Abstract: An electric vehicle propulsion system having a motor with first and second electrically isolated windings and a system control unit for controlling the motor, wherein the system control unit includes a first power bridge for driving the first windings and a second power bridge for driving the second windings.

Abstract: An on-board electric vehicle battery charger includes a surge limiter circuit, a power factor control circuit, and a resonant inverter circuit. The power factor control circuit includes a boost regulator circuit providing a fixed voltage on an output capacitor. The resonant inverter circuit uses a resonance capacitor and the leakage inductance of an output transformer to establish a resonance frequency at least 500 times the AC input power frequency.

Abstract: A power bridge for an electric vehicle propulsion system, comprising a switching circuit including first and second switching elements operable between "on" and "off" states and a midpoint detector coupled to the switching circuit for detecting a failure of at least one of the first and second switching elements, where the midpoint detector is capable of detecting and isolating a failure when the switching elements are in the "on" or the "off" states.

Abstract: An electric vehicle relay assembly including a main relay and a flexible circuit electrically connected to the main relay. The relay assembly further includes a connection for mounting the flexible circuit onto the main relay and a wiring board affixed to the flexible circuit. The flexible circuit compensates for mechanical tolerance errors within the connection. The wiring board includes relay circuitry electrically connected to the flexible circuit.

Abstract: A EMI filter for an electric vehicle propulsion system, comprising a first and second capacitive element electrically connected in parallel with first and second power conductors, an inductive element electrically connected in series with the first power conductor and separating the first and second capacitive elements, and first and second junctions electrically connecting the second capacitive element to an electronic switch, wherein the sum of intrinsic inductances of the first and second junctions is less than the intrinsic inductance of the second capacitive element.

Abstract: A coolant pump assembly for an electric vehicle includes a positive displacement pump having an inlet port, an outlet port, and a rotor, a variable-speed ac motor having a rotatable shaft mated with the rotor of the pump for rotating the rotor of the pump to circulate coolant through the inlet and outlet ports of the pump, and a motor control unit, communicating with a DC power source of the electric vehicle, for controlling the speed of the motor to provide a variable coolant flow through the electric vehicle.

Abstract: A power bridge assembly for providing electric current to stator windings of an electric motor used in an electric propulsion system for an electric vehicle. The power bridge is assembled on a laminated bus bar. An upper plate of the bus bar connects to one side of a high voltage battery, a lower plate of the bus bar connects to the other side of the high voltage battery, and an insulation layer is sandwiched between the upper and lower plates. Electrical switches and capacitors sandwich the laminated bus bar. With this structure, two fasteners, one for positive voltage and one for negative voltage, can connect the bus bar, capacitors, and switches both electrically and mechanically. The sandwich structure eliminates parasitic inductance from the electrical connections.

Abstract: A method for testing a power bridge for an electric vehicle propulsion system, the power bridge including a switching circuit having first and second switching elements operable between "on" and "off" states. The method comprises the steps of selectively switching the first and second switching elements between the "on" and "off" states, monitoring the first and second switching elements to determine whether the first and second switching elements operate between the "on" and "off" states when selectively switched, and indicating a failure o#the switching circuit when at least one of the first and second switching elements does not operate between the "on" and "off" states when selectively switched.

Abstract: A fault detection circuit for detecting leakage currents between a DC power source and chassis of an automobile, includes a voltage sensor coupled to the DC power source, the voltage sensor including an analog reference and a chassis ground. A differential amplifier is coupled to the voltage sensor and detects variations in the analog reference and the chassis ground. A voltage comparator unit determines whether the variations detected in the differential amplifier is above a predetermined threshold value. A built-in test circuit tests whether the fault detection circuit is operating correctly.