斩波串级调速系统谐波分析及电流振荡

Harmonics calculation in chopped wave cascade speed control system and oscillating current

斩波串级调速系统属于有应用前景的节能降耗技术,其核心部分采用电力电子装置,是入网电流的主要谐波源,同时消耗大量无功功率,对其谐波的分析与计算可被用来评估对电网的危害以及是否要加入补偿装置。从理论上详细分析斩波串级调速系统定、转子电流谐波,逆变两侧电流谐波,入网电流谐波及其特点,采用Graham-Schonholzer与Dobinson方法计算了转子及逆变阀侧、源侧电流谐波,并通过仿真实验验证了其正确性,阐明了斩波串级调速系统在特定转速附近引起的电流振荡问题。所提出的方法在指导补偿装置的具体设计以及避免入网电流振荡方面有一定的工程实用价值。

The chopped wave cascade speed control system is a type of energy-saving equipment having a promising future because of the lower control power and the higher energy efficiency. Using electronics and electric devices as its kernel component, it is one of the main harmonic sources for the power grid, and consuming lots of reactive power. The analysis and calculation about its harmonics could be used to evaluate hazards and burden to the power grid and to decide whether the compensating device is added. The current harmonic from it and the characteristics on the harmonics were illustrated iu details. The calculation methods about it were presented and summed up. The correctness of the above theory and analysis were validated by the simulation model. In addition, the oscillating current in some special speed range was discussed and probed. The methods and explanations offered are meaningful and worthy for engineering design of the chopped wave cascade speed control system.