Method and apparatus for controlling a high-speed AC permanent magnet synchronous motor coupled to an industrial turbo engine
AssigneeFord Global Technologies, LLC
InventorBing Cheng
Life of this patent
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Abstract
A method and apparatus for controlling a permanent magnet synchronous motor (8) coupled to a turbo engine such that transient current and steady state current are minimized. The method comprises the steps of, for a given DC bus voltage, determining an acceleration profile as a function of a voltage-offset value, a low-speed rated speed value, a high-speed rated speed value, a first desired speed for warming up the turbo engine, and a second desired speed where the turbo engine has sufficient torque to accelerate to its rated speed without the aid of the permanent magnet synchronous motor (8).
Claims14
A method for starting a turbo engine coupled to a rotary machine for a given DC bus voltage, said method comprising the steps of:
- accelerating the rotary machine to a turbo warm-up speed along a low-speed V/f profile;
- starting the turbo engine at a turbo starting speed, where said turbo starting speed is less than said turbo warm-up speed;
- maintaining the rotary machine at said turbo warm-up speed for a predetermined time to warm-up the turbo engine;
- thereafter, accelerating the rotary machine from said turbo-warm-up speed to a switching speed along said low-speed V/f profile having a first slope;
- thereafter, accelerating the rotary machine from said switching speed to a second speed along a high-speed V/f profile having a second slope;
- thereafter, accelerating the rotary machine from said second speed to a turbo uncoupling speed;
- and
- uncoupling the rotary machine from the turbo engine;
- and
- accelerating the turbo engine from said turbo uncoupling speed to a desired speed.
The method as in claim further 8, further comprising determining said actual high-speed rated speed value as a function of an optimal high-speed low DC voltage rated speed value, an optimal high-speed high DC voltage rated speed value, a minimum DC bus voltage, a maximum DC bus voltage, and the given DC bus voltage.
Dependencies are inferred from the claim text.