High gain - high power (HGHP) DC-DC converter for DC microgrid applications: design and testing

The use of green energy sources to feed DC microgrids is gaining prominence over traditional centralised AC systems. DC microgrids are characterised by the use of intermediate DC-DC converter which acts as power conditioning units. Hence, the choice of an appropriate DC-DC converter becomes significant as the overall system efficiency is strongly dependent on the converter’s performance. This paper proposes a novel high gain high power (HGHP) DC-DC converter for DC microgrid, which is of one of the significant step forward in the development of DC microgrids. The suitability of the proposed HGHP DC-DC converter is demonstrated by experimental tests of the 60V/1.1kV, 3kW converter; test results validate the converter’s suitability for DC distribution. A significant number of performance parameters of the proposed converter is compared with state of the art converter topologies demonstrating the superior capabilities of the proposed converter. This paper also portrays the potential benefits that could be reaped by trending towards DC instead of existing AC system. The advantages and challenges to be confronted in the foreseeable future while implementing sustainable DC microgrids are also highlighted. Finally, this paper encapsulates renewable energy fed DC microgrid system as an appropriate, technically feasible, economically viable and competent solution for efficiently utilising the sustainable energy sources

Hybrid power generation forecasting using CNN based BILSTM method for renewable energy systems

ABSTRACTThis paper presents the design of a grid-connected hybrid system using modified Z source converter, bidirectional converter and battery storage system. The input sources for the proposed system are fed from solar and wind power systems. A modified high gain switched Z source converter is designed for supplying constant DC power to the DC-link of the inverter. A hybrid deep learning (HDL) algorithm (CNN-BiLSTM) is proposed for predicting the output power from the hybrid systems. The HDL method and the PI controller generate pulses to the proposed system. A closed loop control framework is implemented for the proposed grid integrated hybrid system. A 1.5 Kw hybrid system is designed in MATLAB/SIMULINK software and the results are validated. A prototype of the proposed system is developed in the laboratory and experimental results are obtained from it. From the simulation and experimental results, it is observed that the ANN controller with SVPWM (Space vector Pulse width Modulation) gives a THD (Total harmonic distortion) of 2.2% which is within the IEEE 519 standard. Therefore, from the results, it is identified that the ANN-SVPWM method injects less harmonic currents into the grid than the other two controllers

Interleaved high gain DC-DC converter for integrating solar PV source to DC bus

In this paper, a novel non-isolated DC-DC converter topology is proposed for solar photovoltaic (PV) application. The proposed converter is constructed from an interleaved boost converter (IBC) to reduce the input current ripple. Voltage gain is extended by (i) using voltage lift technique, (ii) replacing the conventional inductors of the IBC by coupled inductors (CIs) with appropriate turns ratio and (iii) connecting a voltage multiplier cell (VMC) across the secondary windings of the CIs. As the voltage gain is extended mainly at the secondary side of the CIs, the switches are subjected to low voltage stress which is only 12.63% of the output voltage. The converter yields a high voltage conversion ratio of 15.83. Experimental results obtained from a 24 V/380 V, 225 W prototype converter operating at 91.6% efficiency serves as a proof of the presented concept which has been employed to achieve high voltage conversion ratio (15.83) with low input current ripple (20%)

Centralized power management and control of a Low Voltage DC Nanogrid

This paper discusses FPGA-based power sharing control of a solar PV-powered low-voltage DC (LVDC) nanogrid. The proposed LVDC nanogrid control algorithm monitors power generation, storage, and load power and shifts between sources and load to maintain power balance. The controller effectiveness is studied for varying input and varying load conditions via simulation studies and hardware implementation. A proposed system simulation model with a control algorithm is built into MATLAB and performance analysis is carried out. The power sharing control algorithm and MPPT algorithm are built using Xilinx blocks in MATLAB and programmed into FPGA controller Furthermore, experimentation is carried out on the proposed model to validate the simulation results. Hardware results obtained under different atmospheric and load conditions are presented and discussed