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Summary: Conventionally, voltage profile are regulated by controllers that are not operational flexible to the system dynamism and challenges offered by the integration of renewable energy sources. Consequently, there is a need for the adaptive coordinating mechanism as an interface between the passive network and the new active network. This will provide a platform for the smooth integration of distributed energy resources in most developing countries where traditional network is still operational. This paper proposes an algorithm for real‐time multiperiod adaptive compensation of network reactive power support based on hierarchical structure and decentralized layered multiagent system voltage coordinating scheme. A multiperiod voltage control algorithm replicates the daily load flow evaluation aiming at ameliorating voltage fluctuation over a 24‐hour simulation period. The algorithm applies the decentralized voltage control mechanism to monitor the network parameters and dynamically evaluate the capacity of the capacitor banks (CBs) to be injected for voltage compensation. This mitigates the challenges associated with under and over reactive power compensation experienced in the day‐ahead programming and manual switching operation. The algorithm works in conjunction with an on‐load tap changing transformer (OLTC) and energy storage system (ESS). The ESS complements the OLTC during switching delay, dip in its output root mean square and voltage fluctuation as network loading condition varies. The effectiveness of the proposed method is verified on standard IEEE 33 and 118‐bus distribution systems. The results show an improved voltage performance and reduction in stress/complexity associated with load and renewable generation forecast in manual switching operations. [ABSTRACT FROM AUTHOR]

Microgrid (MG) operation is one of the operational requirements of modern utilities for not only maintaining reliable and uninterrupted supply under faulty conditions but also for achieving desired economic goals in the competitive electricity market environment. Under faulty conditions, the electrical distribution system (EDS) becomes islanded microgrid (IMG) with either micro turbine (MT) or renewable energy (RE) based distribution generation (DG) units. However, the power generation from RE based DGs is stochastic nature and it may become either surplus or deficit to the network connected load. Also, the reactive power (VAr) support from DGs is limited. Under this scenario, there is a need for the integration of energy storage systems (ESSs) and reactive power compensators like switched/ fixed capacitor banks (CBs). In this paper, a novel optimization approach for determining the locations and capacities of ESSs combined with CBs along with DGs is proposed based on improved variant of dragonfly algorithm (DFA). Different performance variables of basic DFA are tuned by a self-adaptive mechanism in SADFA for attaining the global solution with least computational efforts. Simulation results on IEEE 33-bus are compared with literature works and also other algorithms namely basic DFA, PSO, BOA, and FSA. The islanded network is suffered with a loss of 97.1229 kW, whereas, it is reduced to 74.2305 kW, 47.3380 kW and 37.6792 kW, by integrating CBs, DGs and simultaneous CBs and DGs, respectively. Based on the comparative analysis, SAFDA is dominated literature works and all other simulated algorithms. Also, the proposed method for ESSs, CBs and DGs integration is shown its effectiveness for serving the IMG energy requirements with reduced losses and increased economic benefits and its suitability for practical applications. [ABSTRACT FROM AUTHOR]

This paper presents a system for compensating DC link current pulsation in four-wire inverters with energy storage operating under unbalanced load conditions. This phenomenon occurs when an inverter with an independent power control in each of the phases attempts to locally balance the voltage imbalance in the grid. Such a condition creates a DC link current pulsation, which is destructive for energy storage connected to the DC link. The conditions when this situation appears are presented in detail in the paper. A solution to this problem is proposed in the form of a dual active bridge converter and a capacitor bank to actively compensate this pulsation. The control algorithm is proposed based on a proportional-resonant controller. This paper presents the technical background and method by which the controller parameters were calculated, implemented and tested in a real-time system. The test results are presented and discussed, concluding that the proposed solution is an attractive option for protecting the energy storage from DC link current pulsation. The dual active bridge converter combined with resonant controller can compensate the DC link current pulsation almost entirely. [ABSTRACT FROM AUTHOR]