A method of operating an electrical feeder permits the electrical feeder voltage to be maintained at the minimum voltage within a voltage range based upon dynamic grouping together of electrical generators on the electrical feeder with demand response loads on the electrical feeder. A method of assessing the proper operation of a voltage control device on the electrical feeder involves detecting a number of properties of the electrical power in the electrical feeder both prior to and subsequent to a change in an operational parameter of a voltage control device. An expected effect upon the electrical feeder of one or more distributed generators is filtered from this in order to determine a net effect of the voltage control device itself on the electrical feeder. Based upon the detected net effect and a predicted baseline effect for the voltage control device, it can be determined whether the voltage control device is functioning properly.

A means and method for measuring precise voltage phasors on medium-voltage alternating current (AC) distribution grids, using existing distribution transformers as voltage sensors. The errors introduced by the distribution transformers are minimized by taking into account the transformer's vector impedance, combined with measuring the transformer secondary current phasor. The invention includes a means and a method of measuring the distribution transformer's vector impedance.

We describe a modular adjustable power factor renewable energy inverter system. The system comprises a plurality of inverter modules having a switched capacitor across its ac power output, a power measurement system coupled to a communication interface, and a power factor controller to control switching of the capacitor. A system controller receives power data from each inverter module, sums the net level of ac power from each inverter, determines a number of said capacitors to switch based on the sum, and sends control data to an appropriate number of the inverter modules to switch the determined number of capacitors into/out of said parallel connection across their respective ac power outputs.

Embodiments disclosed herein relate to a battery energy storage system (BESS) that can be used to store energy that is produced by conventional sources (e.g., coal, gas, nuclear) as well as renewable sources (e.g., wind, solar), and provide the stored energy on-demand.

An electric power system includes an OLTC transformer including a plurality of primary and secondary windings inductively coupled to each other. The electric power system includes at least one on-load tap changer coupled to at least one of the primary and secondary windings that is selectively configurable to regulate the portion of the primary and secondary windings inductively coupled to each other. The electric power system also includes a plurality of buses coupled to the transformer and are positioned downstream therefrom. The electric power system further includes at least one processor coupled to the tap changer configured to regulate a voltage bandwidth of the tap changer as a function of estimated voltage values of at least one bus as estimated based on a priori values of power/current transmitted through each bus. The a priori values are substantially based on measured power/current transmission through the on-load tap changer.

A method and system to control distributed energy resources in an electric power system includes generation, storage and controllable loads. The system uses time synchronized measurements of voltage phasor and current phasors and their derivative information that may include real and reactive power to regulate and decouple both static and dynamic effects of real and reactive power flow through the local electric power system connected to the area electric power system. The method and system provides precise real and reactive power demand set point pairs; damping of real and reactive power fluctuations in the local electric power system; decoupling between real and reactive power demand response set points by means of a multivariable control system that uses time synchronized measurements of voltage and current phasors and their derivative information.

A system may include an electric field sensor, an analog to digital converter, and an estimator. The electric field sensor may measure electric fields of electric power grid. The analog to digital converter may generate digital output based upon measurements from the electric field sensor. The estimator may estimate phasor data of the electric power grid based upon the digital output.

Disclosed are methods and apparatus to improve the stability of power distribution systems. The methods and apparatus include using edge processing to decrease the detection and reaction times associated with disturbances within the power distribution system. The edge processor can compare sampled phasor data with center of inertia data associated with the power distribution system.

Data quality of Phasor Measurement Unit (PMU) is receiving increasing attention as it has been identified as one of the limiting factors that affect many wide-area measurement system (WAMS) based applications. In general, existing PMU calibration methods include offline testing and model based approaches. However, in practice, the effectiveness of both is limited due to the very strong assumptions employed. This invention presents a novel framework for online error detection and calibration of PMU measurement using density-based spatial clustering of applications with noise (DBSCAN) based on much relaxed assumptions. With a new problem formulation, the proposed data mining based methodology is applicable across a wide spectrum of practical conditions and one side-product of it is more accurate transmission line parameters for the energy management system (EMS) database and protective relay settings. Case studies are presented to demonstrate the effectiveness of the proposed method.

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.