A system for controlling fault tolerance may include a first controller connected to a driver, a first switch connected in parallel to the first controller, a first capacitor connected in parallel to the first switch, a second switch connected in parallel to the first capacitor and different from the first switch, a first power supply connected in parallel to the first capacitor and connected in series to the second switch, and a second capacitor connected to the first switch and a ground of the first power supply and different from the first capacitor. When the first controller is broken down, the second switch may be turned off to interrupt power supply from the first power supply, and the first switch may be turned on to discharge electric charges charged in the second capacitor.

A motor control device includes an energization controller that generates energization control signals of a bridge driver, an ADC that samples and converts analog feedback voltages corresponding to output voltages of the bridge driver into digital feedback signals, and a zero-crossing detector that receives the feedback signals so as to perform zero-crossing detection for determining commutation timing and PWM duty of the energization control signal. Sampling timings of the ADC are switched to one of PWM on period and PWM off period according to the PWM duty. The energization controller PWM drives lower side switches of the bridge driver, and the sampling timings of the ADC are set to the PWM off period. The ADC performs an ADC process of the feedback voltage both in the PWM on period and in the PWM off period, and the zero-crossing detector adopts one of ADC results according to the PWM duty.

The invention relates to a motor control processing unit for a motor control device which comprises a voltage source inverter unit, configured to control the voltage source inverter unit to provide a motor voltage following a pulse-width modulation, PWM, scheme, wherein the motor control processing unit is configured to control the voltage source inverter unit according to a flat PWM scheme, which comprises a flat-bottom or flat-top PWM scheme, at least at some times in order to provide a precise motor control with minimized losses. The invention also relates to a corresponding method.

Methods and systems of optimizing efficiency of a motor drive or generator are provided. The methods include measuring data corresponding to input power and output power of a motor drive or generator at a control parameter and different load values. The methods include generating a three-dimensional surface model based on the measured data. The three-dimensional surface model can estimate an efficiency of the motor drive or generator at the control parameter and at unmeasured load values. The methods can include determining optimal efficiency of the motor drive or generator at the different load values and the unmeasured load values based on the three-dimensional surface model.

A heat pump device includes an inverter control unit outputting PWM signals to an inverter; a current detection unit detecting a current value flowing in the inverter and outputting the current value after reducing a current value having a first frequency or higher in detected current value; and a drive-signal stop unit that, when the current value output from the current detection unit is equal to or larger than an interruption level, stops output of PWM signals to the inverter. Particularly, the inverter control unit generates a voltage command value such that the voltage command value becomes a value equal to or larger than a lower limit determined according to the first frequency and generates PWM signals based on generated voltage command value and a carrier signal, thereby causing a voltage output time to the motor to be a predetermined time or longer.

A method for operating an electric drive system is provided. For example, a controller retrieves, from memory, a predictive model indicating predictive winding temperatures associated with known negative temperature coefficient (NTC) temperatures, wherein the predictive model is based on historical NTC temperatures and historical winding temperatures, as well as one or more operating parameters. The controller receives current NTC information indicating one or more current NTC readings corresponding to one or more switching devices within the inverter. The controller determines estimated winding temperatures corresponding to the electric machine based on the predictive model and the one or more current NTC readings as well as current operating parameters. The controller provides instructions to adjust inputs to the electric machine based on the estimated winding temperatures.

One or more example embodiments provide systems and methods for using impedance separation and impedance shaping.

The invention results in improved switching from the idling mode to an active short circuit mode of an electric machine. According to the invention, the switch from the idling mode to the active electric short circuit mode is delayed until predefined voltage conditions have been reached on the external terminals of an electric machine or until the rotor of the electric machine is in a predetermined position corresponding to the required voltage conditions.

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.

Provided is a work machine capable of improving workability. The work machine is provided with: a motor 14; a first power supply unit 180 connected to a battery pack 5 and supplying a boosted power to the motor 14; and a second power supply unit 130 connected to an external AC power supply and supplying a boosted power to the motor 14. The voltage and current of the first power supply unit 180 and the voltage and current of the second power supply unit 130 can be variably controlled by a control circuit 182 and a control circuit 136, respectively. The control circuits 136, 182 perform control so that the power output from the respective first power supply unit 180 and the second power supply unit 130 is combined and supplied to the motor 14.