Physics Informed Reinforcement Learning for Power Grid Control using Augmented Random Search

Wide adoption of deep reinforcement learning in energy system domain needs to overcome several challenges , including scalability, learning from limited samples, and high-dimensional continuous state and action spaces. In this paper, we integrated physics-based information from the generator operation state formula, also known as Swing Equation, into the reinforcement learning agent's neural network loss function, and applied an augmented random search agent to optimize the generator control under dynamic contingency. Simulation results demonstrated the reliability performance improvements in training speed, reward convergence, and future potentials in its transferability and scalability

Intelligent Integration of Renewable Energy Resources Review : Generation and Grid Level Opportunities and Challenges

This paper reviews renewable energy integration with the electrical power grid through the use of advanced solutions at the device and system level, using smart operation with better utilisation of design margins and power flow optimisation with machine learning. This paper first highlights the significance of credible temperature measurements for devices with advanced power flow management, particularly the use of advanced fibre optic sensing technology. The potential to expand renewable energy generation capacity, particularly of existing wind farms, by exploiting thermal design margins is then explored. Dynamic and adaptive optimal power flow models are subsequently reviewed for optimisation of resource utilisation and minimisation of operational risks. This paper suggests that system-level automation of these processes could improve power capacity exploitation and network stability economically and environmentally. Further research is needed to achieve these goals

Real-Time Event-Driven Load Shedding for Power System Transient Stability Control using Deep Learning Techniques

With the increasing integration of variational renewable energy and the more active demand side responses, there are more challenges in maintaining secure and reliable power system operation due to the escalated stochasticity and variations in the system. This can be experienced from recent rolling blackouts over the world. Event-driven load shedding (ELS) serves as a fast and effective stability control scheme for power system after a risky disturbance occurs, which can suppress grid oscillation, recover system stability, and prevent cascading failure. Unlike the response-driven control schemes, ELS executes the load shedding action immediately following the disturbance, which aims to control power system stability at an earlier stage with the minimum amount of control cost. The digitalized power systems deploy advanced measurement devices such as phasor measurement units and smart meters, which provides the adequate sensing infrastructure to implement real-time stability assessment and control. However, the conventional approaches for ELS rely on numerical simulations and iterative optimizations which are computationally burdensome and thus slow reactive to the real-time system variations. More recently, artificial intelligence (AI) techniques provide a new way to realize real-time ELS owing to their fast decision making capability. This research identifies the key issues in existing AI based ELS approaches and proposes a series of novel methodologies based on deep learning techniques to enhance overall ELS performance in practical situations. A deep neural network (DNN) model is first presented to improve the decision-making accuracy on ELS strategy. Moreover, considering the unbalanced control cost induced by an over- and under-estimated ELS amount, a risk-averse learning method for DNN is proposed to increase the likelihood of control success with negligible impairment on control cost. On top of those, a GraphSAGE-based ELS model is proposed to capture and embed the topological structure of power system into deep learning, which further improves the overall control performance of ELS. The proposed methodologies have been tested on New England 39 bus system and Nordic power system. The proposed deep learning methods have shown more exceptional control performance of ELS as compared to the existing methods

Data-Driven Power System Stability Analysis and Control

In recent years, with the expansion of power system size, the increase of interconnection and the use of large-scale renewable energy, power system stability and safe operations have become more prominent, causing challenges to the normal operation of power grid. Traditional analysis rely on detailed models of the system. But for real power systems, the operating state of the system is variable, and the model-based analysis methods may not accurately reflect the real operating state of the system. Therefore, this dissertation is focused on data-driven stability analysis and control. First, a method for locating the oscillation source of multi-machine systems is proposed. The electromagnetic torque expressions of various generators in a multi-machine system are deduced, and it is found that in each oscillation mode, the electromagnetic torque can be decomposed into a damping torque and a synchronous torque. Based on this development, an oscillation source positioning scheme based on decoupling mode is proposed. Then, a transfer and CNN-LSTM-based method is developed to accelerate and improve the accuracy of the dynamic frequency prediction process. The proposed method exploits system spatial-temporal information and mines the local features of inputs, which highly improves the performance compared with other machine learning methods. Next, a Distributional Soft Actor-Critic (DSAC) method is developed to solve the emergency frequency control problem. The frequency control is formulated as a MDP problem and solved through a novel distributional deep reinforcement learning method. Further, high penetration renewable energy source increase the system uncertainties and impact the cyber security. We propose a detection method based on Bayesian GAN. It can successfully distinguish between securely operating measurements and those that have been attacked with imbalanced training data. Simulation results of this dissertation show the effectiveness of the proposed methods

A Parallel Fast-Track Service Restoration Strategy Relying on Sectionalized Interdependent Power-Gas Distribution Systems

In the distribution networks, catastrophic events especially those caused by natural disasters can result in extensive damage that ordinarily needs a wide range of components to be repaired for keeping the lights on. Since the recovery of system is not technically feasible before making compulsory repairs, the predictive scheduling of available repair crews and black start resources not only minimizes the customer downtime but also speeds up the restoration process. To do so, this paper proposes a novel three-stage buildup restoration planning strategy to combine and coordinate repair crew dispatch problem for the interdependent power and natural gas systems with the primary objective of resiliency enhancement. In the proposed model, the system is sectionalized into autonomous subsystems (i.e., microgrid) with multiple energy resources, and then concurrently restored in parallel considering cold load pick-up conditions. Besides, topology refurbishment and intentional microgrid islanding along with energy storages are applied as remedial actions to further improve the resilience of interdependent systems while unpredicted uncertainties are addressed through stochastic/IGDT method. The theoretical and practical implications of the proposed framework push the research frontier of distribution restoration schemes, while its flexibility and generality support application to various extreme weather incidents.©2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Solution of the emergency control of synchronous generator modes based on the local measurements to ensure the dynamic stability

Stochastic renewable sources of energy have been causing changes in the structure and operation of power systems. High penetration of this type of generation results in decreased inertia of a power system, increased active power fluctuations, and a higher probability of false tripping of emergency control devices. Traditional algorithms of emergency control are not adaptable and flexible enough for systems with high penetration of renewables and flexible alternating current transmission systems. Integration and development of phasor measurement units make it possible to create adaptable emergency control systems, which would require minimal pre-defined data. The purpose of this study is to develop an adaptable algorithm for turbine fast valving control synthesis and transient stability estimation for a generator. The suggested algorithm is based on the equal area criterion in the domain synchronous generator “torque–load angle”. The measurements of the generator operation under consideration are used as the input data for the steam turbine fast valving control synthesis. Thus, the algorithm becomes adaptable because no pre-defined parameters of a power system model are required. The suggested algorithm was tested on the power system model NE39bus using Matlab/Simulink. The efficiency of the suggested algorithm is verified and demonstrated. © 2022 The Authors. IET Generation, Transmission & Distribution published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology