**ABSTRACT:**** **

*This *paper present analysis of hybrid active power filter with synchronous reference frame control algorithm. The proposed topology consist of active power filter and passive power filter are connected in shunt with the mains feeding a nonlinear load. The shunt passive power filter is tuned to eliminate most dominate 5th order load current harmonic. The shunt active power filter is used compensate all other higher order load current harmonics. This approach help toreduce the overall rating of shunt active power filter, and maintain unity power factor at line side with low THD, which makes system more economical for industrial usage. Detail design steps for 5th order tuned filter is also discussed and results are presented. The proposed shunt active power filter is also tested for dynamic loading condition. Hardware results for the verification of proposed control algorithm is also presented and discussed.

**KEYWORDS:**

- Hybrid Active Filter
- Passive Filter
- Total Harmonic Distortion
- Synchronous Reference Frame
- Unity Power Factor

** ****SOFTWARE:** MATLAB/SIMULINK

** ****CIRCUIT DIAGRAM:**

Fig. 1: Main Power Circuit Diagram of HAPF

** ****EXPECTED SIMULATION RESULTS:**

** **

** **

Fig. 2: Simulation Result ofSPPF (a) Phase-A Output Load Current

without Compensation (b) Phase-A Source Current with Compensation

(c) Phase-A 5th Order Harmonic Current

(d) Phase-A Source Voltage and Source Current

Fig. 3: FFT Curve ofSPPF (a) FFT of Output Load Current without

Compensation (b) FFT o f Source Current with Compensation

Fig. 4: Simulation Result of SAPF Under Fixed Load (a) Phase-A Output

Load Current without Compensation (b) Phase-A Source Current after

Compensation (c) D C Bus Voltage Across Capacitor (d) Phase-A Actual

Compensating Current (e) Phase-A Source Voltage and Source Current

Fig. 5: Simulation Result ofSAPF under Dynamic Load (a) Phase-A

Output Load Current without Compensation (b) Phase-A Source Current

after Compensation (c) Phase-A Actual Compensating Current (d) DC

Bus Voltage Across Capacitor

Fig. 6: Hysteresis Controller Results (a) Reference and Actual

Compensating Currents of Phase-A (b) Line-Line Voltage of lnverter

Fig.7: FFT Curve of Source Current after Compensation by using SAPF

under Fixed Load (b) under Dynamic Load

Fig. 8: Simulation Result ofHAPF(a) Phase-A Load Current without

Compensation,(b) Phase-A Source Current with Compensation,

(c) Phase-A Phase Voltage and Current, (d) DC Link Voltage oflnverter,

(e) Phase-A Actual Compensating Current

Fig. 9: Simulation Result ofHAPF (a) Three Phase Output Load

Current, (b) Three Phase Load Current, (c) Three Phase Source Current,

(d) FFT Curve of Source Current with Compensation

**CONCLUSION:**

** **This paper analyze the performance and simulation of hybrid active power filter (HAPF). Through the simulation analysis, this paper verified the mitigation of harmonic, to achieve unity power factor with reduced rating of SAPF. Proposed control technique is able to give fast dynamic response during variable load condition, which demonstrate the robustness of controllers. The proposed topology is an effort to provide cost effective solution for harmonic elimination in various industrial application

**REFERENCES:**

[I] B. Singh, V. Verma, A. Chandra and K. AI-Haddad ” Hybrid filter for power quality improvement” *IEEE proc. Gener. Transm. Distrib. , *Volume:152, No.3 , May 2005.

[2] J. Arrillaga and N. R. Watson, Power System Harmonics, 2nd ed. Hoboken, NJ: Wiley, 2003

[3] B. Singh, K. AI-Haddad, and A. Chandra, ” A reviewof active filter for power quality improvement,” *IEEE Trans. Ind. Electron. , *Vol. 46, nO.5 pp. 960-971 , Oct.l999.

[4] H. Akagi, ” Active harmonic filters” *Proc. IEEE, *vol. 93, no. 12, pp.2128-2141 , Dec. 2005.

[5] K. K. Shyu, M. Yang, Y.M. Chen, and Y.F.Lin, “Model reference Adaptive control design for a shunt active po we filter systems,” *TEEE Trans. Tnd. Electron., *vol. 55, no. 1, pp. 97-106, Jan. 2008.