Data-Efficient Strategies for Probabilistic Voltage Envelopes under Network Contingencies
This work addresses data-efficient voltage envelope estimation for power grid operators, representing an incremental improvement with specific gains in computational efficiency.
The paper tackles the problem of constructing probabilistic voltage envelopes in power grids with network contingencies by introducing a multi-task vertex degree kernel (MT-VDK) that reduces computational complexity and hyperparameter needs, achieving over 50% reduction in mean prediction error for novel N-1 contingencies and using sixteen times fewer power flow solutions than Monte-Carlo methods.
This work presents an efficient data-driven method to construct probabilistic voltage envelopes (PVE) using power flow learning in grids with network contingencies. First, a network-aware Gaussian process (GP) termed Vertex-Degree Kernel (VDK-GP), developed in prior work, is used to estimate voltage-power functions for a few network configurations. The paper introduces a novel multi-task vertex degree kernel (MT-VDK) that amalgamates the learned VDK-GPs to determine power flows for unseen networks, with a significant reduction in the computational complexity and hyperparameter requirements compared to alternate approaches. Simulations on the IEEE 30-Bus network demonstrate the retention and transfer of power flow knowledge in both N-1 and N-2 contingency scenarios. The MT-VDK-GP approach achieves over 50% reduction in mean prediction error for novel N-1 contingency network configurations in low training data regimes (50-250 samples) over VDK-GP. Additionally, MT-VDK-GP outperforms a hyper-parameter based transfer learning approach in over 75% of N-2 contingency network structures, even without historical N-2 outage data. The proposed method demonstrates the ability to achieve PVEs using sixteen times fewer power flow solutions compared to Monte-Carlo sampling-based methods.