Hybrid Control of DG to Mitigate Voltage Variation Aristides Kiprakis Dr Robin Wallace University of Edinburgh, UK

Automatic Voltage / Power Factor Control (AVPFC) Active exchange between constant voltage and constant Power Factor (PF) modes Operates in a defined voltage / PF envelope Increases exported energy min disconnection period from over-voltage Can provide voltage support Low cost implementation

Research Updates - I Combined AVPFC & Voltage Regulator (VR) major increase in allowable generator capacity VR under MVAr flow control mode rather than Line Voltage Rise Compensation mode Developed controller operating at continuous PF that increases exported energy Fuzzy controller observes the terminal voltage and adjusts the PF set-point accordingly

Research Updates - II DG capacity was further increased by applying similar fuzzy controller to governor Can also be combined with a Voltage Regulator to increase DG capacity even more

Technology Availability Developed several potential solutions Proof of Concept models being built to prove feasibility However… generator manufacturers must implement them plant developers must use them and, ultimately, DNOs need to allow their use in the network

CIRED 2003 This work is part of a larger ongoing programme at the University of Edinburgh Papers presented at CIRED 4.44 - Intelligent generator control 4.62 - Domestic CHP 4.63 - Optimal accommodation of DG