Mitsubishi Denki Kabushiki Kaisha

Kobelco Construction Machinery Co., Ltd.

Michio Kataoka

Masayuki Komiyama

Masato Koyama

Toshio Sora

Shigenori Higashino

An object of the invention is to maintain high vehicle driving performance and system efficiency by preventing reductions in the traction characteristic and the maximum driving speed of a vehicle. The invention relates to an electrical system for an electric automotive vehicle for driving the vehicle by supplying an electric power of a direct-current power supply to an electric motor for driving wheels via a semiconductor power converter for driving the wheels such as an inverter and speed-variably driving this electric motor or an electrical system for an electric automotive vehicle using an engine and a direct-current power supply as driving sources. A booster chopperis connected between a battery deviceoras the direct-current power supply and an inverteror a semiconductor power converter, and is controlled so that a direct-current input voltage of the inverteror the like becomes substantially constant.

Hybrid vehicle power control apparatus and hybrid construction equipment using the power control apparatus

A fault detector for detecting faults in a DC capacitor circuit connected to the DC buses of an inverter circuit using semiconductor device for converting direct current into alternating current to suppress the voltage pulsation and comprising a plurality of parallel-connected capacitor circuits each having a plurality of series-connected DC capacitors. The fault detector comprises a comparison means connected to the junctions of the series-connected DC capacitors to compare the respective potentials of the parallel-connected capacitor circuits, and detects the short-circuit and time-aging of the DC capacitors of the parallel-connected capacitor circuits rapidly on the basis of the output signal of the comparison means.

Fault detector for detecting faults in a DC capacitor circuit

An inverter having an output connected to a load through a reactor and an output filter capacitor terminal voltage of the capacitor is monitored, and an interlock operation for interrupting the delivery of the inverter transistor drive signals is released when the terminal voltage does not exceed a predetermined level. When the interlock operation for cutting off the drive signals of the transistors has started and continued for a predetermined time, it is further continued when the terminal voltage of the output filter capacitor does not drop below a set level and is released for the first time when the output filter capacitor is sufficiently discharged to render the terminal voltage the set level or below.

Inverter apparatus

A low-noise transformer, particularly for the use as an output transformer of an inverter, comprising a sound-proof envelope surrounding at least one of the windings for absorbing or screening noise originating from vibration due to electromagnetic force.

Growing community of inventors

Kobe, Japan

Michio Kataoka