Ebara Corporation

Kabushiki Kaisha Toshiba

Toshiba Corporation

Fuji Electric Holdings Co., Ltd.

Yukio Murai

Katsuya Okumura

Manabu Tsujimura

Fumio Kuriyama

Hiroshi Sobukawa

Masahito Kawai

Kaoru Nakajima

Kenichi Kajiwara

Nobuhiro Higaki

Masahiko Kishi

Seiichi Toguchi

Masahiro Minami

Hiroaki Ichikawa

A photovoltaic inverter control method includes steps of monitoring a variation in output voltage of a solar battery by a power and voltage monitoring circuit () and, when the variation occurs, accelerating or decelerating an electric motor () to maximize the output voltage of the solar battery (), whereby the electric motor for driving, for example, a pump and a fan by the solar battery as a power source can be driven by a photovoltaic inverter always at the maximum power point of the solar battery.

Method and device for controlling photovoltaic inverter, and feed water device

According to the present invention, in a water supply apparatus which converts output power of a solar cell with an inverter to drive a motor pump for pumping up water, a DC brushless motor having no sensor for detecting a position of a rotatable shaft is used as a motor for driving the pump. Further, the water supply apparatus, having a pump and a frequency converter for supplying electric power to the pump and controlling a rotational speed of the pump, includes a standard current value table in which rotational frequencies of the pump and standard current values as criteria for shutoff operation at the rotational frequencies are associated with each other, a rotational frequency detecting device for detecting a rotational frequency of the pump, a standard current value acquiring device for acquiring a standard current value corresponding to the rotational frequency detected by the rotational frequency detecting device with reference to the standard current value table, a current detecting device for detecting a current value supplied to the pump, and a comparing device for comparing the current value detected by the current detecting device with the standard current value acquired by the standard current value acquiring device.

Water supply

A pump system comprising a pump having a centrifugal impeller driven by an electric motor, a pair of upper and lower float switches for detecting a high water level HWL and a low water level LWL, respectively, a controller for outputting a control signal on the basis of preset rotational speeds for low and high-speed operations and a preset rotational speed increment rate, together with output signals from the upper and lower float switches, and a frequency converter for varying the rotational speed of the electric motor on the basis of the control signal from the controller, the pump system is capable of exhibiting the required pumping performance and of controlling the flow rate and the pump head.

Pump system and method for operating the same

An evacuation apparatus and method using a turbomolecular pump having a rotor provided with a plurality of rotor blades and a spacer provided with a plurality of stator blades so that gas molecules are sucked in from a suction port, compressed and discharged from an exhaust port of the turbomolecular pump is disclosed. A heat exchanger is provided at the suction port side of the turbomolecular pump to freeze-trap gas molecules from being cooled by a helium refrigerator. The gate valve is disposed upstream of the heat exchanger and is provided in a suction pipe which extends between the vacuum vessel and the turbomolecular pump. In exhausting the vacuum vessel, the gate valve is opened and, in this state, the turbomolecular pump and the helium refrigerator are run. During regeneration, the gate valve is closed, the turbomolecular pump is run, and the heat exchanger is heated by means of a heater or by operation of the helium refrigator being suspended, thereby sublimating molecules freeze-trapped in the heat exchanger.

Evacuation apparatus and evacuation method

A turbomolecular pump having a rotor provided with a plurality of rotor blades and a spacer provided with a plurality of stator blades so that gas molecules are sucked in from a suction port, compressed and discharged from an exhaust port. The pump further has a heat exchanger provided inside the suction port, the heat exchanger being connected to a refrigerator through a refrigerant pipe and a gate valve provided on the upstream side of the suction port. Gases having low molecular weights, particularly water vapor, are freeze-trapped on the heat exchanger. Thus, it is possible to efficiently exhaust gases having low molecular weights, particularly water vapor, and hence to obtain a high vacuum of good quality. In addition, it is easy to start and suspend operation of the system and possible to run it on a continuous basis.

Turbomolecular pump and method of operating the same

Growing community of inventors

Kanagawa, Japan

Yukio Murai