Method and Means for Controlling Power Delivery to an Equipment for Counter-Acting Formation of Ice or for Removing Snow/Ice on a Constructional Element

• US 20100224621A1
• Filed: 05/07/2007
• Published: 09/09/2010
• Est. Priority Date: 05/08/2006
• Status: Abandoned Application

• Current Assignee: Norsk Miljokraft Forskning Og Utvikling AS
• Original Assignee: Norsk Miljokraft Forskning Og Utvikling AS
• Inventors: Mortensen, Kjell
• Application Number:
  US12/227,142
• Publication Number:
  US 20100224621A1
• Time in Patent Office: Days
• US Class Current: 219/490
• CPC Class Codes: B64D 15/20 Means for detecting icing or initiating de-icing
• CPC Class Codes: F03D 80/40 Ice detection; De-icing means
• CPC Class Codes: F05B 2260/80 Diagnostics
• CPC Class Codes: F05B 2270/708 with comparison tables
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

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.

Claims

1. A method for controlling the supply of electrical power by way of high frequency alternating current from an equipment (11) for supplying power to a heat emission equipment (3) for preventing the formation of ice or for removing ice or snow from a constructional element (1), wherein the control is effected using a controller (13) based on input data representing physical parameter values as measured by sensors (4, 14, 15, 17, 18, 19) arranged at or nearby the constructional elements (1), as well as based on stored, historical data relating to snow and ice conditions for the constructional element (1), providing an adaptive manner of control, characterized in that

current input data relating to the value of the effective surface temperature of the constructional element (1) and to values of the following parameters:

the amount of snow/ice on the constructional element (1), air temperature, wind velocity, precipitation, velocity of the constructional element (1), and vibrations of the constructional element (1), is compared, in the controller (13), to stored data relating to historical values of the same parameters, recorded as a function of time, and

using stored algorithms, the controller (13) calculates, based on said relevant input and historical data, whether delivery of power is required, and in that case also the amperage and frequency values necessary to remove snow/ice from the constructional element (1), the frequency affecting a time constant of change in the surface temperature of the constructional element (1),

according to the result of the calculation, the controller (13) then issues a start or stop signal as well as an output control signal including amperage and frequency values to the power supply equipment (11), and

the controller (13) updates its historical data with new parameter value data resulting from a current condition of snow/ice on the constructional element (1) according to a predetermined procedure.

2. The method of claim 1, characterized in that the frequency used is in the range of 0-1000 kHz.

3. The method of claim 1, characterized in that the predetermined procedure for updating the historical data includes all pertinent parameters for detecting and preventing/removing ice/snow from the structure.

5. The means of claim 1, characterized in that the means is configured for controlling the supply of electrical power to an electrically conductive foil on at least a wing of a wind turbine.

4. A means for controlling the supply of electrical power by way of high frequency alternating current from an equipment (11) for supplying power to a heat emission equipment (3) for preventing the formation of ice or for removing ice or snow from a constructional element (1), comprising a controller (13) operating based on input data representing physical parameter values as measured by sensors (4, 14, 15, 17, 18, 19) arranged at or nearby the constructional element (1), and based on stored, historical data relating to snow and ice conditions for the constructional element (1), whereby the controller (13) is of the adaptive type, characterized in

that the controller (1) is configured for comparing current input data relating to the value of effective surface temperature for the constructional element (1) and to values of the following parameters:

the amount of snow/ice on the constructional element (1), air temperature, wind velocity, precipitation, velocity of the constructional element (1), and vibrations of the constructional element (1), to stored data relating to historical values of the same parameters, recorded as a function of time, and

that the controller (13) is further configured for computing, using stored algorithms and based on said relevant input and historical data, whether delivery of power to the heat emission equipment (3) is required, and in that case also the amperage and frequency values necessary to remove snow/ice from the constructional element (1), the frequency affecting a time constant of change in the surface temperature of the constructional element (1),

that the controller (13) is further configured to, according to the result of said calculation, issue a start or stop signal as well as an output control signal including amperage and frequency values to the power supply equipment (11), and

that the controller is configured to update its historical data with new parameter value data resulting from a current condition of snow/ice on the constructional element, according to a predetermined procedure.

6. The means of claim 4, characterized in that the power supply equipment is formed by an adjustable frequency transformer receiving power from an external power grid (10).