim 31, wherein

the control circuit is a circuit for controlling operations of turning on/off the discharge current according to pulse width modulation signals.