초록 ▼

A maximum power point tracking method, applied to a tracking device, employs a DC/DC converter connecting with a solar cell array, and including a controller actuating the DC/DC converter to perform an active resistance characteristic; a maximum power point tracking circuit adjusting the active resi

A maximum power point tracking method, applied to a tracking device, employs a DC/DC converter connecting with a solar cell array, and including a controller actuating the DC/DC converter to perform an active resistance characteristic; a maximum power point tracking circuit adjusting the active resistance of the DC/DC converter; monitoring a change of an output power of the solar cell array in determining a direction for adjusting the active resistance of the DC/DC converter; and the maximum power point tracking circuit repeatedly adjusting the active resistance of the DC/DC converter. If the change of the output power of the solar cell array is positive, the active resistance of the DC/DC converter is adjusted in the same direction; but, conversely, if the change of the output power of the solar cell array is negative, the active resistance of the DC/DC converter is adjusted in an opposite direction.

대표청구항 ▼

What is claimed is: 1. A maximum power point tracking method for a solar power system, comprising: connecting a DC/DC converter with a solar cell array, and including a controller actuating the DC/DC converter to perform an active resistance characteristic; a maximum power point tracking circuit ad

What is claimed is: 1. A maximum power point tracking method for a solar power system, comprising: connecting a DC/DC converter with a solar cell array, and including a controller actuating the DC/DC converter to perform an active resistance characteristic; a maximum power point tracking circuit adjusting the active resistance of the DC/DC converter; monitoring a change of an output power of the solar cell array in determining a direction for adjusting the active resistance of the DC/DC converter; and the maximum power point tracking circuit repeatedly adjusting the active resistance of the DC/DC converter to track a maximum power point of the output power of the solar cell array; wherein if the change of the output power of the solar cell array is positive, the active resistance of the DC/DC converter is adjusted in the same direction; but, conversely, if the change of the output power of the solar cell array is negative, the active resistance of the DC/DC converter is adjusted in an opposite direction. 2. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the maximum power point tracking circuit practicing the steps of: step A, providing an initial value and a new interval value of an active resistance control signal to the DC/DC converter so that a voltage and a current of the DC/DC converter being stabilized after a time interval; step B, calculating an initial value of the output power of the solar cell array; step C, regarding the initial value of the active resistance control signal as an old value, and regarding the initial value of the output power of the solar cell array as an old value; step D, adding the old value and the new interval value of the active resistance control signal to obtain a new value of the active resistance control signal and regarding the new interval value of the active resistance control signal as an old interval value, after the time interval, the voltage and the current of the DC/DC converter being stabilized; step E, calculating a new value of the output power of the solar cell array; step F, comparing the new value of the output power of the solar cell array with the old value; step G, if the new value of the output power of the solar cell array being greater than the old value, the new interval value of the active resistance control signal being identical with the old interval value; if the new value of the output power of the solar cell array being smaller than the old value, the new interval value of the active resistance control signal being opposite to the old interval value; step H, the new value of the active resistance control signal replacing the old value, and the new value of the output power of the solar cell array replacing the old value; step I, repeating the steps D through H. 3. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the DC/DC converter includes an input capacitor, an inductor, a power electronic switch, a diode and an output capacitor. 4. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the controller includes a current detector, a multiplier, an amplifier and a pulse width modulation circuit, the multiplier connects with the maximum power point tracking circuit. 5. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the controller outputs a driving signal for turning on or off a power electronic switch of the DC/DC converter. 6. The maximum power point tracking method for the solar power system as defined in claim 3, wherein the controller detects a current of the inductor, and generates a pulse width modulation signal with an average value proportional to a product of the current of the inductor and the active resistance control signal so that the DC/DC converter is acted as an active resistor. 7. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the output power of the solar cell array is obtained from a square value of an average current of an inductor multiplied by the active resistance control signal. 8. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the DC/DC converter connects with a DC/AC inverter. 9. The maximum power point tracking method for the solar power system as defined in claim 1, wherein the DC/DC converter connects with at least one of a battery and a DC load. 10. A maximum power point tracking device for a solar power system, comprising: a DC/DC converter connecting with a solar cell array which supplies an output power such that the solar cell array supplies the output power through the DC/DC converter which is acted as an active resistance characteristic; and a maximum power point tracking circuit connecting with an controller of the DC/DC converter, the maximum power point tracking circuit outputting an active resistance control signal to the controller of the DC/DC converter; wherein the maximum power point tracking circuit adjusting the active resistance of the DC/DC converter so as to detect a maximum power point of the output power of the solar cell array, and to continuously perturb the output power of the solar cell array around an operation point corresponding to the maximum power point. 11. The maximum power point tracking device for the solar power system as defined in claim 10, wherein the solar power system connects with a DC/AC inverter such that a DC power supplied from the solar power system is converted into an AC power for supplying to a distribution power system. 12. The maximum power point tracking device for the solar power system as defined in claim 10, wherein the solar power system connects with at least one of a battery and a DC load. 13. The maximum power point tracking device for the solar power system as defined in claim 10, wherein the DC/DC converter further includes an input capacitor, an inductor, a power electronic switch, a diode and an output capacitor. 14. The maximum power point tracking device for the solar power system as defined in claim 13, wherein the controller of the DC/DC converter includes a current detector, a multiplier, an amplifier and a pulse width modulation circuit, and wherein the multiplier connects with the maximum power point tracking circuit. 15. The maximum power point tracking device for the solar power system as defined in claim 14, wherein the controller of the DC/DC converter outputs a driving signal for turning on or off the power electronic switch of the DC/DC converter. 16. The maximum power point tracking device for the solar power system as defined in claim 14, wherein the current detector detects a current of the inductor of the DC/DC converter. 17. The maximum power point tracking device for the solar power system as defined in claim 14, wherein the current of the inductor of the DC/DC converter and the active resistance control signal of the maximum power point tracking circuit are multiplied and modulated to generate the driving signal for turning on or off the power electronic switch of the DC/DC converter so that the DC/DC converter is acted as an active resistor. 18. The maximum power point tracking device for the solar power system as defined in claim 10, wherein the output power of the solar cell array is obtained from a square value of an average current of an inductor multiplied by the active resistance control signal.