弱电网下矿井提升机变频调速系统稳定性控制策略研究

Research on Stability Control Strategy of Variable Frequency Speed Regulation System Used for Mine Hoist in Weak Grid Condition

变频调速系统在现代矿业生产中应用广泛,然而实际生产中发现配电变压器容量会影响到调速系统的稳定性。首先建立了变频器的输出阻抗模型,将变频器控制系统等效成诺顿电路,根据阻抗稳定性判据分析了配电变压器容量对调速系统稳定性的影响,针对传统控制策略下变频调速系统对弱电网适应能力较低的问题,提出了陷波反馈控制策略,该策略可保证系统在弱电网下依然能够稳定运行。最后搭建了双变频器实验系统,实验结果验证了所提策略的可行性和有效性。

The frequency conversion speed regulation system is widely used in modern mining production,but it has been found in practice that the capacity of the distribution transformer will affect the stability of the speed regulation system.First,the output impedance model of the inverter was established,in which the inverter control system was equivalent to a Norton circuit.The influence of the distribution transformer capacity on the stability of the speed control system was analyzed according to the impedance stability criterion.In order to solve the problem that the frequency conversion speed regulation system has low adaptability to weak grid under traditional control strategy,a notch filter-based feedback control strategy was proposed.This strategy can ensure that the system can still run stably under weak grids.Finally,a dual inverter experimental system was built,and the experimental results verified the feasibility and effectiveness of the proposed strategy.