Dc-link capacitor protection
AssigneeDanfoss Power Electronics A/S
InventorPetar Ljushev
Life of this patent
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Abstract
The invention provides an inverter system and a method of using said inverter system. A rectifier stage of the inverter system is used to charge a DC link stage to a first voltage level and a control module determines whether voltages over series connected capacitors of the DC link stage are balanced. If those voltages are balanced, the rectifier stage charges the DC link stage to a second voltage level higher than the first voltage level.
Claims20
A method of operating an inverter system, the inverter system comprising a rectifier stage, a DC link stage, an inverter stage and a control module, the method comprising:
- using the rectifier stage to charge the DC link stage to a first voltage level;
- activating the control module;
- using the control module to determine whether voltages over series connected capacitors of the DC link stage are balanced;
- and
- in the event that the control module determines that said voltages are balanced, using the rectifier stage to charge the DC link stage to a second voltage level, wherein the second voltage level is higher than the first voltage level.
An inverter system comprising a rectifier stage, a DC link stage, an inverter stage and a control module, wherein:
- the rectifier stage is configured to charge the DC link stage to a first voltage level;
- the DC link stage comprises two or more series connected capacitors;
- the control module is configured to determine whether voltages over the series connected capacitors of the DC link stage are balanced;
- and
- the rectifier is configured to charge the DC link stage to a second voltage level under the control of said control module, in the event that the control module determines that voltages over series connected capacitors of the DC link stage are balanced.
A computer program product configured to:
- charge a DC link stage of an inverter system to a first voltage level;
- determine whether voltages over series connected capacitors of the DC link stage are balanced;
- and
- in the event that the control module determines that said voltages are balanced, charge the DC link stage to a second voltage level, wherein the second voltage level is higher than the first voltage level.
Dependencies are inferred from the claim text.