A power semiconductor device includes trenches disposed in a first base layer of a first conductivity type at intervals to partition main and dummy cells, at a position remote from a collector layer of a second conductivity type. In the main cell, a second base layer of the second conductivity type, and an emitter layer of the first conductivity type are disposed. In the dummy cell, a buffer layer of the second conductivity type is disposed. A gate electrode is disposed, through a gate insulating film, in a trench adjacent to the main cell. A buffer resistor having an infinitely large resistance value is inserted between the buffer layer and emitter electrode. The dummy cell is provided with an inhibiting structure to reduce carriers of the second conductivity type to flow to and accumulate in the buffer layer from the collector layer.

Power semiconductor device

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

Distributed Power Harvesting Systems Using DC Power Sources

Method for distributed power harvesting using DC power sources

A method for providing maximum power point tracking for an energy generating device (202) using a local buck-boost converter (206) coupled to the device (202) is provided. The method includes operating in a tracking mode, which includes initializing a conversion ratio for the buck-boost converter (206) based on a previous optimum conversion ratio. A device power associated with the initialized conversion ratio is calculated. The conversion ratio is repeatedly modified and a device power associated with each of the modified conversion ratios is calculated. A current optimum conversion ratio for the buck-boost converter (206) is identified based on the calculated device powers. The current optimum conversion ratio corresponds to one of a buck mode, a boost mode and a buck-boost mode for the buck-boost converter (206).

Method and system for providing local converters to provide maximum power point tracking in an energy generating system

A system and method for DC to AC conversion in a power generating array (200). The system and method includes a number of inverters (220) coupled to a group of solar panels (205). A group controller (250) coordinates operation of the inverters (220) for interleaved switching of the inverters (220). The group controller communicates (250) via a local area network (245), a wireless network (670), or both, to coordinate operation with additional groups (602, 604, 606) of inverters (220) coupled in parallel with additional solar panels (205).

System and method for an array of intelligent inverters

A device for operating lamps, such as fluorescent lamps includes an input protection circuit, a filter, a DC to DC converter, a power output stage, a lamp connecting circuit and a control circuit. The control circuit includes a pulse width modulator, a multivibrator and a start/stop controller. The pulse width modulator varies the duty cycle of a control signal supplied to the DC to DC converter based on a feedback signal from the DC to DC converter. The multivibrator assists in the control of the DC to DC converter. The start/stop controller initiates the operation of the power output stage when an output of the DC to DC converter reaches a predetermined level and halts the operation of the power output stage if a failure is detected.

Walter Zeitler

Papers

DC operated electronic ballast for fluorescent light