Modeling and Simulation of a Distribution STATCOM (D-STATCOM) for Power Quality Problems-Voltage Sag and Swell Based on Sinusoidal Pulse Width Modulation (SPWM)

ABSTRACT:

This paper presents the systematic procedure of the modeling and simulation of a Distribution STATCOM (DSTATCOM) for power quality problems, voltage sag and swell based on Sinusoidal Pulse Width Modulation (SPWM) technique. Power quality is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure of end use equipments. The major problems dealt here is the voltage sag and swell. To solve this problem, custom power devices are used. One of those devices is the Distribution STATCOM (D-STATCOM), which is the most efficient and effective modern custom power device used in power distribution networks. D-STATCOM injects a current in to the system to correct the voltage sag and swell.The control of the Voltage Source Converter (VSC) is done with the help of SPWM. The proposed D-STATCOM is modeled and simulated using MATLAB/SIMULINK software.

KEYWORDS:

  1. Distribution STATCOM (D-STATCOM)
  2. MATLAB/SIMULINK
  3. Power quality problems
  4. Sinusoidal Pulse  Width Modulation (SPWM)
  5. Voltage sag and swell
  6. Voltage  Source Converter (VSC)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Schematic representation of the D-STATECOM for a typical custom

power application.

EXPECTED SIMULATION RESULTS:

 Fig. 2. Voltage Vrms at load point, with three-phase fault: (a) Without DSTATCOM and (b) With D-STATCOM, 750I-lf .

Fig. 3. Voltage vrms at load point, with three phase-ground fault: (a)

Without D-STATCOM and (b) With D-STATCOM.

Fig. 4. Voltage Vrms at load point, with line-ground fault: (a) Without DSTATCOM and (b) With D-STATCOM.

Fig. 5. Voltage vrms at load point, with line-line fault: (a) Without DSTATCOM and (b) With D-STATCOM.

Fig. 6. Voltage vrms at load point, with line-line-ground fault: (a) Without

D-STATCOM and (b) With D-STATCOM.

CONCLUSION:

This paper has presented the power quality problems such as voltage sags and swell. Compensation techniques of custom power electronic device D-ST ATCOM was presented. The   design and applications of D-STATCOM for voltage sags, swells and comprehensive results were presented. The Voltage Source Convert (VSC) was implemented with the help of Sinusoidal Pulse Width Modulation (SPWM). The control scheme was tested under a wide range of operating conditions, and it was observed to be very robust in every case. For modeling and simulation of a D-ST ATCOM by using the highly developed graphic facilities available in MA TLAB/SIMULINK were used. The simulations carried out here showed that the D-STATCOM provides relatively better voltage regulation capabilities.

 REFERENCES:

[I] O. Anaya-Lara, E. Acha, “Modeling and analysis of custom power  systems by PSCAD/EMTDC,” IEEE Trans. Power Delivery, vol. 17, no .I, pp. 266-272, January 2002.

[2] S. Ravi Kumar, S. Sivanagaraju, “Simualgion of D-Statcom and DVR in  power system,” ARPN jornal of engineering and applied science, vol. 2,   no. 3, pp. 7-13, June 2007.

[3] H. Hingorani, “Introducing custom power”, IEEE Spectrum, vol. 32, no.6, pp. 41-48, June 1995.

[4] N. Hingorani, “FACTS-Flexible ac transmission systems,” in Proc. IEE 5th Int Conf AC DC Transmission, London, U.K., 1991, Conf Pub.  345, pp. 1-7.

[5] Mahesh Singh, Vaibhav Tiwari, “Modeling analysis and soltion to  power quality problems,” unpublished.

Neuro Fuzzy based controller for Power Quality Improvement

International Conference on Computational Intelligence and Communication Networks, 2015

ABSTRACT: Use of power electronic converters with nonlinear loads leads to power quality problems by producing harmonic currents and drawing reactive power. A shunt active power filter provides an elegant solution for reactive power compensation as well as harmonic mitigation leading to improvement in power quality. However, the shunt active power filter with PI type of controller is suitable only for a given load. If the load is varied, the proportional and integral gains are required to be fine tuned for each load setting. The present study deals with hybrid artificial intelligence controller, i.e. neuro fuzzy controller for shunt active power filter. The performance of neuro fuzzy controller over PI controller is examined and tabulated. The salvation of the problem is extensively verified with various loads and plotted the worst case out of them for the sustainability of the neuro fuzzy controller.

 

KEYWORDS:

  1. Active Power Filter
  2. Neuro Fuzzy Controller
  3. Back Propagation Algorithm
  4. Soft Computing

 

SOFTWARE: MATLAB/SIMULINK

 

BLOCK DIAGRAM:

Fig 1. Schematic Diagram of Shunt Active Power Filter

  

EXPECTED SIMULATION RESULTS:

   

Fig 2. (a) Waveform of Load Current, Compensating Current, Source

Current and Source Voltage for Case V of Table1 (1kVA with α=60o) and

(b) Waveform of Source Voltage and in phase Source Current of Fig. (a) Reproduced

 

CONCLUSION:

The application of hybrid artificial intelligence technique on shunt active power filter is proved to be an eminent solution for the mitigation of harmonics and the compensation of reactive power. The hybrid artificial intelligence used here is the neuro fuzzy controller. It takes the linguistic inputs as a fuzzy logic controller and it adapts any situation in between the running of the program as the neural network. The simulation results states that the active power filter controller with neuro fuzzy controllers have been seen to eminently minimize harmonics in the source current when the load demands non sinusoidal current, irrespective of whether the load is fixed or variable when compared to PI Controller. Simultaneously, the power factor at source also becomes the unity, if the load demands reactive power. The neuro fuzzy controller is far superior to the PI controller for all the loads. In the present work, a range of values of the load is considered to robustly test the controllers. It has been demonstrated that neuro fuzzy controller offers more acceptable results over the PI controller. The neuro fuzzy controller, therefore, significantly improves the performance of a shunt active power filter.

 

REFERENCES:

  • Laszlo Gyugyi, “Reactive Power Generation and Control by Thyristor Circuits”, IEEE Transactions on Industry Applications, vol. IA-15, no. 5, September/October 1979.
  • Akagi, Y. Kanazawa, and A. Nabae, “Instantaneous reactive power compensators comprising switching devices without energy storage components,” IEEE Transaction Industrial Applications, vol. IA-20, pp. 625-630, May/June 1984.
  • Z. Peng, H. Akagi, and A. Nabae, “A study of active power filters using quad series voltage source pwm converters for harmonic compensation,” IEEE Transactions on Power Electronics, vol. 5, no. 1, pp. 9–15, January 1990.
  • Conor A. Quinn, Ned Mohan, “Active Filtering of Harmonic Currents in Three-phase, Four-Wire Systems with Three-phase and Single-phase Non-Linear Loads”, IEEE-1992.
  • A. Morgan, J. W. Dixon, and R. R. Wallace, “A three-phase active power filter operating with fixed switching frequency for reactive power and current harmonic compensation,” IEEE Transactions on Industrial Electronics, vol. 42, no. 4, pp. 402–408, August 1995.