Optimal Perturbation Tolerance in VSC-Connected Hybrid Networks Using an Expert System on Chip

Abstract

A major challenge in the stable operation of hybrid power networks is that such systems operate under the influence of perturbations from source fluctuations and from dynamic storage operations. In the current practice, hybrid power networks are operated and controlled by higher-level supervisory control systems using approaches such as the droop control logic that may not make use of the accurate network models, full-state measurements, and learning mechanisms to deal with the convoluted perturbations on voltage source converters (VSCs). These perturbations could result from natural variations, parameter uncertainties, grid faults, variable loadings, controller settings, and other exogenous disturbances. So far, these perturbations have been considered as lumped terms that do not represent the correlation of perturbations across the network components. In this paper, an integrated, on-chip expert system (EXPSOC) is proposed to compute the correlation between power variables in separate modules, to perform state estimation of power and voltage variables and to improve the tolerance of perturbations in the hybrid networks. Results show the optimality of the approach in controlling dynamic power perturbations and in keeping the stability of the voltage, frequency, and power variables at the level of grid-connected VSCs.