A method for compensating self-induced voltage variations includes computing a first reactive power value (Q.sub.1), obtaining a voltage value at a point of interconnection (POI) between at least one power source and a power grid, comparing the voltage value with one or more pre-defined voltage limits, computing at least one compensation factor (CF) corresponding to at least one portion of the first reactive power value (Q.sub.1) based on an output of the comparison between the voltage value and the one or more pre-defined voltage limits, computing a second reactive power value (Q.sub.2) as a function of the at least one portion of the first reactive power value (Q.sub.1) and the at least one CF, generating a reactive power compensation command based on the computed second reactive power value (Q.sub.2), and transmitting the reactive power compensation command to a power converter.

According to the overload current limiting method for a voltage source converter, when a pole control system receives a water-cooling overload current limiting instruction, an active and reactive instruction are changed at the same time according to a specified slope, so that an absolute value of an arm current of the converter decreases in a fixed slope, and can be ensured that active power and reactive power fall to zero at the same time, and a water-cooling load limiting aim of the converter can be achieved by reducing the arm current. After a water-cooling overload power limiting instruction received by the pole control system is cancelled, a current value of the active power and the inactive power remain unchanged. When a water-cooling overload power limiting instruction is received again, decrease continues on the basis of current power values until the power falls to zero.

A device for testing a power module of a set of power modules connected together includes reactive power compensation means capable of compensating the reactive power transferred between a tested power module and the other power modules, and means for monitoring the power generated by the tested power module including means for comparing said generated power with at least one threshold value.

According to the overload current limiting method for a voltage source converter, when a pole control system receives a water-cooling overload current limiting instruction, an active and reactive instruction are changed at the same time according to a specified slope, so that an absolute value of an arm current of the converter decreases in a fixed slope, and can be ensured that active power and reactive power fall to zero at the same time, and a water-cooling load limiting aim of the converter can be achieved by reducing the arm current. After a water-cooling overload power limiting instruction received by the pole control system is cancelled, a current value of the active power and the inactive power remain unchanged. When a water-cooling overload power limiting instruction is received again, decrease continues on the basis of current power values until the power falls to zero.

Provided is a server (10) including an attribute information receiving unit (15) which receives attribute information of an electric power output apparatus (30) from the electric power output apparatus (30) having a function of outputting electric power; an output condition transmitting unit (18) which transmits an output condition determined in accordance with the attribute information to the electric power output apparatus (30); a processing result receiving unit (16) which receives a processing result obtained by performing predetermined processing on output waveform data at the time when the electric power output apparatus (30) outputs electric power according to the output condition; and an evaluating unit (17) which evaluates an electric power output performance of the electric power output apparatus (30) on the basis of the processing result and the output condition.

A DC/AC converter apparatus is disclosed for converting DC power of a DC energy source into AC power for supplying a load and or the utility grid. The DC/AC converter apparatus is adapted to automatically control the amount of both active and reactive electrical power that is exchanged with the utility grid in order to optimize the electrical power usage of the micro grid.

A power metering circuit includes a current input path for receiving an analog current input at a first analog to digital converter; a voltage input path for receiving an analog voltage input at a second analog to digital converter; a multiplier configured to multiply an output of the current input path and the voltage input path; a notch filter configured to receive an output of the multiplier, the notch filter having a stop band based on a line frequency; and a control circuit for setting a sampling frequency of the first analog to digital converter and the second analog to digital converter to a multiple of the line frequency.

A power factor correction system according to the present disclosure includes an inverter connected in parallel with at least one load and a controller configured to command an output voltage of the inverter to provide reactive power to the at least one load when a voltage source is available to the load and real power and reactive power to the at least one load when the voltage source is unavailable to the load.

To provide a power system analysis support system in which the amount of data to be sent from a measuring device to an analysis support apparatus can be reduced. A measuring device includes a measuring unit which performs measurement related to a power system, a storage unit which stores measurement values measured by the measuring unit, a parameter generator which generates a predetermined parameter indicating a probability density function of the measurement value from the plurality of measurement values stored in the storage unit, and a communication unit which sends the predetermined parameter generated by the parameter generator to an analysis support apparatus. The analysis support apparatus includes a communication unit which receives the predetermined parameter from the measuring device, and a probability density function generator which generates a probability density function of the measurement value from the received predetermined parameter.

Fault isolation and service restoration in an electrical grid are provided. An approach for receiving a notification message including a state of an electrical component on an electrical grid, and determining, by a computing system, a command message including at least one action to take in response to the state of the electrical component, is described. The approach further includes sending the command message to at least one of the electrical component and other electrical components on the electrical grid.