METHOD FOR CALCULATING STEP POWER OF MOTOR OPERATED VALVE AND FOR DIAGNOSING PERFORMANCE OF MOTOR OPERATED VALVE WITHOUT USING SENSOR

摘要

PURPOSE: A method for calculating stem power of a motor operated valve and for diagnosing performance of the motor operated valve are provided to calculate step power by using a signal flowing through a power line connected to the motor operated valve. CONSTITUTION: Analog current and a voltage signal applied to a power line connected to a motor of a motor operated valve are detected(S510). The detected analog current and voltage signal are converted into a digital signal(S20). Then, a stator magnetic flux is estimated by using the converted current and voltage signal(S540). A first motor torque is calculated by using the stator magnetic flux and the converted current signal. Then, a step factor equation and a stem factor are prepared so as to calculate stem power of the motor(S560,S570).