Abstract:
In this work, a new series solar inverter configuration is proposed to share the power in terms of voltage,
unlike parallel inverter configurations. In a single-stage parallel
inverter, elevated DC potential and circulating current due to
common-mode voltage (CMV) would degrade the solar inverter’s
life. The proposed topology eases the stress on the DC bus and
protects the solar inverter from the issues associated with elevated DC potential (Potential induced degradation effect, switch
operating voltage stress, etc.). The inherent boosting capability
of the proposed series inverter with two modular inverters is
demonstrated through two switching algorithms. In the first
switching algorithm, the switching combinations are devised to
yield the maximum voltage across the load. The second switching
algorithm demonstrates the method of eliminating CMV by
choosing the appropriate switching combination of two inverters.
The eliminated instantaneous CMV would give the provision of
operating proposed topology with common DC bus along with the
flexibility of DC bus grounding. For the proposed configuration
with devised switching techniques, the closed-loop controller
is designed by computing the plant’s equivalent characteristic
impedance using a state-space model. The effectiveness of the
proposed configuration, along with the closed-loop control, is
validated through hardware
