A Low-cost Voltage Stabilization and Power Quality Enhancement Scheme for a Small Renewable Wind Energy Scheme

1
A Low-cost Voltage Stabilization and Power
Quality Enhancement Scheme for a Small Renewable
Wind Energy Scheme

• By
• Dr. A.M Sharaf (SM-IEEE)
• Weihua Wang (MscE. Student)
• Dept. of Electrical and Computer Engineering
• University of New Brunswick

2
OUTLINE

• Introduction
• System Description
• Novel PWM Switching Control Scheme
• Modulated Power Filter Compensator
• Simulation Results
• Conclusion

3
Introduction

• Motivation of renewable wind energy
• Fossil fuel shortage and its escalating prices
• Reducing environmental pollution caused by
  conventional methods for electricity generation

4
Introduction

• Challenges of the reliability of wind power
  system
• Load excursion
• Wind velocity variation
• Conventional passive capacitor compensation
  devices become ineffective

5
System Description

• Self-excited induction generator (SEIG)
• Transformers and short feeder
• Hybrid loads linear load and non-linear load
• The modulated power filter compensator (MPFC)

6
Novel PWM Switching Control Scheme
7
Novel PWM Switching Control Scheme

• Multi-loop dynamic error driven
• The voltage stabilization loop
• The load bus dynamic current tracking loop
• The dynamic load power tracking loop
• Using proportional, integral plus derivative
  (PID) control scheme
• Simple structure and fast response

8
Novel PWM Switching Control Scheme

• Objective
• To stabilize the voltage under random load and
  wind speed excursion
• Maximize power/energy utilization
• The control gains (Kp, Ki) are selected using a
  guided trial and error method to minimize the
  objective function, which is the sum of all three
  basic loops.

9
The Functional Model of MPFC

• The capacitor bank and the RL arm are connected
  by a 6-pulse diode to block the reverse flow of
  current.
• Capacitor size normally selected as 40-60 of
  the non-linear load KVAR capacitor.

10
Proposed MPFC Scheme and Its Functional Model
11
Simulation Results

• Digital simulation environment
• MATLAB 7.0.1/SIMULINK
• Sequence of load excursion
• From 0s to 0.2s Both Linear Load 200 kVA (50)
  and nonlinear Load 200 kVA (50) connected
• From 0.2s to 0.4s Linear Load 200 kVA(50)
  connected only
• From 0.4s to 0.6s No load is connected

12
System Dynamic Response Without MPFC
13
System Dynamic Response With MPFC
14
Error plane of the dynamic error driven controller
15
Conclusions

• The digital simulation results validated that the
  proposed low cost MPFC scheme is effective in
  voltage stabilization for both linear and
  nonlinear electrical load excursions.
• The proposed MPFC scheme will be easily
  integrated in renewable wind energy standalone
  units in the range from 600kW to 1600kW.

16
Reference

• 1 A.M.Sharaf and Liang Zhao, A Novel Voltage
  Stabilization Scheme for Standalone Wind Energy
  Using a Facts Dual Switching Universal Power
  Stabilization Scheme, 2005
• 2 M.S. El-Moursi and Adel M. Sharaf, 'Novel
  STATCOM controller for voltage stabilization of
  wind energy scheme', Int. J. Global Energy
  Issues, 2006
• 3 A. M. Sharaf and Guosheng Wang, Wind Energy
  System Voltage and Energy Enhancement Using Low
  Cost Dynamic Capacitor Compensation Scheme, 2004
• 4 A.M. Sharaf and Liang Yang, 'A Novel
  Efficient Stand-Alone Photovoltaic DC Village
  Electricity Scheme, 2005

17
Reference

• 5 Pradeep K. Nadam, Paresk C. Sen, 'Industrial
  Application of Sliding Mode Control', IEEE/IAS
  International Conference On Industrial Automation
  and Control, Proceedings, pp. 275-280, 1995
• 6 Paresk C. Sen, 'Electrical Motor and
  Control-Past, Present and Future', IEEE
  Transactions on Industrial Electronics, Vol.37,
  No.6, pp.562-575, December 1990
• 7 Edward Y.Y. Ho, Paresk C. Sen, 'Control
  Dynamics of Speed Drive System Using Sliding Mode
  Controllers with Integral Compensation', IEEE
  Transactions on Industry Applications, Vol.21,
  NO.5, pp 883-892, September/October 1991.