Synchronous Voltage Controllers: Voltage-Based Emulation of Synchronous Machines for the Integration of Renewable Energy Sources

Mahdi Ashabani,Jaesung Jung

doi:10.1109/access.2020.2976892

Abstract

Recently, significant attention has been paid to the integration of renewable energy sources into power systems by similar characteristics of synchronous machines (SMs). The conventional method to emulate SMs is to use power components, typically known as power-based virtual synchronous machines (PB-VSMs). This paper looks at the development of a new approach to mimic SMs using voltage components called voltage-based virtual synchronous machines (VB-VSMs). A VB-VSM is a cascaded double-loop controller with current and voltage regulation as opposed to a single-loop PB-VSM. Further, the dynamic model of an automatic voltage regulator (AVR) and a physical rotor field circuit are integrated into the controller. In addition to grid-responsive features, the VB-VSM can also eliminate an extra synchronization unit, typically a phase-locked loop (PLL), as the internal controller acts in a similar fashion to regular PLLs in research literature. Since the controller adopts voltage components for synchronization, control, and emulation purposes, it can be regarded as a synchronous voltage controller (SynVC). Extensive case studies under various conditions are carried out to demonstrate the performance of a SynVC.

Highlights

There has been significant attention recently on efforts to emulate the characteristics of synchronous machines (SMs) with VSCs to ensure the compatibility of modern VSC-dominated grids with the traditional grids, which are populated with SMs [1]–[9], and induction machines (IMs) [10]
To evaluate the performance of the synchronous voltage controller (SynVC), the system shown in Fig. 7 was simulated in the Simulink environment
At t = 2 s the local load was connected to the feeder and at t = 3 s the feeder voltage reference in model 1 was changed from 160 V to 170 V and in model 2 and model 3, reactive power references changed to 2,500 VAr and 4,750 VAr, respectively

Summary

Introduction

There has been significant attention recently on efforts to emulate the characteristics of SMs with VSCs to ensure the compatibility of modern VSC-dominated grids with the traditional grids, which are populated with SMs [1]–[9], and induction machines (IMs) [10] This is due to the fact that the increasing use of renewable energy resources, distributed generation (DG), and power electronic loads such as variable frequency drives has changed the behavior of power systems from being somewhat predictable to becoming more complex and chaotic. With the extensive use of VSCs in power systems, these techniques fall short of ensuring seamless integration of VSCs into power systems due to the interaction with SMs and IMs [8], [9]

Results

Discussion

Conclusion