公开(公告)号：US5265002A

公开(公告)日：1993-11-23

申请号：US757334

申请日：1991-09-10

Applicant: Akira Bando ,  Chikara Tanaka ,  Keiji Saito ,  Tadao Kawai ,  Eizo Kita ,  Keiichi Mitsuhashi ,  Yasuteru Oono ,  Hiroto Nakagawa

Inventor： Akira Bando ,  Chikara Tanaka ,  Keiji Saito ,  Tadao Kawai ,  Eizo Kita ,  Keiichi Mitsuhashi ,  Yasuteru Oono ,  Hiroto Nakagawa

IPC: H02H7/12 ,  H02H7/125 ,  H02M7/12 ,  H02M7/155 ,  H02M7/162

CPC classification number: H02H7/125

Abstract: A semiconductor power conversion system comprising a multiphase bridge circuit which includes semiconductor devices having a controllable firing function and a reverse blocking characteristic, a gate control circuit which gives firing commands to the semiconductor devices, a short circuiting switch in which switching devices having a controllable firing function and a reverse blocking characteristic are connected in parallel with a DC output side of the multiphase bridge circuit, and a protection control device for performing a control for protecting the multiphase bridge circuit. The protection control device includes a device for detecting a commutation failure of the multiphase bridge circuit, and a device in response to the detection of the commutation failure for producing a blocking command for blocking the firing of the semiconductor devices of the multiphase bridge circuit and producing a short-circuiting command for firing the switching device which is short-circuited which bypasses current of the commutation failure. The protection control device further includes a device for detecting ending of a short-circuit based on the ceasing of current conduction of the short circuiting switch and for halting the blocking of the firing of the semiconductor devices of the multiphase bridge circuit.

Abstract translation: 一种半导体功率转换系统，包括多相桥式电路，其包括具有可控的点火功能和反向阻断特性的半导体器件，向半导体器件发出触发命令的栅极控制电路，其中具有可控射击的开关器件的短路开关 功能和反向阻断特性与多相桥式电路的直流输出侧并联连接，以及保护控制装置，用于进行保护多相桥式电路的控制。 保护控制装置包括用于检测多相桥式电路的换向故障的装置，以及响应于检测到换向失败的装置，用于产生用于阻断多相桥式电路的半导体装置的点火的阻塞命令并产生 用于点燃短路的开关器件的短路命令，其绕过换向故障的电流。 保护控制装置还包括用于基于短路开关的电流导通的停止以及用于停止多相桥式电路的半导体装置的点火来检测短路结束的装置。

公开(公告)号：US5026256A

公开(公告)日：1991-06-25

申请号：US285753

申请日：1988-12-16

Applicant: Takao Kuwabara ,  Hisao Inoue ,  Hiroto Nakagawa ,  Eizo Kita

Inventor： Takao Kuwabara ,  Hisao Inoue ,  Hiroto Nakagawa ,  Eizo Kita

IPC: F03B15/06

CPC classification number: F03B15/06 ,  Y02E10/226

Abstract: The operation of a variable speed electric driven pump turbine is monitored continuously during pumping to detect the operation point of the pump turbine, and to prevent it from falling into a hump characteristic region, which is recognizable on a graph of total dynamic head versus flow rate. Stalling occurs in the hump characteristic region as a result of a partial reverse flow of the water with respect to the runner. When the operation point of the pump turbine approaches the hump characteristic region, a corrective action is taken that includes increasing the output level of the electric driven pump turbine to increase its rotating speed, temporarily.

公开(公告)号：US5160244A

公开(公告)日：1992-11-03

申请号：US564138

申请日：1990-08-08

Applicant: Takao Kuwabara ,  Eizo Kita

Inventor： Takao Kuwabara ,  Eizo Kita

IPC: F03B15/06 ,  F03B15/04 ,  F04D15/00

CPC classification number: F04D15/0066 ,  F04D15/00 ,  F04D15/0027 ,  Y02E10/226

Abstract: A variable-speed pump system comprising: a hydraulic machine having a flow adjusting means and including at least a pumping function; a rotary machine operatively connected to the hydraulic machine and including at least a motor function for rotating the hydraulic machine; a frequency converter for driving the rotary machine; and a control system for controlling variable-speed operation of the rotary machine according to a command signal from an external unit. The pump system also includes an electric power control system, a flow adjustment control system, and a rotational speed control system. The power control system has a negligibly small time constant, compared to the time constant of the rotational speed control system. The flow adjustment control system and/or the rotational speed control system has a means for setting a transmission function in such a manner that a mechanical load of the hydraulic machine is not reduced while the rotational speed thereof is increasing, and that the mechanical load is not increased while the rotational speed is lowering.

Abstract translation: 一种变速泵系统，包括：具有流量调节装置并且至少包括泵送功能的液压机; 旋转机械，其可操作地连接到所述液压机器，并且至少包括用于旋转所述液压机器的马达功能; 用于驱动旋转机器的变频器; 以及用于根据来自外部单元的命令信号来控制旋转机器的变速操作的控制系统。 泵系统还包括电力控制系统，流量调节控制系统和转速控制系统。 与转速控制系统的时间常数相比，功率控制系统的时间常数可以忽略不计。 流量调节控制系统和/或转速控制系统具有用于设定传动功能的装置，使得液压机械的机械负载在其转速增加时不降低，并且机械负载为 转速降低时不增加。

公开(公告)号：US5099409A

公开(公告)日：1992-03-24

申请号：US496302

申请日：1990-03-20

Applicant: Akira Bando ,  Chikara Tanaka ,  Keiji Saito ,  Tadao Kawai ,  Eizo Kita ,  Keiichi Mitsuhashi ,  Yasuteru Ohno ,  Hiroto Nakagawa

Inventor： Akira Bando ,  Chikara Tanaka ,  Keiji Saito ,  Tadao Kawai ,  Eizo Kita ,  Keiichi Mitsuhashi ,  Yasuteru Ohno ,  Hiroto Nakagawa

IPC: H02H7/12 ,  H02H7/122 ,  H02H7/125 ,  H02M7/162 ,  H02P9/00

CPC classification number: H02M7/1623 ,  H02H7/1255

Abstract: An improved electric power conversion system comprising a multi-phase bridge circuit composed of semiconductors such as thyristors and an associated firing circuit. It is so constructed that: if the AC input current Iac flowing in the bridge circuit is equal to or larger in value that the DC output current Idc flowing out of the bridge circuit, it will be decided than an inner defect or fault is caused, and possible expansion of inner defect will be prevented by disabling the firing circuit to extinguish the thyristors in the bridge circuit, and if the AC input current Iac is smaller than the DC output current Idc in value, the bridge is permitted to continue the operation of power conversion, thus eliminating unnecessary interruption which otherwise would be caused by exterior disturbances. Also, an improved electric power conversion system may be equipped with a device to prevent an adverse effect from being caused by abnormal rise of thyristors' temperature.

公开(公告)号：US4920277A

公开(公告)日：1990-04-24

申请号：US230434

申请日：1988-08-10

Applicant: Takao Kuwabara ,  Hiroto Nakagawa ,  Eizo Kita

Inventor： Takao Kuwabara ,  Hiroto Nakagawa ,  Eizo Kita

IPC: F03B15/06

CPC classification number: F03B15/06 ,  Y02E10/226

Abstract: A variable speed hydro-power plant includes a pump turbine (2) having a S-shaped characteristics at the turbine operation. A current time turbine operating point is grasped on a turbine characteristics diagram of the pump turbine (2). A limit operation characteristics curve (nr) of the pump turbine (2) is formed in advance so as to not reach the S-shaped characteristics turbine operation region. A reach of the limit operation characteristics curve (nr) is detected, a rotating speed (N) of the pump turbine (2) is lowered. An inrush of the pump turbine (2) into the S-shaped characteristics turbine operation region is eliminated, so the continuation of a stable and reliable turbine operation can be guaranteed.