Control device for semiconductor switch on an inverter and method for the actuation of an inverter
The invention relates to a control device ( 4 ) for the actuation of a semiconductor switch ( 1 ) on an inverter having an actuation switch ( 16 ) that is designed to generate a driver signal ( 18 ) depending on a switch signal ( 5 ) generated by a control regulation of the inverter, and a driver circuit ( 15 ) that is connected between the actuation circuit ( 16 ) and a control input ( 13 ) of the semiconductor switch ( 1 ), and which is designed to receive the driver signal ( 18 ) and a control signal ( 7 ) depending on the driver signal ( 18 ), said control signal actuating a semiconductor switch ( 1 ) for the generation and infeed into the control input ( 13 ) of the semiconductor switch ( 1 ), wherein the actuation circuit ( 16 ) is designed to generate the driver signal ( 18 ) as a consequence of driver signal pulses with a predetermined and adjustable pulse length such that the semiconductor switch ( 1 ) is not fully conductive in the event of an actuation with the control signal ( 7 ) during the pulse length.
1. A control device ( 4 ) for actuating a semiconductor switch ( 1 ) of an inverter ( 10 ), having:
an actuation circuit ( 16 ) configured to generate a driver signal ( 18 ) on the basis of a switching signal ( 5 ) generated by a control system ( 50 ) of the inverter ( 10 );
a regulation circuit ( 17 ) coupled to the actuation circuit ( 16 ) and configured to generate a regulation signal ( 19 ) for regulating the driver signal ( 18 ) and to feed said regulation signal into the actuation circuit ( 16 ); and
a driver circuit ( 15 ) coupled between the actuation circuit ( 16 ) and a control input ( 13 ) of the semiconductor switch ( 1 ) and configured to receive the driver signal ( 18 ) and to generate a control signal ( 7 ) which actuates the semiconductor switch ( 1 ) on the basis of the driver signal ( 18 ) and to feed said control signal into the control input ( 13 ) of the semiconductor switch ( 1 ),
the actuation circuit ( 16 ) configured to generate the driver signal ( 18 ) as a sequence of driver signal pulses ( 18 k ) with a predetermined and adjustable pulse length (T), resulting in the semiconductor switch ( 1 ) being not completely conductive during the pulse length (T) when actuated with the control signal ( 7 ).
2. The control device ( 4 ) as claimed in claim 1 , wherein the pulse length (T) is able to be adjusted in such a manner that the semiconductor switch ( 1 ) has a predetermined current value when being actuated with the control signal ( 7 ).
3. The control device ( 4 ) as claimed in claim 1 , wherein the regulation circuit ( 17 ) is configured to record a first measurement signal ( 9 ) representing the intermediate circuit voltage and to generate the regulation signal ( 19 ) on the basis of the first measurement signal ( 9 ).
4. The control device ( 4 ) as claimed in claim 1 , wherein the regulation circuit ( 17 ) is coupled to a current sensor output ( 14 ) of the semiconductor switch ( 1 ) and configured to record a second measurement signal ( 8 ) representing a current through the semiconductor switch ( 1 ) and to generate the regulation signal ( 19 ) on the basis of the second measurement signal ( 8 ).
5. The control device ( 4 ) as claimed in claim 1 , wherein the driver circuit ( 15 ) has an adjustable control resistance for generating the control signal ( 7 ), and the actuation circuit ( 16 ) is configured to generate an actuating signal ( 20 ) for adjusting the adjustable control resistance on the basis of the regulation signal ( 19 ) and to feed said actuating signal into the driver circuit ( 15 ).
6. The control device ( 4 ) as claimed in claim 1 , wherein the semiconductor switch ( 1 ) is an IGBT switch ( 1 ).
7. The control device ( 4 ) as claimed in claim 1 , wherein the inverter ( 10 ) has a half-bridge circuit, and the actuation circuit ( 16 ) is configured to respectively actuate one of the semiconductor switches ( 1 ) in a half-bridge with the driver signal ( 18 ) and to permanently close the other of the semiconductor switches ( 1 ) in the half-bridge.
8. A drive system ( 100 ) for an n-phase electrical machine ( 3 ), where n≧1, having:
an intermediate circuit capacitor ( 2 ) which is connected to two input voltage connections (T+; T−);
an inverter ( 10 ) having a multiplicity of semiconductor switches ( 1 a , . . . , 1 f ), which inverter is coupled to the intermediate circuit capacitor ( 2 ), is fed with electrical energy from the intermediate circuit capacitor ( 2 ) and is configured to generate an n-phase supply voltage for the electrical machine ( 3 );
a multiplicity of control devices ( 4 a , . . . , 4 f ) as claimed in claim 1 which are each designed to generate a control signal ( 7 a , . . . , 7 f ) for actuating one of the semiconductor switches ( 1 a , . . . , 1 f ) of the inverter ( 10 ); and
a control system ( 50 ) which is coupled to the multiplicity of control devices ( 4 a , . . . , 4 f ) and is configured to generate switching signals ( 5 a , . . . , 5 f ) for the semiconductor switches ( 1 a , . . . , 1 f ) of the inverter ( 10 ).
9. The drive system ( 100 ) as claimed in claim 8 , wherein the semiconductor switches ( 1 a , . . . , 1 f ) are IGBT switches.
10. The drive system ( 100 ) as claimed in claim 8 , wherein the inverter ( 10 ) has a half-bridge circuit, and the actuation circuit ( 16 ) is configured to respectively actuate one of the semiconductor switches ( 1 ) in a half bridge with the driver signal ( 18 ) and to permanently close the other of the semiconductor switches ( 1 ) in the half-bridge.
11. A method ( 30 ) for actuating an inverter ( 10 ), having the steps of:
generating ( 31 ) a driver signal ( 18 ) for at least one of the semiconductor switches ( 1 a , . . . , 1 f ) of the inverter ( 10 ), the driver signal ( 18 ) having a sequence of driver signal pulses ( 18 k );
generating a regulation signal ( 19 ) for regulating the driver signal ( 18 ); and
amplifying ( 32 ) the driver signal ( 18 ) in order to generate a control signal ( 7 a , . . . , 7 f ) which actuates the at least one semiconductor switch ( 1 a , . . . , 1 f ), the driver signal pulses ( 18 k ) each having a predetermined and adjustable pulse length (T), with the result that the semiconductor switch ( 1 a , . . . , 1 f ) is not completely conductive during the pulse length (T) when being actuated with the control signal ( 7 a , . . . , 7 f ).
12. The method ( 30 ) as claimed in claim 11 , also having the steps of:
recording ( 33 a ) a first measurement signal ( 9 ) representing the intermediate circuit voltage; and
generating ( 34 a ) a regulation signal ( 19 ) for regulating the pulse length (T) of the driver signal pulses ( 18 k ) on the basis of the first measurement signal ( 9 ).
13. The method ( 30 ) as claimed in claim 11 , also having the steps of:
recording ( 33 b ) a second measurement signal ( 8 ) representing a current through the at least one semiconductor switch ( 1 a , . . . , 1 f ); and
generating ( 34 b ) a regulation signal ( 19 ) for regulating the pulse length (T) of the driver signal pulses ( 18 k ) on the basis of the second measurement signal ( 8 ).