Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
  • G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
  • G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
  • G01K7/18—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer
  • G01K7/183—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer characterised by the use of the resistive element
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K13/00—Thermometers specially adapted for specific purposes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/008—Details of transformers or inductances, in general with temperature compensation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2823—Wires
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/29—Terminals; Tapping arrangements for signal inductances
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
  • G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
  • G01K7/22—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor
  • G01K7/223—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor characterised by the shape of the resistive element

Definitions

• the present invention relates to the monitoring of electrical systems embedded on an aircraft. It is more particularly aimed at measuring the temperature of a wound electrical component.
• State of the art :
• a flammable product at high temperature such as engine oil.
• the safety rules require that the skin temperature of each housing does not exceed the critical temperature of 204 ° C, threshold of auto-ignition of the engine oil.
• the solution currently used consists of an integrated temperature probe outside the winding which sends an alert message if the critical temperature is exceeded.
• This solution has the first disadvantage of being expensive because it introduces additional specific equipment, the temperature probe, foreign to the component to monitor. It poses integration difficulties, the temperature probes have not been specifically designed to be adapted to the component. Finally, they provide a local temperature at the point of the surface of the component where the sensor of the probe was fixed. The indication by the probe of a suitable temperature does not necessarily guarantee that the critical temperature has not been exceeded elsewhere on the component.
• the dimensioning and the position of the probe requires characterizing the probe / coil component assembly in order to reduce the risk of exceeding the critical temperature or raising false alarms to the detection system, and also to avoid the mass and cost impact of oversizing of the winding, caused by the need to limit its self-heating in particular in pulsed type applications and to make room for the measurement error.
• the aim of the invention is to provide a simple and robust solution to these integration problems, in particular for wound components, while ensuring that the temperature measurement makes it possible to comply with the safety instruction without having to take a margin of error. security too important.
• the invention relates to a method for measuring the temperature of a high power wound component for aeronautical applications, comprising measuring the potential difference between the terminals of a resistive material gauge wire in which a direct current is passed through. and known, the resistance of the gauge wire varying with temperature according to a known law, and a calculation step transforming the potential difference in mean temperature of the gauge wire, said gauge wire being wound inside the winding, in turns arranged in a series of turns "go" and a series of turns "return” associated two by two with a geometry and a substantially equal position.
• gauge wire has a diameter in a range of 0.05 mm to 0.25 mm and has a length adjusted to obtain, by making at least twenty turns, resistance variations included between 2 and 8 Ohms for a temperature varying between -60 ° C and 200 ° C.
• the invention achieves its objective because the heat being produced inside the component, the average temperature inside the component obtained by measuring on the gauge wire increases that which can be reached on the surface. So, the more precise the measurement, the closer we can get to the threshold, being sure not to exceed it. Moreover, especially for In the case of wound components, the measurement must compensate for the disturbances caused by the presence of magnetic fields whose gradients create an electromotive force in the windings they pass through. The fact of having "go" turns and “return” turns compensating each other two by two considerably simplifies the measuring circuit. In addition, we are interested here in high power components in aeronautics, whose winding diameter can vary between 1 cm and 30 cm.
• the use of a conductive material whose resistivity varies linearly with the temperature in the measured temperature range simplifies the calculations.
• the gauge wire is copper
• the current material whose resistivity is a linear function of the temperature in the operating range for aeronautical applications is copper
• Precise measurement of the temperature is obtained by connecting two wires to the ends of the gauge wire for the measurement of the potential difference.
• the invention also relates to a high power wound component for aeronautical applications, characterized in that it comprises a wire of resistive material whose resistance varies with temperature according to a known law, said wire of conductive material being wound to the inside the winding and arranged in a series of turns "go" and a series of "return” turns, associated in pairs with a geometry and a substantially equal position, said gauge wire being more than a diameter taken in a range ranging from 0.05mm to 0.25mm with a length adjusted to obtain, by making at least twenty turns, resistance variations of between 2 and 8 Ohms for a temperature ranging between -60 ° C and 200 ° C, and two connectors capable of connecting the ends of said gauge wire to external electronic devices. It relates more particularly to a wound component comprising at least two active windings, one surrounding the other and the turns of the gauge wire being inserted between the two active windings.
• this component comprises two additional connections reported at the terminals of the gauge wire.
• Such a component is able to be connected with the measuring devices necessary to determine the average temperature inside the component.
• the invention also relates to an electronic device for aeronautical applications comprising at least one component according to the invention, a direct current generation means connected to the ends of the gauge wire, a means for measuring the potential difference between the complementary connections and a means calculation device adapted to transform the signal of the potential difference measuring means and the information on said direct current into a temperature signal.
• the invention relates to a method for manufacturing a wound component according to the invention comprising a step of calibrating the length of the gauge wire to obtain a given resistance at a given temperature, before the installation of the gauge wire in the wound component, and a step of connecting two complementary output son to the terminals of the gauge son corresponding to the calibrated resistance.
• Figure 2 shows the schematic diagram of two turns running the measuring current in the opposite direction.
• Figure 3 shows the principle of 4-wire measurement on the gauge wire.
• a typical wound component for example a transformer as shown in FIG. 1, comprises two active windings, 2 and 3. They are configured such that there is an outer winding 3 surrounding the inner winding 2, the whole wrapping a column 4 with a central core.
• the heating of the component is mainly due to Joule losses in the active windings because of the strong currents used. Indeed, it is a question of estimating heating of wound components of high power, preferentially for aeronautical applications.
• a gauge wire 1 copper small diameter is wound on a cylinder between the two active windings. Measuring the resistance variation of the gauge wire 1 related to the variation in the resistivity of the material in the component as a function of the temperature makes it possible to obtain a temperature measurement representative of that of the inside of the winding, and therefore to increase the temperature. which is observed on the skin of the component. Copper is chosen because it makes it possible to obtain correct measurements with small diameters of wire.
• it is a common electronic material, compared, for example platinum used in some temperature measuring devices.
• the device is easy to integrate in the manufacture of the component described because it is sufficient to wind the gauge wire 1 at the same time as the active inner winding 2, on its outer surface, before assembling it with the rest component, which does not require any additional operation.
• the components whose temperature is to be monitored have a diameter of between 1 and 30 cm.
• the diameter of the gauge wire used is generally between 0.25 and 0.05 mm, resulting, for nominal resistance of 6 ohms at ambient temperature (20 ° C.), a gauge wire length of between 17 meters and 1.5 meters. at least twenty turns. This length can impact the final diameter of the component, the son can represent between 0.1 and 10% of the total volume of drivers.
• Figure 1 shows an embodiment with two active windings.
• the gauge wire is wound inside the winding placed between the two innermost windings.
• the gauge wire is wound against the inner face of this winding.
• the temperature of the wound components is monitored in a range of about -60 ° C to + 200 ° C.
• Ro Resistance of the gauge wire at 0 ° C in Ohms.
• the value of Ro sought during this calibration is between 2 and 8 Ohms. This makes it possible to have variations in the resistance value of several ohms, between 2 and 8 ohms, over the range of temperature variations expected for the component in operation.
• the magnitude of this variation in resistance for the target temperature range allows a measurement with a precision greater than 1%, significantly improved over that of conventional means, such as that it is detailed further on an example.
• this material will have a resistivity of between 1 and 10 10 "8 Ohms.m, preferably between 1 and 7 10" 8 Ohms.m, and will produce son gauge whose resistance will vary substantially within the ranges mentioned above above for the operating temperature range of the coiled component.
• the winding of the gauge wire is performed by folding the wire on itself in the middle and then winding this double wire.
• two sets of turns are associated two by two in a turn "Go" 5 and a turn “Return” 6 as illustrated in Figure 2.
• These two turns have substantially the same position in space and the same form. It is therefore the same magnetic flux that passes through them and thus the electromotive forces created at their terminals are equal and of opposite signs.
• the resultant electromotive forces observed at the terminals of the gauge wire therefore remains substantially zero.
• Other geometrical arrangements of the winding of the gauge wire can be envisaged to thus match the turns "Go" 5 and "Return” 6 two by two.
• the voltage measurement is performed using the so-called 4-wire method, or KELVIN method.
• 4-wire method or KELVIN method.
• the gauge wire (1) is connected at both ends to a current generating means 10 and the two complementary wires, 8a and 8b, are connected to a potential measuring means, a voltmeter 9.
• the impedance of the voltmeter 9 being very high, the current flowing through the connection wires is negligible and the difference in potential over the exact length of wire corresponding to the resistor Ro is measured with great precision.
• the intensity of the current passing through the gauge wire is also indicated with good accuracy by the current generating means.
• the brass wires are provided with a certain tolerance on their variation of radius.
• the average radius may vary by +/- 2.5% for 0.1 mm diameter wires.
• the uncertainties on the measured temperature will be of the order of 5% if one relies on the nominal data.
• the measurement accuracy is further improved by calibrating the gauge wire before integrating it into the component.
• calibrating the gauge wire Given the order of magnitude of a few Ohms of the resistance of the gauge wire (see the example provided in the table (1), calibration can be achieved with a micro-Ohmmeter to reach accuracies of the order of 0.2% on the resistance Ro.
• the operator When the operator has identified the precise length corresponding to the theoretical value of the resistance over 6m (see Table 1 for an example embodiment with the tolerances accepted), he connects to the corresponding terminals 7a and 7b, the complementary son 8a and 8b used for potential measurement, then winding up the gauge wire into the wound component.
• This measurement means makes it possible to have a temperature probe having an accuracy of +/- 0.3%, compared with the current average average value of 1% with temperature probes glued to the component. .
• the cost of manufacturing a temperature probe according to the invention is less.
• the errors introduced by the uncertainties on the value of the current I delivered by the means 10 by measuring directly the resistance of the gauge wire between the terminals 8a and 8b are furthermore freed from error.
• a resistor of known value is placed at a point in the circuit of the current I not subject to the temperature variations of the wound component. The potential variation across the resistor is measured and the resistance of the gauge wire is obtained directly by a ratio between the two measured potential differences.
• the assembly installed in the aircraft consists of this component modified with a current generator, a voltmeter and a calculation module able to provide the temperature from the measurements made these last three components being similar in complexity to ohmmeters available on the market.
• Table (1) Example concerning an autotransformer, evaluation of the measurement error on the temperature between -55C ° and + 175C °

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Nonlinear Science (AREA)
• Measurement Of Resistance Or Impedance (AREA)
• Measuring Temperature Or Quantity Of Heat (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49054624

Family Applications (1)

Country Status (9)

Families Citing this family (3)

Family Cites Families (10)

• 2013
  • 2013-02-14 FR FR1351290A patent/FR3002036A1/fr active Pending
• 2014
  • 2014-02-13 RU RU2015136512A patent/RU2645900C2/ru active
  • 2014-02-13 EP EP14708631.8A patent/EP2956749A1/fr not_active Ceased
  • 2014-02-13 CA CA2900701A patent/CA2900701A1/fr not_active Abandoned
  • 2014-02-13 BR BR112015019330A patent/BR112015019330A2/pt not_active Application Discontinuation
  • 2014-02-13 JP JP2015557502A patent/JP2016507070A/ja active Pending
  • 2014-02-13 WO PCT/FR2014/050292 patent/WO2014125220A1/fr active Application Filing
  • 2014-02-13 US US14/767,270 patent/US9816876B2/en active Active
  • 2014-02-13 CN CN201480008687.1A patent/CN105209873A/zh active Pending

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events