Optimization of Active Distribution Networks with Soft Open Points

Active distribution networks (ADNs) integrate distributed energy resources, such as photovoltaics and energy storage, into the low- and medium-voltage grid, requiring advanced methods to balance power flows, maintain voltage quality and ensure reliability. Soft Open Points (SOPs) are power electronic devices installed at normally open points to provide fully controllable active and reactive power exchange between adjacent feeders. Optimisation of ADNs with SOPs encompasses planning and real-time operation, addressing objectives such as loss minimisation, voltage regulation, hosting capacity enhancement, network reinforcement deferral and resilience under fault conditions. Techniques span stochastic and chance-constrained programming to manage renewable and load uncertainties, convex reformulations like second-order cone programming for rapid solution of nonconvex power-flow models, and multi-objective metaheuristics for simultaneous consideration of cost, power quality and system security. Practical implementations demonstrate that SOP-enabled architectures can defer costly infrastructure upgrades, reduce renewable curtailment, improve feeder utilisation and strengthen fault-ride-through capability, thereby advancing decarbonisation and grid stability across diverse network settings.

Research from Nature Portfolio

Recent studies have introduced a multi-resource dynamic coordinated planning approach for flexible distribution networks equipped with SOPs. This method defines long-term allocation strategies under source-load uncertainties within a probabilistic framework, mitigating risks of voltage violations and line overloads. Practical network trials reveal that tuning acceptable violation probabilities balances investment efficiency against operational security, yielding substantial cost advantages over conventional planning. The research underscores the capacity of SOP-based systems to manage high penetrations of distributed generation with enhanced controllability and to accommodate evolving energy-transition requirements.

Optimization of Active Distribution Networks with Soft Open Points publication trend

The graph below shows the total number of articles in optimization of active distribution networks with soft open points across all publications each year (not limited to Nature Index journals).

Technical terms

Active Distribution Network (ADN): A power distribution system integrating distributed energy resources that requires active control of power flows and voltages to maintain reliability and efficiency.

Soft Open Point (SOP): A power electronic device located at a normally open point in a distribution network, providing controllable active and reactive power exchange between feeders.

Chance constraint: A probabilistic constraint in optimisation that limits the risk of violating system limits under uncertainty by specifying an acceptable probability of constraint breach.

Second-order cone programming (SOCP): A convex optimisation technique that approximates nonconvex power flow problems to enable efficient and reliable solution of network control tasks.

Cost–benefit analysis: A framework for quantifying and comparing economic advantages of SOP services, assessing multiple value streams against investment and operational costs.

References

1. Multi-resource dynamic coordinated planning of flexible distribution network. Nature Communications (2024).
2. Comparative analysis of services from soft open points using cost–benefit analysis. Applied Energy (2023).
3. Coordinated Control Method of Voltage and Reactive Power for Active Distribution Networks Based on Soft Open Point. IEEE Transactions on Sustainable Energy (2017).
4. Multi-objective operation optimization of an electrical distribution network with soft open point. Applied Energy (2017).
5. Multi-stage expansion planning of energy storage integrated soft open points considering tie-line reconstruction. Protection and Control of Modern Power Systems (2022).