Impact of Line Impedances and Loads on Compensation Capability of Electric Springs

The electric spring is used as a demand side management device in the smart grid. Electric springs can be effective in applications such as voltage and power regulation, three-phase load balancing, harmonics compensation, and improve voltage stability by utilizing inverters and mounting on the consumer side. On the other hand, the increasing expansion of renewable energies, the emergence of micro-grids, and electric vehicles are exacerbating power quality issues such as undervoltage, overvoltage, unbalanced loads, and harmonics in the power distribution grid. Therefore, electric springs can provide appropriate voltage quality for critical loads (E.g., building security systems, computers, and digital systems) by connecting series to non-critical loads (E.g., electric water heater, washing machine, and air conditioner) and using different control methods. In this paper, the effect of changes in the magnitude and angle of each line impedance, noncritical load, and critical load on the ability of voltage compensating of electric spring is investigated. For this purpose, two operating modes of overvoltage and undervoltage have been considered to obtain the compensation limits of electric spring. Finally, in this paper, an allowable range for the magnitude and angle of each impedance is proposed, in which the electric spring can compensate for voltage fluctuations without instability.

کلیدواژه ها:

Smart Load ، Electric Spring ، Power Quality ، Voltage Regulation ، Demand Side Management