Fuji Electric Co., Ltd.

Fuji Electric Systems Co. Ltd.

Yoshihiro Matsumoto

Kenji Okamoto

Shinji Uchida

Takashi Aihara

Takao Maeda

Naoto Fukasawa

The control apparatus according to the invention includes a keypad detachable from the control apparatus and including a communication device that facilitates communicating with a personal computer such that the keypad detached from the control apparatus is connected to the personal computer for setting the operations of the control apparatus and, then, the keypad is attached to the control apparatus to make the control apparatus conduct the control operations based on the setting contents set in the keypad. The control apparatus according to the invention facilitates setting the operations thereof in any place different from the place, therein the control apparatus is installed, and reducing the electric power fed to the control apparatus during the setting operation.

Control apparatus including detachable keypad with communication port connecting personal computer to the keypad

An inverter device is provided that can measure a decrease in cooling capacity caused by a finite service life of a cooling fan or clogging of a cooling fin, without being affected by an ambient temperature or a load state. A thermal time constant is calculated in a thermal time constant calculation circuit from a temperature detection value from a temperature detection circuit and a time signal from a timer on the basis of an operation/stop command for the inverter device. The calculated value of the thermal time constant calculated in the thermal time constant calculation circuit is compared by a comparator with a reference value of the thermal time constant that is stored in advance in a memory. Whether the cooling capacity has decreased is determined based on the comparison results.

Cooling capacity measurement method for inverter device

An inverter apparatus that can lengthen a lift span provides only a noise absorption film capacitor in a DC intermediate circuit between rectifying and inverter circuits, instead of a conventional electrolytic capacitor. In a voltage command generating unit, when a frequency set by a frequency setting unit is within a predetermined range including the frequency of an AC input power supply, PLL control is performed to make the frequency set by an output voltage command signal equal to the frequency of the AC input power supply voltage, and to substantially synchronize the peak value of the inverter circuit output voltage with the peak value of a voltage formed between both ends of the film capacitor. Accordingly, output voltage amplitude is generated when the frequency set by the output voltage command signal equals the frequency of the voltage of the AC input power supply.

Voltage-source inverter apparatus utilizing ripple voltage

A method of manufacturing a noise-cut filter having distributed inductances and distributed capacitances is produced wherein conductive spiral coil patterns are formed on the opposite surfaces of a dielectric sheet, such that the spiral coil patterns are aligned with each other in a direction perpendicular to the plane of the dielectric sheet, and a main circuit pattern is constructed by bonding a main circuit conductor to the spiral coil pattern formed on one of the opposite surfaces of the dielectric sheet. The main circuit conductor is formed by stamping with a punch press so that the conductor has a cross sectional area large enough to allow the passage of current of a main circuit, and has substantially the same shape as the spiral coil pattern. Further, a grounding wire is bonded to the spiral coil pattern formed on the other surface of the dielectric sheet, so that the grounding wire leads the current involving noises which flows from the main circuit pattern into the spiral coil pattern via the dielectric sheet, to a ground terminal.

Noise-cut filter for power converter

A noise-cut filter having distributed inductances and distributed capacitances is provided wherein conductive spiral coil patterns are formed on the opposite surfaces of a dielectric sheet, such that the spiral coil patterns are aligned with each other in a direction perpendicular to the plane of the dielectric sheet, and a main circuit pattern is constructed by bonding a main circuit conductor to the spiral coil pattern formed on one of the opposite surfaces of the dielectric sheet. The main circuit conductor is formed by stamping with a punch press so that the conductor has a cross sectional area large enough to allow the passage of current of a main circuit, and has substantially the same shape as the spiral coil pattern. Further, a grounding wire is bonded to the spiral coil pattern formed on the other surface of the dielectric sheet, so that the grounding wire leads the current involving noises which flows from the main circuit pattern into the spiral coil pattern via the dielectric sheet, to a ground terminal.

Noise-cut LC filter for power converter with overlapping aligned coil

A noise-cut filter device for a power converter, including at least one noise-cut filter, for filtering switching noise occurring upon a switching operation of a semiconductor switching device of the power converter is disclosed. In this filter device, the noise-cut filter includes first and second planar conductors, and a dielectric sheet having upper and lower surfaces on which the first and second conductors are disposed to face each other through the dielectric sheet. The first and second planar conductors cooperate with the dielectric sheet to form a circuit having both functions of an inductor and a condenser. The current of a main circuit of the power converter flows through the opposite ends of the first planar conductor, while the current based on the switching noise, which flows from the first conductor to the second conductor, is led to ground by the second conductor.

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Mie, Japan

Yoshihiro Matsumoto