Load sharing and power quality enhanced operation of a distributed microgrid
- 1 January 2009
- journal article
- Published by Institution of Engineering and Technology (IET) in IET Renewable Power Generation
- Vol. 3 (2), 109-119
- https://doi.org/10.1049/iet-rpg:20080001
Abstract
Control methods for proper load sharing between parallel converters connected in a microgrid and supplied by distributed generators (DGs) are described. It is assumed that the microgrid spans a large area and it supplies loads in both in grid-connected and islanded modes. A control strategy is proposed to improve power quality and proper load sharing in both islanded and grid-connected modes. It is assumed that each of the DGs has a local load connected to it which can be unbalanced and/or non-linear. The DGs compensate the effects of unbalance and non-linearity of the local loads. Common loads are also connected to the microgrid, which are supplied by the utility grid under normal conditions. However, during islanding, each of the DGs supplies its local load and shares the common load through droop characteristics. Both impedance and motor loads are considered to verify the system response. The efficacy of the controller has been validated through simulation for various operating conditions using PSCAD. It has been found through simulation that the total harmonic distortion (THD) of the microgrid voltage is ∼10% and the negative and zero sequence components are ∼20% of the positive sequence component before compensation. After compensation, the THD remains <0.5%, whereas negative and zero sequence components of the voltages remain <0.02% of the positive sequence component.Keywords
This publication has 10 references indexed in Scilit:
- Decentralized Control for Parallel Operation of Distributed Generation Inverters Using Resistive Output ImpedanceIEEE Transactions on Industrial Electronics, 2007
- Power Management Strategies for a Microgrid With Multiple Distributed Generation UnitsIEEE Transactions on Power Systems, 2006
- Dynamic Stability of Power Systems with Power Electronic Interfaced DGPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2006
- A grid-interfacing power quality compensator for three-phase three-wire microgrid applicationsIEEE Transactions on Power Electronics, 2006
- A Wireless Controller to Enhance Dynamic Performance of Parallel Inverters in Distributed Generation SystemsIEEE Transactions on Power Electronics, 2004
- Load compensating dstatcom in weak ac systemsIEEE Transactions on Power Delivery, 2003
- Parallel operation of single phase inverter modules with no control interconnectionsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- A new approach to load balancing and power factor correction in power distribution systemIEEE Transactions on Power Delivery, 2000
- Control of parallel inverters in distributed AC power systems with consideration of line impedance effectIEEE Transactions on Industry Applications, 2000
- Control of parallel connected inverters in standalone AC supply systemsIEEE Transactions on Industry Applications, 1993