tailieunhanh - AC drive ride-through techniques

While most AC drive applications do not require the drive to ride through a power interruption, many of those that do are crucial to a process. In those applications where ride through is required, it is often very important that the ride through provided meets the demand of the application to the extent that the process is not adversely affected. | AC Drive Ride-Through Techniques 5 7 02 While most AC drive applications do not require the drive to ride through a power interruption many of those that do are crucial to a process. In those applications where ride through is required it is often 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 and variations 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 stems from 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 .