BACKGROUND

Field of the Disclosure

The present disclosure is related to photovoltaic systems in general, and more particularly to the safety-enhancing modules for quickly discharging capacitors in photovoltaic systems.

Description of Related Art

Photovoltaic systems are becoming increasingly common for power generation. Photovoltaic systems are safe, clean sources of power, which function reliably and last many years once installed. The use of these systems is only expected to grow in the future as the costs of these systems continues to decrease, and alternative energy resources are implemented in the energy economy.

In a case of fire or other emergency, when any electrical power generation or distribution system must be shut down quickly, there are known electrical hazards associated with electrical power generation and distribution systems. Thus, safety systems form an important part of electrical power generation and distribution systems to account for this, and there are methods and systems known for de-energizing traditional electrical power systems during emergencies. However, photovoltaic systems present some unique difficulties, which are not adequately resolved by conventional safety systems.

BRIEF SUMMARY

One embodiment of the disclosure is drawn to a photovoltaic system connected to an inverter having an input capacitor. The photovoltaic system includes at least one photovoltaic module and a maximum power point tracking (MPPT) controller coupled between the input capacitor of the inverter and the at least one photovoltaic module. The MPPT controller includes a direct current (DC) converter configured to reduce, in a forward buck mode, a voltage of the at least one photovoltaic module, to supply power from the at least one photovoltaic module to the input capacitor of the inverter.

The photovoltaic system also includes a microcontroller unit (MCU) configured to control the DC converter to allow the at least one photovoltaic module to operate at a maximum power point. The DC converter is software-configurable to increase, in a reverse boost mode, a voltage of the input capacitor of the inverter, to dissipate power from the input capacitor in the at least one photovoltaic module, and the MPPT controller is configured to, based upon one or more triggers, automatically change the DC converter from the forward buck mode to the reverse boost mode to dissipate energy stored in the input capacitor of the inverter.

One embodiment of the disclosure is drawn to a system connecting at least one photovoltaic module to an inverter having an input capacitor. The system includes a maximum power point tracking (MPPT) controller coupled between the input capacitor of the inverter and the at least one photovoltaic module. The MPPT controller includes a direct current (DC) converter configured to reduce, in a forward buck mode, a voltage of the at least one photovoltaic module, to supply power from the at least one photovoltaic module to the input capacitor of the inverter.

The system also includes a microcontroller unit (MCU) configured to control the DC converter to allow the at least one photovoltaic module to operate at a maximum power point. The DC converter is software-configurable to increase, in a reverse boost mode, a voltage of the input capacitor of the inverter, to dissipate power from the input capacitor in the at least one photovoltaic module, and the MPPT controller is configured to, based upon one or more triggers, automatically change the DC converter from the forward buck mode to the reverse boost mode to dissipate excess energy stored in the input capacitor.

One embodiment of the disclosure is drawn to a method for transferring energy between at least one photovoltaic module and an inverter having an input capacitor. The method includes coupling a maximum power point tracking (MPPT) controller between the input capacitor of the inverter and the at least one photovoltaic module. The MPPT controller includes a direct current (DC) converter configured to reduce, in a forward buck mode, a voltage of the at least one photovoltaic module, to supply power from the at least one photovoltaic module to the input capacitor of the inverter, and a microcontroller unit (MCU) configured to control the DC converter to allow the at least one photovoltaic module to operate at a maximum power point. The DC converter is software-configurable to increase, in a reverse boost mode, a voltage of the input capacitor of the inverter, to dissipate power from the input capacitor in the at least one photovoltaic module.

The method also includes bucking, as controlled by the MCU, the voltage of the at least one photovoltaic module to the inverter via the DC converter in the forward buck mode to supply power to the input capacitor of the inverter, monitoring, by the MCU, one or more triggers for an emergency shutdown condition, and changing, as controlled by the MCU, upon a determination by the MCU from the monitoring that an emergency shutdown condition has been met, the DC converter from the forward buck mode to the reverse boost mode.

