[中文]交流变频器穿越技术
尽管大多数交流变频器的应用并不要求变频器能够穿越供电间断的工况,而变频器的穿越技术对某些工艺过程却关系重大。在此类应用中,通过变频器提供的穿越技术,以满足工艺不受供电间断的影响是至关重要的。对不同变频器制造商生产的各类型变频器,变频器应用和特性调整中变量的安全系数成为掌控穿越技术的难点。本文无法涵盖实现穿越技术的各个方面。本文的目的是:提供变频器在供电间断期间的基本运行信息,以及为保持变频器在供电间断期间具有更好的运行性能而提供的一些现有的、具有实际指导意义的、“真实环境”下的解决方案。在此,本文作者要对Jim Ehlert,Jeff Theisen以及Gary Woltersdorf为本文提供的帮助表示感谢!
术语“穿越”,对不同的人具有不同的含义。大多数情况下,它表示瞬时停电期间保持工艺命令和工艺控制的要求。这里有必要讨论一下瞬时的定义。在一些系统中,电机轴上瞬时失电200毫秒是无关紧要的,而对于其它系统则会导致灾难性的后果。在某些场合,电源波动期间对电机的控制和(或)保持电机的转速及转矩是非常重要的。而在其它情形中,穿越是指保持诸如通讯和存储等逻辑功能的能力,以便在电源恢复时能够及时、平滑地恢复逻辑控制功能。综合这两种解释,可以将穿越分为“电源穿越”和“逻辑穿越”两类。本文讨论的命题中,电源穿越定义为保持对电机输出电流,而逻辑穿越定义为保持控制回路有效,一旦供电恢复,即可重新连接并驱动电机。本文将对两种穿越进行探讨,且以电源穿越作为侧重点。
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[外文]AC Drive Ride-Through Techniques
While most AC drive applications do not require the drive to ride through a power interruption, manyof those that do are crucial to a process. In those applications where ride through is required, it isoften very important that the ride through provided meets the demand of the application to the extent
that the process is not adversely affected. The shear number of variables between applications, andvariations in drive features of different drives and drive manufacturers can make handling ride through
a real challenge. This document can not begin to cover all aspects and implementations of ride through. It is the goal of the author to provide some basic background information as well as present
some practical “real world” solutions for better drive performance during utility power disruptions.Special thanks to Jim Ehlert, Jeff Theisen and Gary Woltersdorf for help with this paper.
The term “Ride Through” very often means different things to different people. In most cases it stemsfrom the desire to maintain some degree of order and control of a process during a momentary power
interruption. Even the definition of momentary is called into question. 200 milliseconds without power at the motor shaft may be no big deal for some systems while for others it could spell disaster. In
some cases it is important to control the motor and or maintain motor speed and torque during the power disturbance. For other situations ride through is the ability to maintain logic functions such as
communications and memory so that a graceful and timely recovery from the power disturbance can be achieved. These two main interpretations of ride through can be categorized as “Power Ride Through” or “Logic Ride Through”. For the purpose of discussion in this paper, Power ride through
is defined as maintaining output current to the motor while logic ride through is keeping the control circuit active and ready to reconnect to the motor when line power is restored. Both will be explored in this paper with an emphasis on power ride through.
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