ABSTRACT:
A
new buck-boost based single phase transformerless grid connected photo voltaic
(PV) inverter which is having the capability to operate two serially connected
subarrays at their respective maximum power point is proposed in this paper.
The series connection of the two subarrays and the buck-boost nature of the
inverter reduces the number of serially connected modules in a subarray.
Further, independent operation of the two subarrays enhances the overall power
extraction from the subarrays while they are experiencing significant mismatch
at their operating conditions, e.g. insolation level and/or operating
temperature. The topological structure of the inverter and its control
technique ensures negligible amount of high frequency components in its common
mode voltage. As a consequence the overall leakage current associated with the
subarrays are restricted well within the permissible limit specified in the
standard, VDE 0126-1-1. The operating principle of the proposed scheme along
with its rigorous analysis has been presented. The reference current generation
for the buck-boost inductor and the controller configuration of the proposed
inverter have been elaborated in detail. Detailed simulation study with a 1.3
kW PV system has been carried out to show the viability of the proposed scheme.
KEYWORDS:
1. Buck-boost
inverter
2. Maximum
power point
3. Single
phase
4. Transformerless
5. Grid
connected inverter
6. Difference in operating condition
7. Series
connection
8. Sub-arrays
SOFTWARE:
MATLAB/SIMULINK
CONCLUSION:
A
new buck-boost based transformerless grid connected solar PV inverter which is
capable of operating two serially connected subarrays at their respective
maximum power points while significant amount of difference is present in their
operating conditions, was proposed in this paper. The buckboost nature of the
inverter along with its ability to operate two serially connected subarrays at
their respective maximum power point enhances the overall power extraction from
the subarrays while they are experiencing wide difference at their operating conditions.
A simple inductor current control technique which is independent of modes of
operation (CCM or DCM) was adopted to control ig. The topological
structure of the inverter and its control technique restrict the overall
leakage current associated with the subarrays within the permissible limit. The
operating principle of the proposed inverter was mentioned. The reference
current generation for the buck-boost inductor and the controller configuration
of the proposed inverter was elaborated in detail. A 1.3 kW PV system with the
proposed inverter was simulated, and the simulation results were presented to
confirm the viability of the proposed inverter.
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