Improving the Integration of Wind Power Generation Into AC Microgrids Using Flywheel Energy Storage

Abstract

The connection of wind power generation into ac microgrids (MGs) is steadily increasing. This incorporation can bring problems onto the power quality and dynamics of the electrical grid due to the lack of controllability over the wind. In this work, a flywheel energy storage (FES) is used to mitigate problems introduced by wind generation into MGs. A dynamic model of the FES device is briefly presented and a technique to control the power exchanged between the device and the power system is proposed. The control technique has three modes, namely: voltage control (VC), frequency control (FC), and active power stabilization (APS). Simulation tests on the behavior of the FES device are analyzed when it works in combination with wind generation in the electrical microgrid. Results show an acceptable performance of the proposed control techniques along with a high effectiveness to smooth the active power fluctuations of wind generation. Index Terms-Distributed generation (DG), flywheel energy storage (FES), frequency control, fuzzy logic controller (FLC), microgrid (MG), voltage control, wind power generation.

Performance Comparison of Grid-Faulty Control Schemes for Inverter-Based Industrial Microgrids

“…Although this property is maintained for the type III voltage sag (see Figure 12), the improvement is not as pronounced due to the absence of negative sequence and the higher values of the residual phase voltages. Another point to take into account is that the microgrid is intentionally separated from the utility grid when using the IVS control scheme, which makes the voltage regulation in the PCC better using the GCCS1 scheme; see the previous results of Tables [4][5][6]. Finally, it should be noted that the impact of the characteristics of the voltage sags on the transient response of the system is small, as shown in Tables 4-6 …”

“…On the one hand, the microgrid operates normally in grid-connected mode, interconnected to the utility grid. In some circumstances, it can intentionally separate from the grid and operate autonomously as an independent island, which is known as islanded mode [6][7][8]. On the other hand, the power inverters can be programmed to equivalently operate as power-controlled current or voltage sources, depending on the needs of the microgrid [8].…”

A Review of Flywheel Energy Storage System Technologies and Their Applications

“…The common multilevel converter topologies in industry are diode-clamped converters or neutral-point-clamped (NPC) converters, cascaded H-bridge (CHB) converters, and flying capacitor (FC) converters. A three-level twelve-pulse NPC converter topology for FESS is proposed in [46]. Two NPC converters are connected in BTB combination to connect the FESS to the PCC between the electrical grid and wind generation.…”

The influence of different storage technologies on large power system frequency response

“…The secondary AC excitation system provides adjustable speed control, independent and fast control (produce/absorb) of active and reactive power. Since a flywheel is a rotating mass connected to the machine rotor, therefore, it can be modelled as an additional inertia coupled to DFIG [10], [11]. A FESS unit with 1.8-10 MVA power capacity usually has inertia constant ranging from 10 -40 s [5], [6].…”