Robust control strategy of VSC-HVDC systems based on feedback linearization and disturbance compensation method

Improved sliding mode direct power control for low-carbon oriented MMC-HVDC of asymmetric offshore wind power flexible systems

“…The dual closed-loop vector control strategy is divided into the PI control strategy based on the dq coordinate system (Du et al, 2022) and the PR control strategy based on the αβ coordinate system (Semih et al, 2021), which can control the positive and negative sequence currents, but the control structure is more complicated and the control effect is affected by the performance of the phase-locked loop. In contrast, the direct power control strategy (Shang et al, 2011;Alessandra et al, 2023;Habib et al, 2023;Ping et al, 2023) establishes the control model with active and reactive power, omits the current inner loop, and simplifies the design of the control system. Literature (Shang et al, 2011) proposes a direct power control strategy for grid-connected inverters by combining the αβ coordinate system, and effective suppression of active and reactive power two-fold fluctuations can be realized by calculating the power compensation components.…”

“…Literature (Habib et al, 2023) proposes a direct power control strategy based on resonant regulator for PWM rectifiers, which can realize the control of active and reactive power fluctuation components by constructing the DC voltagepower closed loop and resonant closed loop. Literature (Ping et al, 2023) and literature (Alessandra et al, 2023) used sliding mode variable structure control and differential-free beat control for direct power control of VSC and MMC, respectively, by adding a power compensation term to guarantee that the grid-side current is free of distortion. Literature (Mei et al, 2021a) proposed a power sliding mode variable structure compensation strategy, which can suppress the power fluctuation component of the two-fold frequency without guaranteeing the distortion-free grid-side current, but it cannot completely eliminate the power fluctuation of the two-fold frequency.…”