Abstract: This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.

Abstract: This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.

Abstract: A power conversion device achieves size reduction and reliability by reducing the number of components of the system. The power conversion device has a semiconductor module of a half-bridge configuration in which two semiconductor elements are arranged in series. The semiconductor module has a cuboidal shape and has, along a longitudinal direction thereof, a positive pole terminal, a negative pole terminal, and terminals for inputting or outputting alternating current or for forming a single phase of the power conversion device. In the vertical direction corresponding to a widthwise direction of the cuboid, a plurality of the semiconductor modules are arranged vertically, forming a plurality of phases of the power conversion device. The semiconductor modules of the plurality of phases are installed in contact with a cooling unit, and one or more capacitors are disposed so as to face the cooling unit across the semiconductor modules of the plurality of phases.

Abstract: A power conversion device achieves size reduction and reliability by reducing the number of components of the system. The power conversion device has a semiconductor module of a half-bridge configuration in which two semiconductor elements are arranged in series. The semiconductor module has a cuboidal shape and has, along a longitudinal direction thereof, a positive pole terminal, a negative pole terminal, and terminals for inputting or outputting alternating current or for forming a single phase of the power conversion device. In the vertical direction corresponding to a widthwise direction of the cuboid, a plurality of the semiconductor modules are arranged vertically, forming a plurality of phases of the power conversion device. The semiconductor modules of the plurality of phases are installed in contact with a cooling unit, and one or more capacitors are disposed so as to face the cooling unit across the semiconductor modules of the plurality of phases.

Abstract: An oven observing equipment capable of observing the inside of an oven turned to a high temperature precisely includes: a housing 13 having an intake part for cooling air, and a discharging part for discharging the cooling air after being used for cooling; and an imaging device 20 contained in this housing 13 near the discharge part. This imaging device 20 is composed of integrated combination of an image sensor 16; plate-like thermoelectric cooling elements 18a to 18d arranged in a state that their heat-absorbing faces surround the periphery of a body of the image sensor; thermoconductive blocks 17a to 17d embedded in the gaps between the image sensor body and the thermoelectric cooling elements 18a to 18d; and cooling fins 19a to 19d formed on the heat-radiating faces of the thermoelectric cooling elements 18a to 18d are integrated with each other.

Abstract: An oven observing equipment capable of observing the inside of an oven turned to a high temperature precisely includes: a housing 13 having an intake part for cooling air, and a discharging part for discharging the cooling air after being used for cooling; and an imaging device 20 contained in this housing 13 near the discharge part. This imaging device 20 is composed of integrated combination of an image sensor 16; plate-like thermoelectric cooling elements 18a to 18d arranged in a state that their heat-absorbing faces surround the periphery of a body of the image sensor; thermoconductive blocks 17a to 17d embedded in the gaps between the image sensor body and the thermoelectric cooling elements 18a to 18d; and cooling fins 19a to 19d formed on the heat-radiating faces of the thermoelectric cooling elements 18a to 18d are integrated with each other.

Abstract: Filter capacitor voltage “Ecf1” is detected and then after d-axis voltage correction value “dvd”, q-axis voltage correction value “dvq”, q-axis current correction value “diq”, and frequency correction value “d&ohgr;1” have been computed from the AC components of “Ecf1” and the results have been added to the corresponding d-axis voltage command, q-axis voltage command, q-axis current, and frequency command, the DC current of the power converter is controlled. Thus, the AC components included in the DC current are offset and the AC components are suppressed effectively.

Abstract: The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.

Abstract: A railway vehicle operation-control system includes at least one central processing unit being connected to a plurality of devices, which are connected in parallel, via information communication means, the plurality of the devices having at least one operational state-monitoring function which transmits information on operational states of each device to the central processing unit; wherein a total controlled-variable necessary for the system is attained by allocating the total control variable to each device based on operational states determined from results of monitoring performed by the operational state-monitoring function, and a performance margin which is defined as a difference between a permissible power-output value and a current power-output value for each device while monitoring and reflecting the performance margin of each device.

Abstract: The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.

Abstract: The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.

Abstract: The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.

Abstract: A railway vehicle operation-control system includes at least one central processing unit being connected to a plurality of devices, which are connected in parallel, via information communication means, the plurality of the devices having at least one operational state-monitoring function which transmits information on operational states of each device to the central processing unit; wherein a total controlled-variable necessary for the system is attained by allocating the total control variable to each device based on operational states determined from results of monitoring performed by the operational state-monitoring function, and a performance margin which is defined as a difference between a permissible power-output value and a current power-output value for each device while monitoring and reflecting the performance margin of each device.