Coordinated output control of multiple distributed generation schemes

Abstract

This paper presents candidate strategies for the coordinated output control of multiple distributed generation schemes. The proposed strategies are underpinned by power flow sensitivity factors and allow real-time knowledge of power system thermal ratings to be utilised. This could be of value in situations where distribution network power flows require management as a result of distributed generation proliferation. Through off-line open-loop simulations, using historical data from a section of the UK distribution network, the candidate strategies are evaluated against a benchmark control solution in terms of annual energy yields, component losses and voltages. Furthermore, the individual generator annual energy yields and generatorapportioned losses are used to assess the net present values of candidate control strategies to distributed generation developers. Nomenclature C 1,2,3 Variable costs (£M) C control Cost of the distributed generator output control system (£M) G id Unique identifier (id) of distributed generator, G 0,x,y G P Real power output of the generator at the initial (0), intermediate (x) and final (y) time-steps (MW) G P,m Real power output of distributed generator, G, at node m (MW) 'G P,m Real power output of distributed generator, G, at node m before control actions have been implemented (MW) "G P,m Real power output of distributed generator, G, at node m after control actions have been implemented (MW) ΣG P,m Total real power injection at node m from multiple distributed generators (MW) J Jacobian matrix of AC load flow K Proportionality factor M LIFO Matrix denoting the last-in first-off constraint order of distributed generation schemes M PFSF Matrix of power flow sensitivity factors 'S i,k Apparent power flowing from node i to node k before control actions are implemented (MVA) U i,k Utilisation of component between node i and node k U Tar Target utilisation of component after control actions have been implemented V Vector of nodal voltages (kV) dP i,k / dG P,m Power flow sensitivity factor representing the change in real power flow from node i to node k due to change in real power output of generator connected to node m i Busbar node k Busbar node m Busbar node n Number of stakeholder investors in real-time thermal rating system t Integration time-step (h) x Ranked order of constraint for a distributed generator ΔG P,m Required change in real power output of the generator, G, at node m (MW) ΔP i,k Required change in real power flowing from node i to node k for network power flow management (MW) Φ Egalitarian broadcast reduction signal (%)θ Vector of nodal voltage angles (rad) AuRA-NMS Autonomous regional active network management system AC Alternating current B Busbar C Component 5 CAISO Californian independent system operator DG Distributed generation DNO Distribution network operator GSP Grid supply point LIFO Last-in first-off PFSF Power flow sensitivity factor (defined as dP i,k / dG P,m ) ROC Renewables Obligation Certificate RTTR Real-time thermal rating (defined as S lim ) SCADA S...

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