Regulation of inverter DC input voltage in photovoltaic arrays
First Claim
1. A control module for controlling a power converter configured to couple to a solar panel to provide an output voltage and an output current to a bus, the control module comprising:
- a plurality of input ports, each given input port of the plurality of input ports configured to receive a different one of a plurality of parameters comprising;
a first parameter indicative of an input current of the power converter provided by the solar panel;
a second parameter indicative of an input voltage of the power converter provided by the solar panel;
a third parameter indicative of an output voltage of the power converter; and
a fourth parameter indicative of an output current of the power converter; and
a controller configured to regulate the input voltage, input current, output voltage, and output current of the power converter according to a maximum power point tracking (MPPT) algorithm and an output power control algorithm, using the first, second, third, and fourth parameters as input values;
wherein according to the output power control algorithm, the controller is configured to;
allow changes in the output voltage of the power converter to move the input voltage of the power converter away from a maximum power point (MPP) voltage value corresponding to an MPP of the solar panel, and create localized power gradients of a characteristic of output power of the power converter versus an overall voltage on the bus;
track, over a time period of specific duration, minimum voltage output values and maximum voltage output values for the output voltage of the power converter; and
upon expiration of the time period;
identify a peak minimum voltage output value of the tracked minimum voltage output values and a peak maximum voltage output value of the tracked maximum voltage output values; and
control a timing and slope of the localized power gradients according to the peak minimum voltage output value and the peak maximum voltage output value.
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Accused Products
Abstract
A converter unit configured to couple to a photovoltaic panel (PV) may include a controller to sense an output voltage and output current produced by the photovoltaic panel, and manage the output voltage of a corresponding power converter coupled to a DC bus to regulate the resultant bus voltage to a point that reduces overall system losses, and removes non-idealities when the panels are series connected. The controller may also adapt to output condition constraints, and perform a combination of input voltage and output voltage management and regulation, including maximum power point tracking (MPPT) for the PV. The output voltage and output current characteristic of the power converter may be shaped to present a power gradient—which may be hysteretically controlled—to the DC bus to compel an inverter coupled to the DC bus to perform its own MPPT to hold the DC-bus voltage within a determinate desired operating range.
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Citations
35 Claims
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1. A control module for controlling a power converter configured to couple to a solar panel to provide an output voltage and an output current to a bus, the control module comprising:
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a plurality of input ports, each given input port of the plurality of input ports configured to receive a different one of a plurality of parameters comprising; a first parameter indicative of an input current of the power converter provided by the solar panel; a second parameter indicative of an input voltage of the power converter provided by the solar panel; a third parameter indicative of an output voltage of the power converter; and a fourth parameter indicative of an output current of the power converter; and a controller configured to regulate the input voltage, input current, output voltage, and output current of the power converter according to a maximum power point tracking (MPPT) algorithm and an output power control algorithm, using the first, second, third, and fourth parameters as input values; wherein according to the output power control algorithm, the controller is configured to; allow changes in the output voltage of the power converter to move the input voltage of the power converter away from a maximum power point (MPP) voltage value corresponding to an MPP of the solar panel, and create localized power gradients of a characteristic of output power of the power converter versus an overall voltage on the bus; track, over a time period of specific duration, minimum voltage output values and maximum voltage output values for the output voltage of the power converter; and upon expiration of the time period; identify a peak minimum voltage output value of the tracked minimum voltage output values and a peak maximum voltage output value of the tracked maximum voltage output values; and control a timing and slope of the localized power gradients according to the peak minimum voltage output value and the peak maximum voltage output value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A control system for controlling a power converter configured to couple to a solar panel to provide an output voltage and output current to a voltage bus residing at an overall bus voltage, the control system comprising:
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a sensing circuit configured to sense input current and input voltage of the power converter derived from the solar panel, and further configured to sense the output voltage and the output current of the power converter; a controller configured to; regulate the input voltage of the power converter according to the sensed input current and sensed input voltage of the power converter and according to the sensed output voltage and sensed output current of the power converter, to optimize power derived from the solar panel according to a maximum power point (MPP) of the solar panel; allow changes in the output voltage of the power converter to move the input voltage of the power converter away from an MPP voltage value corresponding to the MPP of the solar panel, and create localized power gradients of a characteristic of output power of the power converter versus the overall bus voltage, wherein each of the localized power gradients compels an inverter coupled to the voltage bus and performing maximum power point tracking (MPPT) to track the overall bus voltage and maintain the overall bus voltage within an overall bus voltage range that ensures that the overall bus voltage is at a specified preferred value; and track, over a time period of specific duration, minimum voltage output values and maximum voltage output values for the output voltage of the power converter; and upon expiration of the time period; identify a peak minimum voltage output value of the tracked minimum voltage output values and a peak maximum voltage output value of the tracked maximum voltage output values; and control a timing and slope of the localized power gradients according to the peak minimum voltage output value and the peak maximum voltage output value. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for controlling a power converter coupled to a solar panel to provide an output voltage and an output current to a voltage bus, the method comprising:
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monitoring input voltage and input current of the power converter; monitoring the output voltage and the output current of the power converter; regulating the input voltage of the power converter according to a Maximum Power Point Tracking (MPPT) algorithm using parameters corresponding to; the monitored input voltage and monitored input current of the power converter; and the monitored output voltage and output current of the power converter; and regulating output power of the power converter, comprising; deliberately allowing changes in the output voltage of the power converter to move the input voltage of the power converter away from a maximum power point (MPP) voltage value corresponding to an MPP of the solar panel, and creating localized power gradients of a characteristic of output power of the power converter versus an overall bus voltage, wherein the power gradient compels an inverter coupled to the voltage bus and performing MPPT to track an overall bus voltage of the voltage bus and maintain the overall bus voltage within a specified preferred range; tracking, over a time period of specific duration, minimum voltage output values and maximum voltage output values for the output voltage of the power converter; and upon expiration of the time period; identifying a peak minimum voltage output value of the tracked minimum voltage output values and a peak maximum voltage output value of the tracked maximum voltage output values; and controlling a timing and slope of the localized power gradients according to the peak minimum voltage output value and the peak maximum voltage output value. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A converter unit comprising:
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a power converter having an input configured to couple to a solar panel to obtain an input voltage and input current from the solar panel, and an output configured to couple to a voltage bus to provide a converter output voltage and a converter output current to the voltage bus; and a control unit comprising; one or more input ports configured to receive a plurality of parameters comprising; a first parameter indicative of an input current of the power converter; a second parameter indicative of an input voltage of the power converter; a third parameter indicative of the converter output voltage; and a fourth parameter indicative of the converter output current; and a controller configured to; implement a Maximum Power Point Tracking (MPPT) algorithm using the first, second, third, and fourth parameters as input values, to regulate the input voltage, input current, output voltage, and output current of the power converter; deliberately allow changes in the output voltage of the power converter to move the input voltage of the power converter away from a maximum power point (MPP) voltage value corresponding to an MPP of the solar panel, and create localized power gradients of a characteristic of output power of the power converter versus an overall voltage on the voltage bus, wherein the localized power gradients allow tracking to a specified value of the overall voltage on the voltage bus, for maximum power transfer over the voltage bus; track, over a time period of specific duration, minimum voltage output values and maximum voltage output values for the output voltage of the power converter; and upon expiration of the time period; identify a peak minimum voltage output value of the tracked minimum voltage output values and a peak maximum voltage output value of the tracked maximum voltage output values; and control a timing and slope of the localized power gradients according to the peak minimum voltage output value and the peak maximum voltage output value. - View Dependent Claims (29, 30, 31, 32)
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33. A system for harnessing photonic energy to provide power to one or more loads, the system comprising:
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a plurality of solar power panels, wherein each given solar panel of the plurality of solar panels provides a respective output current and a respective output voltage; a DC voltage bus providing a DC bus voltage; a plurality of converter units coupled to the DC voltage bus, each converter unit of the plurality of converter units configured to provide a respective converter output voltage to the DC voltage bus, wherein each given solar panel is coupled to a corresponding converter unit of the plurality of converter units to provide its respective output current and its respective output voltage as inputs to its corresponding converter unit, wherein each corresponding converter unit comprises a switching power module that produces a respective converter output voltage and respective converter output current, and wherein each corresponding converter unit is configured to; regulate an input voltage of its switching power module according to an MPPT (maximum power point tracking) algorithm receiving parameters as inputs, wherein the parameters correspond to one or more of; the input voltage and input current of the switching power module; and the respective converter output voltage, and the respective converter output current; and regulate the respective converter output voltage according to a function of output power provided by the switching power module with respect to the converter output voltage, wherein according to the function, the corresponding converter unit is configured to deliberately allow changes in the respective converter output voltage to move the input voltage of its switching power module away from a maximum power point (MPP) voltage value corresponding to an MPP of the given solar panel, and create localized power gradients of a characteristic of output power of the respective switching power module versus the DC bus voltage; track, over a time period of specific duration, minimum voltage output values and maximum voltage output values for the output voltage of the power converter; and upon expiration of the time period; identify a peak minimum voltage output value of the tracked minimum voltage output values and a peak maximum voltage output value of the tracked maximum voltage output values; and control a timing and slope of the localized power gradients according to the peak minimum voltage output value and the peak maximum voltage output value; and a DC/AC inverter that performs MPPT and inverts the DC bus voltage to an AC power signal for distribution to one or more AC loads. - View Dependent Claims (34, 35)
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Specification