Summary
This paper discusses current limitation for HVDC grid forming converters. Section 1 gives a general introduction where different ways of limiting converter current during grid events are discussed. For grid forming converters, directly changing current orders via K-factor to limit current, is not applicable since grid forming properties are then lost. It is stated that a reasonable alternative to limit the current, is instead to limit only the current magnitude to support frequency and voltage. This can be done either by altering the voltage behind impedance or by scaling the current reference vectors if an embedded current controller is employed. Section 3 describes how the voltage behind impedance can be altered in a consistent way to achieve this for different grid events and that this method is analogous to limiting the current magnitude.
Read more Read lessSection 4 discusses the expected unlimited current response for a converter, and what the consequences of limiting the current magnitude would be. Section 5 gives a discussion and conclusion. It has been seen that the unlimited converter current during a grid event depends on the type of grid event, the total converter impedance and on the operating point of the converter.
Even for a grid forming software-controlled converter, it is not correct to state that the fault current will be inherent, since the current will be rapidly limited even for rather modest grid events.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | C4_11702_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Sweden |
| Study committees |
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| File size | 2 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
SAMUELSSON Pär - Hitachi Energy; BJÖRKLUND Erik - Hitachi Energy; ABDALRAHMAN Adil - Hitachi Energy
