The '''Holomorphic Embedding Load-flow Method''' ('''HELM'''){{nnbsp}}<ref group="note">HELM is a trademark of Gridquant Inc.</ref>) is a solution method for the [[Power flow study|power flow]] equations of electrical power systems. Its main features are that it is [[Direct method (computational mathematics)|direct]] (that is, non-iterative) and that it mathematically guarantees a consistent selection of the correct operative branch of the multivalued problem, also signalling the condition of voltage collapse when there is no solution. These properties are relevant not only for the reliability of existing off-line and real-time applications, but also because they enable new types of analytical tools that would be impossible to build with existing iterative load flow methods (due to their convergence problems). An example of this would be [[decision support software|decision-support tools]] providing validated action plans in real time.
The HELM load flow algorithm was invented by Antonio Trias and has been granted two US Patents.<ref name="patent-7519506">
