Abstract: Disclosed is a hybrid-type construction machine equipped with a swing hydraulic motor 27 and a swing electric motor 25 in combination to save energy, the construction machine ensuring high operability of a swing body 20 and providing high energy efficiency. In accordance with the amount of manipulation of a swing control lever 72, the construction machine changes a rate of a torque of the swing electric motor 25 with respect to that of the swing hydraulic motor 27. The construction machine also controls a relief pressure and the torque of the swing electric motor 25 in accordance with the amount of manipulation of a swing control lever 72, a pressure of the swing hydraulic motor 27, and a rotating speed of the swing electric motor 25.

Abstract: A hybrid construction machine drives the upper swing structure using a hydraulic motor and an electric motor together and is capable of regenerating the energy of the upper swing structure in deceleration or stopping into electric power and using the regenerated electric power for assisting the hydraulic motor for driving the upper swing structure. The opening area characteristics of a meter-out restrictor and a bleed-off restrictor of a swing directional control valve are set to become larger than for construction machines driving the upper swing structure with the hydraulic motor alone. Torque of the electric motor is controlled so that the total sum of the actual torque occurring in the hydraulic and electric motors in deceleration or acceleration of the hydraulic motor equals the torque occurring when the opening area of the meter-out restrictor or the bleed-off restrictor is set at the prescribed opening area.

Abstract: Provided is a high mobility railroad vehicle system configured to reciprocally carry out a direct drive between a non-electrically driven section and an electrically driven section without installing new facilities such as oil supply equipment and without considering distinction between the non-electrically and electrically driven sections. A railroad vehicle system is provided with an overall control apparatus to respectively control an external electric power supply means, an internal electric power supply means, an electricity storage means, electric power conversion means and a motor driving means. The railroad vehicle system judges or previously notifies as to whether the present driving railroad section is the electrically driven section or non-electrically driven section in accordance with driving position information received from a position information generation means such as a ground facility on a railroad equipped outside of the vehicle and a global positioning system (GPS).

Abstract: A pulse width modulation method has the steps of operating a second instruction signal so that each of the differences between two or three arbitrary instruction signals in three first instruction signals may become more than the predetermined value, and modulating in pulse width based on the second instruction signal.

Abstract: A gate driver circuit of a voltage drive type power semiconductor switching device capable of speeding up di/dt and dv/dt even during large-current driving to thereby reduce the switching loss is disclosed. This power semiconductor switching device gate driving circuit includes a drive circuit which applies a drive signal to the gate electrode of the power semiconductor switching device and a measurement unit for measuring a flow current of the power semiconductor switching device. Based on a detected value of the flow current of the power semiconductor switching device, the gate is made variable in mirror voltage thereof.

Abstract: A pulse width modulation method has the steps of operating a second instruction signal so that each of the differences between two or three arbitrary instruction signals in three first instruction signals may become more than the predetermined value, and modulating in pulse width based on the second instruction signal.

Abstract: A pulse width modulation method has the steps of operating a second instruction signal so that each of the differences between two or three arbitrary instruction signals in three first instruction signals may become more than the predetermined value, and modulating in pulse width based on the second instruction signal.

Abstract: A gate driver circuit of a voltage drive type power semiconductor switching device capable of speeding up di/dt and dv/dt even during large-current driving to thereby reduce the switching loss is disclosed. This power semiconductor switching device gate driving circuit includes a drive circuit which applies a drive signal to the gate electrode of the power semiconductor switching device and a measurement unit for measuring a flow current of the power semiconductor switching device. Based on a detected value of the flow current of the power semiconductor switching device, the gate is made variable in mirror voltage thereof.

Abstract: An aquarium-cleaning device, particularly an aquarium-cleaning device in which spent grain charcoal is used as formed charcoal. The formed charcoal provided by drying, forming, and carbonizing organic substances produced in food industries is used as a microorganism carrier. Such problems with a conventional device that the structure of the aquarium-cleaning device is complicated, the washing operation thereof is troublesome, and a filter medium must be frequently replaced can be solved by using the spent grain charcoal performing higher water-quality purification than a conventional activated charcoal as an aquarium-cleaning material.

Abstract: A woven or knit fabric comprising air-jet interlacing spun yarns comprising polyester fibers of low titanium oxide content; a woven or knit fabric comprising air-jet interlacing spun yarns comprising polyester staple fibers obtained by graft polymerization of a hydrophilic compound; a woven or knit fabric comprising air-jet interlacing spun yarns comprising side by side crimped staple fibers; a woven or knit fabric comprising air-jet interlacing spun yarns comprising low-shrinkage staple fibers and copolymerized polyester staple fibers; and a process for producing these. A woven or knit fabric of polyester staple fibers that is bulky, excelling in moisture retention, lightweightness, water absorptivity, quick dryability, etc. and exhibits excellent anti-pilling properties can be obtained.

Abstract: A pulse width modulation method has the steps of operating a second instruction signal so that each of the differences between two or three arbitrary instruction signals in three first instruction signals may become more than the predetermined value, and modulating in pulse width based on the second instruction signal.

Abstract: In calculation 3 phase AC output current Iu, Iv,Iw of an inverter based on the input DC current Idc of the inverter, it is difficult to detect the DC current Idc when the line-to-line voltage pulse width is narrow, thereby the DC current Idc pulse width becomes narrower. The frequency Fc of the carrier wave C is lowered in a phase whose line-to-line voltage is high, thereby the DC current Idc pulse width is set wider. As a result, the current detection is enabled.

Abstract: In detecting an output current of a power converter based on a DC current Idc of the power converter, the pulse width of the DC current Idc becomes narrower when the pulse width of a line voltage is narrower, and its detection becomes difficult. A voltage command correction unit 9 according to the present invention corrects voltage commands such that pulse width of a line voltage becomes zero when the pulse width of the line voltage is less than the minimum pulse width, not to output a line pulse, and an error generated by the correction is integrated. This integrated error is added to the line voltage in the next time, and the integrated pulse width of the line voltage is outputted when the pulse width becomes larger than or equal to the minimum pulse width.

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: An induction motor control apparatus includes a first constant correction unit for correcting primary resistance based on quantity obtained by multiplying quantity of a voltage command from a frequency voltage control unit by the output of a correction unit, the quantity of the voltage command being a result of partial differentiation with the primary resistance; a second constant correction unit for correcting the inductance based on quantity obtained by multiplying quantity of the voltage command, the quantity of the voltage command being a result of partial differentiation with the inductance; and a third constant correction unit for correcting the inductance ratio based on quantity obtained by multiplying quantity of the voltage command, the quantity of the voltage command being a result of partial differentiation with the inductance ratio, suppressing the deterioration of control performance caused by the setting errors.

Abstract: In calculation 3 phase AC output current Iu, Iv,Iw of an inverter based on the input DC current Idc of the inverter, it is difficult to detect the DC current Idc when the line-to-line voltage pulse width is narrow, thereby the DC current Idc pulse width becomes narrower.

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 single-phase PWM converter system in accordance with the present invention employs a sample-and-hold circuit which samples and holds a direct current in the state wherein one of two-phase gate signals of a positive or negative side arm is ON and the other phase is OFF, determines the sign of an output of the sample-and-hold circuit according to the two-phase gate condition, detects a phase current at the input side of the converter, and controls a voltage at the input side of the converter so that the detected current value agrees with a power supply current command. Further, a three-phase PWM converter system in accordance with the present invention detects the effective current and the ineffective current of the power supply current from the direct current, and based on the values, controls the PWM converter so that the sine wave power supply current whose power supply power factor is 1 is provided.

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.