Systems and methods to balance solar panels in a multi-panel system
View Patent ↗Systems and methods to balance currents among a plurality of photovoltaic units connected in series. In aspect, a management unit is coupled between a photovoltaic energy production unit and a string of energy production units. The management unit has an energy storage element (e.g., a capacitor) connected to the photovoltaic energy production unit. The management unit further has a switch to selectively couple to the energy storage element and the photovoltaic energy production unit to the string. The management unit allows the current in the string to be larger than the current in the photovoltaic energy production unit.
1. A photovoltaic energy production system, comprising:
a power bus;
a plurality of photovoltaic energy production units;
a plurality of first management units coupled between the plurality of photovoltaic energy production units and the power bus to supply electricity generated by the photovoltaic energy production units onto the power bus, the first management units to determine operating parameters of the photovoltaic energy production units, each of the first management units being capable of adjusting a respective photovoltaic energy production unit to a maximum power point of the respective photovoltaic energy production unit; and
a second management unit, elected from the first management units, to receive the operating parameters of the photovoltaic energy production units, the second management unit to determine at least one parameter for the first management units, the first management units to operate at least one of the photovoltaic energy production units at a maximum power point according to the at least one parameter.
2. The system of claim 1 , wherein the power bus is a string bus.
3. The system of claim 1 , wherein the plurality of first management units connect the plurality of photovoltaic energy production units in series on the string bus.
4. The system of claim 1 , wherein the second management unit communicates with the first management units over the power bus.
5. The system of claim 1 , wherein each of the first management units has only one output; and outputs of the first management units are connected in series on the power bus.
6. The system of claim 1 , wherein the operating parameters of the photovoltaic energy production units received in the second management units include current, voltage, and temperature measurements from the first management units.
7. The system of claim 6 , wherein the second management unit is configured to calculate estimated maximum power points of the plurality of photovoltaic energy production units; and the at least one parameter is determined for the first management units based on the estimated maximum power points.
8. The system of claim 7 , wherein the at least one parameter includes one of: duty cycle, and phase shift.
9. A method, comprising:
electing a second management unit from a plurality of first management units,
receiving, from the plurality of first management units and by the second management unit, operating parameters of a plurality of solar modules, each of the plurality of first management units being coupled with a respective solar module of the plurality of solar modules to determine operating parameters of the respective solar module and coupled between the respective solar module and a power bus to supply electricity generated by the respective solar module onto the power bus;
determining, by the second management unit, at least one control parameter based on the operating parameters of the plurality of solar modules; and
transmitting, by the second management unit, the at least one control parameter to the first management units to operate at least one of the solar modules at a maximum power point.
10. The method of claim 9 , wherein the power bus comprises a string of the plurality of first management units connected in series.
11. The method of claim 9 , further comprising:
calculating, by the second management unit, estimated maximum power points of the solar modules, wherein the at least one control parameter is determined based on the estimated maximum power points of the solar modules.