Ferdian Ronilaya, Hajime Miyauchi
The frequency and voltage of a distributed variable-speed wind turbine (VSWT) that drives a permanent magnet synchronous generator (PMSG) is vigorously affected by wind speed fluctuations. In practice, a power imbalance between supply and demand often occurs when the VSWT-PMSG is connected to a weak micro grid (MG). If load demand fluctuations become high, a weak MG cannot stabilize the frequency and voltage. Hence, battery storage should be installed for the MG to adjust the energy supply and demand. To enable flexible control of the active and reactive power flow from/to the battery storage, grid-connected inverters are used. For a system that has highly nonlinear components, conventional linear proportional-integral-derivative (PID) controllers can cause MG system performance deterioration. Moreover, these controllers exhibit slow, oscillating responses, and complex equations are required to obtain the best responses in other controllers. To cope with these limitations, this paper proposes a PID-type fuzzy controller (PIDfc) design to control a grid-connected inverter of the battery. Several simulation tests are performed to examine the scheme's effectiveness. The results show that the proposed PIDfc controller demonstrates improved performance and adequate responses. © 2014 Praise Worthy Prize S.r.l. - All rights reserved.
Department of Electrical Power Engineering, The State Polytechnic of Malang, Indonesia; Department of Frontier Technology for Energy and Devices, Kumamoto University, Japan