高频斩波串级调速系统功率因数的分析与计算

2011.№1 大 电 机 技 术13

高频斩波串级调速系统功率因数的分析与计算

张军伟1,2, 王兵树1,3, 万军1,3, 甄亚1

(1.华北电力大学控制科学与工程学院，河北保定 071003; 2.华北电力职业技术学院,

河北保定 071056; 3.保定华仿电控有限公司变流技术研究所，河北保定 071051)

[摘 要]相对于变频调速系统，高频斩波串级调速系统具有节能效率高、结构简单、技术难度小等优点，在交

流调速中得到了广泛应用。但和传统串级调速一样，该系统的严重缺点之一是功率因数低，而且随着负载变化和

速度的调节，系统功率因数的变化范围很大。所以有必要准确分析计算其功率因数。本文介绍了高频斩波串级调

速系统的工作原理，在此基础上提出了一种新的计算高频斩波串级调速系统功率因数的简化算法，总结了影响高

频斩波串级调速系统功率因数的几大因素，最后通过建立试验系统进行验证，证实该算法的可靠性，对实际工程

设计有实用价值。

[关键词]高频斩波；串级调速；功率因数；算法

[中图分类号]TM32 [文献标识码] A [文章编号] 1000-3983(2011)01-0013-06

Analysis and Calculation for Power Factor of the High-frequency Chopped

Wave Cascade Speed Control Drive System

ZHANG Jun-wei1,2, WANG Bing-shu1,3, WAN Jun1,3, Zhen Ya1

(1.College of Control Science and Engineering, North China Electric Power University, Baoding

071003, China; 2.North China Electric Power VOC.&TECH. College, Baoding 071056, China;

3. Converter Simulation and Power Control Technique Institution, Baoding 071051, China)

Abstract: Compared with frequency conversion speed control, high-frequency chopped wave cascade

speed control drive system has such advantages as good efficiency on energy saving, simple structure

and little technical difficulty,etc. So, it is widely used in AC governing speed field. However, as the

traditional cascade speed governing drive, low power factor is the same overt weakness to the

high-frequency chopped wave cascade speed control drive system. In addition, the power factor could

change in a large range with the speed adjustment and changing load. So it is very necessary to analyse

and calculate the power factor accurately. A compact algorithm to calculate the power factor of

chopped wave cascade speed control drive system is put forward on the basic of introduction of the

radical theory about it. A few of factors impacting on the power factor of chopper cascade speed

control drive system are summed up. At last, A simulation validating system is founded, and which

prove that the algorithm is reliable and practical on engineering design.

Key words: high frequency chopped wave; cascade speed control; power factor; algorithm

引言

高频斩波串级调速装置是一种调速性能优良、性价比高的调速节能产品，适合于电厂风机和泵类负载的调速节能运行。但是和传统串级调速系统一样，高频斩波的串级调速方法也存在着功率因数低，随转速和负载调节变化范围大的缺点[1-3]。由于工程中一般提高功率因数

基金项目：科技型中小企业技术创新基金：高压大容量异步电动机高频斩波串级调速系统(06c26211300065) 的方法是通过无功补偿的手段来实现，就要求必须准确地计算系统的功率因数，从而为其工程设计提供必要的依据。

传统串调系统计算功率因数的方法计算过程复杂，误差较大，难以准确、有效地反映系统的有、无功变化。本文提出的计算方法依照能量守恒原理，借助理想变压器，将定子感应电势由转子电势等效，从而简化了求取定子电势和电流的过程，在分析换相重叠角对定子电流、逆变电流的影响时，只考虑其主要作用，即对相角的影响，最后得到的计算结果通过了建立的试验系统的验证。