TDB intelligent motor protector the application

1 introduction In the modern industry, motor as a drag mechanical, become the foundation of all power machinery, with the improvement of science and technology and the continuous improvement of the process control, especially automation production requirement, the urgent need to rotary joints develop and perfect the motor control and protection of equipment, so as to achieve production process and large mechanical remote control, the remote measure, remote communication, fault diagnosis and centralized control etc.

Function. Meanwhile, oil chemical industry characteristics itself is large flux, full load of continuous operation and so on motor equipment reliability and stability requirement is extremely high, once the accident, must be immediately found the cause of the problem and promptly eliminate, in order to ensure timely production resumed. Joshua chemical group in the past has been using thermal relay as motor overload protection and control component, but because components of quality and technology restriction, yet cannot satisfy the process automation development requirements. For this reason, we after many years to try to repeat practice, finally choosing a new type of intelligent protector motor (hereafter referred as motor protector).

As the motor protection components, and have achieved some useful experience. Especially in our new 80000 tons of jinni ionic membrane caustic soda reconstruction project, 120000 tons of ionic membrane caustic soda engineering, 80000 tons of PVC engineering, 80000 tons of epoxy propane and 50000 tons of grain of alkali etc national key project construction process, through the use of low voltage distribution system more than 1600 motor protector, not only effectively the safe operation of motor, replaced by the thermal relay, and the use of advanced communications technology, to rotary union achieve some of the motor control automation, and has obtained the remarkable economic benefit, therefore, below motor protector the engineering application in the simple introduction. 2 basic working principle: Motor protector is the last ten years to develop a new type of electronic up multi-functional comprehensive motor protection device. It sets (light) load protection, phase lock, (own) pressure, stall, leakage, grounding and unbalanced three-phase protective low voltage protection in a suit, with high precision and power saving set, action quick, reliable working etc, and is an ideal replacement of traditional thermal relay products. It is usually composed of a current sensor, compare circuit, SCM, or export relays for several parts.

The basic principle and process as shown in figure 1 shows: Sensors will motor current changes to reflect the protector the line to the sampling port, rectification, filtering and other links, convert and electromotor current proportional to the dc voltage signal, sent to the corresponding section and given protection parameters comparison processing, to SCM loop processing, promote the power loop, make the relay action. When the motor drive in part because overload current increases, the obtained from current sensor voltage signal will be increased, the voltage values greater than the protector the setting value, overload loop, RC circuit after a certain time delay (adjustable) time delay, drive export relay action, make contact device to fiber optic rotary joint cut off the main circuit. Owe pressure and phase lack protection function part, basically the same principle. 3 system function (1) protection functions.

Motor protector of motor can realize the comprehensive protection, its specific functions have grounding protection, broken phase protection, short circuit protection, (light) load protection, not balanced load protection, stall protection, low voltage and overvoltage protection. When the motor normally work, the protector of through panel LCD screen, real-time display motor work current and voltage. Has communication function of motor protector in microprocessor when leisure time will acquisition of the signal through the CAN bus spread to the background microcomputer. When a fault occurs, the protector action quickly, the same fault type, time, and motor operating parameters, then through the CANBUS network to daemon machine report. (2) the on-line monitoring functions.