Method and device for setting a dead time of switching elements of a half bridge, and inverter
AssigneeRobert Bosch GmbH
InventorHans Geyer
Life of this patent
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Abstract
The invention relates to a method for setting a dead time between the opening of a first switching element (31) of a half bridge (2) and the closing of a second switching element (32) of the half bridge (2), comprising the steps: reducing the dead time of a switching cycle relative to the dead time of a preceding switching cycle, and determining a temperature of at least one of the switching elements (31, 32); wherein the steps of reducing the dead time and of determining the temperature are repeated for subsequent switching cycles until a critical dead time is reached, in the case of which a termination condition, which depends on the determined temperature, is fulfilled; and wherein the dead time is set using the critical dead time.
Claims14
A method for setting a dead time between the opening of a first switching element (31) of a half bridge (2) and the closing of a second switching element (32) of the half bridge (2), the method comprising:
- reducing the dead time of a switching cycle relative to the dead time of a preceding switching cycle, and
- ascertaining a temperature of at least one of the switching elements (31, 32);
- wherein the steps of reducing the dead time and ascertaining the temperature are repeated for subsequent switching cycles until a critical dead time at which a stop condition is satisfied that depends on the temperature ascertained is reached;
- wherein the dead time is set in the light of the critical dead time;
- and
- wherein the setting of the dead time occurs by adding a predefined safety buffer time to the critical dead time.
A device (1) for setting a dead time between the opening of a first switching element (31) of a half bridge (2) and the closing of a second switching element (32) of the half bridge (2), the device comprising:
- a control device (11) configured to drive the half bridge (2) in such a way that the second switching element (31) of the half bridge (2) is closed after a dead time following the opening of the first switching element (31);
- and
- a temperature ascertainment device (12) that is designed to ascertain a temperature of at least one of the switching elements (31, 32);
- wherein the control device (11) is designed to reduce the dead time of a switching cycle relative to the dead time of a preceding switching cycle, wherein the temperature ascertainment device (12) is designed, following the reduction of the dead time, to ascertain the temperature of at least one of the switching elements (31, 32), wherein the control device (11) and the temperature ascertainment device (12) are designed to repeat the reduction of the dead time and the ascertainment of the temperature for subsequent switching cycles until a critical dead time is reached at which a stop condition is satisfied that depends on the ascertained temperature, wherein the control device (11) is designed to set the dead time in the light of the critical dead time, and wherein the setting of the dead time occurs by adding a predefined safety buffer time to the critical dead time.
Dependencies are inferred from the claim text.