ABSTRACT:
An improved control strategy for the
three-phase grid-connected inverter with space vector pulse width modulation (SVPWM) is proposed. When
the grid current contains harmonics, the d- and q-axis grid currents will be
interacted, and then the waveform quality of the grid current will be poorer.
As the reference output voltage cannot directly reflect the change of the reference
grid current, the dynamic response of the grid-connected inverter is slow. In
order to solve the aforementioned problems, the d- and q-axis grid currents in
the decoupled components of the grid current controller can be substituted by
the d- and q-axis reference grid currents, respectively. The operating
principles of the traditional and proposed control methods are illustrated. Experimental
results for a 15-kVA three-phase grid-connected inverter with SVPWM verify the
theoretical analysis. Compared with the traditional control strategy, the
grid-connected inverter with the improved control strategy has high waveform
quality of the grid current, small ripple power, and fast dynamic response.
KEYWORDS:
1. Inverters
2. LCL filter
3. Grid-connected
4. SVPWM
5. Total harmonic distortion.
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
EXPERIMENTAL RESULTS:
CONCLUSION:
This paper has proposed an improved
SVPWM control strategy for the three-phase grid connected inverter. The
reference grid current is used in the decoupled components of the grid current
controller in the proposed control method to replace the grid current.
Experimental results of a 15-kVA three-phase SVPWM grid-connected inverter show
that the grid-connected inverter with the proposed control strategy has high
waveform quality of the grid current, small ripple power, and fast dynamic
response compared with the traditional control strategy.
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