Towards digitalized and automated substations: implementation of adaptive protection control unit and monitoring system for modern distribution networks under increased hosting capacity of distributed renewable sources.

Maximizing the hosting capacity of modern distribution networks to accommodate more distributed renewable sources is key driver to realise energy system security and Net-Zero carbon goals. Protection systems under increased share of renewable sources became more challenging with diverse topology changes originated from the addition, disconnection, or islanding of distributed generation to secure increasing energy demands. This paper aims to implement an adaptive protection control unit interlinked with an interactive monitoring system to enable the real-world application of smart adaptive protection schemes for modern distribution networks under increased hosting capacity of distributed renewable sources. An adaptive protection control kit is experimentally developed to enable the automatic adjustment of optimal relay settings in response to network topology changes arising from the integration of distributed generation. A set of relay settings are pre-optimized within a small-scale meshed network under possible network topologies and stored offline via a master microcontroller which then uses the online breaker status to identify the corresponding network topology and accordingly adjust the pre-optimized relay settings. A human machine interface is further designed and interlinked with the experimentally developed control kit via a slave microcontroller, providing real-time data of actual current measurements and waveforms together with topological changes and self-adaptation of pre-optimized relay settings. Experimental results showed successful adjustment of pre-optimized relay settings in response to topological changes while achieving coordination time intervals within acceptable limits under the tested network topologies

Optimal relay coordination of an adaptive protection scheme using modified PSO algorithm.

Recently, future smart grids are described by a dominantly fluctuating character due to the power consumption change from peak to off-peak loading conditions, the operation of micro-grids in grid-connected or islanded mode and other possible network topologies resulting in an effective change in network impedances and short circuit current level. Therefore, the situation from protection sensitivity, selectivity and speed may become more and more challenging. In this paper, Adaptive protection scheme is proposed to respond to structural variations occurred in interconnected power systems. A designed software based on Modified Particle Swarm Optimization (MPSO) algorithm is suggested to solve the relay coordination problem in modern distribution networks. In this study, the 14 IEEE bus system is tested via three power system scenarios showing the effect of adding and disconnecting of DG units and the occurrence of sudden line outages on the system. The obtained results show that the proposed algorithm has achieved optimum relay settings for each existing network topology

Developing an adaptive protection scheme towards promoting the deployment of distributed renewable sources in modern distribution networks: operational simulation phase.

The large-scale integration of renewables into the electricity grid as distributed generation sources for providing clean energy supply together with the recent introduction of the smart grid concept, have accelerated the need to modernize the existing protection schemes to accommodate the challenges originated from distributed generation. This paper presents an adaptive protection scheme that has been developed to allow automatic adjustment of optimal relay settings in response to multiple network topologies and unexpected variations arising from renewable energy systems integration towards promoting their deployment in modern distribution networks. A Simulink model is developed to simulate the operation of the adaptive protection scheme, being interlinked to a linear-programming technique to allow optimizing the relay settings in response to dynamic changes of network topology associated with the integration of distributed generation sources. The performance of the developed adaptive protection scheme in accommodating the dynamic changes of network topology has been assessed under two proposed network topologies using a small-scale network that has been built in the lab as part of experimental work for the purpose of implementing the adaptive control unit. Results have demonstrated the effectiveness of the developed approach in optimizing the relay settings in response to the subjected topology changes, achieving minimum relay trip times while ensuring a suitable relay coordination is satisfied in each of the tested network topologies

Optimal tuning of power systems stabilizers and AVR gains using particle swarm optimization. Expert Systems with Applications.

Abstract In this paper, the problem of simultaneous and coordinated tuning of stabilizers parameters and automatic voltage regulators (AVRs) gains in multi-machine power systems is considered. This problem is formulated as an optimization problem, which is solved using particle swarm optimization technique. The objective of the parameters optimization is formulated as nonlinear problem with constraints to represent the allowable region of the system parameters. The effectiveness of the proposed technique for tuning of multi-controllers in a large power system is tested by applying it to the well-known New England system.