The objective is to provide a power system voltage reactive power monitoring control device with which a balance between the power system voltage and the reactive power can be maintained even when, for example, the output of renewable energy varies over time due to the weather, or the power supply configuration or system configuration changes, and a power system voltage reactive power monitoring control device with which the economic efficiency can be improved. This power system voltage reactive power monitoring control device, which supplies transmission data to individual devices capable of adjusting the voltage and the reactive power of a power system, is characterized in that one or more indices indicating the stability of the power system are used to determine one or more target value restrictions, information about the target value is obtained from the target value restrictions, transmission data containing information about the target value is supplied to the individual devices, and the voltage and reactive power at the relevant installation site are adjusted by the individual devices.

A method for identifying a location of a fault in an electrical power distribution network that includes identifying an impedance of an electrical line between each pair of adjacent utility poles, measuring a voltage and a current of the power signal at a switching device during the fault, and estimating a voltage at each of the utility poles downstream of the switching device using the impedance of the electrical line between the utility poles and the measured voltage and current during the fault. The method calculates a reactive power value at each of the utility poles using the estimated voltages, where calculating a reactive power value includes compensating for distributed loads along the electrical line that consume reactive power during the fault, and determines the location of the fault based on where the reactive power goes to zero along the electrical line.

A method for detecting an output impedance angle of an inverter includes controlling an inverter to output a second voltage signal and a current signal based on a first voltage signal; receiving the signals, and calculating and outputting first and second active powers, and first and second reactive powers using the signals; calculating and outputting third and fourth active powers, and third and fourth reactive powers based on the first and second active powers, the first and second reactive powers, and the predetermined impedance angle; determining whether the amplitude is a constant value; if so, determining whether an absolute value of the first differential value of the third and fourth reactive powers is less than a first power reference value; if so, the impedance angle outputted from the inverter is the impedance angle; if not, setting the impedance angle as the predetermined impedance angle plus or minus the compensation angle.

The present invention discloses a testing method for dynamic model parameters of a wind power plant, wherein under testing conditions including stable running of wind turbine generators and reactive-load compensation equipment, stable wind speed between a cut-in wind speed and a rated wind speed, and the wind power plant output smaller than a rated output, finishes a wind speed transient disturbance test, a wind power plant unit tripping and inputting disturbance test, a wind power plant power change test, a disturbance test for reactive-load compensation equipment of the wind power plant, a tripping disturbance test for hydroelectric power plant and thermal power plant near the wind power plant and a manual single-phase ground short circuit test at the outgoing line part of the wind power plant, and records running curves of the wind power plant under each condition to finish the parameter test. The present invention realizes the advantage of providing precise measurement data for the stability analysis of an electric power system and the production dispatching of a power grid.

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.

A computer-implementable control algorithm that measures: 1) the reactive power; 2) the power factor; 3) the voltage; and 4) the line frequency. The algorithm calculates the differential compensation capacitance required that is either positive (capacitance to be added), or negative (capacitance to be removed). The new compensation capacitance is calculated from the sum or difference of the differential compensation capacitance and the current compensation capacitance. The algorithm compares the capacitor switching bit pattern for the current compensation capacitance and the capacitor switching bit pattern for the new compensation capacitance, and selects a capacitor switching bit map accordingly. The capacitor switch combination for the new compensation capacitance is switched in incrementally according to the capacitor switching bit map. To reach the selected capacitor switch combination, only one switch is switched at a time to minimize the line transient noise. This part of the algorithm continues to run until the PF is corrected, with the capacitor switches being switched on/off each delayed by a millisecond interval to minimize line transient noise.

A method for identifying a location of a fault in an electrical power distribution network that includes identifying an impedance of an electrical line between each pair of adjacent utility poles, measuring a voltage and a current of the power signal at a switching device during the fault, and estimating a voltage at each of the utility poles downstream of the switching device using the impedance of the electrical line between the utility poles and the measured voltage and current during the fault. The method calculates a reactive power value at each of the utility poles using the estimated voltages, where calculating a reactive power value includes compensating for distributed loads along the electrical line that consume reactive power during the fault, and determines the location of the fault based on where the reactive power goes to zero along the electrical line.

DC/AC converter apparatus, for converting DC power of a DC energy source into AC power for supplying a load and or the utility grid, 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 system and method for establishing a microgrid from an existing electrical grid whereby the system provides a remote terminal that collects data from the electrical grid and the microgrid and communicates the data back to and from the microgrid and the electrical grid, whereby the remote terminal unit may continuously monitor specific parameters from the microgrid and the electrical grid, such as distributed generators, converters, and loads, including power levels, charge levels, voltage levels, current flow, temperature, breaker status, and other information pertinent to the microgrid and the electric grid, while the RTU is designed for microgrid islanding and power flow.