Review of Power System Support Functions for Inverter-Based Distributed Energy Resources- Standards, Control Algorithms, and Trends

Abstract

Penetration of renewable energy in power systems has been increasing in the past decades in response to increased global electricity demand and concerns for the environment. Distributed energy resources (DERs) based on renewables have experienced rapid growth thanks to the incentive programs and broad-based participation. With the growing prevalence of DERs, the risk of grid instability and vulnerability increases due to the intermittent nature of renewable energy. At the same time, the voltage and frequency deviation problems emerge more often when the reverse power flow occurs under supply-demand imbalance in distributed power systems. Standards and grid codes have been issued for DER inverters to interconnect with the distribution grid. The updated standard and grid codes expect DERs to provide a variety of power system support functions in order to incorporate higher DER penetration and to maximize DER value to the grid. This paper provides an overview of the power system support functions from renewable DER inverters, which are categorized as: voltage regulation by active/reactive power control, frequency regulation by active power control, voltage ride-through, and frequency ride-through. The benefits and drawbacks of each algorithm are presented and compared with its predecessor, manifesting the logic in the evolution of the algorithms.

Overview of Demand-Response Services: A Review

“…Renewable-based distributed energy resources (DERs) have grown rapidly owing to incentive schemes and widespread involvement [10]. DERs is a larger word that refers to technologies like distributed generation (DG), backup generation, energy storage, and demand-side management (DSM) [11].…”

Energy Management in High RER Multi-Microgrid System via Energy Trading and Storage Optimization

“…The output of the ESS is disabled if any of the overcharging (13) and undercharging ( 14) limits are violated. Reactive power capabilities 𝑄 𝑙𝑖𝑚𝑖𝑡 (𝑡) are set as (15).…”

“…This deregulated market enables DER as an entity that is both a commodity and a reliable asset, besides providing support functions to the grid. The primary grid support functions attributed to DERs include voltage control with active/reactive power [14], frequency regulation through active power control [15], low voltage ride through (LVRT) [16], frequency ride through, and islanding [17]. The combination of DERs with fixed and flexible loads, and storage units, that are capable of running in grid-connected as well as in islanded mode makes a microgrid [18].…”

Analysis of Voltage Rise Phenomena in Electrical Power Network With High Concentration of Renewable Distributed Generations

“…Repeated switching of RDG systems on and off or complete disconnection of RDG from the grid and other methods suggested in [4][5][6][7][8][9][10][11][12][13][14] in response to voltage rise and the reverse power flow issues could only provide a temporary measure. Consequently, the resultant effects can impose consequent cycling of network voltage control equipment with associated asset life and maintenance impacts, can cause partial/total outages or excessive under voltages at the far end of the DN, damaging online power component, end-use equipment and voltage instability [15][16][17]. Hence, permanent solution is required.…”