Improved Predictive Direct-Power-Control of Offshore VSC-HVDC Converter without PLL Scheme

摘要

In this paper, a developed direct power control (DPC) strategy without the phase-locked loop (PLL) scheme is presented. The new system is based on predictive control theory to achieve the deadbeat control of instantaneous power for the voltage source converter (VSC). Theoretical principles of proposed predictive-based DPC (P-DPC) strategy are discussed. The operation and performance of this P-DPC system are illustrated both in steady-state and dynamic behavior. It is shown that the P-DPC exhibits several advantages, particularly no needing to detect the position of voltage vector, without complex coordinate transformation. Both simulation and experimental results show the excellent performance and verify the validity of the proposed control methods. It also provides an available control strategy for offshore VSC-HVDC engineering.