| 摘要 |
In order to remove snow or ice from an exposed constructional element (1) by means of electric current in a heat emission equipment (3), the supply of power is controlled by way of a controller (13) operating based on physical parameter values as measured by sensors (4, 14, 15, 17, 18, 19) at the constructional element (1) and based on historical data relating to snow and ice conditions. The input data are the effective surface temperature of the constructional element (1) as well as the amount of snow/ice on the constructional element (1), air temperature, wind velocity, precipitation, velocity of the constructional element (1), and vibrations thereof. These input data are compared to stored historical data in the controller (13). The controller (13) then calculates, using stored algorithms, whether the supply of power is necessary, and in that case also the necessary amperage and frequency values, the frequency affecting a time constant of change in the surface temperature of the constructional element. The controller then provides a start or stop signal as well as an output control signal to power supply equipment (11), and the controller then updates its historical data with new data. Preferably, the invention is used on the blades of a wind turbine. |
