Neuro-fuzzy current controller for three-level cascade inverter based D-STATCOM

ABSTRACT:

Distribution STATCOM (D-STATCOM) is a custom power device connected in parallel to power system. In this paper, Neuro-Fuzzy Controller (NFC) which has robust structure is proposed for control of D-STATCOM’s dq-axis currents. Designed NFC is first order Mamdani type NFC structure and has two inputs, one output and six layers. DSTATCOM is based on three-level cascaded inverter and this inverter is controlled with Sinusoidal Pulse Width Modulation (SPWM) technique. dSPACE’s DS1103 control card is used for real-time implementation of D-STATCOM’s control algorithm. The performance of D-STATCOM using NFC is evaluated by changing of reference reactive current (iqref) as on-line. Under this condition, some experimental results obtained from experimental setup are given.

 KEYWORDS:

  1. D-STATCOM
  2. Neuro-Fuzzy Current Controller
  3. SPWM
  4. Three-Level Cascade Inverter

 SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig.1. Three-level cascaded inverter based D-STATCOM

EXPECTED SIMULATION RESULTS:

 

Fig.2. Changing of dc link voltages

 Fig.3. iqref tracking performance of iq

Fig.4. Phase-a current and voltage waveforms of D-STATCOM

 

Fig.5. Changing of modulation index

Fig.6. Changing of phase angle

 CONCLUSION:

In this paper, NFC is developed to synthesize the current control loop of D-STATCOM. NFC which is a combination of ANN and FLC gives the D-STATCOM a good dynamic response and excellent tracking ability in changing of iqref. Experimental results show that Neuro-Fuzzy current controlled D-STATCOM can provide the desired reactive power exact and fast within own rated power limits even in the worst operating condition.

REFERENCES:

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[2] C. Schauder, H. Mehta, “Vector Analysis and Control of Advanced Static VAr Compensators,” Generation, Transmission and Distribution, IEE Proceedings C, vol.140, pp. 299-360, 1993.

[3] V. Blasko, V. Kaura, “A New Mathematical Model and Control of A Three-Phase AC-DC Voltage Source Converter,” IEEE Transactions on Power Electronics, vol.12, pp. 116-123, 1997.

[4] P. W. Lehn, M. R. Iravani, “Experimental Evaluation of STATCOM Closed Loop, IEEE Transactions on Power Delivery,” vol.13, pp. 1378-1384, 1998.

[5] P. Rao, M. L. Crow, Z. Yang, “STATCOM Control for Power System Voltage Control Applications,” IEEE Transactions on Power Delivery, vol.15, pp.1311-1317, 2000.