Yuntao Zou

Area of research

Electrical and Electronic Engineering · Control and Systems Engineering

Research interest

Research topics from publications: An Inner-Loop Control Method for the Filter-less, Voltage Sensor-less, and PLL-less Grid-Following Inverter-Based Resource; An Ultra-Fast Inrush-Current-Free Startup Method for Grid-tie Inverter without Voltage Sensors; A Voltage Sensor-Less and PLL-Less Inner-Loop Control Method for Grid-Tied Inverter-Based Resources; Y-Matrix Modulation for SC-MMC Medium Voltage Grid-Tie Converter. Representative work: This paper presents an inner-loop control method for the filter-less, voltage sensor-less, and PLL-less inverter-based resource (IBR) under grid-following operation mode. The innovative concepts of the proposed control structure incorporate the removal of the voltage sensors at the point of common coupling (PCC), the removal of the inverter output filter or interface inductance, and the removal of the traditional phase-locked loop (PLL) circuits. Furthermore, the virtual impedance control is applied to compensate for the inverter voltage reference change due to the removal of the interface inductance. With the proposed control method, the physical interface inductor and the bulky high-voltag This paper proposes an ultra-fast inrush-current-free startup method for grid-tie inverters without voltage sensors and phase-locked loop (PLL). Traditionally, the grid-tie inverter needs the voltage measured from points of common couplings (PCC) to generate the phase angle via PLL for inverter pulse-width-modulation (PWM) signals. The startup procedure is slow and inrush current occurs if the initial PWM does not match the unknown grid voltage well. This paper proposes a startup method that only uses measured inverter ac currents to generate the initial PWM by controlling the current to zero. The generated PWM pattern can be used to reproduce the real grid voltage regardless of the grid imp