Abstract:
A drive circuit is provided for reducing conducted electromagnetic interference provided by a power line to a motor controller. The power line includes a first alternating current (AC) line output and a second AC line output. The drive circuit includes an EMI filter having a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first input terminal is configured to be coupled to the first AC line output and the second input terminal is configured to be coupled to the second AC line output. The drive circuit further includes at least two series-coupled filter capacitors positioned after the EMI filter and a power factor correction (PFC) choke. The PFC choke is coupled at a first end to the second output terminal and at a second end between the series-coupled filter capacitors.
Abstract:
An object is to improve the accuracy of power factor adjustment. Power-factor command values corresponding to individual wind turbines are determined by correcting a predetermined power-factor command value for an interconnection node using power factor correction levels set for the individual wind turbines.
Abstract:
A power factor correction system includes a rectifier that rectifies the voltage of an alternating current (ac) power source to produce a voltage waveform that transitions, in a half sinusoid, from a minimum amplitude to a maximum amplitude and back to the minimum amplitude twice in the period of the ac power source. A phase winding of a motor conveys current induced by the voltage waveform, and a regulator regulates the flow of the current conveyed by the phase winding for storage as energy in a storage component.
Abstract:
A current control module generates a voltage request based on a d-axis current (Idr) demand. A switching control module controls a motor based on the voltage request and generates an out-of-volts (OOV) signal based on a comparison of the voltage request and an available voltage. An Idr injection module generates the Idr demand based on a direct current (DC) bus voltage, a rotational speed, and a demanded torque and selectively applies a first adjustment to the Idr demand. The Idr injection module identifies whether an improvement resulted from the first adjustment, wherein the improvement is identified based on at least one of (i) a measured current of the motor and (ii) the OOV signal. The Idr injection module selectively applies a second adjustment to the Idr demand based on whether the improvement is identified.
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:
An object is to improve the accuracy of power factor adjustment. Power-factor command values corresponding to individual wind turbines are determined by correcting a predetermined power-factor command value for an interconnection node using power factor correction levels set for the individual wind turbines.
Abstract:
A fan includes a motor control device which is electrically connected with a motor and an alternating current power source. The motor control device includes a converting circuit, a power factor correction circuit and a motor controlling circuit. The voltage of the alternating current power source is converted to be direct current voltage by the converting circuit and the power factor correction circuit, and then the direct current voltage is outputted to the motor control circuit. The motor controlling circuit generates a driving signal in accordance with the direct current voltage for driving the motor to operate.
Abstract:
The switching rectifier and switching inverter on a motor drive unit are modulated to indirectly change the magnitude of current and voltage stored in DC link by controlling the magnetic field of the motor to correct for both power factor lead and power factor lag over a wide range of motor speeds and conditions while maintaining a predetermined motor operating point.
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 variable speed drive control system operates a variable speed drive to power a first load from a power source simultaneously powering a second load. An AC reactive power is monitored which may comprise or consist of an AC reactive power of the second load. Responsive to the monitored AC reactive power, the variable speed drive is controlled to counter the AC reactive power of the second load.