Patent ID: 6023134
Filing Date: 2000-02-08
Classification: F02C,Y02T,Y10S

Abstract:
A power conversion system for bi-directionally converting electrical power to and from hydraulic power, adapted to be connected to and between an on-board hydraulic system and an on-board electrical system of a vehicle, said power conversion system comprising:a hydraulic machine, that can operate selectively as a hydraulic motor and as a hydraulic pump, and that has a first rotatable power input/output element and a first hydraulic port;an electrical machine, that can operate selectively as an electrical generator and as an electrical motor, and that has a second rotatable power input/output element that is mechanically coupled to said first rotatable power input/output element;a hydraulic switching arrangement hydraulically connected to said hydraulic machine and adapted to controllably hydraulically connect said hydraulic machine with the on-board hydraulic system, wherein said hydraulic switching arrangement has a first port adapted to be hydraulically connected to the on-board hydraulic system and a second port connected to said first hydraulic port of said hydraulic machine;an electrical switching arrangement electrically connected to said electrical machine and adapted to controllably electrically connect said electrical machine with the on-board electrical system;a control unit connected for signal transmission to said hydraulic switching arrangement and to said electrical switching arrangement, adapted to detect at least one control data selected from an electrical operating condition of the on-board electrical system, a hydraulic operating condition of the on-board hydraulic system, and a control selection input, and adapted to actuate and control said hydraulic switching arrangement and said electrical switching arrangement responsively to said at least one control data so as to actuate a selected one of a first operating mode in which said hydraulic machine operates as said hydraulic motor and said electrical machine operates as said electrical generator, and a second operating mode in which said electrical machine operates as said electrical motor and said hydraulic machine operates as said hydraulic pump, responsively to said at least one control data;a hydraulic machine control and regulation unit connected to said hydraulic machine for controlling and regulating the operation thereof;a first pressure sensor adapted to sense a system pressure in the on-board hydraulic system and connected for signal transmission to said control unit;a second pressure sensor interposed and adapted to sense a hydraulic pressure prevailing between said second port of said hydraulic switching arrangement and said first hydraulic port of said hydraulic machine and connected for signal transmission to said hydraulic machine control and regulation unit; anda rotational speed sensor arranged and adapted to sense a rotational speed of said first rotatable power input/output element of said hydraulic machine and connected for signal transmission to said hydraulic machine control and regulation unit.