新型高功率因数串级调速系统的研究

本文进行了普通串级调速系统的理论分析並提出了改善功率因数的新观念。提出串级调速系统的速度——转矩特性在不同转速情况下的理论公式。这种系统的最大转矩比电动机的固有最大转矩要小一些,但在调速时保持不变。普通串级调速系统的功率因数很低(大约是0.5至0.6)。为了改善功率因数作者与合作者已经发展了一种建立在强迫换流原理基础上的新系统。它的相量图和计算公式已导出。新系统的功率因数可达0.9以上。已有三台新装置投入工业运转。最大容量245千瓦电机,调速40％。实验结果表述于论文中。每年由于改善功率因数可节电11万度。如与滑差电机相比较,每年可节电44万度。新系统的控制方法和普通串级调速系统一样简便。

A Research of New Scherbius System with High Power Factor

In this paper, a theoretical analysis of commercial use of the Scherbius (cascade) system and a new idea to improve the power factor are given. The power factor of the common Scherbius system is very low (about 0.5 to 0.6). In order to increase it the author and coworkers have developed a new system which is based on the use of a forced commutative converter. The power factor of this new system may reach 0.9 and even exceed it. Three industrial devices of this type have been operating in three factories. The experimental results are shown in this paper. In one year an amount of 110 MWH electroenergy is saved by increasing the power factor (for 245KW motor). Compared to the use of the slip-difference machine, the use of the new system saves 440 MWH electro-energy in one year. The control of this new system is as simple as the common scherbius system.