CANopen PLC in wind power system

Source: CAN Newsletter December 2011

Renewable energy industry, especially wind power plants is booming in China. Domestic suppliers spend a lot of effort on independent development and technique acquisition of wind power equipments. Currently, Chinese manufacturers are capable of producing high-speed gear case, motor and blade. But the core of the wind power control system – wind power controller, is mainly imported from foreign suppliers. By researching the control systems of some dominated domestic wind power equipment manufacturers, the control system and the host machine of most factories are acquired for a whole set. Because of the hard operation environment of wind power equipment, limited mounting space and strong data processing requirement, the existing general PLC cannot meet with the technical requirement. The working temperature of general PLCs is normally between 0 °C and +50 °C, but the temperature requirement on wind power equipment is between ­- 25 °C and +60 °C. Although some companies use general PLCs as main controller, a heater is mounted in the machine cabinet when designing the system in order to insure a reliable operation at low temperature. This processing works, but it’s possible that the PLC could not operate immediately after power-up at ultra-low temperature, and the heater occupies space in the limited PLC mounting room. General PLCs produced by ­Chinese manufacturers cannot process large-scale data because of poor pre-design. Non-Chinese companies mainly use embedded PLCs as main controllers to fulfill the requirement of wind power control system.

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