Abstract: A gate driver for a semiconductor power device and a method of driving the gate of a semiconductor power device. The current flowing through the semiconductor power device, caused by a first gate drive voltage during the present switching cycle, is sensed. Based on a second drive signal to be used in the next switching cycle, a second current is determined for that second drive signal, which are then compared to an EMC model. The EMC model defines a plurality of EMC values for respective gate drive voltages and currents conducted through the semiconductor power device. A gate drive voltage adjustment value is selected from a plurality of gate drive voltage adjustment values in the EMC model based on the predicted EMC value generated by the semiconductor power device when being driven using the second drive voltage and conducting the second current. The second gate drive voltage is adjusted using the selected gate drive voltage adjustment value for the next switching cycle.

Abstract: There is provided a method and control system for controlling a switching device in a power converter according to a modulation scheme. The switching device couples a direct current (DC) source to provide an alternating current (AC) output at a particular switching frequency. The method comprises the step of, in each switching period, switching the switching device between active configurations providing a finite voltage at the output and inactive configurations providing a zero voltage at the output. The ratio between the total period of time in which the switching device is in an active configuration and the total period of time in which the switching device is in an inactive configuration is the same for each switching period and is determined according to the desired voltage at the AC output.

Abstract: Conducting emission suppression in a power circuit for an electric motor comprises a negative temperature co-efficient resistor and capacitor connecting one of the power lines to ground. The NTC resistor is self-stabilizing so that changes in the load current are automatically compensated for.

Abstract: A supply voltage compensation circuit comprising a processor arranged to sense a signal indicative of a supply voltage on an input wherein if the signal indicates that the supply voltage is under a predetermined threshold, the processor is arranged to provide an output signal arranged to couple an auxiliary energy source to provide voltage compensation for supply under voltage.

Abstract: A method is disclosed for controlling at least four switching components of a multi-level converter. The method comprises receiving first and second control signals for controlling a dual-level inverter having two switching components, and processing the first and second received control signals to produce at least four switching component control signals for controlling the switching components of a multi-level converter. Also disclosed are a control logic system, a multi-level converter system and a computer readable medium.

Abstract: A method comprises: applying control signals to an inverter switching network according to a selected switching sequence, wherein a switching sequence is applied corresponding to a desired sector of a switching scheme in which a demand vector is currently located, the switching scheme corresponding to the demand vector in a space vector modulation scheme having stationary active vectors around the periphery and a stationary zero vector at an origin; storing a plurality of simultaneous switching schemes in which, for a single switching cycle, a switch in each of at least two phases of the inverter switching network is switched simultaneously from a first state to a second state with a corresponding switch in at least one other phase of the inverter switching network being in a given state and in which the switch in each of the at least two phases is switched simultaneously from the second state to the first state with the switch in the at least one other phase being in the given state; and applying a simultane

Abstract: A method is provided of determining a time interval between switching events for a switching device in a power converter, the switching device being for coupling a direct current (DC) source to provide an alternating current (AC) output at a particular switching frequency. The method comprises selecting an initial length of a time interval between a first switching event and a second, subsequent switching event for the switching device and obtaining a current measurement value for the switching device when the time interval between the first switching event and the second, subsequent switching event takes said initial length. The method further comprises changing the length of the time interval between the first switching event and the second, subsequent switching event and obtaining a current measurement value for the switching device when the length of the time interval is changed. The current measurement values which have been obtained are used to detect generation of a current in the switching device.

Abstract: There is provided a method and control system for controlling a switching device in a power converter according to a modulation scheme. The switching device couples a direct current (DC) source to provide an alternating current (AC) output at a particular switching frequency. The method comprises the step of, in each switching period, switching the switching device between active configurations providing a finite voltage at the output and inactive configurations providing a zero voltage at the output. The ratio between the total period of time in which the switching device is in an active configuration and the total period of time in which the switching device is in an inactive configuration is the same for each switching period and is determined according to the desired voltage at the AC output.

Abstract: A damage limitation approach comprising determining that a voltage produced by a rectifier circuit is indicative of a fault and consequently controlling a switch operable to bypass a resistive element of a circuit via which the rectifier circuit is supplied.

Abstract: A power supply arranged to charge a smoothing capacitance via a resistive element for soft-starting in the event that one or more conditions for normal operation are not complied with is arranged to detect that a voltage across at least part of the smoothing capacitance exceeds an excess voltage threshold and, responsive to the detecting, interrupt charging of the smoothing capacitance via the resistive element for soft-starting.

Abstract: Conducting emission suppression in a power circuit for an electric motor comprises a negative temperature co-efficient resistor and capacitor connecting one of the power lines to ground. The NTC resistor is self-stabilising so that changes in the load current are automatically compensated for.

Abstract: A circuit for monitoring the operation of an electric motor comprises means for deriving a motor signal indicative of a relatively low frequency characteristic of the motor commutation current (for example the back EMF ripple) by rejecting the high frequency components which are mainly the result of the commutation events. The circuit also includes means for producing a pulse from the low frequency characteristic which has a duration related to the motor speed.