Analysis of Energy Feed System of Metro under Adaptive Moment of Inertia VSG Control

Because of the short distance between subway stations, frequent starting and braking, a lot of energy will be produced during regenerative braking. The traditional regenerative braking energy utilization scheme of inverter feedback type can feed back the energy to the AC power grid, but the inverter control technology is single, lacking the inertia and damping of synchronous generator, which can not provide high-quality frequency and voltage support for the distribution network Virtual synchronous generator (VSG) introduces the moment of inertia and damping coefficient of synchronous generator into the control of inverter, enhances the anti-interference ability of power grid, and the virtual inertia and damping coefficient are flexible and adjustable. Therefore, based on the analysis of the VSG control strategy, combined with the VSG power angle curve, this paper studies an adaptive moment of inertia VSG control strategy, and applies it to the subway energy feed system. Finally, the simulation model of the system in Matlab / Simulink environment is built. The results show that: compared with the traditional inverter control technology, when the scheme is disturbed, the frequency and power response speed is faster, the overshoot is smaller, and the steady state can be recovered faster.