Solarcity Corporation

Enecsys Limited

Tesla, Inc.

Lesley Chisenga

Gehan Anil Joseph Amaratunga

Asim Mumtaz

Cuauhtemoc Rodriguez

Paul Randal Engle, Jr

Andrew John Matthews

Andrabadu Viraj

Paul James Garrity

Aaron Jungreis

Gehan Amil Joseph Amaratunga

The invention relates to a grid synchroniser for connecting an AC output of a power converter to the AC grid mains. In one aspect the invention provides a grid synchroniser comprising an inverter controller to control an AC output of the inverter, the controller including a receiver to receive grid data from a grid sensor location remote from said inverter. In another aspect we describe techniques for rapid removal of charge from a control terminal of a power switching device such as a MOSFET, IGBT or Thyristor using a particular driver circuit.

Grid synchronisation

Some embodiments of the invention provide a method for balancing the power output to each phase of a set of micro-inverters. The method of some embodiments is performed by a gateway, which receives output messages from a plurality of micro-inverters. The gateway identifies the phase of each micro-inverter and calculates the output of the plurality of micro-inverters to each power line of a multi-phase system. The gateway then sends control signals to the micro-inverters to control the output of each micro-inverter to maintain a balanced aggregate power output to each phase of the power grid.

Power balancing in a multi-phase system

Improved techniques for photovoltaic power generation are described. Inverter failure is can be a significant problem in solar photovoltaic systems as it can lead to loss of opportunity to harvest energy. A solar photovoltaic (PV) power generation system is described comprising solar PV panels and power conditioning units. A dc power distribution bus is coupled to the solar PV panels and the power conditioning units to switchably share dc power from the solar PV panels between the power conditioning units. Power distribution controllers detect a faulty power conditioning unit and reroute power from a solar PV panel coupled to the faulty power conditioning unit to other power conditioning units via the dc distribution bus.

Solar photovoltaic systems

This invention is generally concerned with power supply circuits, and more particularly, with circuits to supply power to a mains supply, such as domestic grid mains, from a photovoltaic device. A photovoltaic power conditioning circuit for providing power from a photovoltaic device to an alternating current mains power supply line, the circuit comprising: a DC input to receive DC power from said photovoltaic device; an AC output configured for direct connection to said AC mains power supply line; a DC-to-AC converter coupled to said DC input and to said AC output to convert DC power from said photovoltaic device to AC power for output onto said power supply line; and an electronic controller directly coupled to said power supply line to measure a voltage of said power supply line and a current in said supply line and to control said DC-to-AC converter responsive to said measuring.

Power supply circuits

We describe a power conditioning unit with maximum power point tracking (MPPT) for a dc power source, in particular a photovoltaic panel. A power injection control block has a sense input coupled to an energy storage capacitor on a dc link and controls a dc-to-ac converter to control the injected mains power. The power injection control block tracks the maximum power point by measuring a signal on the dc link which depends on the power drawn from the dc power source, and thus there is no need to measure the dc voltage and current from the dc source. In embodiments the signal is a ripple voltage level and the power injection control block controls an amplitude of an ac current output such that an amount of power transferred to the grid mains is dependent on an amplitude of a sinusoidal voltage component on the energy storage capacitor.

Power conditioning units

The invention relates to a grid synchronizer for connecting an AC output of a power converter to the AC grid mains. In one aspect the invention provides a grid synchronizer comprising an inverter controller to control an AC output of the inverter, the controller including a receiver to receive grid data from a grid sensor location remote from said inverter. In another aspect we describe techniques for rapid removal of charge from a control terminal of a power switching device such as a MOSFET, IGBT or Thyristor using a particular driver circuit.

We describe a photovoltaic (PV) power generation system comprising at least two PV panels and a power conditioning unit. The dc power outputs of the PV panels are connected in parallel to a dc power input of the power conditioning unit. The power conditioning unit comprises a dc-to-dc converter having an input coupled to the dc power input and an output coupled to a dc link of the unit, a dc-to-ac converter having an input coupled to the dc link and an ac mains power supply output, and an energy storage capacitor coupled to the dc link. The power conditioning unit is configured to perform maximum power point tracking (MPPT) responsive to a level of power flowing into the dc power input, and the level of power flowing into said dc power input is sensed at the dc link. In preferred implementations the energy storage capacitor is a non-electrolytic capacitor.

Solar photovoltaic system with maximized ripple voltage on storage capacitor

A power conditioning unit with maximum power point tracking (MPPT) for a dc power source in a photovoltaic panel is provided. The power conditioning unit includes a power injection control block having a sense input coupled to an energy storage capacitor on a dc link for controlling a dc-to-ac converter to control the injected mains power. The power injection control block tracks the maximum power point by measuring a signal on the dc link which depends on the power drawn from the dc power source, and thus there is no need to measure the dc voltage and current from the dc source. The measured signal is a ripple voltage level and the power injection control block controls the amplitude of an ac current output such that the amount of power transferred to the grid mains is dependent on the amplitude of a sinusoidal voltage component on the energy storage capacitor.

Growing community of inventors

Redwood Shores, CA, United States of America

Lesley Chisenga