Topology-Aware Graph Reinforcement Learning for Energy Storage Systems Optimal Dispatch in Distribution Networks
Authors: Shuyi Gao, Stavros Orfanoudakis, Shengren Hou, Peter Palensky, Pedro P. Vergara
Organizations: Department of Electrical Sustainable Energy, Delft University of Technology, Mekelweg 4, Delft, 2628 CD, The Netherlands · Beijing Energy Quant Ltd., Haidian, Beijing, 53100, China
Optimal dispatch of energy storage systems (ESSs) in distribution networks involves jointly improving operating economy and voltage security under time-varying conditions and possible topology changes. To support fast online decision making, we develop a topology-aware Reinforcement Learning architecture based on Twin Delayed Deep Deterministic Policy Gradient (TD3), which integrates graph neural networks (GNNs) as graph feature encoders for ESS dispatch. We conduct a systematic investigation of three GNN variants: graph convolutional networks (GCNs), topology adaptive graph convolutional networks (TAGConv), and graph attention networks (GATs) on the 34-bus and 69-bus systems, and evaluate robustness under multiple topology reconfiguration cases as well as cross-system transfer between networks with different system sizes. Results show that GNN-based controllers consistently reduce the number and magnitude of voltage violations, with clearer benefits on the 69-bus system and under reconfiguration; on the 69-bus system, TD3-GCN and TD3-TAGConv also achieve lower saved cost relative to the NLP benchmark than the NN baseline. We also highlight that transfer gains are case-dependent, and zero-shot transfer between fundamentally different systems results in notable performance degradation and increased voltage magnitude violations. This work is available at: https://github.com/ShuyiGao/GNNs_RL_ESSs and https://github.com/distributionnetworksTUDelft/GNNs_RL_ESSs.
Figures & tables
Figure 1: Architecture of the proposed GNN-based RL framework for distribution-network ESS optimal dispatch, consisting of the graph feature encoder, the ESS dispatch environment, the experience replay buffer, and the actor–critic networks.
Figure 2: The average reward of RL algorithms during 1000 episodes of training on (a)34 buses system, (b)69 buses system.
Figure 3: Comparison of RL algorithms on 34 buses system, (a)electricity price and ESS nodes’ active power, (b)-(f) ESS nodes’ SOC and charging/discharging strategy of NLP, TD3-NN, TD3-GCN, TD3-TAGConv, TD3-GATConv on Node 34.
Figure 4: ESS nodes’ voltage magnitude on 34 buses system, (a)without ESS control, (b)NLP, (c)TD3-NN, (d)TD3-GCN, (e)TD3-TAGConv, (f)TD3-GATConv.
Algorithms
TD3-NN
TD3-GCN
TD3-TAGConv
TD3-GATConv
NLP
Training [ h/m/s ]
2h36m6.6s
5h22m14.7s
5h58m55.8s
7h28m51.3s
-
Execution [ s ]
0.0998 (0.0990, 0.1007)
0.1968 (0.1935, 0.2001)
0.1909 (0.1898, 0.1920)
0.2274 (0.2256, 0.2291)
19.77
Saved costs [$]
197.92 (195.71, 200.13)
179.74 (175.12, 184.38)
188.04 183.53, 192.54)
195.28 (191.48, 199.07)
260.40 (252.34, 268.47)
Accuracy vs NLP [ % ]
76.31 (75.46, 77.15)
69.51 (67.72, 71.31)
72.61 (70.95, 74.26)
75.46 (74.02, 76.90)
-
Accuracy vs TD3-NN [ % ]
-
91.92 (89.87, 93.96)
96 (93.58, 98.43)
99.57 (97.68, 101.46)
-
Average Voltage Violation Counts [-]
4
5
4
5
-
Table 1: RL algorithms’ average training time [ h/m/s ], mean and 95% confidence bounds of execution time [ s ] and performances on 34 buses testsets.
Algorithms
TD3-NN
TD3-GCN
TD3-TAGConv
TD3-GATConv
NLP
Training [ h/m/s ]
2h47m42.6s
5h32m22.5s
6h11m58.2s
7h50m39.6s
-
Execution [ s ]
0.1340 (0.1327, 0.1354)
0.2351 (0.2323, 0.2378)
0.2381 (0.2347, 0.2415)
0.2878 (0.2830, 0.2927)
144.37
Saved costs [$]
458.98 (450.91, 467.06)
498.83 (489.58, 508.07)
466.44 (453.93, 478.96)
439.42 (388.57, 490.281)
868.19 (830.15, 906.25)
Accuracy vs NLP [ % ]
54.56 (53.69, 55.44)
59.30 (58.21, 60.38)
55.54 (54.25, 56.82)
52.74 (47.19, 58.29)
-
Accuracy vs TD3-NN [ % ]
-
109.87 (106.65, 113.10)
102.54 (100.86, 104.21)
97.99 (87.13, 108.86)
-
Average Voltage Violation Counts [-]
77
54
33
151
-
Table 2: RL algorithms’ average training time [ h/m/s ], mean and 95% confidence bounds of execution time [ s ] and performances on 69 buses testsets.
ID
Reconfiguration
Connections
TP1
–
Baseline topology
TP2
1 within a branch
(25,26) ⇒ (24,26)
TP3
1 within a branch
(32,33) ⇒ (31,33)
TP4
2 within a branch
(11,12) ⇒ (10,12); (29,30) ⇒ (28,30)
TP5
2 within a branch
(15,16) ⇒ (14,16); (33,34) ⇒ (32,34)
TP6
1 whole branch
(10,31) ⇒ (8,31)
Table 3: Topological Variation Scenarios or Evaluating the Generalization of GNN-based RL Algorithms on 34 Buses System.
ID
Reconfiguration
Connections
TP1
–
Baseline topology
TP2
1 within a branch
(67,68) ⇒ (13,68)
TP3
1 within a branch
(45,46) ⇒ (44,46)
TP4
2 within a branch
(35,36) ⇒ (34,36); (13,69) ⇒ (14,69)
TP5
2 within a branch
(50,51) ⇒ (49,51); (52,53) ⇒ (9,53)
TP6
1 whole branch
(12,13) ⇒ (11,13)
Table 4: Topological Variation Scenarios or Evaluating the Generalization of GNN-based RL Algorithms on 69 Buses System.
Figure 5: 34 buses system RL algorithms’ operational accuracy [ % ] on topological variations
Figure 6: 69 buses system RL algorithms’ operational accuracy [ % ] on topological variations
Figure 7: 34 buses system RL algorithms’ mean 95% confidence bounds of average voltage violation [p.u.] on topological variations.
Figure 8: 69 buses system RL algorithms’ mean 95% confidence bounds of average voltage violation [p.u.] on topological variations.
Figure 9: RL algorithms’ (a)operational accuracy [ % ] and (b) mean 95% confidence bounds of average voltage violation [p.u.] on 69 buses system with agents trained on 34 buses system
Figure 10: RL algorithms’ (a)operational accuracy [ % ] and (b) mean 95% confidence bounds of average voltage violation [p.u.] on 34 buses system with agents trained on 69 buses system
Extreme weather events and cyberattacks can cause component failures and disrupt the operation of power distribution networks (DNs), during which reconfiguration and load shedding are often adopted for resilience enhancement. This study introduces a topology-aware graph reinforcement learning (RL) framework for outage management that embeds higher-order topological features of the DN into a graph-based RL model, enabling reconfiguration and load shedding to maximize energy supply while maintaining operational stability. Results on the modified IEEE 123-bus feeder across 300 diverse outage scenarios demonstrate that incorporating the topological data analysis (TDA) tool, persistence homology (PH), yields 9-18% higher cumulative rewards, up to 6% increase in power delivery, and 6-8% fewer voltage violations compared to a baseline graph-RL model. These findings highlight the potential of integrating RL with TDA to enable self-healing in DNs, facilitating fast, adaptive, and automated restoration.
Roshni Anna Jacob, Prithvi Poddar, Jaidev Goel +3
The University of Texas at Dallas, Richardson, TX, USA · University at Buffalo, Buffalo, NY, USA · Virginia Tech, Blacksburg, VA, USA
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Pascal Henrich, Jonas Sievers, Maximilian Beichter +3
Karlsruhe Institute of Technology, Karlsruhe, Germany
Fault location in distribution grids is critical for reliability and minimizing outage durations. Yet, it remains challenging due to partial observability, given sparse measurement infrastructure. Recent works show promising results by combining Recurrent Neural Networks (RNNs) and Graph Neural Networks (GNNs) for spatio-temporal learning. Still, many modern GNN architectures remain untested for this grid application, while existing GNN solutions have not explored GNN topology definitions beyond simply adopting the full grid topology to construct the GNN graph. We address these gaps by (i) systematically comparing a newly proposed graph-forming strategy (measured-only) to the traditional full-topology approach, and (ii) introducing STGNN (Spatio-temporal GNN) models based on GraphSAGE and an improved Graph Attention (GATv2), for distribution grid fault location; (iii) benchmarking them against state-of-the-art STGNN and RNN baselines on the IEEE 123-bus feeder. In our experiments, all evaluated STGNN variants achieve high performance and consistently outperform a pure RNN baseline, with improvements up to 11 percentage points F1. Among STGNN models, the newly explored RGATv2 and RGSAGE achieve only marginally higher F1 scores. Still, STGNNs demonstrate superior stability, with tight confidence intervals (within +/- 1.4%) compared to the RNN baseline (up to +/- 7.5%) across different experiment runs. Finally, our proposed reduced GNN topology (measured-only) shows clear benefits in both (i) model training time (6-fold reduction) and (ii) model performance (up to 11 points F1). This suggests that measured-only graphs offer a more practical, efficient, and robust framework for partially observable distribution grids.