Programmable controllers in the wind power industry are mostly used in variety units of wind power machine to gather data and working conditions. Through analyzing, calculating, making decision to manage a controlling and protecting actions series such as starting, stopping, starting oil pumps and changing directions, the controller can assist to recognize whole automatic control the generator unit of single wind power. Additionally, it is also installed with the function of data exchange with the upper computer so as to allow the upper computer to grab the working conditions and apply control on the lower computers, providing ease for the wind power field management.
As the PLCs are mostly practical to the engine room and cabinet of fans, operating as field regulation and yawing correspondingly. Therefore, PLC belongs to a control system set. Two PLCs are corresponded throughout field bus. The main control of the system hardware of PLC composed fans is made up of modules. The room of control has sufficient space to make sure the measuring quantity and safety operation. The controllers of PLC are linked by optical cables, conversed through an Internet protocol and are outfitted with functions controlling, monitoring and managing by the principal computer. The interface is programmed by database. The PLC sales revenue implemented to the wind power industry in 2009 reaches to 55 million yuan. Dissimilar from the other OEM industries, the sector of wind power mostly implements medium and large PLCs. Siemens is most popular in this kind of applications. Besides that, there are Schneider and Rockwell have some applications as well.
On the other hand, controllers of the PLC in the industry of wind power at current are still special ones, produced by professional manufacturers themselves, for example Vestas. In addition, some other manufacturers, for example BACHANN, MITA, GE and Beckhoff and so on, also supply such the products. The growth of PLC application in the industry of wind power is highly reliant on its substitution of special controller. On the other hand, presently, the replacement still has dominant obstacles: first, using the customers’ habits; second, technical difficulties. PLC still delays behind special controllers in the motion control. As to great units of power machine, the technological break turns to be particularly big. Even though PLC has benefits about low prices, yet as to users in this new developing industry not very regarding product costs, such benefit is not that apparent.