Abstract: A damping filter network includes a damping filter having a damping filter resistor and a damping filter capacitor connected in series and a tone decoder having an input arranged to be connected to a system input and an output connected to a damping switch. The tone decoder has a pass-band between a lower frequency threshold and an upper frequency threshold, the damping filter resistor and the damping filter capacitor selected to perform damping at frequencies within the pass-band; wherein the tone decoder is configured to detect the frequency of the system input voltage and to close the switch so as to connect the damping filter to ground when the frequency is within the tone decoder pass-band and to open the switch to disconnect the damping filter from ground when the frequency is outside the pass-band.

Abstract: A motor drive comprises a rectifier arranged to receive an externally supplied AC voltage and to generate a DC bus voltage. An inverter is arranged to receive the DC bus voltage and to generate an AC output voltage for supply to an external load. A DC bus portion is connected between the rectifier and the inverter. The DC bus comprises first and second conductors, wherein an inductor is connected in series along the first conductor between the rectifier and the inverter. A DC link capacitor is connected in parallel between the conductors. A controller is arranged to supply a plurality of perturbation signals at a first node between the rectifier circuit portion and the DC bus portion, to measure a respective response signal at a second node between the DC bus and the inverter and is is arranged to generate a parameterised model of a transfer function of the DC.

Abstract: A power converter comprises a buck converter portion, an energy storage portion, and a controller. A first inductor is connected between the cathode of a first diode at an input node, and a capacitor at an output node. The input node is connected to an input voltage via a first switch. A second inductor in the energy storage portion is magnetically coupled to the first inductor and is connected to a second diode. The cathode of the second diode is connected to a first terminal of the energy storage element, and a second terminal of the energy storage element is connected to a second terminal of the second inductor. The first terminal of the energy storage element is connected to the input node via a second switch. When the input voltage is not less than a threshold, the second switch is opened.

Abstract: A power converter comprises a buck converter portion, an energy storage portion, and a controller. A first inductor is connected between the cathode of a first diode at an input node, and a capacitor at an output node. The input node is connected to an input voltage via a first switch. A second inductor in the energy storage portion is magnetically coupled to the first inductor and is connected to a second diode. The cathode of the second diode is connected to a first terminal of the energy storage element, and a second terminal of the energy storage element is connected to a second terminal of the second inductor. The first terminal of the energy storage element is connected to the input node via a second switch. When the input voltage is not less than a threshold, the second switch is opened.

Abstract: A motor drive comprises a rectifier arranged to receive an externally supplied AC voltage and to generate a DC bus voltage. An inverter is arranged to receive the DC bus voltage and to generate an AC output voltage for supply to an external load. A DC bus portion is connected between the rectifier and the inverter. The DC bus comprises first and second conductors, wherein an inductor is connected in series along the first conductor between the rectifier and the inverter. A DC link capacitor is connected in parallel between the conductors. A controller is arranged to supply a plurality of perturbation signals at a first node between the rectifier circuit portion and the DC bus portion, to measure a respective response signal at a second node between the DC bus and the inverter and is is arranged to generate a parameterised model of a transfer function of the DC.

Abstract: A power converter comprises a buck converter portion, an energy storage portion, and a controller. A first inductor is connected between the cathode of a first diode at an input node, and a capacitor at an output node. The input node is connected to an input voltage via a first switch. A second inductor in the energy storage portion is magnetically coupled to the first inductor and is connected to a second diode. The cathode of the second diode is connected to a first terminal of the energy storage element, and a second terminal of the energy storage element is connected to a second terminal of the second inductor. The first terminal of the energy storage element is connected to the input node via a second switch. When the input voltage is not less than a threshold, the second switch is opened.