Droop based steady state control algorithm for a meshed HVDC grid

Abstract

In this paper, a steady state model of a power flow control algorithm for a meshed HVDC grid proposed. The objective of a power flow control in a DC grid, as in a point-to-point transmission, concerns controlling the DC voltage in the system within its limits and fulfill the power input/output at the PCC (Point of Common Coupling) to the AC system, without exceeding maximum currents through the valves, lines or cables. The best power flow control can be achieved with the use of DC-DC converters at the nodes of the meshed HVDC grid. However, the use of the DC-DC converters in such a DC grid is quite costly, especially if implemented in an offshore environment. The main contribution of this paper is to demonstrate how the control of steady state power flow in the DC grid can be achieved without using the DC-DC converters. The control algorithm is derived based on the principles of droop control.