Circuit arrangement, electrical system, and method for ascertaining barrier layer temperatures of gate-controlled semiconductor components
A circuit arrangement, an electrical system, and a method for determining barrier layer temperatures of gate-controlled semiconductor components. First and second semiconductor components of the circuit arrangement are connected in parallel and activated using a gate control circuit which, in an active forward mode of the two semiconductor components, varies a first gate voltage of the first semiconductor component using a first signal, and to varies a second gate voltage of the second semiconductor component using a second signal that is opposite the first signal. An evaluation unit of the circuit arrangement is configured to use first and second current measuring devices to measure first and second gate currents of the first and second semiconductor components, respectively, and to determine in each case, based on the particular varied gate voltages and the respective corresponding gate currents, respective barrier layer temperatures of the two semiconductor component.
1 . A circuit arrangement for ascertaining barrier layer temperatures of gate-controlled semiconductor components, comprising:
a first semiconductor component;
a second semiconductor component;
a gate control circuit;
a first current measuring device;
a second current measuring device; and
an evaluation unit,
wherein
the first semiconductor component and the second semiconductor component are gate-controlled semiconductor components that are connected in parallel to one another, so that a respective conductance of the first and second semiconductor components is settable by the gate control circuit,
the gate control circuit is configured to, at least within a predefined time period, in an active forward mode of the first and second semiconductor components, vary a first gate voltage of the first semiconductor component using a first signal, and vary a second gate voltage of the second semiconductor component using a second signal that is opposite the first signal, a total conductance of the first and second semiconductor components that results from the parallel connection remaining essentially constant,
the evaluation unit is configured to:
detect a first gate current of the first semiconductor component using the first current measuring device, and detect a second gate current of the second semiconductor component using the second current measuring device, and
ascertain, based on the varied first and second gate voltages, respectively, and the first and second gate currents, respectively, a respective barrier layer temperature of the first semiconductor component and of the second semiconductor component.
2 . The circuit arrangement as recited in claim 1 , wherein at least one of the first semiconductor component or the second semiconductor component is:
a MOSFET, or
an IGBT, or
an HEMT.
3 . The circuit arrangement as recited in claim 1 , wherein the predefined time period is a measuring time period for detecting particular barrier layer temperatures.
4 . The circuit arrangement as recited in claim 1 , wherein the first signal and the second signal are at least one of the following:
identical signals that are phase-shifted by 180° relative to one another,
sinusoidal signals, or
signals with asymmetrical half-waves.
5 . The circuit arrangement as recited in claim 1 , wherein the evaluation unit is configured to adapt at least one of the first signal or the second signal, as a function of at least one of the following:
respective individual conductances of the first semiconductor component and of the second semiconductor component,
individual working currents of the first semiconductor component and of the second semiconductor component,
a total conductance of the first semiconductor component and the second semiconductor component,
a total working current of the first semiconductor component and the second semiconductor component,
the respective barrier layer temperatures of the first semiconductor component and of the second semiconductor component,
respective operating points of the first semiconductor component and of the second semiconductor component, or
an overall temperature of the first semiconductor component and the second semiconductor component.
6 . The circuit arrangement as recited in claim 5 , wherein the evaluation unit is configured to ascertain, based on respective adaptations of at least one of the first signal or the second signal, at least one of:
a state of the first and second semiconductor components, or
a state of corresponding circuit components.
7 . The circuit arrangement as recited in claim 1 , further comprising:
at least one further parallel connection made up of a third semiconductor component and a fourth semiconductor component, wherein respective barrier layer temperatures of the third semiconductor component and of the fourth semiconductor component are ascertained analogously to the barrier layer temperatures of the first semiconductor component and of the second semiconductor component.
8 . An electrical system, comprising:
a circuit arrangement for ascertaining barrier layer temperatures of gate-controlled semiconductor components, including:
a first semiconductor component;
a second semiconductor component;
a gate control circuit;
a first current measuring device;
a second current measuring device; and
an evaluation unit,
wherein
the first semiconductor component and the second semiconductor component are gate-controlled semiconductor components that are connected in parallel to one another, so that a respective conductance of the first and second semiconductor components is settable by the gate control circuit,
the gate control circuit is configured to, at least within a predefined time period, in an active forward mode of the first and second semiconductor components, vary a first gate voltage of the first semiconductor component using a first signal, and vary a second gate voltage of the second semiconductor component using a second signal that is opposite the first signal, a total conductance of the first and second semiconductor components that results from the parallel connection remaining essentially constant,
the evaluation unit is configured to:
detect a first gate current of the first semiconductor component using the first current measuring device, and detect a second gate current of the second semiconductor component using the second current measuring device, and
ascertain, based on the varied first and second gate voltages, respectively, and the first and second gate currents, respectively, a respective barrier layer temperature of the first semiconductor component and of the second semiconductor component;
wherein the electrical system is configured to operate the first semiconductor component and the second semiconductor component, at least temporarily, repeatedly, in the forward mode.
9 . The electrical system as recited in claim 8 , wherein the electrical system is at least one of the following:
a drive converter,
a DC/DC voltage converter,
an AC/AC voltage converter,
an inverter,
a rectifier,
a switch mode power supply, or
an electrical system of a vehicle.
10 . A method for ascertaining barrier layer temperatures of gate-controlled semiconductor components, comprising the following steps:
varying, at least within a predefined time period, in an active forward mode of first and second semiconductor components, a first gate voltage of the first semiconductor component using a first signal, and varying a second gate voltage of the second semiconductor component using a second signal opposite the first signal, a total conductance of the first and second semiconductor components that results from the parallel connection remaining essentially constant;
detecting a first gate current of the first semiconductor component and a second gate current of the second semiconductor component, and
ascertaining a respective barrier layer temperature of the first semiconductor component and of the second semiconductor component, based on the varied first and second gate voltages, respectively, and the first and second gate currents, respectively.