Efficient design of ‘High Power and Low Loss DC-DC Converter Using Modified PQ Theory’

Abstract

The use of LCL DC-DC converters in high efficiency mining applications for Megawatt range
power transport has gone up in past years. . These converters comprise LCL tank resonant
circuit between two voltage source converters in which the losses are reduced by the use of
capacitors. The flows of power between the bridges are also administered for loss reduction.
However, the control techniques are more complicated and there are stability issues in real-time
implementations. In order to mitigate these issues, this paper proposes a high power and low loss
bidirectional LCL converter through assistance of modified pq theory. The study also proposes a
constructive control mechanism basing upon the single phase pq theory and Second Order
Generalized Integrator (SOGI). Furthermore, Second Order Generalized Integrator (SOGI) are
used to generate best orthogonal signals for pq theory. The simulation of proposed efficient LCL
converter is developed in MATLAB/SIMULINK environment. The functioning of the LCL
converter was analysed under uniform circumstances. The results show that the proposed
efficient LCL converter achieved a higher power transfer capability and effectively reduced
harmonics. Furthermore, the result was established that the efficiency of the developed control is
suitable for mining applications.