Multi-cellular photovoltaic panel system with DC-DC conversion replicated for groups of cells in series of each panel and photovoltaic panel structure

A multi-cellular photovoltaic panel, comprising:

• connection terminals structured to connect the panel to an external circuit;
• an inner DC bus coupled to the connection terminals;
• a plurality of groups of photovoltaic cells structured to generate voltages, respectively;
• a plurality of DC-DC converters formed on the panel, each converter having inputs coupled to a respective group of photovoltaic cells and outputs coupled to the DC bus, each converter structured to regulate voltage generated by the respective group of photovoltaic cells to which it is coupled, each DC-DC converter including:
• a power switch;
• and
• a control logic circuit structured to process monitored values of electrical input or output parameters and execute an algorithm of maximum power point tracking of the corresponding group of photovoltaic cells of the panel to produce a drive control signal to control the power switch of the DC-DC converter, wherein the control logic circuit of each DC-DC converter is realized via hardware and includes:
• logic circuitry structured to generate a digital control value;
• a digital-to-analog converter structured to convert the digital control value into an analog reference signal;
• and
• a PWM drive comparator having an input coupled to receive the analog reference signal and an output coupled to the power switch of the DC-DC converter,
• wherein each DC-DC converter includes a multiplier having an output coupled to said logic circuitry and structured to produce a digital value of power yielded from the group of cells at a sampling instant, the multiplier being structured to produce the digital value by multiplying instantaneous values of current delivered by the corresponding group of photovoltaic cells by the voltage produced by the corresponding group of photovoltaic cells.

A photovoltaic energy conversion method, comprising:

• producing photovoltaic energy using a plurality of multi-cellular photovoltaic panels, each panel having at least two groups of photovoltaic cells, each group of photovoltaic cells having a DC-DC converted coupled thereto, the producing including:
• generating respective voltages from respective groups of photovoltaic cells on each photovoltaic panel;
• and
• individually regulating the respective voltages, the regulating including:
• DC-DC converting the voltages using the DC-DC converters respectively coupled to the groups of photovoltaic cells;
• and
• processing monitored values of at least one of electrical input and output parameters and executing an algorithm of maximum power point tracking of said respective group of photovoltaic cells of the panel to produce a drive control signal that controls a power switch of a corresponding one of the DC-DC converters, wherein the individually regulating includes:
• comparing an output power of the corresponding group of photovoltaic cells at a current sampling instant with an output power of the corresponding group of photovoltaic cells at a preceding sampling instant;
• and
• updating, based on the comparing, a tracked reference value of a working point of maximum electrical power yield of the corresponding group of photovoltaic cells, by incrementing or decrementing by a fixed quantity a reference signal that is applied to a input of a drive comparator of the corresponding DC-DC converter.

A photovoltaic energy conversion system, comprising:

• a plurality of multi-cellular photovoltaic panels each including:
• a plurality of groups of photovoltaic cells structured to generate voltages, respectively;
• a DC bus;
• and
• a plurality of DC-DC converters having respective inputs coupled respectively to the groups of photovoltaic cells and respective outputs connected to said DC bus, each converter being structured to regulate the voltage generated by a corresponding group of the groups of photovoltaic cells;
• each converter including a power switch and a control logic circuit structured to process monitored values of at least one of electrical input and output parameters and execute an algorithm of maximum power point tracking of said corresponding group of photovoltaic cells of the panel for producing a drive control signal for controlling the power switch of the DC-DC converter;
• wherein the control logic circuit of each DC-DC converter is realized via hardware and includes:
• logic circuitry structured to generate a digital control value;
• a digital-to-analog converter structured to convert the digital control value into an analog reference signal;
• and
• a PWM drive comparator having an input coupled to receive the analog reference signal and an output coupled to the power switch of the DC-DC converter;
• and
• wherein each DC-DC converter includes a multiplier having an output coupled to said logic circuitry and structured to produce a digital value of power yielded from the group of cells at a sampling instant, the multiplier being structured to produce the digital value by multiplying instantaneous values of current delivered by the corresponding group of photovoltaic cells by the voltage produced by the corresponding group of photovoltaic cells.