基于负荷虚拟同步机的三相电压型PWM整流器

Three Phase Boost Type PWM Rectifier Based on Virtual Synchronous Machine Technology

随着清洁能源和可控负荷及其变流装置大量接入电网,虚拟同步机技术逐渐成为当前研究热点。虚拟同步机技术是指通过模拟同步机组的机电暂态特性,使采用变流器的电源或负荷具有同步机组的惯量、阻尼、频率和电压调整等运行外特性的技术。在新能源、可控负荷及其并网变流器大量接入电网的条件下,提出了负荷虚拟同步机双模控制方式,应用虚拟同步电动机技术的可控负荷可感知电网的状态,自动调整吸收功率的快慢,变"切负荷"为降功率运行,从而达到辅助电网故障穿越的目的。在火电机组仍为调频主力机组的背景下,虚拟同步机技术实际上加强了电网与新能源和可控负荷的联系,有助于提高新能源/可控负荷的生存能力,有助于共同维持系统的稳定运行。搭建了基于EMTDC/PSCAD的仿真模型,设计了样机,仿真和实验结果验证了所提方法及控制策略的正确性和有效性。

With the rapid increase of the installed power capacity using clean energy and controllable load,virtual synchronous machine technology has attracted much attention. Virtual synchronous machine technology enable the power supply system and load with a converter to have some external characteristics similar to those synchronous generators,including inertia,damping,frequency and voltage regulation,by simulating the electromechanical transient characteristics of synchronous generators. This paper summarized the three-phase boost type PWM rectifier based on virtual synchronous machine technology. The virtual synchronous motor technology can make the load to adjust power absorption speed sensitively and automatically,changing ＂load shedding＂ to power reduction operation,so as to achieve the purpose of crossing the auxiliary power system fault. Under the condition environment that the thermal power unit is still the main FM unit,virtual machine technology actually strengthens the connection between grid and converters. It is helpful to improve the survival ability of new energy/controllable load and it helps to maintain the stability of the system. Simulation and experimental results verify the validity and effectiveness of the proposed VSM and control strategy.