MEASUREMENT OF A DC SERIES MOTOR TORQUE BASED ON PLC TECHNIQUES

Abstract

In this paper, a system is established and designed for DC series motors torque measurement based on PLC (Programmable Logic Controller) techniques instead of using old traditional mechanical methods. The researchers tried to exploit the techniques available in PLC type LOGO! ^® V6 to design the above mentioned system which measures the torque with a simple method. Measuring the torque in this system is based on two parts, the first part is to measure the supply voltage, current and speed of the DC series motor by Hall Effect sensors, then enters these values to the PLC. The second one is to calculate and process the torque of the motor depending on the mentioned above values by building a representative model based on mathematical equations representing the operation of the DC series motor. By comparing the results of both methods, it shows that the results are approximately the same but our system is much easier than the traditional systems. Our system contains a subsystem which enables the operator to monitor the mechanical output power and the percentage efficiency of the motor during its operation. To protect the operator and the motor from the risky situations of overload and over speed, which often happens when operating DC series motors, an overload and an over speed protections were included in our system.