How to Protect Electrical Grids from Inter-Phase Short-Circuits?

High-voltage direct current (HVDC) transmission grids are crucial for transporting energy over long distances. However, inter-phase short-circuits can cause commutation failures, compromising system efficiency. A new study has developed an advanced strategy to prevent these faults. Scientists found that traditional methods are insufficient for handling inter-phase short-circuits because they fail to accurately measure voltage drops. To solve this problem, they created an algorithm that calculates real-time voltage drops phase by phase, without the need for complex integrations. This algorithm is fast and precise, allowing for rapid activation of advance firing controls. Additionally, they developed another algorithm that predicts the zero-crossing shift of the commutation voltage. Simulated tests have shown that this new strategy significantly reduces commutation failures compared to traditional methods.

The new phase-by-phase voltage drop calculation algorithm is a real game-changer in the field of HVDC grids. Using only two adjacent sampling points, it manages to keep voltage indices stable during normal operation and respond quickly in case of faults. This is made possible by a series of mathematical equations that calculate the voltage difference between phases in real-time. Additionally, the zero-crossing shift prediction algorithm uses advanced predictive models to anticipate voltage changes. These algorithms were tested on an advanced simulation platform, PSCAD V46/EMTDC, which confirmed their effectiveness. The results showed a significant reduction in commutation failures, improving the stability and efficiency of HVDC grids.