Design Of Permanent-magnet Directly-driven Bi-directional Tidal Power Generation System Controller

Nowadays problems of energy shortage and environmental pollution havebecome increasingly prominent, the concept of new-energy generation is urgentlyneeded. As an important form of new-energy generation, the fault detectioncapabilities and the intelligence degree of tidal power generation system depend onits information transmission, network building, data monitoring and other aspects.Thus, the controller area network technology and virtual instrument technology isapplied in the tidal power generation system, the establishment of data transmissionand reception carrier really has important theoretical and practical value.Controller Area Network originated in automotive applications, and graduallyextended to other industrial areas, which actually has many advantages, for example,stable, reliable, flexible, simple and so on; considerable development of computercontrol systems has really happened in the defense and aerospace fields, inapplications of virtual instrument technology, computer hardware and operatingsystem is taken as the basis combining with LabVIEW software environment toolkit,its measurement and control functions are achieved. This paper applies these twotechnologies to the tidal power system design, and it has achieved good results andeffects.In this paper, a distributed control system based on CAN bus communication isused for tide power generation system. The paper elaborates application details ofCAN bus in tide power generation backgrounds, which includes network design,application layer protocol development, interface circuit hardware design andsoftware design. In hardware design, STC89C52is used as system microprocessor,execution components is controlled by data acquisition of flow rate signal. And thedata transmission between underwater and onshore is realized by CAN intelligentnode, then controller communicates with the host computer and the transmissionsystem using RS232serial ports. Hardware design includes power supply module,A/D conversion module, drive module, serial communication module and CAN nodemodule. In software design, according to requirements of controller functions, themain program is divided into the three units; program modular design is respectivelyrealized through appropriate interface functions. And it includes A/D conversionmodule, I2C communication module, relay control, serial communication moduleand CAN communication module.To prove that circuit system work well, laboratory tests are carried out, whichincludes executive parts control and communication stability test and experimentaldata analysis. The results obtained from laboratory tests show that executive parts act properly in simulation environment, CAN bus communication operates stably in500meters distance at bit rate of100Kbps. In the continuous adjustment of flow ratevalues, the system experimental data results are correct, which shows variousindicators of system meets predetermined requirements.