The application of droop-control in distributed energy resources to extend the voltage collapse margin

The growth in distributed energy resources has the potential to reduce system stresses caused by transmission grid congestion by supplying power and voltage regulation closer to load centers. However, the additional voltage regulation provided by these resources can mask the onset of voltage collapse. Local voltage support flattens the slope in the upper region of the power-voltage nose curve. Coordinating voltage-regulation behavior with the droop-control scheme in distributed resources improves the observation of voltage collapse margins. Incorporating distributed resource models in the continuation power flow analysis, allows the exploration of the power transfer gains by the application of distributed resources. The analysis provides insight to the impact of droop control on the behavior of the power-voltage curve and voltage collapse. The analysis is applied to a fixed speed induction generator wind farm with separate reactive compensation and the interconnection to the local power system. Results reveal that coordinating the droop control strategy allows the distributed resource to significantly increase the voltage collapse margin without hiding the threat of voltage stability problems.

[1]  H. Sasaki,et al.  A New Formulation for FACTS Allocation for Security Enhancement against Voltage Collapse , 2002, IEEE Power Engineering Review.

[2]  P. Karlsson,et al.  Stability of voltage and frequency control in distributed generation based on parallel-connected converters feeding constant power loads , 2005, 2005 European Conference on Power Electronics and Applications.

[3]  Mariesa L. Crow,et al.  Computational methods for electric power systems , 2002 .

[4]  Claudio A. Canizares,et al.  Analysis of SVC and TCSC controllers in voltage collapse , 1999 .

[5]  M.R. Iravani,et al.  Power Management Strategies for a Microgrid With Multiple Distributed Generation Units , 2006, IEEE Transactions on Power Systems.

[6]  W. F. Long,et al.  Determination of Needed FACTS Controllers That Increase Asset Utilization of Power Systems , 1997 .

[7]  C.W. Taylor,et al.  Benefits of SVC and STATCOM for electric utility application , 2003, 2003 IEEE PES Transmission and Distribution Conference and Exposition (IEEE Cat. No.03CH37495).

[8]  Venkataramana Ajjarapu,et al.  The continuation power flow: a tool for steady state voltage stability analysis , 1991 .

[9]  M.J.H. Sterling,et al.  Reactive power dispatch incorporating voltage stability , 1992 .

[10]  I. Kamwa,et al.  Causes of the 2003 major grid blackouts in North America and Europe, and recommended means to improve system dynamic performance , 2005, IEEE Transactions on Power Systems.

[11]  R. Seydel.  Practical bifurcation and stability analysis : from equilibrium to chaos , 1994 .

[12]  A. Keyhani,et al.  Control of distributed generation systems - Part II: Load sharing control , 2004, IEEE Transactions on Power Electronics.

[13]  P. Ashmole,et al.  Flexible AC transmission systems , 1995 .

[14]  L.C.P. da Silva,et al.  Investigation of the relationship between ill-conditioned power flow and voltage collapse , 2000 .

[15]  N.K. Trehan,et al.  Electric utility deregulation: failure or success , 2004, IEEE Symposium Conference Record Nuclear Science 2004..

[16]  R.H. Lasseter,et al.  Autonomous control of microgrids , 2006, 2006 IEEE Power Engineering Society General Meeting.

[17]  Venkataramana Ajjarapu,et al.  An optimal reactive power planning strategy against voltage collapse , 1994 .

[18]  Jan T. Bialasiewicz,et al.  Power-Electronic Systems for the Grid Integration of Renewable Energy Sources: A Survey , 2006, IEEE Transactions on Industrial Electronics.

[19]  A. M. Abed.  WSCC voltage stability criteria, undervoltage load shedding strategy, and reactive power reserve monitoring methodology , 1999, 1999 IEEE Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.99CH36364).