Predictive Control of a Three-Level Boost Converter and an NPC Inverter for High-Power PMSG-Based Medium Voltage Wind Energy Conversion Systems

• Published in: IEEE transactions on power electronics 2014-10, Vol.29 (10), p.5308-5322
• Main Authors: Yaramasu, Venkata, Bin Wu
• Format: Article
• Language: English
• Subjects: Boost converter; Capacitors; current control; dc-ac power conversion; dc-dc power conversion; dc-link capacitor voltages balancing; digital control; diode-clamped converters; Diodes; direct-driven; discrete time signals; Electric currents; Electrical equipment; finite control-set model predictive control (FCS-MPC); gearless; grid-connected; Inverters; Mathematical models; medium voltage (MV); megawatt (MW) level; multilevel inverters; neutral-point-clamped (NPC) converter; passive front-end (PFE); permanent magnet synchronous generator (PMSG); Predictive control; renewable energy; state-space model; Switches; three-level boost (TLB) converter; variable speed; Voltage control; Wind energy; wind energy conversion system (WECS); Wind power; Wind turbines
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2013.2292068

In this paper, a new medium voltage power converter topology using a diode rectifier, three-level boost (TLB) converter, and neutral-point-clamped (NPC) inverter is proposed for a high-power permanent magnet synchronous generator-based wind energy conversion system. The generator-side TLB converter performs the maximum power point tracking and balancing of dc-link capacitor voltages, while the grid-side NPC inverter regulates the net dc-bus voltage and reactive power to the grid. A significant improvement in the grid power quality is accomplished as the NPC inverter no longer controls the dc-link neutral point voltage. A model predictive strategy is proposed to control the complete system where the discrete-time models of the proposed power electronic converters are used to predict the future behavior of control variables. These predictions are evaluated using two independent cost functions, and the switching states which minimize these cost functions are selected and applied to the generator- and grid-side converters directly. In order to comply with the high-power application, the switching frequencies of the TLB converter and NPC inverter are minimized and maintained below 1.5 and 1 kHz, respectively. The proposed topology and control strategy are verified through MATLAB simulations on a 3-MW/3000-V/577-A system and dSPACE DS1103-based experiments on 3.6-kW/208-V/10-A prototype.