|
Advances in Energy Research Volume 3, Number 2, 2015 , pages 081-95 DOI: https://doi.org/10.12989/eri.2015.3.2.081 |
||
|
Modified droop control scheme for load sharing amongst inverters in a micro grid |
||
Urvi N. Patel, Dipakkumar Gondalia and Hiren H. Patel
|
||
| Abstract | ||
| Microgrid, which can be considered as an integration of various dispersed resources (DRs), is characterized by number of DRs interfaced through the power electronics converters. The microgrid comprising these DRs is often operated in an islanded mode. To minimize the cost, reduce complexity and increase reliability, it is preferred to avoid any communication channel between them. Consequently, the droop control method is traditionally adopted to distribute active and reactive power among the DRs operating in parallel. However, the accuracy of distribution of active and reactive power among the DRs controlled by the conventional droop control approach is highly dependent on the value of line impedance, R/X i.e., resistance to reactance ratio of the line, voltage setting of inverters etc. The limitations of the conventional droop control approach are demonstrated and a modified droop control approach to reduce the effect of impedance mis-match and improve the time response is proposed. The error in reactive power sharing is minimized by inserting virtual impedance in line with the inverters to remove the mis-match in impedance. The improved time response is achieved by modifying the real-power frequency droop using arctan function. Simulations results are presented to validate the effectiveness of the control approach. | ||
| Key Words | ||
| droop control; virtual impedance loop; arctan function; reactive power sharing | ||
| Address | ||
| Urvi N. Patel: Department of Electrical Engineering, C.K. Pithawalla College of Engineering & Technology, Near Malvan Temple, Dumas Road, Surat, Gujarat, India Dipakkumar Gondalia and Hiren H. Patel: Department of Electrical Engineering, Sarvajanik College of Engineering & Technology, near Athwagate, Surat, Gujarat, India | ||
