Design and Implementation of Sliding Mode and PI Controllers based Control for Three Phase Shunt Active Power Filter

ABSTRACT:

This paper presents a simulation and experimental comparative study of Sliding Mode Controller (SMC) and Proportional Integral (PI) regulator based the control of the DC bus voltage of three phase shunt Active Power Filter (APF). The capacitor that feeds the active filter plays the role of a voltage source. This tension must be kept constant, so as not to degrade the filter performances, and not to exceed the voltage of semiconductors. The main cause of the variation of this voltage is the change in the pollutant load, which creates an active power exchange with the network (if the inverter provides power active, then the average voltage across the capacitor will decrease and if the inverter consumes power active, then the average voltage across the capacitor will increase). The algorithm used to identify the reference currents is based on the Self Tuning Filter (STF). This study was verified experimentally, using a hardware prototype based on dSPACE-1104.

KEYWORDS:

1.      Active Power Filter (APF)

2.       Sliding Mode Controller (SMC)

3.      Self Tuning Filter (STF)

4.       Proportional Integral (PI) Controller

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Basic compensation principle of the shunt APF.

 EXPECTED SIMULATION RESULTS:

Fig.2. Simulation APF with PI: capacitor voltage Vdc (V); source current iS (A) and load current iL(A).

Fig.3. Simulation APF with SMC: capacitor voltage V_dc (V); source current i_S (A) and load current i_L(A).

CONCLUSION:

 Two different control strategies for a three-phase shunt active power filter employing a digital signal processor DSP were presented in this paper. The first is based on sliding mode control SMC and the second uses a single proportional-integral controller PI. These controllers are used in order to regulate the DC voltage of the three phase shunt active power filter and improving the dynamical performances. Several tests have been performed in order to prove the efficiency of the type of the control. The results obtained by simulations and Experimental, show that the SMC controller offers better performances than the PI.

REFERENCES:

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