Method for determining a coil temperature of an electric machine
AssigneeAudi AG
InventorBernhard Karl
Life of this patent
Estimating the term…
Abstract
A method for determining an actual temperature of a coil of an electric machine, includes detecting a voltage in a no-load state of the electric machine; detecting a current strength in an induced short circuit state of the electric machine; calculating an actual stator coil resistance as a function of the voltage detected during the no-load state and the current strength detected during the active short circuit” state; and calculating the actual temperature of the coil of the electric machine as a function of the actual stator coil resistance.
Claims8
A method for determining a temperature of a stator coil of an electric machine, comprising:
- measuring in a no-load state of the electric machine an open-circuit voltage across the stator coil of the electric machine;
- determining from the measured open-circuit voltage a magnetic flux through the stator coil;
- shorting the stator coil of the electric machine to produce an induced short circuit state and measuring in the induced short circuit state a short-circuit current strength;
- calculating a stator coil resistance as a function of the magnetic flux determined during the no-load state and the short-circuit current strength measured during the induced short circuit state;
- and
- calculating the temperature of the stator coil of the electric machine as a function of the stator coil resistance.
A vehicle comprising a control device configured to determine a temperature of a stator coil of an electric machine, said control device being configured to block semiconductors of a power electronics of the electric machine and measure in a no-load state of the electric machine an open-circuit voltage across the stator coil of the electric machine, to determine from the measured open-circuit voltage a magnetic flux through the stator coil, to switch the electric machine into an induced short circuit state and measure in the induced short circuit state a short-circuit current strength, to calculate a stator coil resistance as a function of the magnetic flux determined during the no-load state and the short-circuit current strength measured during the induced short circuit state, and to calculate the temperature of the coil of the electric machine as a function of the stator coil resistance.
Dependencies are inferred from the claim text.