Abstract: Current sharing between the plurality of parallel-connected ARCP or hard-switching converter legs is balanced by a control arrangement. The control arrangement senses a leg output current in each of the parallel-connected converter legs and have an individual autonomous leg-specific switching instant adjustment for the main switches of each of the parallel-connected converter legs to shift the first mode A commutation of the respective converter leg later in time and to shift the second mode B commutation of the respective converter leg earlier in time by a variable timestep proportional to the value of the sensed leg current of the respective converter leg. In other words, if the value of the sensed leg output current in one converter leg is larger than in the other converter leg, then in mode A, the higher-current leg will commutate later than the leg with less current, and in mode B, the higher-current leg will commutate earlier than the leg with less current.

Abstract: A power converter system includes auxiliary resonant commutated pole converter legs, particularly ARCP half-bridge legs, connected in parallel between a common dc system and a common ac system or between two common dc systems. Commutations of the parallel-connected converter legs are initiated by simultaneous commutation commands. A control arrangement is provided to balance a current sharing between the parallel-connected ARCP converter legs by means of having an individual autonomous leg-specific boost current adjustment for each of the parallel-connected ARCP converter legs for adjusting boost currents in a direction that a differential output current is reduced. Each individual boost current adjustment is dependent on the magnitude of the leg current of the respective ARCP converter leg only.

Abstract: A method for controlling an electrical converter for driving an electrical machine comprises the steps of: estimating a stator flux vector depending on at least one measurement in the electrical converter; determining an optimized pulse pattern for the electrical converter depending on a reference angular stator frequency; determining a reference stator angle of the stator flux vector depending on the reference angular stator frequency; determining a reference stator flux vector depending on the optimized pulse pattern and the reference stator angle; determining a difference between the reference stator flux vector and the estimated stator flux vector; modifying switching instants of the optimized pulse pattern, such that the difference is minimized; and applying at least a part of the modified optimized pulse pattern to the electrical converter.

Abstract: A method for controlling an electrical converter for driving an electrical machine comprises the steps of: estimating a stator flux vector depending on at least one measurement in the electrical converter; receiving a rotor speed of the electrical machine; determining an optimized pulse pattern for the electrical converter depending on the rotor speed; determining a rotor angle of a rotor flux vector depending on the rotor speed; determining a reference stator angle of the stator flux vector depending on the rotor angle; determining a reference stator flux vector depending on the optimized pulse pattern and the reference stator angle; determining a difference between the reference stator flux vector and the estimated stator flux vector; modifying switching instants of the optimized pulse pattern, such that the difference is minimized; and applying at least a part of the modified optimized pulse pattern to the electrical converter.

Abstract: A saturable-core inductor includes a magnetic core structure having a non-saturable part and a saturable part. The non-saturable core part includes at least one core body arranged to form a closed magnetic circuit with at least one air gap. The saturable core part includes a core bridge element inserted into each of the at least one air gap to form a magnetic bridge across the air gap for the closed magnetic circuit. Each bridge element and the core bodies are configured to be unsaturated at predetermined low current levels to provide a low-current high inductance. Each bridge element is configured to saturate fully first with increasing current levels and to quickly drop the inductance from the low-current high inductance to a low inductance, while the air gap is configured to prevent the core bodies from a full saturation.

Abstract: A power converter system including an auxiliary resonant commutated pole converter leg, particularly an ARCP half-bridge, and a resonant swing time controller for the ARCP converter leg. The resonant swing time controller is configured to control a resonant swing time duration of ARCP commutations to a reference value of the resonant swing time by means of a closed loop feedback of an actual resonant swing time duration. In an embodiment, the resonant swing time controller is configured to provide, based on an error between the actual resonant swing time duration and the reference value, control values to adjust a turn-on instant of at least one auxiliary switching device of the ARCP converter leg earlier or later in time so that resonant swing time duration of ARCP commutations is controlled towards the reference value.

Abstract: Current sharing between the plurality of parallel-connected ARCP or hard-switching converter legs is balanced by a control arrangement. The control arrangement senses a leg output current in each of the parallel-connected converter legs and have an individual autonomous leg-specific switching instant adjustment for the main switches of each of the parallel-connected converter legs to shift the first mode A commutation of the respective converter leg later in time and to shift the second mode B commutation of the respective converter leg earlier in time by a variable timestep proportional to the value of the sensed leg current of the respective converter leg. In other words, if the value of the sensed leg output current in one converter leg is larger than in the other converter leg, then in mode A, the higher-current leg will commutate later than the leg with less current, and in mode B, the higher-current leg will commutate earlier than the leg with less current.

Abstract: A power converter system includes auxiliary resonant commutated pole converter legs, particularly ARCP half-bridge legs, connected in parallel between a common dc system and a common ac system or between two common dc systems. Commutations of the parallel-connected converter legs are initiated by simultaneous commutation commands. A control arrangement is provided to balance a current sharing between the parallel-connected ARCP converter legs by means of having an individual autonomous leg-specific boost current adjustment for each of the parallel-connected ARCP converter legs for adjusting boost currents in a direction that a differential output current is reduced. Each individual boost current adjustment is dependent on the magnitude of the leg current of the respective ARCP converter leg only.

Abstract: A power inverter system includes switching mode inverter legs connected in parallel between a common DC input and, via leg output inductors, a common phase output to feed a phase output current to a common load. The commutations of the parallel-connected inverter legs are initiated by essentially simultaneous commutation commands. The leg output current is sensed before and after a commutation in each of the parallel-connected inverter legs to obtain a pre-commutation current value and a post-commutation current value. Alternatively, a voltage pulse over the leg output inductor is sensed in each of the parallel-connected inverter legs during the commutation.

Abstract: A control apparatus for ARCP (Auxiliary Resonant Commuted Pole) power inverters include a modulator and a modulation control. The modulator is configured to carry out a commutation of an ARCP inverter by selectively using a Continuous PWM (CPWM) modulation and a Discontinuous PWM (DPWM) modulation. The modulation control is configured to dynamically select either the CPWM modulation or the DPWM modulation in a such a way that switching losses of the ARCP inverter are reduced while a failure of the commutation of the ARCP inverter due to a neutral point voltage unbalance of the ARCP inverter is avoided.

Abstract: A method for operating an electric power converter and an electric power converter configured to convert DC power into AC power supplied to a three-phase AC network, conclude, during the converting, that a single-phase tripping has started in the three-phase AC network connected to the three-phase output of the converter, and after the concluding that the single-phase tripping has started in the three-phase AC network, control an active current in the three-phase output of the converter such that a negative sequence voltage in the three-phase output of the converter remains at or below a predetermined level, wherein the converter is configured to perform the controlling until concluding that the single-phase tripping has ended in the three-phase AC network.

Abstract: A method for operating an electric power converter and an electric power converter configured to convert DC power into AC power supplied to a three-phase AC network, conclude, during the converting, that a single-phase tripping has started in the three-phase AC network connected to the three-phase output of the converter, and after the concluding that the single-phase tripping has started in the three-phase AC network, control an active current in the three-phase output of the converter such that a negative sequence voltage in the three-phase output of the converter remains at or below a predetermined level, wherein the converter is configured to perform the controlling until concluding that the single-phase tripping has ended in the three-phase AC network.

Abstract: A method and a control system adapted to control a power conversion system connected to an AC power grid, wherein the control system is adapted to receive an externally provided reactive power reference and the control system includes a controller adapted to control the reactive power fed to the AC grid by the power conversion system and to produce a reactive current reference, an active current reference, a total current limiter for producing limited active and reactive current references. The total current limiter operates in reactive current priority limiting the active current reference. Further including means adapted to produce a capacity signal indicating the current capacity of the power conversion system.

Abstract: A method and a control system adapted to control a power conversion system connected to an AC power grid, wherein the control system is adapted to receive an externally provided reactive power reference and the control system includes a controller adapted to control the reactive power fed to the AC grid by the power conversion system and to produce a reactive current reference, an active current reference, a total current limiter for producing limited active and reactive current references. The total current limiter operates in reactive current priority limiting the active current reference. Further including means adapted to produce a capacity signal indicating the current capacity of the power conversion system.

Abstract: A communication method and system are provided that include providing synchronization information about a co-sited downlink carrier. This information may be transmitted to from a base station to a mobile device. The mobile device may receive this information and perform handover or measurements based on the received synchronization information.

Abstract: A method and system for cell identification for uplink interference avoidance that includes a network device and mobile device in a communications network. Inter-frequency measurements are performed by a mobile device on a downlink carrier currently not used by the mobile device. A result of the inter-frequency measurements is compared with another value. Second measurements are initiated on the downlink carrier currently not used by the mobile device based on the comparison. A cell is identified based on the second measurements. The inter-frequency measurements may include receive signal strength indicator (RSSI) measurements, received signal code power (RSCP) measurements, or average channel power-to-total signal power ratio (Ec/Io) measurements. The second measurements may include signal quality measurements.

Abstract: A communication method and system are provided that include providing synchronization information about a co-sited downlink carrier. This information may be transmitted to from a base station to a mobile device. The mobile device may receive this information and perform handover or measurements based on the received synchronization information.

Abstract: A method and system for soft handover area detection for uplink interference avoidance that includes a network device and mobile device in a communications network. A trigger criteria threshold is determined for the mobile device. The mobile device is using a downlink carrier. If a trigger criteria has risen above or fallen below the trigger criteria threshold, inter-frequency measurements of co-sited cells are performed and compared to determine if a soft handover area exists. Co-sited cells are searched for downlink carriers and reselection is initiated from the downlink carrier to a co-sited cell downlink carrier if the co-sited cell downlink carrier is useable by the mobile device. Reselection is initiated from the downlink carrier to a non co-sited cell downlink carrier if no co-sited cell downlink carrier useable by the mobile device is found. The system provides for reselection while uplink carrier interference is avoided.

Abstract: A communication method and system are provided that include providing synchronization information about a co-sited downlink carrier. This information may be transmitted to from a base station to a mobile device. The mobile device may receive this information and perform handover or measurements based on the received synchronization information.

Abstract: A method and system for soft handover detection for uplink interference avoidance that includes a network device and mobile device in a communications network. The mobile device uses a downlink carrier. A parameter, such as a signal strength or a signal quality, of the downlink carrier and one of a co-sited downlink carrier or neighboring downlink carrier is measured. A soft handover area is detected by the network device or the mobile device based on comparing the signal strength or the signal quality of the downlink carrier with the signal strength or the signal quality of one of the co-sited downlink carrier or the neighboring downlink carrier. The downlink carrier, the co-sited downlink carrier or the neighboring downlink carrier may be from a core band, (e.g., 2.0 GHz), or extension band, (e.g., 2.5 GHz), of frequencies or combination thereof. The system provides for handovers while uplink carrier interference is avoided.