Method and system to start multiple AC motors supplied by a power converter via a common AC bus
First Claim
1. A method to start at least two AC motors which are supplied from a common AC bus, which in turn is supplied from a power converter, wherein at least one of the AC motors is an electrically excited synchronous motor comprising an excitation circuit, the method comprising:
- starting first the synchronous motor,during starting of remaining of the at least two AC motorsdetermining a reactive power supplied by the power converter,determining an increase of a field current or of a field voltage of the synchronous motor in linear dependence on the reactive power supplied by the power converter, andapplying the increased field current or field voltage to the excitation circuit of the synchronous motor.
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Accused Products
Abstract
A method to start at least two AC motors that are supplied from a common AC bus, which in turn is supplied from a power converter. At least one of the AC motors is an electrically excited synchronous motor including an excitation circuit. The synchronous motor is started first. During starting of remaining of the at least two AC motors a reactive power supplied by the power converter is determined and an increase of a field current or of a field voltage of the synchronous motor in linear dependence on the reactive power supplied by the power converter is determined. The increased field current or field voltage is applied to the excitation circuit of the synchronous motor.
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Citations
9 Claims
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1. A method to start at least two AC motors which are supplied from a common AC bus, which in turn is supplied from a power converter, wherein at least one of the AC motors is an electrically excited synchronous motor comprising an excitation circuit, the method comprising:
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starting first the synchronous motor, during starting of remaining of the at least two AC motors determining a reactive power supplied by the power converter, determining an increase of a field current or of a field voltage of the synchronous motor in linear dependence on the reactive power supplied by the power converter, and applying the increased field current or field voltage to the excitation circuit of the synchronous motor. - View Dependent Claims (2, 3, 4)
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5. A system, comprising:
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at least two AC motors, wherein at least one of the motors is an electrically excited synchronous motor comprising an excitation circuit, a common AC bus to supply the at least two AC motors, a power converter to supply the common AC bus, and a first control unit to control the excitation circuit, wherein the first control unit starts the first synchronous motor, and determines the reactive power (Q) of the power converter during starting of remaining of the at least two AC motors determines an increase of a field current or of a field voltage of the synchronous motor in linear dependence on the reactive power supplies by the power converter, and applies the increased field current or field voltage to the excitation circuit of the synchronous motor. - View Dependent Claims (6, 7, 8, 9)
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Specification