Patent ID: 8054609

Claim:
A system to control, protect and monitor the status of forced cooling motors for power transformers, reactors, and other electrical devices, wherein: an electronic module ( 2 ) is installed directly in the a connection box ( 3 ) of an electric motor ( 1 ) with the electronic module ( 2 ) replacing an original cover of the connection box ( 3 ): the electronic module ( 2 ) contains a circuit for on-off control ( 5 ) of the motor ( 1 ), which can be powered by any values of voltage and current (CT): such electronic module ( 2 ) has serial communication interfaces ( 9 ) that are interconnected to a communication network with an existing digital, system ( 4 ), allowing the digital system( 4 ) to send commands to turn-on or turn-off the motor ( 1 ) to a CPU microcontroller (CPU), which then turns the motor on or off ( 1 ) through the control circuit ( 5 ): the electronic module ( 2 ) contains a voltage and current measurement module (M) in the CPU that transmits to the CPU the measurements of motor voltage and current, allowing the CPU to calculate the torque developed by the motor ( 1 ) during starting and under steady conditions, to perform thermal protection of the motor ( 1 ) preserving it from damage due to mechanical or electrical overload, and to inform the existing digital system ( 4 ), through communication interfaces ( 9 ), of an occurrence of an abnormal alarm ( 8 ), a condition of the motor ( 1 ) as on or off, and of a self-diagnostic condition ( 9 A): the CPU also interacts with an interface composed of a keyboard and display (TD), through which the user can check the alarms and measurements of the motor ( 1 ) for maintenance purposes; the CPU also contains output contacts (S) that allow it to make self-diagnosis signals ( 10 ), including alarms ( 8 ) and status ( 6 ) of the motor ( 1 ) as connected/disconnected to preserve it against damages due to mechanical or electrical overloading; the electronic module ( 2 ) also contains accelerometers ( 13 ) for measuring vibration of the motor ( 1 ) in three orthogonal axes allowing the CPU to perform vibration monitoring of the motor ( 1 ) and issue alarms ( 8 ) for excessive vibration: and the electronic module ( 2 ) also contains a sensor for revolutions per minute (R), which allows the CPU to measure through the measurement. circuit ( 15 ) the rotational speed of the motor ( 1 ), allowing the CPU to monitor the condition of the motor ( 1 ) based on its speed.