05701-A-0329 Among the heating methods such as induction heating, infrared heating and resistance heating, for blade mould heating, resistance wire heating has the advantages of durable components, easy maintenance and replacement, simple operation and low cost. Resistance wire heating is the pre-buried heating resistance wire in the FRP layer of the mould, and the heating resistance wire is laid under the heating layer (resin + aluminium powder) of the mould [3]. Although the resistance wire heating method is more commonly used, with the growth of wind turbine capacity, the size of wind turbine blades increases, and the heating system of megawatt-class large wind turbine blade moulds has the characteristics of multiple and complex division areas.

05701-A-0329 based on the resistance wire heating mode of the mould heating system appears to lack of reliability, the temperature is not easy to control, prone to the phenomenon of local temperature is too high, so for the blade forming mould temperature control system puts forward a higher process requirements. As a cpu unit, the module type plc has high reliability, strong anti-interference ability, and is suitable for multi-channel temperature control. cj1g series plc has a temperature control unit that supports 2-loop or 4-loop pid control or on/off control, of which the 2-loop mode has a heating circuit break detection function; at the same time, pid constants used for pid control can be set with self-adjustment (at).

05701-A-0329 forward operation (cooling) or reverse operation (heating) can be selected; can be input directly from the temperature sensor; sampling period of 500ms; each loop has 2 points of internal alarm; for 2-loop mode, current transformers are connected to each loop to detect heater circuit breakage. As the blade forming mould is divided into multiple circuits for heating, so in a total controller for the coordination of the heating temperature of each circuit on the basis of each single-loop temperature collection and the respective area of the temperature field of the heating, thermostat to maintain and cool the work.