Interpretable Policy Distillation for Power Grid Topology Control
Summary
Deep reinforcement learning (RL) for real-time power grid operation often uses large, opaque neural policies. This research demonstrates that a Proximal Policy Optimization (PPO) agent, trained on Grid2Op's standard 14-bus environment with a stability-oriented reward and stress-focused data collection, can be effectively compressed. The PPO "teacher" policy was distilled into compact decision tree and random forest surrogates. Both surrogates surpassed the original PPO agent in mean reward and survival length during held-out validation episodes, achieving this at a significantly reduced inference cost. The decision tree, small enough for direct inspection, exhibited high exact-action agreement with the PPO policy's argmax. Interestingly, feature importance analysis revealed a representational shift: the PPO policy primarily used line-loading signals, whereas the distilled tree relied on bus-topology variables. This approach transforms a black-box neural controller into an auditable, lightweight rule-like surrogate suitable for real-time deployment, while also surfacing risks associated with deterministic actions and topology-specific generalization.
Key takeaway
For MLOps Engineers deploying AI in critical infrastructure like power grids, consider policy distillation to enhance model interpretability and reduce inference costs. If you are struggling with black-box neural controllers, distilling them into compact decision trees can provide auditable, high-performing surrogates. This approach allows for real-time deployment on constrained hardware while maintaining or even improving operational performance and surfacing potential generalization risks.
Key insights
Policy distillation can transform complex RL agents into interpretable, high-performing, and deployable surrogates for critical infrastructure control.
Principles
- Stress-focused data collection improves distillation.
- Compact surrogates can exceed teacher performance.
- Feature importance shifts reveal policy differences.
Method
A PPO teacher agent is trained on a stability-oriented reward with stress-focused data. This policy is then distilled into decision tree and random forest surrogates for deployment.
In practice
- Deploy decision trees for real-time grid control.
- Use stress data to improve policy robustness.
- Analyze feature importance for policy transparency.
Topics
- Reinforcement Learning
- Policy Distillation
- Power Grid Control
- Decision Trees
- Model Interpretability
- Grid2Op
Best for: AI Engineer, AI Scientist, Machine Learning Engineer, MLOps Engineer, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by Artificial Intelligence.