To meet the needs of energy storage system configuration with distributed power supply and its operation in the active distribution network (ADN), establish the dynamics of the all-vanadium redox flow battery energy storage system (BESS). On this basis, an energy storage operation of ADN strategy is proposed to stabilise the power fluctuation of the system. The energy storage configuration model with optimising objectives such as the fixed cost, operating cost, direct economic benefit and environmental benefit of the BESS in the life cycle of the energy is constructed, and the energy storage installation capacity, power and installation position are used as decision variables, which are solved by the dynamic programming algorithm. On the basis of case 33 and case 69 node examples and typical daily load and distributed generations output curve, the simulation analysis is carried out to obtain the optimal configuration result. At the same time, the system tie-line power and the dynamic characteristics of the energy storage system before and after the installation of the energy storage device are obtained. The simulation results show the validity of the model.

Dynamic VAR planning for voltage stability enhancement is a challenging topic for power systems with a growing penetration level of wind power. As a critical step of VAR planning, candidate bus selection (CBS) can reduce the scale of the problem and improve the optimality of the planning decisions. This study proposes a new zoning-based CBS method towards multiple voltage resilience indices. First, a set of resilience-oriented metrics are proposed to comprehensively evaluate voltage performance in pre-contingency and post-contingency stages, considering the extent of the voltage deviation and voltage recovery time, as well as the post-contingency steady-state voltage profile. Then, a zoning-based approach is developed based on fuzzy C-means clustering and Morris screening to categorise buses into different zones with capacity sensitivity analysis. Finally, a comprehensive multi-objective CBS scheme is proposed for voltage resilience enhancement. Simulation results show that, compared with conventional approaches, the method can achieve more voltage stability improvement with the fewer or the same number of candidate buses.

Monitoring and diagnostics of metal-oxide surge arresters (MOSAs) have been a research topic for decades. During these years, many monitoring and diagnostic methods have been developed. However, only a few studies perform a comparative analysis of these methods with respect to their performance in different operating conditions. This study briefly explains the most commonly analysed MOSA monitoring techniques and performs a comparative analysis of these techniques on an experimental basis, considering different operating conditions of the arrester. The experimental setting is made to simulate different operating conditions regarding operating voltage root mean square value, voltage harmonics, and temperature conditions. The results show the reliability of MOSA indicators in the analysed conditions, suggesting which indicators and methods should be used for the purpose of MOSA diagnostics.

The deployment of renewable energy sources has been rapidly increasing due to environmental constraints but renewable electricity suppliers face an inevitable problem of uncertainty which is caused by the intermittent nature of renewable sources. In real-time operation, compromises have been made in cost and power to balance the power which reduces supplier benefits. Therefore, the functions of Weibull and Beta distribution of probability are used to handle the adverse impact of wind speed uncertainty and solar irradiation, respectively, and scenarios are reduced using the forward-reduction algorithm. Moreover, to measure the deviation of renewable power, underestimation and overestimation cost functions are utilised. This study proposes a suitable double-sided strategic bidding problem as a multi-objective optimisation problem to maximise the profits of suppliers and buyers to minimise uncertainty of rivals and renewable power. The formulated problem is solved by Technique for Order of Preference by Similarity to Ideal Solution along with Gravitational Search Algorithm, and simulation results are obtained in absence and presence of both solar and wind power on IEEE standard 30-bus and 57-bus test systems. The obtained results prove the suitability of the proposed bidding strategy in the presence of uncertainty of solar and wind power.

Detection of fault in compensated transmission lines during power swing is a complicated task. The distance relay functioning is blocked during stable power swing while it is expected to react as quickly as possible to faults. Non-linear behaviour of metal–oxide varistor and thyristor-controlled series capacitor (TCSC) make even the issue more complicated. In this study, the cumulative sum of the phase current second harmonic is proposed as a unique fault isolation feature. Various low-impedance, high-impedance, symmetric, and asymmetric types of fault signals are collected and to exhibit the algorithm robustness, several disturbance events and measurement noise are applied. The algorithm is conducted over a single machine infinite bus, and a Western System Coordinating Council 9-bus, 3-machine network with TCSC compensated lines. The results of extensive simulations indicate that the algorithm performs excellent regarding some recently developed algorithms. Accurate single, two of three faulty phases are marked despite disturbances and powerful swing. As so, a simple and effective fault detection algorithm has been introduced, which correctly resolves the challenges.