Study of Power Grid Connection with an Unstable Source from Elevator Energy Regenerative Unit (EERU)

This paper presents a study of power grid connection with an unstable source from elevator energy regenerative unit (EERU). The investigated system used a Permanent Magnet Synchronous Motor (PMSM). The EERU is installed for this system to generate electricity according to the generative mode of the elevator which delivers power to the grid as an unstable power source. To meet standard specifications in term of power quality and safety for grid connection, the phase angle and the amplitude as well as the frequency of the grid voltage are considered for grid connection. Phase lock loop (PLL) algorithm is therefore very important and selected for grid synchronization. The study is done by simulation using Matlab/Simulink program. The simulation used phase lock loop to synchronize between two systems. The results of this simulation will lead to a proper design of the grid connection with EERU as an unstable power source.