Inverter Arrangement, Electric Drive System, and Method for Discharging a DC Link Capacitor in an Inverter Arrangement
AssigneeRobert Bosch GmbH
InventorsEdwin Eberlein, Martin Trunk, Timo Bartsch
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Abstract
The invention relates to the discharging of a DC link capacitor in an inverter arrangement, thereby allowing, for example, a DC link capacitor to be discharged while an electric machine that is connected to the inverters can operate in an idling mode as a safe mode. The DC link capacitor is discharged by very briefly triggering a semiconductor switch within the inverter. According to the invention, the inverter bridge arm with the smallest phase voltage is selected for the very brief triggering process.
Claims10
An inverter system (2), comprising:
- a full bridge circuit having a plurality of bridge arms (20-i), wherein each bridge arm (20-i) comprises a first semiconductor switch (21-i) and a second semiconductor switch (22-i) which are respectively interconnected at a node (23-i);
- a control device (30) which is designed
- to ascertain a primary bridge arm having the lowest phase voltage between the respective node (23-i) of the bridge arm (20-i) and a reference potential,
- to close the first semiconductor switch (21-i) of the primary bridge arm,
- to pulse the second semiconductor switch (22-i) of the primary bridge arm, and
- to open the semiconductor switches (21-i, 22-i) of the full bridge which are not in the primary bridge arm.
A method for discharging an intermediate-circuit capacitor (10) in an inverter arrangement (2) comprising a full bridge circuit which comprises a plurality of bridge arms (20-i), and each bridge arm (20-i) comprises a first semiconductor switch (21-i) and a second semiconductor switch (22-i) which are respectively interconnected at a node (23-i), including the steps of:
- ascertaining (S1) a primary bridge arm having the lowest phase voltage between the respective node (23-i) of the bridge arm (20-i) and a reference potential;
- closing (S2) the first semiconductor switch (21-i) of the primary bridge arm;
- pulsing (S3) the second semiconductor switch (22-i) of the primary bridge arm;
- and
- opening (S4) the semiconductor switches (21-i, 22-i) of the full bridge which are not in the primary bridge arm.
Dependencies are inferred from the claim text.