Harmonic voltage
compensation of the load connected to the point of common coupling (PCC) by
using a series of active power filter (SAPF) based on a single phase cascaded multilevel
inverter is proposed. The proposed multilevel inverter are presented in detail.
The inverter has the ability of acting as a harmonic source when the reference
is a non-sinusoidal signal. To achieve this, a simple control technique is
performed with the proposed inverter. A prototype of 7-level inverter based
SAPF is manufactured without using a parallel passive filter (PPF) because it
is designed to show SAPF own compensation capacity alone. Filtering ability of
the SAPF is shown both in simulation and experimental studies. The validity of
the proposed inverter based SAPF is verified by simulation as well as
experimental study. The results show that the proposed multi-level inverter is
suitable for SAPF applications.
KEYWORDS:
1. Active
power filter
2. Multilevel
inverter
3. Harmonic
compensation
4. Half-bridge
cascaded
5. Power
quality
SOFTWARE: MATLAB/SIMULINK
Fig. 1. The scheme of the
proposed system.
EXPECTED SIMULATION RESULTS:
(a) Simulation result (50 V/div), (5 ms/div)
Fig. 2. The waveform of VPCC before compensation
(a) Simulation result (50 V/div), (5 ms/div)
Fig. 3. The waveforms of the load voltage and the
proposed inverter voltage after compensation.
CONCLUSION:
This paper proposes a single phase cascaded inverter
based SAPF. The 7-level inverter topology and operation principle is introduced.
With the proposed topology, the number of output levels can easily be
increased. Switching signals of the semiconductor devices used in the inverter
are also obtained by a simple method. A SAPF with the proposed inverter
topology is simulated.The aim of the simulation is to compensate the load
voltage harmonics connected to PCC. In addition to the simulation, the proposed
SAPF prototype is designed. Using this prototype, experimental study is
performed. Simulation and experimental results similar each other proves the
accuracy of the analysis. The load waveform that is highly distorted with a THD
value of 24.12% is compensated with the proposed inverter based SAPF and the
THD value is reduced to 3.80% in experimental study. This shows that the
proposed inverter is suitable for SAPF applications.
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