Patents by Inventor Rong Fan Liu

Rong Fan Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6794838
    Abstract: A method of regulating the power demanded by a rail motor including a current collector system cooperating with a catenary supplied with direct current power by power supply substations distributed along the track includes the steps of: measuring the catenary voltage Vcat at the rail motor, measuring the catenary current Icat at the rail motor, evaluating the no-load voltage Vcat0 of the substation supplying power to the catenary to which the rail motor is connected, evaluating the maximum power available to the catenary from the equation: P ⁢   ⁢ max = ( Vcat 0 ) 2 4 * R where R is the resistance of the catenary, and limiting the power demanded by the rail motor to a power limit Plim less than or equal to the calculated maximum power Pmax.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: September 21, 2004
    Assignee: Alstom
    Inventors: Jean-Michel Debard, Rong-Fan Liu
  • Publication number: 20030197493
    Abstract: A method of regulating the power demanded by a rail motor including a current collector system cooperating with a catenary supplied with direct current power by power supply substations distributed along the track includes the steps of: measuring the catenary voltage Vcat at the rail motor, measuring the catenary current Icat at the rail motor, evaluating the no-load voltage Vcat0 of the substation supplying power to the catenary to which the rail motor is connected, evaluating the maximum power available to the catenary from the equation: 1 P ⁢   ⁢ max = ( Vcat 0 ) 2 4 * R
    Type: Application
    Filed: April 3, 2003
    Publication date: October 23, 2003
    Applicant: ALSTOM
    Inventors: Jean-Michel Debard, Rong-Fan Liu
  • Patent number: 6411051
    Abstract: This monitoring apparatus for monitoring the adhesion of a motive power unit of an electric rail vehicle set comprises a power control stage for controlling the power supplied to the motor of the motive power unit, and an adhesion monitoring stage proper delivering to the power control stage a reference signal generated on the basis of at least one operating characteristic of the motor so as to keep the slip of the wheels of the motive power unit under control. The apparatus further comprises means for generating an activation signal for activating the monitoring apparatus and means for injecting the activation signal into the reference signal so as to cause it to deliver a modified reference signal.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: June 25, 2002
    Assignee: Alstom
    Inventor: Rong Fan Liu
  • Patent number: 6114829
    Abstract: A traction system in voltage mode includes power supply buses of an electric traction vehicle, the power supply buses each including a 2F filter with the midpoints of the 2F filters being linked together.
    Type: Grant
    Filed: January 26, 1999
    Date of Patent: September 5, 2000
    Assignee: Alstom Transport S.A.
    Inventor: Rong Fan Liu
  • Patent number: 5687071
    Abstract: A voltage lowering device includes at least one pair of forced commutation single-phase rectifiers connected to secondary windings of a main traction transformer. The power drawn from a direct current mains power supply passes through the main traction transformer and is recovered at a secondary winding by means of a forced commutation single-phase rectifier operating as a voltage increasing controlled rectifier. The other forced commutation single-phase rectifiers operate as synchronous voltage inverters. An asynchronous traction system supplied by a single-phase mains power supply includes a voltage lowering device as previously described.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: November 11, 1997
    Assignee: Gec Alsthom Transport SA
    Inventors: Marc Debruyne, Rong Fan Liu