Abstract:
A motor drive device has an abnormality detection function for a power supply unit between its own device and a power supply, and includes: a forward converter that is inputted AC power from the power supply via the power supply input part, and converts the AC power into DC power; a reverse converter that converts the DC power from the forward converter into AC power; a DC link capacitor provided to a DC link between the forward converter and the reverse converter; a voltage detection part that detects voltage of the DC link capacitor; and an abnormality detection part that obtains a voltage change amount for a predetermined time of the DC link capacitor based on voltage values detected by the voltage detection part, and performs abnormality detection on the power supply input part based on the voltage change amount thus obtained.
Abstract:
A method of controlling a full-scale converter system in which both the grid-side inverter unit and the generator-side inverter unit have a series-connection of parallel inverters and form a generator-side and grid-side voltage-center-point at a voltage level between the inverters connected in series. The voltage-center-points are electrically connected by a center-line conductor. Conversion operation with a de-rated maximum active power-output is performed in response to at least one of (i) the grid-side inverter and (ii) the generator-side inverter of the first converter-string being disabled, by disabling active power production of at least one of (i) the grid-side inverter and (ii) the generator-side inverter of the second converter-string, or correspondingly reducing active power production of the second converter-string, thereby preventing a compensation current along the center-line conductor.
Abstract:
An AC-rotating-electric-machine control apparatus includes two or more electric-power conversion circuits that control respective voltages to be applied to the two or more groups of multi-phase armature windings, for each of the two or more groups of multi-phase armature windings; each of the two or more electric-power conversion circuits has two or more switching devices for opening or closing the corresponding group of multi-phase armature windings, for each of the phases; the two or more switching devices are switching-controlled in such a way that opening operation or duty control can be applied to the corresponding group of multi-phase armature windings.
Abstract:
Systems and methods for controlling operation of a power converter based on grid conditions are provided. In particular, a first gating voltage can be applied to a switching element of a power converter associated with a wind-driven power generation system. The first gating voltage can be greater than a threshold voltage for the switching element. A grid event associated with an electrical grid coupled to the power generation system can be detected. A second gating voltage can be applied to the gate of the switching element during the detected grid event. The second gating voltage can be greater than the first gating voltage.
Abstract:
A method and a control device for regulating a drive device includes an electric motor with a motor shaft and a converter for supplying power to the electric motor. To this end, measured values of measured variables, which characterize a power loss of the drive device, are detected and a converter output voltage is adjusted depending on the detected measured values in such a way that the power loss decreases.
Abstract:
Power conversion systems and methods are provided for ride through of abnormal grid conditions or disturbances, in which a system rectifier is operated in a first mode to regulate a DC voltage of an intermediate DC circuit, an inverter is operated in the first mode to convert DC power from the intermediate DC circuit to provide AC output power to drive a load. In response to detecting an abnormal grid condition, the system changes to a second mode in which the rectifier is turned off and the inverter regulates the DC voltage of the intermediate DC circuit using power from the load.
Abstract:
A motor-driven apparatus in one aspect of the present disclosure includes: a brushless motor; a full-wave rectifier circuit; a drive circuit; a controller; and a forcible stop unit. The forcible stop unit performs a forcible stop control to temporarily forcibly stop a switching operation of a plurality of switching elements during a stop period when a full-wave rectified voltage is smaller than an induced voltage generated by a plurality of coils, and the switching operation of the plurality of switching elements is to be stopped.
Abstract:
A motor driving device includes: a converter that converts AC power into DC power; a DC link capacitor provided for the DC link; an inverter that converts DC power into AC power for a motor; an initial charging circuit that charges the DC link capacitor; a potential difference determination unit that determines a potential difference between both ends of the initial charging circuit; a direct current detecting unit that detects direct current supplied to the initial charging circuit; an alternating current detecting unit that detects alternating current supplied to a motor; and an abnormality determination unit that determines that abnormal heat generation occurs in the initial charging circuit when the alternating current detecting unit detects alternating current and the direct current detecting unit detects direct current, in a case in which a potential difference occurs between both of the ends of the initial charging circuit.
Abstract:
A motor drive of an embodiment of the present invention includes a PWM converter for converting AC power inputted from a low voltage AC power source into DC power by PWM control, an inverter for converting the received DC power to AC power to drive a motor, and a capacitor connected between the PWM converter and the inverter. The PWM converter is operated so as to limit input and output currents or input and output power to predetermined values, and supplied from the low voltage AC power source with a lower voltage than a voltage required to drive the motor. The PWM converter boosts a DC link voltage being an output voltage to the voltage able to drive the motor, and thereby serves to increase the potential difference of the capacitor between charged and discharged states to reduce the capacitance of the capacitor.
Abstract:
A motor-driven apparatus in one aspect of the present disclosure includes: a brushless motor; a full-wave rectifier circuit; a drive circuit; a controller; and a forcible stop unit. The forcible stop unit performs a forcible stop control to temporarily forcibly stop a switching operation of a plurality of switching elements during a stop period when a full-wave rectified voltage is smaller than an induced voltage generated by a plurality of coils, and the switching operation of the plurality of switching elements is to be stopped.