Abstract: A method of managing an energy storage system that includes a plurality of smart energy storage cells, and a related method of operation for said smart cells. The cells are arranged into a two-dimensional array, and at least one management unit for controlling and monitoring the smart cells is coupled to the array. The smart cells and management units engage in wireless communication that has relatively short range and is relatively directional, with the direction being electronically-steerable in the plane of the array. The management method assigns direction codes to each smart cell which the cells utilize to steer the directions of their communication links, thereby organizing the smart cells into a plurality of serially-linked communication networks. The methods include steps for automatically determining the size and arrangement of the array, including the orientation of each smart cell.
Abstract: A smart junction box for a photovoltaic solar power module, and related method of operation. The junction box includes a plurality of active bypass circuits for protecting the solar cells from reverse bias, a novel power supply circuit in several embodiments that can operate with input voltages of either positive or negative polarity, a capacitor for storing and supplying energy, and a master control circuit. The master control circuit is able to enable/disable the power supply, force the bypass switches to open, and modulate the on-resistance of the bypass switches. The master control circuit performs these functions in a coordinated way to maintain the voltage across the capacitor within predetermined limits, thereby ensuring the internal circuitry is powered under all operating conditions including: full sunlight, partial shading, full shading, and safe mode for reducing the risk of electrical shock to firefighters.
Abstract: The invention comprises: a smart junction box with a safe mode for photovoltaic solar power modules; and the related method of operation. Power MOSFETs are used as active bypass diodes during the normal operation of the smart junction box, but in safe mode the power MOSFETs are turned on continuously, thereby reducing the output voltage to a safe level of approximately 200 mV. A Non Volatile Memory (NVM) keeps the module in the safe mode after power from the PV cells is interrupted by momentary shading or night. The smart junction box includes transmitter and receiver circuits for wirelessly communicating with other smart junction boxes. The smart junction box enters safe mode in response to receiving a shut-down signal, and exits safe mode in response to receiving a restart signal. The smart junction box acts as a signal repeater, thereby ensuring that the shut-down and restart signals propagate to all junction boxes in the solar array.
Abstract: A solar power module, and related method of operation, that protects the bypass diodes in the solar power module from overheating due to partial shading, and also protects firefighters and installer personnel from electrical shock hazard. The solar power module includes active bypass switches, and isolation switches that disconnect the PV cells from the bypass switches when all the bypass switches are closed concurrently, thereby allowing the PV cells to continue supplying power to the control circuitry. The isolation switches are also used to maintain the solar power module in a safe state during installation, or in case of fire.
Abstract: A protection circuit for metal-oxide-semiconductor field-effect transistors (MOSFETs) that are used as active bypass diodes in photovoltaic solar power systems is disclosed. The protection circuit comprises, a detection circuit for detecting the start of a surge event, a switch disposed to connect the MOSFET's drain to it's gate in response to the start of the surge, a diode in series with the switch, a bistable circuit for keeping the switch closed during the surge, and a means of resetting the bistable circuit after the surge.
Abstract: An active bypass diode circuit that mitigates the hazard of arc flash events in a Photovoltaic (PV) solar power array, and a PV solar power module that utilizes a plurality of said active bypass circuits are disclosed The active bypass circuit comprises a diode, a switch in parallel with the diode, a control circuit for opening and closing the switch, a circuit for detecting arc flash events, a power management circuit, a power supply circuit, and a capacitor. When an arc flash event is detected, all the switches are closed concurrently, reducing the voltage produced by the PV string to a level that is too low the sustain the arc, and thereby terminating the arc.