HIGH PERFORMANCE OF POWER TRANSFER IN HYBRID AC-DC MICROGRID WITHOUT STORAGE SYSTEM

This paper aims to look at the use of an intermittent renewable energy source (RES) connected to the grid in a hybrid alternating current (AC) - direct current (DC) microgrid concept, without a storage system. It is known that intermittent RES sometimes has excess energy and sometimes lacks, so this condition requires a storage system. A way to solve this problem is to use an AC-DC bidirectional converter as an interlinking converter (IC). The IC connected DC and AC sub microgrids. It also manages the power transfer in the system. The control uses three inputs, the Vage from the DC sub microgrid, the Vage and current from the AC sub microgrid. The control uses pulse width modulation (PWM) and also d-q rotating coordinate system. What is new from this research is that the Vage from the AC sub microgrid is only used for input to the phase lock loop (PLL). This is to maintain the converter phase shift equal to the network. The simulation was built on Simulink / Matlab and adding power changes in the DC sub microgrid and the load changes in the AC sub microgrid. The results prove that the built-in IC works on the systems with stable Vages, frequencies, and the total harmonic distortion (THD) is less than 8% that meets the Institute of Electrical and Electronics Engineers (IEEE) Standard 519TM2014 requirements. The efficiency of the IC is reaches 99.4% as a rectifier and 99.6% as an inverter. The contribution of the proposed study can provide better performance than the previous study by showing the power transfer between ac and dc sub microgrid with eliminating delay and overshoot.