Abstract: The 24 MVA back-to-back three-level active neutral point clamped (3L-ANPC) converter is adopted for high-speed maglev. The DC bus is shared by two rectifiers and two inverters. In this paper, under various power factors, the offset mechanisms of neutral point voltage (NPV) at the rectifier side and inverter side are analyzed. The specific effects on the NPV of different voltage vectors are also analyzed. On this basis, to obtain the controllable area of the NPV when the modulation ratio and power factor both change, accordingly, the NPV offset models are established for the parallel and series modes of high-speed maglev inverters. To ensure the NPV balance in the full speed range, a cooperative control strategy based on shifting the modulation wave is proposed. To reduce the influence of the rectifier power factor and modulation ratio on the NPV, carrier-based pulse width modulation (CBPWM) with half-wave symmetry of phase voltage is adopted. It is proven that it has the self-balancing ability of the NPV. Simulation and hardware-in-the-loop experiments show that the proposed strategy has the advantages of a shorter time for the NPV to return to equilibrium, a larger controllable range, etc. Moreover, the NPV balance can be guaranteed for high-speed maglev operations at full speed.