Power conversion system for bi-directional conversion between hydraulic power and electrical power

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;
• 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;
• 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;
• and
• an electronic power control unit that is electrically connected to at least one terminal of said electrical switching arrangement and that is further adapted to be connected to the on-board electrical system so as to form an electrical series connection, in order, of said electrical machine, said electrical switching arrangement, said electronic power control unit and the on-board electrical system.

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;
• 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;
• 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 that:
• comprises an operating mode logic circuit,
• is connected for signal transmission to said hydraulic switching arrangement and to said electrical switching arrangement,
• is 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
• is 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;
• at least one pressure sensor adapted to be connected to and sense a hydraulic pressure in the on-board hydraulic system;
• at least one pressure signal line connecting said at least one pressure sensor to said operating mode logic circuit for transmitting a pressure dependent data signal indicative of said hydraulic pressure in the on-board hydraulic system from said at least one pressure sensor to said operating mode logic circuit;
• at least one voltage sensor adapted to be connected to and sense a voltage in the on-board electrical system;
• at least one voltage signal line connecting said at least one voltage sensor to said operating mode logic circuit for transmitting a voltage dependent data signal indicative of said voltage in the on-board electrical system from said at least one voltage sensor to said operating mode logic circuit;
• at least one controllable electrical disconnect switch connected to said electrical switching arrangement and adapted to be connected to the on-board electrical system interposed between said electrical switching arrangement and the on-board electrical system;
• and
• respective control signal lines connecting said operating mode logic circuit respectively to said hydraulic switching arrangement, said electrical switching arrangement and said at least one disconnect switch;
• and
• wherein said operating mode logic circuit is adapted to evaluate said data signals, to generate control signals dependent thereon and responsive thereto, and to transmit said control signals onto said control signal lines.

In an air-craft having at least one engine, at least one primary hydraulic pump connected to one engine of said at least one engine to be driven thereby, a hydraulic conduit system hydraulically connected to said at least one primary hydraulic pump, at least one primary electrical generator connected to one engine of said at least one engine to be driven thereby, and an electrical conductor system electrically connected to said at least one primary electrical generator,

• an improved power conversion and transfer system interconnected between said hydraulic conduit system and said electrical conductor system for bi-directionally converting and transferring electrical power in said electrical conductor system to and from hydraulic power in said hydraulic conduit system, said improved 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 controllably hydraulically connecting said hydraulic machine with said hydraulic conduit system, wherein said hydraulic switching arrangement has a first port hydraulically connected to said hydraulic conduit 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 controllably electrically connecting said electrical machine with said electrical conductor 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 said electrical conductor system, a hydraulic operating condition of said hydraulic conduit 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 said hydraulic conduit 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;
• and
• a 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.