依托全球天然气消费力度的持续上涨，地下天然气压力能的回收利用有效推进能源结构转型，对人类社会和生存环境的可持续发展具有深远意义。为兼顾天然气压差发电装置的运行能效以及功率体积比，选用高速双三相永磁同步电机实施直驱并网。建立基于天然气膨胀机的气-机-电综合模型，构建背靠背双PWM变流器矢量控制系统，并针对高速电机的谐波问题与电流耦合分别设计基于准比例谐振调节器的谐波电流环和基于有源电阻的复矢量解耦基波电流环。仿真与实验结果表明，所设计的系统模型及控制策略能够有效提升电流环的抗干扰能力与稳定性，为高速直驱压差发电系统的工程化应用提供了理论依据与技术支撑。

Relying on the continuous increase in global natural gas consumption, the recovery and utilization of underground natural gas pressure energy effectively promote the transformation of the energy structure and have far-reaching significance for the sustainable development of human society and the living environment. To balance the operating energy efficiency and power-to-volume ratio of the natural gas pressure difference power generation device, a high-speed dual three-phase permanent magnet synchronous motor is selected for direct-drive grid connection. An integrated gas-mechanical-electric model based on the natural gas expander is established, and a vector control system for the back-to-back dual PWM converter is constructed. In response to the current coupling and harmonic issues of the high-speed motor, a complex vector decoupling fundamental current loop based on active resistance and a harmonic current loop based on the quasi-proportional resonant regulator are respectively designed. Considering the time-segmented law of natural gas operating conditions and focusing on the characteristic ratio of the turbine expander, a dual-mode pressure difference power generation maximum power point tracking control strategy based on the optimal characteristic ratio is proposed to balance the efficiency and stability of the system operation under severe and stable natural gas operating conditions. The simulation and experimental results demonstrate the correctness and validity of the system model and control strategy.