Power Transmission Topics Page
Inspect and maintain motors from the moment you invest in them.
Proper lubrication, testing, cooling, and contamination mitigation extend uptime.
Motor spares in inventory can experience a generation gap.
Bearing protection is needed if inverter-duty motors are to live up to their name.
White Papers: In Depth Research
Reducing servomotor instability
Author: Marcus Schick
Instability in a motor is uncontrolled and unintended motion at the motor shaft and can occur at any frequency. It's caused by excessive gain in the speed controller of the drive, and the gain setting of the speed controller determines how much torque the drive will generate. As servo drives become more prevalent in industry, they are being applied in a wider range of applications. Servo motors sometimes make a "growling" noise, which can be eliminated by reducing the gain on the speed controller, but lower speed controller gains can lead to an increase in position error and a decrease in performance. This paper looks at the methods that can be used to eliminate servo instability.
High slip braking software
The techniques for braking of high inertial loads to a stop traditionally involved either Dynamic Braking or DC Injection Braking technology.
This article examines a new load-braking alternative called High-Slip Braking (HSB). We identify the different aspects of HSB, look at what it does, how it works, and how it is different from other braking methods. We also provide examples of "real-world" successes, and discuss the new technology's cost effectiveness.
General-purpose permanent magnet motor drive without speed and position sensor
Author: Jun Kang
Worldwide, about two-thirds of the electricity is consumed by motors used in powers industrial facilities. According to DOE report, the motor systems are responsible for 63% of all electricity consumed by U.S. industry and electric bill represents more than 97% of total motor operating costs.
Rapidly increasing energy cost and strong global interest in reducing carbon dioxide emissions are encouraging industry to pay more attention to high-efficiency motors.
Permanent Magnet (PM) motors have higher efficiency than induction motors because there are no I2R losses of the rotor. But widespread use of the PM motors has been discouraged by price and requirement of a speed encoder.
Recent release of low-cost high-performance CPUs and establishment of the speed sensorless control theory (hereinafter referred to as an open-loop vector control method) enables the advent of a general-purpose open-loop control PM drive. In this white paper, the open-loop PM motor control technology is introduced and its characteristics and major application fields are described.
Optimizing energy in industrial plants
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