Tuningless Load Frequency Control Through Active Engagement of Distributed Resources

Abstract

Abstract-The increasing share of volatile and inverter-based energy sources render electric power grids increasingly susceptible to disturbances. Established Load Frequency Controls (LFCs) schemes are rigid and require careful tuning, making them unsuitable for dynamically changing environments. In this paper, we present a fast and tuningless frequency control approach that tackles these shortcomings by means of modern grid monitoring and communications infrastructures in a two-fold concurrent process. First, direct observation of supply and demand enables fast power balancing decoupled from the total system dynamics. Second, primary resources are actively involved in frequency restoration by systematic adjustment of their frequency reference setpoints. In contrast to the commonly used Automatic Generation Control (AGC), the proposed Direct Load Frequency Control (DLFC) does not require an integrator for frequency control in the closed loop even under partial grid observability. The approach is Lyapunov-stable for a wide range of system parameters, including ramping limits of controlled resources. A performance study against AGC has been conducted on a threearea power system in simulations as well as in a real laboratory grid with an installed generation capacity of 110 kW.

Load frequency control scheme design considering flexible disturbances

“…Feedforward control avoids the use of the feedback signal ACE, thus elevating the system response velocity. In [24], feedforward control‐based power balancing is achieved with the aid of distributed generation, which is useful for local estimation and compensation of power imbalance.…”

Decentralized and discretized control for storage systems offering primary frequency control

“…By replacing (19) in (8), the estimated RMSE of the m-th homogeneous cluster e cl,m rmse is given by…”

“…However, communications in electric power systems are subject to various sources of uncertainty and delays stemming from the employed transmission technologies, relaying and the nature of packet-switching networks [4,5]. In closed-loop feedback control these factors compromise stability margins [5] and require thorough analysis and tuning, as demonstrated for primary and secondary frequency control in [6,7,8]. Several different types of networks exist in power system communications, where the round-trip time of single data packages is typically in the order of seconds [4].…”

Robust Allocation of Reserve Policies for a Multiple-Cell Based Power System

“…The setup is based on a configuration of SYSLAB, which is a laboratory testing facility for Smart Grid concepts located at the Risø campus of the Technical University of Denmark. Figure 3 shows the SYSLAB facility [24,25], which is a 400 V three-phase grid designed for studying advanced grid control and communication concepts. The facility has 16 busbars and 116 automated coupling points.…”