Mitigating Voltage and Frequency Fluctuation in Microgrids Using Electric Springs

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Electric spring and smart load: technology, system-level impact and opportunities

Increasing use of renewable energy sources to combat climate change comes with the challenge of power imbalance and instability issues in emerging power grids. To mitigate power fluctuation arising from the intermittent nature of renewables, electric spring has been proposed as a fast demand-side management technology. Since its original conceptualization in 2011, many versions and variants of electric springs have emerged and industrial evaluations have begun. This paper provides an update of existing electric spring topologies, their associated control methodologies, and studies from the device level to the power system level. Future trends of electric springs in large-scale infrastructures are also addressed

Use of Smart Loads for Power Quality Improvement

Electric spring (ES) was originally proposed as a distributed demand-side management technology for making noncritical loads adaptive to the availability of intermittent renewable power generation. The second generation of ES, fed with batteries (ES-2) and associated with a noncritical load, can form a new kind of combined smart load and distributed energy storage technology for smart grids. With its four-quadrant operation, ES-2 is able to offer ancillary grid services in addition to its major functions of voltage and frequency regulation. This paper presents the operating principles and the input current control of ES-2 for power quality improvement such as power factor correction and harmonics reduction. The operating principles and the proposed input current control have been verified with the experimental results obtained from a small-scale power grid. Another weak single-phase power system fed by intermittent wind power is set up to prove the combined operation of ES-2 for power quality improvement and ES-1 (ES with capacitor storage) for voltage stabilization. The experimental results show that ES-2 with input current control can carry out power quality improvement as its ancillary function

Voltage regulation using three phase electric spring by fuzzy logic controller

Introduction. The renewable energy sources such as solar and wind power have increased significantly in recent years. However, as the generation of renewable energy has become more integrated, its intermission and instability have a major impact on the power system’s stability, such as voltage instability and frequency flicker. Purpose. In order to address the different power quality issues brought on by intermittent and unreliable renewable energy sources, electric spring offers a novel solution. It was proposed as a technique for regulating load and adjusting output power. For the integration of electric springs with noncritical loads, a contemporary control mechanism is described in this paper. Novelty. The suggested work is innovative in that it presents an improved control technique that efficiently maintains voltage stability as voltage changes. Method. The proposed technique is based on an analysis of the initial conditions and input data for developing fuzzy rules for calculating compensating voltages in relation to the difficulties. Results. This suggested fuzzy controller will be able to maintain the regular operation of the electric spring of power output control stability as well as continuing to provide power factor improvement and voltage control for significant loads, including the home’s protection system. Practical value. A detailed study of typical voltage regulation is undertaken, supported by simulation results, to demonstrate the effectiveness of the applied control scheme in cancelling the corresponding issues with power quality

Extending the Operating Range of Electric Spring using Back-To-Back Converter: Hardware Implementation and Control

This paper presents the first hardware implementation and control of an electric spring based on a back-to-back converter configuration. Because of its ability to provide both active and reactive power compensation, this back-to-back electric spring (ES-B2B) can substantially extend the operating range of the original version of the electric spring (ES-1) and provide enhanced voltage support and suppression functions. The hardware system and control of the ES-B2B have been successfully developed and tested. The experimental results have confirmed the effectiveness of the ES-B2B in supporting and suppressing the mains voltage. Particularly, the voltage suppression ability of the ES-B2B is superior over that of ES-1. The use of ES-B2B in a simulation study of a weak power grid has also been conducted. The ES-B2B has been found to be highly effective in mitigating voltage fluctuation caused by intermittent renewable power generation

A Review of Active Management for Distribution Networks: Current Status and Future Development Trends

Driven by smart distribution technologies, by the widespread use of distributed generation sources, and by the injection of new loads, such as electric vehicles, distribution networks are evolving from passive to active. The integration of distributed generation, including renewable distributed generation changes the power flow of a distribution network from unidirectional to bi-directional. The adoption of electric vehicles makes the management of distribution networks even more challenging. As such, an active network management has to be fulfilled by taking advantage of the emerging techniques of control, monitoring, protection, and communication to assist distribution network operators in an optimal manner. This article presents a short review of recent advancements and identifies emerging technologies and future development trends to support active management of distribution networks