Abstract— AC motors are the main workhorses in
process industries. Their malfunction may not only lead
to repair or replacement of the motor, but also cause
significant financial losses due to unexpected process
downtime. Reliable thermal protection of ac motors is
crucial for reducing the motor failure rate and prolonging
a motor’s lifetime. In this paper, conventional thermal
protection devices and state-of-the-art thermal protection
techniques are reviewed with their advantages and
limitations discussed. Since 2001, the research team at
the author’s company and at the Georgia Institute of
Technology has been cooperatively developing a series of
active motor thermal protection methods, as a low-cost
alternative approach to the traditional passive and sensorbased
methods. These active thermal protection methods
monitor the average stator temperature via stator
resistance estimation based on the dc equivalent model of
ac motors, using only motor stator voltage and current
measurements. In this paper, an overview of the active
thermal protection techniques for line-started, soft-starterconnected
and inverter-fed ac motors is presented, with
their advantages and drawbacks discussed. The active
thermal protection techniques are capable of providing
accurate, and non-invasive thermal protection of ac
motors.
Index Terms – AC motor, inverter, starter, stator
resistance, stator temperature, temperature estimation,
thermal protection.
Abstract— AC motors are the main workhorses inprocess industries. Their malfunction may not only leadto repair or replacement of the motor, but also causesignificant financial losses due to unexpected processdowntime. Reliable thermal protection of ac motors iscrucial for reducing the motor failure rate and prolonginga motor’s lifetime. In this paper, conventional thermalprotection devices and state-of-the-art thermal protectiontechniques are reviewed with their advantages andlimitations discussed. Since 2001, the research team atthe author’s company and at the Georgia Institute ofTechnology has been cooperatively developing a series ofactive motor thermal protection methods, as a low-costalternative approach to the traditional passive and sensorbasedmethods. These active thermal protection methodsmonitor the average stator temperature via statorresistance estimation based on the dc equivalent model ofac motors, using only motor stator voltage and currentmeasurements. In this paper, an overview of the activethermal protection techniques for line-started, soft-starterconnectedand inverter-fed ac motors is presented, withtheir advantages and drawbacks discussed. The activethermal protection techniques are capable of providingaccurate, and non-invasive thermal protection of acmotors.Index Terms – AC motor, inverter, starter, statorresistance, stator temperature, temperature estimation,thermal protection.
การแปล กรุณารอสักครู่..
