The present application claims the benefit of priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2006-185557, filed on Jul. 5, 2006, the entire contents of which are incorporated herein by reference.
1. Field of Art
The present invention relates to an electric motor car drive control apparatus for controlling a train drive system, which drives a locomotive or a motor railcar, including a plurality of permanent magnet synchronous motors (referred in the drawings to “PMSM”) each respectively configured as a drive motor, and a plurality of VVVF (variable voltage variable frequency: referred in the drawings to “VVVF”) inverters each respectively adapted for an individual driving of a corresponding permanent magnet synchronous motor.
2. Description of Relevant Art
According to a relevant art employing induction motors (referred in the drawings to “IM”) as drive motors, two or four induction motors are connected in parallel as a control unit to be controlled with a single VVVF inverter. Accordingly, if any induction motor fails, whole induction motors in the control unit where the failing induction motor belongs are opened together with an associated inverter.
The induction motors 28, 29, 30, and 31 are now referred to IM(1), IM(2), IM(3), and IM(4), respectively, for better understanding. In
As shown in Japanese Patent Application Laid-Open Publication No. 2005-328619 (Japanese Patent Application No. 2004-143577), synchronous motors using permanent magnets may be employed as drive motors. In such a case, each permanent magnet synchronous motor needs a control with a voltage supplied from a VVVF inverter in accordance with a rotation of the rotor, and it is required to provide a single dedicated VVVF inverter per one motor, to implement a so-called individual control. In this individual control, if any motor fails, the opening is to be made by a unit of truck, allowing for a so-called individual opening.
There is thus needed a configuration for the so-called individual control, where opening contactors for VVVF inverters, as well as gate controllers for gate control of the inverters, should be identical in number to the motors to be controlled, as shown in
Such being the case, in a train drive system having permanent magnetic synchronous motors employed as drive motors according to a relevant art, a configuration for individual control is needed, requiring opening contactors for VVVF inverters, as well as gate controllers for gate control of the inverters, to be identical in number to the motors, with an increased cost and an enlarged installation size, as a problem.
The present invention has been devised in view of such points in the relevant art. It therefore is an object of the present invention to provide an electric motor car drive control apparatus enabling, in a train drive system having permanent magnetic synchronous motors employed as drive motors, such a configuration that allows, upon a failure of any motor, a similar control to a centralized control like the case of induction motors, unless an individual opening is required for each motor, thus allowing for a reduced cost and a minimized installation size of the system.
An aspect of the present invention is an electric motor car drive control apparatus which includes a plurality of permanent magnetic synchronous motors provided as car drive motors, a plurality of VVVF inverters adapted to drive the plurality of permanent magnetic synchronous motors in a one-to-one corresponding manner, the plurality of VVVF inverters being grouped into a plurality of control units each respectively composed of two or more VVVF inverters, and a plurality of gate controllers provided one for each control unit.
According to the electric motor car drive control apparatus of this invention, the plurality of permanent magnetic synchronous motors can be individually controlled by the plurality of VVVF inverters, respectively, and twos or mores of the plurality of VVVF inverters can be each controlled concurrently by a single gate controller, so that a simple provision of gate controllers identical in number to a fraction of division by the number of VVVF inverters of the control unit can do well, without needing an equivalent number of gate controllers to the plurality of VVVF inverters, thus allowing for a decreased cost and a minimized installation size of the system.
There will be described below the preferred embodiments of the present invention into details with reference to the accompanying drawings. Like members or elements will be designated by like reference characters.
In the above-noted electric motor car drive control apparatus, the gate controller 22 is configured to control both of gates of the set of VVVF inverters 9, 10. In the event of a failure of either inverter, e.g. VVVF inverter 9, of one control unit, the gate controller 22 works to open the opening contactor 5 associated with that control unit, thereby stopping two VVVF inverters 9, 10 constituting the control unit, while opening both the permanent magnetic synchronous motors 17, 18. In other words, the electric motor car drive control apparatus according to this embodiment is adapted for a control to implement a sort of truck opening.
According to the present embodiment, it is possible to reduce the number of gate controllers, as well as that of opening contactors, to a fraction of division by the number thereof in the control unit, i.e., one half, with respect to that of an electric motor car drive control apparatus employing permanent magnetic synchronous motors according to a relevant art, thus enabling, even for a synchronous motor using permanent magnets, a principal circuit configuration more like to the truck control of induction motors, allowing for a reduced cost and a minimized installation size.
It is noted that in the present embodiment the gate controllers 22 and 23 have CPU's employed therefor, which are each able to control a plurality of motors, and adapted in a wheel slip and skid control to achieve a fast recognition of speeds of the four motors, allowing for implementation of a high-speed slip and skid control by an instantaneous detection of speed differences between those motors.
In the present embodiment, the single gate controller 25 is configured with an incorporated CPU, which is adapted for an individual control of the four VVVF inverters 9 to 12.
In the electric motor car drive control apparatus according to this embodiment, the single gate controller 25 is configured to control the gate of a respective one of four VVVF inverters 9 to 12 in the control unit. In this case, if any VVVF inverter in the control unit, e.g. the VVVF inverter 9, fails, this is followed by control actions to open the whole system in which no opening contactor is provided. In other words, in this embodiment, the electric motor car drive control apparatus is adapted to implement a sort of centralized control.
According to this embodiment of electric motor car drive control apparatus, it is possible to reduce the number of gate controllers to a quarter of that in a relevant art, thus enabling, even for a synchronous motor using permanent magnets, a main circuit configuration more like to the centralized control of induction motors, allowing for a reduced cost and a minimized installation size.
While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes, and it is to be understood that changes and variations may be made without departing from the scope of the following claims.
Number | Date | Country | Kind |
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2006-185555 | Jul 2006 | JP | national |