Mitigating Tap Changer Limit Cycles in Modern Electricity Networks Embedded With Local Generation Units

D. Ranamuka, A. P. Agalgaonkar, K. M. Muttaqi, M. J. E. Alam
2016 IEEE transactions on industry applications  
Cascaded on-load tap changers (OLTCs) are widely used for coarse control of voltages in largely interconnected elec-tric power systems. There could be interactions between load dynamics and OLTC control under certain system operating conditions which may lead to the OLTC limit cycle phenomena, thereby resulting into long-term voltage oscillations in the system. In recent years, renewable and nonrenewable local generation (LG) units have been getting interconnected in modern power systems. The
more » ... ower systems. The existence of OLTC limit cycles in the presence of LG has not been addressed in the literature in greater details. In this paper, the OLTC limit cycle phenomenon, which can occur due to interactions among load dynamics, OLTC controls, and LG operation in electricity networks, has been investigated. Also, a novel strategy is explored for mitigating the power system oscil-lations introduced by OLTC limit cycles, especially for a network embedded with LG. The proposed mitigation strategy including detailed investigations and analyses has been verified for a two-bus test system and successfully tested on a multibus system using MATLAB Abstract--Cascaded on-load tap changers (OLTC) are widely used for coarse control of voltage in largely interconnected electric power systems. There could be interactions between load dynamics and OLTC control under certain system operating conditions which may lead to OLTC limit cycle phenomena thereby resulting into long term voltage oscillations in the system. In recent years, renewable and non-renewable local generation units have been getting interconnected in modern power systems. The existence of OLTC limit cycles in the presence of local generation has not been addressed in the literature in greater details. In this paper, the OLTC limit cycle phenomena, which can occur due to interactions among load dynamics, OLTC controls and the local generation operation in electricity networks has been investigated. Also, a novel strategy is explored for mitigating the power system oscillations introduced by OLTC limit cycles, especially for a network embedded with local generation. The proposed mitigation strategy including detailed investigations and analyses have been verified for a two-bus test system, and successfully tested on a multi-bus system using MATLAB. Index Terms--Limit-cycle phenomena; load dynamics; local generation; on-load tap changer; power system oscillations.
doi:10.1109/tia.2015.2477943 fatcat:u5mj7d7cb5gazc23nzzmi2iriy