Design Of Motor Protector Based On POWERLINK Industrial Ethernet

As the main power source in today’s industrial and agricultural production, motor’s safe and normal operation plays an irreplaceable role in the national economic construction. In order to avoid electrical or mechanical failure caused motor damage and major losses to the safe production, installing the motor protector has a great practical significance.The paper first reviews the various development stages of the domestic motor protector, lists relevant national standards about motor protection, summarizes the existing motor protection program, proposes decomposing positive sequence, negative sequence and zero sequence component of the motor winding current using symmetrical component method, summarizes the corresponding relationship between the motor’s symmetry and asymmetry fault and the winding currents and their sequence component. The paper develops a detailed fault protection criterion, including short-circuits protection, locked rotor protection, open-phase protection, negative sequence current protection, ground fault protection etc. Simulate the accumulation of motor thermal model, and add the leakage blocking, Anti-shake electrical and PTC thermistor temperature protection as the backup protections.To achieve real-time monitoring of the motor running state, POWERLINK industrial Ethernet monitoring network is constructed which has a lot of advantages, such as open source technology, real-time, realizing transplantation without special chip on the existing Ethernet infrastructure.With the functional requirements of motor protector, the Fujitsu MB9BF506N micro controller is used as the main chip to complete the data acquisition and processing, human-computer interaction, alarm and switch input and output. For POWERLINK communication unit hardware design, Altera Cyclone EP3C10E144is selected and embedded Nios II processor which is downloaded the POWERLINK protocol stack. This chip exchanges data through the API interface with the microcontroller and connects RJ45interface with an external PHY chip DP83640to form a POWERLINK slave node.Based on the hardware structure of motor protector, propose perfect software design method, and for data transmission requirements of motor protector, modify the object dictionary of the master and slave nodes, configure the network parameters and mapping parameters, build the POWERLINK communication network successfully.In order to verify the protective function of the motor protector, a lot of testing work was done to prove that the Protection criterions developed in this article and sampling precision fully comply with the relevant national standards. And using the PC as a master node, the PDO cycle communication was tested successfully.