Abstract: An electrical system and method include a DC link, a controlled rectifier connected between the DC link and a power source, an energy storage, a DC to DC converter connected between the DC link and the energy storage, a motor, and a DC to AC converter connected between the DC link and the motor. The converters are configured to transfer power in both directions. The rectifier controls the DC voltage of the DC link when the DC link voltage is in a first voltage range. The DC to DC converter controls the DC voltage of the DC link by charging the energy storage when the DC link voltage is in a second voltage range, which has higher voltage values than the first voltage range, or by discharging the energy storage when the DC link voltage is in a third voltage range, which has lower voltages than the first voltage range.

Abstract: An electrical system and method include a DC link, a controlled rectifier connected between the DC link and a power source, an energy storage, a DC to DC converter connected between the DC link and the energy storage, a motor, and a DC to AC converter connected between the DC link and the motor. The converters are configured to transfer power in both directions. The rectifier controls the DC voltage of the DC link when the DC link voltage is in a first voltage range. The DC to DC converter controls the DC voltage of the DC link by charging the energy storage when the DC link voltage is in a second voltage range, which has higher voltage values than the first voltage range, or by discharging the energy storage when the DC link voltage is in a third voltage range, which has lower voltages than the first voltage range.

Abstract: A method and arrangement in connection with an inverter that comprises several power semiconductor components and a control apparatus arranged to control them is disclosed. The method comprises the steps of determining the temperature or an electric quantity affecting the temperature of one or more power semiconductor components, determining the change of the temperature or an electric quantity affecting the temperature of one or more power semiconductor components, and controlling with the control apparatus the power semiconductor components in response to both a control quantity to generate an output voltage and the change rate of the temperature or a quantity affecting the temperature of the power semiconductor components to reduce temperature variation by slowing down the temperature increase rate as the temperature or quantity affecting the temperature increases and by slowing down the temperature decrease rate as the temperature or quantity affecting the temperature decreases.

Abstract: A method and arrangement in connection with an inverter that comprises several power semiconductor components and a control apparatus arranged to control them, the control apparatus being arranged to control the power semiconductor components in response to a control quantity to generate an output voltage. The method comprises the steps of determining the change of the temperature or a quantity affecting the temperature of one or more power semiconductor components, and controlling with the control apparatus the power semiconductor components in response to both the control quantity to generate an output voltage and the change rate of the temperature or quantity affecting the temperature of the power semiconductor components to reduce the temperature change and the change rate.

Abstract: A choke arrangement and a method in conjunction with an inverter, the phase output of the inverter being configured to be composed of two or more parallel branches, each of which comprises an upper (V1, V3, V5) and a lower (V2, V4, V6) power semiconductor component at the output, the upper one of which being coupled to a positive voltage of a direct voltage intermediate circuit and the lower to a negative voltage, the components being in series, the output of each branch being composed of a point between the components. The arrangement comprises branch-specific single-phase chokes (L1, L2, L3), the first ends of which chokes are arranged to be coupled to the outputs of the power semiconductor components and the second ends together to form the phase output of the inverter.

Abstract: A choke arrangement and a method in conjunction with an inverter, the phase output of the inverter being configured to be composed of two or more parallel branches, each of which comprises an upper (V1, V3, V5) and a lower (V2, V4, V6) power semiconductor component at the output, the upper one of which being coupled to a positive voltage of a direct voltage intermediate circuit and the lower to a negative voltage, the components being in series, the output of each branch being composed of a point between the components. The arrangement comprises branch-specific single-phase chokes (L1, L2, L3), the first ends of which chokes are arranged to be coupled to the outputs of the power semiconductor components and the second ends together to form the phase output of the inverter.