Dynamic frequency and pulse-width modulation of dual-mode switching power controllers in photovoltaic arrays

1. A control system comprising:

an input configured to receive a duty-cycle value;

a conversion block configured to generate a modulus value and a pulse-width value (PWV) based on the received input duty-cycle value; and

a pulse-generator configured to:

generate a pulse-width modulated (PWM) signal; and

simultaneously modulate:

a frequency of the PWM signal according to the generated modulus value; and

a pulse-width of the PWM signal according to the generated PWV; and

an output configured to provide the PWM signal to a switching power converter to control the switching power converter.

2. The control system of claim 1 , wherein the conversion block is configured to:

implement a warp function that maps the modulus value to the input duty-cycle value; and

implement a second function that maps the PWV to the modulus value and to the input duty-cycle value to maintain a desired linear ratio between the PWV and a pulse-period of the PWM signal.

3. The control system of claim 1 , wherein the conversion block is programmable with a mapping algorithm to map the modulus value to the input duty-cycle value, and further to map the PWV to the modulus value and to the input duty-cycle value;

wherein the conversion block is configured to generate the modulus value and the PWV according to the mapping algorithm.

4. The control system of claim 1 , wherein the pulse generator comprises a digital timer having both modulus and pulse-width programming capability, and configured to generate the PWM signal.

5. A power converter comprising:

a signal generating circuit configured to:

receive an input duty-cycle value and generate a modulus value and a pulse-width value (PWV) based on the received input duty-cycle value; and

generate a pulse-width modulated (PWM) signal, wherein in generating the PWM signal, the signal generating circuit is configured to:

simultaneously modulate:

a frequency of the PWM signal according to the generated modulus value; and

a pulse-width of the PWM signal according to the generated PWV; and

a control system configured to:

monitor parameters of the power converter, wherein the parameters comprise one or more of:

input voltage of the power converter;

input current of the power converter;

output voltage of the power converter; or

output current of the power converter; and

generate and supply the input duty-cycle value to the signal generating circuit based on the monitored parameters of the power converter.

6. The power converter of claim 5 , wherein the signal generating circuit is programmable with a mapping algorithm to:

map the modulus value to the input duty-cycle value; and

map the PWV to the modulus value and to the input duty-cycle value to maintain a specified relationship between the PWV and an instantaneous frequency of the PWM signal.

7. The power converter of claim 5 , wherein the signal generating circuit comprises:

a divider circuit configured to receive a first clock signal and the modulus value, and generate a divider modulus control signal based on the first clock signal and the modulus value; and

a pulse generator digital timer configured to generate the PWM signal according to the divider modulus control signal and the PWV.

8. The power converter of claim 5 , further comprising a switching power core configured to receive the PWM signal, and generate the output voltage of the power converter according to the PWM signal.

9. The power converter of claim 8 , wherein the control system comprises:

first analog to digital converters (ADCs) configured to generate first numeric values representative of the input voltage of the power converter and the input current of the power converter;

second ADCs configured to generate second numeric values representative of the output voltage of the power converter and the output current of the power converter; and

a controller configured to calculate the input duty-cycle value from at least the first and second numeric values.

10. The power converter of claim 9 , wherein the controller is programmable with a control algorithm to calculate the input duty-cycle from at least the first and second numeric values and one or more additional input parameters.

11. A method for controlling a switching power converter, the method comprising:

generating a modulus value and a pulse-width value (PWV) from a duty-cycle value (DCV);

generating a pulse-width modulated (PWM) signal, said generating the PWM signal comprising:

simultaneously modulating an instantaneous frequency and a pulse-width of the PWM signal, said simultaneously modulating comprising:

setting a pulse-period corresponding to the instantaneous frequency of the PWM signal according to the modulus value; and

setting the pulse-width of the PWM signal according to the PWV; and

supplying the PWM signal to a switching power core to control a switching of the switching power converter.

12. The method of claim 11 , wherein said generating the modulus value comprises mapping the modulus value to the DCV according to a specified mapping function.

13. The method of claim 11 , wherein said generating the PWV comprises mapping the PWV to the modulus value and to the DCV.

14. The method of claim 11 , wherein said generating the modulus value and the PWV comprises maintaining a specified functional relationship between the PWV and the pulse-period.

15. The method of claim 14 , wherein the specified functional relationship is a specified linear relationship.

16. The method of claim 11 , further comprising the switching power core generating an output voltage according to the PWM signal and an input voltage value.

17. The method of claim 11 , further comprising generating the DCV according to one or more of:

an input voltage of the power converter;

an input current of the power converter;

an output voltage of the power converter; or

an output current of the power converter.

18. A method for using dynamic pulse-width and frequency modulation to control switching of a switching power converter, the method comprising:

determining a duty-cycle value (DCV) for a pulse-width modulated (PWM) signal;

translating the DCV to a first parameter and a second parameter;

simultaneously modulating a pulse-width (PW) and a pulse-period (PP) of the PWM signal, comprising:

modulating the PP according to the first parameter; and

modulating the PW according to the second parameter; and

maintaining a specified functional relationship between the PW and the PP of the PWM signal.

19. The method of claim 18 , wherein said maintaining the specified functional relationship between the PW and the PP of the PWM signal comprises maintaining a linear relationship between the PW and the PP of the PWM signal.

20. The method of claim 18 , wherein said translating comprises:

mapping the first parameter to the DCV according to a function determining a value of the first parameter based on the DCV and one or more of:

a specified DCV range;

a specified minimum value for the first parameter; or

a specified maximum value for the first parameter.

21. The method of claim 18 , wherein said translating comprises:

mapping the second parameter to the first parameter and to the DCV according to a function determining a value of the second parameter based on the DCV and the first parameter and one or more of:

a minimum value for the PWV; or

a specified DCV range.

22. The method of claim 18 , wherein said determining the DCV comprises:

monitoring parameters comprising one or more of:

an input voltage of the switching power converter;

an input current of the switching power converter;

an output voltage of the switching power converter; or

an output current of the switching power converter; and

calculating the DCV according to the monitored parameters.