TY - JOUR
T1 - Design of non-interacting controllers for PV systems in distribution networks
AU - Hossain, M. J.
AU - Mahmud, M. A.
AU - Pota, Hemanshu R.
AU - Mithulananthan, Nadarajah
PY - 2014/11/1
Y1 - 2014/11/1
N2 - This paper makes two contributions. Firstly, it is shown that there may exist oscillations in distribution networks with physically close photovoltaic (PV) units due to their control interactions. The main reason for oscillations is changes in the dynamics of PV units with varying solar irradiance and the decentralized tuning of control parameters for the nominal operating condition. Eigenvalue analysis, nonlinear interaction index, and time-domain simulations are used to assess the degree and impacts of dynamic interactions. Secondly, a decentralized robust control design is proposed to ensure a non-interacting and well-damped response under varying operating conditions for physically close PV units. The control design process uses an estimate of changes in the model due to variations in solar irradiations, changing electric loads, and the dynamics of the physically close PV units. A minimally conservative method is used to capture the estimate as a norm-bounded uncertainty. Time-domain simulations on a test distribution system verify the predictions of the interaction analysis and demonstrate the performance of the proposed robust controller under different system contingencies.
AB - This paper makes two contributions. Firstly, it is shown that there may exist oscillations in distribution networks with physically close photovoltaic (PV) units due to their control interactions. The main reason for oscillations is changes in the dynamics of PV units with varying solar irradiance and the decentralized tuning of control parameters for the nominal operating condition. Eigenvalue analysis, nonlinear interaction index, and time-domain simulations are used to assess the degree and impacts of dynamic interactions. Secondly, a decentralized robust control design is proposed to ensure a non-interacting and well-damped response under varying operating conditions for physically close PV units. The control design process uses an estimate of changes in the model due to variations in solar irradiations, changing electric loads, and the dynamics of the physically close PV units. A minimally conservative method is used to capture the estimate as a norm-bounded uncertainty. Time-domain simulations on a test distribution system verify the predictions of the interaction analysis and demonstrate the performance of the proposed robust controller under different system contingencies.
KW - Distribution systems
KW - dynamic interactions
KW - photovoltaic unit
KW - robust control
KW - stability and uncertainty
UR - http://www.scopus.com/inward/record.url?scp=84908372629&partnerID=8YFLogxK
U2 - 10.1109/TPWRS.2014.2315803
DO - 10.1109/TPWRS.2014.2315803
M3 - Article
AN - SCOPUS:84908372629
VL - 29
SP - 2763
EP - 2774
JO - IEEE Transactions on Power Systems
JF - IEEE Transactions on Power Systems
SN - 0885-8950
IS - 6
M1 - 6802453
ER -