Abstract: The invention is an electromechanical packaging method for high power, high reliability, high frequency, switch mode power converters where high power density is required. An Insulated Metal Substrate (IMS) Printed Circuit Board (PCB) assembly, with a plurality of surface mount semiconductor power devices, is interfaced to a heatsink. Low profile bus bars are used between the IMS PCB and a fiberglass PCB. The fiberglass PCB has a laminated DC bus structure and a plurality of filter capacitors electrically connected across the DC bus structure. Clamp bars, substantially following the footprint of the bus bars, are installed on top of the fiberglass PCB and are used to pull the heatsink-IMS-bus bar-fiberglass PCB-clamp bar sandwich together. The clamping action provides low contact resistance between the bus bars and the two printed circuit boards. The clamping action also supplies the pressure needed between the IMS substrate and the heatsink for good heat transfer across this interface.

Abstract: The invention is a method and apparatus for supplying both positive and negative gate drive power supply potentials to the top switch, in a typical half-bridge semiconductor power topology, from the bottom switch gate drive power supplies and without the use of transformer, capacitive or optical isolation. A known method of providing the positive top switch gate drive supply is enhanced and used in conjunction with a new and novel method for providing the negative top switch gate drive supply. The negative top switch gate drive supply is provided by an additional, lower power semiconductor switch, which is substantially synchronized with the bottom semiconductor switch, except for a slight turn-on delay. When this additional switch is gated “on” and conducting, the negative bottom switch gate drive power is connected to the negative top switch gate drive supply energy storage capacitors.

Abstract: The invention is an electrical power conversion apparatus for converting DC voltage to poly-phase AC current where the AC current is supplied directly to the electric utility grid for power transfer into the grid. The power conversion apparatus has two or more separate, pulse modulated, high frequency power converters per phase. The outputs of the power converters are summed at a common connection point substantially on the load side of the main pulse filter inductors. The high frequency pulse train of each separate power converter is skewed or phase delayed with respect to the other converters on the same AC power phase for the purpose of reducing the amount of high frequency ripple current injected into the electric utility grid.

Abstract: This invention is a multi-port power converter where all ports are coupled through different windings of a high frequency transformer. Two or more, and typically all, ports have synchronized switching elements to allow the use of a high frequency transformer. This concept and type of converter is known. This invention mitigates a number of limitations in the present art and adds new capabilities that will allow applications to be served that would otherwise not have been practical. A novel circuit topology for a four-quadrant AC port is disclosed. A novel circuit topology for a unidirectional DC port with voltage boost capabilities is disclosed. A novel circuit topology for a unidirectional DC port with voltage buck capabilities is disclosed. A novel circuit for a high efficiency, high frequency, bi-directional, AC semiconductor switch is also disclosed.

Abstract: The invention is a device and method for eliminating core excitation losses in a distribution transformer when the transformer is not supplying power to loads. The invention consists of sensors, a control circuit, a user interface and a power contactor. The power contactor is connected on the line side of a transformer and is opened or closed automatically based on preprogrammed time or load criteria determined by the control circuit. In one operational mode and when the transformer is disconnected from the line, the control board generates low power pulses at the transformer load connection points in order to “search” for loads. If a load is detected, the transformer is reconnected by way of contactor closure. If the transformer load drops to zero, for a predetermined amount of time, the transformer is again disconnected and the pulsed load search is reestablished.

Abstract: A control system for maximizing the power supplied by an array of solar cells senses the current and voltage produced and multiplies these to determine the instantaneous power. The array is tilted slightly in a first direction and the effect on the instantaneous power is noted. If an increase in power was produced, a further movement in the same direction is executed; but if the first movement produced a reduction in power, a movement in the opposite direction is executed. The process continues until no increase in power is obtained in either direction. Thereafter, the same process is carried out with respect to a second axis of the solar array.