Realtime Control of Distributed Generation for Voltage Stability Improvement and HV Side Support

As distribution networks continue in integrating Distributed Generation (DG) units, voltage stability problem becomes an important issue. On other hand, future distribution networks have the ability to support the transmission network. Thus, this work presents an online centralized controller for voltage stability improvement and High-Voltage (HV) side support. The method uses multi-step optimization method to obtain the changes in power injection by DG units while satisfy the system security constrains. The control method follows a security purpose and it is formulated based on the sensitivity of the load and the equivalent impedances to power injections from DG units. An 11kV, 77-bus test network with various DG units is used for this work. Simulation results validate the accuracy of the proposed approach in improving the voltage stability of distribution networks and providing ancillary services to HV side.