Abstract:
The present invention relates to a method and a control system for driving a three-strand brushless, electronically commutated electric motor (2), wherein a line AC voltage (UN) is rectified and fed via a slim DC link (8) with minimum DC link reactance as a DC link voltage (UZ) to an inverter (10) that can be driven to supply and commutate the electric motor (2). A pulsating DC voltage (UG) initially generated by rectifying the line AC voltage (UN) is dynamically increased with respect to its instantaneous values by a step-up chopper (18) in such a manner that the resulting DC link voltage (UZ) with a reduced ripple always lies above a defined limit voltage (U18/U1) over time. The control system consists of a network rectifier (6), a downstream slim DC link (8) with minimum DC link reactance and a controllable inverter (10) that can be supplied via the DC link and driven to commutate the electric motor (2). A step-up chopper (18) is integrated therein with a controller (20) designed in such a manner that, the pulsating DC voltage (UG) rectified by the network rectifier (6) is dynamically increased with respect to its instantaneous values in such a manner that the resulting DC link voltage (UZ) with a reduced ripple always lies above a defined limit voltage (U20/U1) over time. Stray inductances (Ls1-Ls3) of the motor winding heads present in the electric motor (2) are used as inductor (L) for the step-up chopper (18).
Abstract:
The present invention relates to a motor controller, including a converter for converting commercial AC power into DC power, an inverter including a plurality of switching elements, the inverter receiving the DC power, converting the DC power into AC power of a specific frequency through switching operations, and supplying the AC power to a three-phase motor, and a noise filter unit connected between the commercial AC power and the converter in order to remove a high frequency current and including normal mode inductors and common mode inductor. Accordingly, the motor control can control the power factor, limit a high frequency current, and eliminate noise components, that is, ripple components of an input current.
Abstract:
A battery charger electrically connected with a power distribution circuit may select a charge rate to charge a vehicle battery in response to whether a load other than the battery charger is electrically connected with the power distribution circuit, and charge the vehicle battery at the selected charge rate.
Abstract:
An object is to improve the accuracy of reactive power adjustment. Reactive-power command values corresponding to individual wind turbines are determined by correcting a predetermined reactive-power command value for an interconnection node A using reactive power correction levels set for the individual wind turbines.
Abstract:
A power inverter control adjusts input power to track with output power to reduce energy handling requirements for an inverter DC bus. Input power to the power inverter circuit is measured and compared with a measurement of inverter output power. The comparison result is applied to a power factor correction circuit to adjust input power to track with output power, while obtaining a good power factor for the power inverter circuit. The energy requirements and ripple voltages or ripple currents on the DC bus are reduced, leading to a reduction in rating specifications for passive energy storage elements on the DC bus.
Abstract:
A power inverter control adjusts input power to track with output power to reduce energy handling requirements for an inverter DC bus. Input power to the power inverter circuit is measured and compared with a measurement of inverter output power. The comparison result is applied to a power factor correction circuit to adjust input power to track with output power, while obtaining a good power factor for the power inverter circuit. The energy requirements and ripple voltages or ripple currents on the DC bus are reduced, leading to a reduction in rating specifications for passive energy storage elements on the DC bus.
Abstract:
A motor controller unit of the type providing optimum motor operation and protection is configured to determine phase rotation correction during motor start-up without stopping and re-configuring. The effects of heat on the squirrel cage (amortisseur) and motor field windings are accurately and automatically determined on a continuing basis to deter nuisance trip occurrence during motor start and restart operations and to prevent damage to the motor windings during continuous motor operation, respectively.