The present disclosure relates to a reactive power compensation system including a reactive power compensation unit for measuring compensate reactive power, an impedance measurement unit for measuring an impedance value of each of a plurality of loads, and a learning control unit for controlling the reactive power compensation unit based on the measured impedance value.

The present disclosure relates to a reactive power compensation system includes a first measurement unit, a second measurement unit, a reactive power compensation unit, and a controller. The first measurement unit measures impedance of each of at least one load. The second measurement unit measures a voltage and current provided to the at least one load. The reactive power compensation unit compensates the leading reactive power or the lagging reactive power. The controller monitors a change of the impedance in real time, checks a change of the voltage or current according to the change of the impedance, and controls the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power.

if

The present disclosure relates to a reactive power compensation system includes a first measurement unit, a second measurement unit, a reactive power compensation unit, and a controller. The first measurement unit measures impedance of each of at least one load. The second measurement unit measures a voltage and current provided to the at least one load. The reactive power compensation unit compensates the leading reactive power or the lagging reactive power. The controller monitors a change of the impedance in real time, checks a change of the voltage or current according to the change of the impedance, and controls the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power.

if

A current control method and system for a voltage asymmetry fault is disclosed. When a voltage asymmetry fault occurs, a first current limit value is obtained based on a post-fault positive-sequence voltage and a pre-fault positive-sequence reactive current, and a second current limit value is obtained based on a post-fault negative-sequence voltage and a pre-fault negative-sequence voltage. A third current limit value and a fourth current limit value are obtained based on the first current limit value and the second current limit value. A magnitude of a positive-sequence reactive current is limited by using the third current limit value, and a magnitude of a negative-sequence reactive current is limited by using the fourth current limit value.

Current imbalance may be detected and components reactively moved to correct the current imbalance. The components, such as rectifiers, machines, etc., may be moved from the most loaded phase to the least loaded phase. The imbalance may be detected at one or more power distribution units. Rebalancing may be performed using a model which preserves the number of components per rack, while limiting per-rack phase imbalance and minimizing imbalance among phases. Once the rebalancing has been computed, instructions for moving components according to the rebalancing may be generated.

A method for operating a charging device of an electrical energy store for a motor vehicle, wherein a dedicated rectifier device for generating a charging voltage for the electrical energy store is associated with each phase of an AC power supply, includes determining for each rectifier device a usage variable descriptive of its prior usage for charging the electrical energy store; when performing a multi-phase charging operation with the charging device, using for each phase a corresponding rectifier device for generating the charging voltage for the electrical energy store; and when performing a single-phase charging operation with the charging device, using the hitherto most underused rectifier device for generating the charging voltage for the electrical energy store based on the usage variable.

A method for operating a charging device of an electrical energy store for a motor vehicle, wherein a dedicated rectifier device for generating a charging voltage for the electrical energy store is associated with each phase of an AC power supply, includes determining for each rectifier device a usage variable descriptive of its prior usage for charging the electrical energy store; when performing a multi-phase charging operation with the charging device, using for each phase a corresponding rectifier device for generating the charging voltage for the electrical energy store; and when performing a single-phase charging operation with the charging device, using the hitherto most underused rectifier device for generating the charging voltage for the electrical energy store based on the usage variable.

A load balancing apparatus for balancing the current supplied on each phase of a multiple phase supply, Each supply phase feeds an AC load, as well as an AC-DC converter. The apparatus measures the current supplied from each phase of the supply as well as the power consumed by each of the AC loads. The power consumed by each of the AC-DC converters is adjusted so that the sum of the current drawn by any one of the AC loads, plus the current drawn by the AC-DC converter on the same supply phase, is substantially balanced between the supply phases. Typically the AC-DC converters supply a common DC battery. In some embodiments each AC load includes a DC-AC converter configured to supply power from the common DC battery to one or more of the AC loads.

A system and method for detecting and localizing excess voltage drop in single or multiple phases of three-phase AC circuits is disclosed. An electrical distribution circuit is provided that includes an input connectable to an AC source, an output connectable to terminals of an electrical machine, the output configured to provide three-phase voltages and currents to the electrical machine, and a diagnostic system configured to detect an excess voltage drop (EVD) in the electrical distribution circuit. The diagnostic system includes a processor that is programmed to receive measurements of the three-phase voltages and currents provided to the electrical machine, compute a negative sequence voltage from the three-phase voltages and currents, determine a localization reference phase angle for each phase based in part on the three-phase voltages and currents, and calculate an EVD in the electrical distribution circuit based on the negative sequence voltage and the localization reference phase angles.

Methods, systems, and devices for portable load balancing and source optimization are described herein. One portable load balancing and source optimization system, includes one or more electric generators that supply three phase electrical power, at least one sensor to sense whether the three phases have become unbalanced beyond a threshold amount, a set of contactors that enable the contacts of the three phases to be changed to adjust the balance of the three phases, and a controller to determine which reversible contactors of the set of contactors to change to adjust that balance of the three phases based on information from the sensor.