Volume 23, Issue 3

In this paper Power factor correction coefficient based transmission pricing is proposed to analyze an individual customer’s effect due to green energy transactions in existing power system. In this novel approach power factor correction coefficient is calculated for each customer under every transaction. This power factor correction coefficient is then added in conventional embedded cost distance based MW-mile and MVA-mile method for transmission pricing calculation for both active and reactive power flow through transmission line. This new proposed transmission pricing method calculate transmission charges for each customer and also help an ISO (independent system operator) to decide whether transaction increases or decreases the transmission cost. On the basis of performance of transaction an ISO can penalize or reward them. Proposed analysis is implemented on a 3-area IEEE-30 bus system with seven tie-lines in MATLAB environment. To show the effectiveness of the proposed method the results are compared with and without power factor correction based transmission pricing for each customer.

This paper presents a new fault classification technique for Thyristor-Controlled Series-Compensated (TCSC) transmission lines using Support Vector Machine (SVM). The proposed technique is based on the utilization of post-fault magnitude of Rate-of-Change-of-Current (ROCC). Fault classification has been carried out by giving ROCC of three-phases and zero sequence current as inputs to SVM classifier. The performance of SVM as a binary-class, and multi-class classifier has been evaluated for the proposed feature. The validity of the suggested technique has been tested by modeling a TCSC based 400 kV, 300 km long transmission line using PSCAD/EMTDC software package. Based on the above model, a large number of diversified fault cases (41,220 cases) have been generated by varying fault and system parameters. The effect of window length, current transformer (CT) saturation, noise-signal, and sampling frequency have also been studied. It has been found that the proposed technique provides an accuracy of 99.98% for 37,620 test cases. Moreover, the performance of the suggested technique has also been found to be consistent upon evaluating in a 12-bus power system model consisting of a 365 kV, 60 Hz, 300 km long TCSC line. Comparative evaluation of the proposed SVM based technique with other recent techniques clearly indicates its superiority in terms of fault classification accuracy.

In this paper, the performance and reliability of the hybrid microgrid system is analyzed with the two different configurations where multiple distributed energy sources supplied the power to the loads through centralized inverter and parallel inverter. The power quality, power sharing, power exchange and voltage and frequency drop parameters are evaluated by applying 1.1 kVA load on the centralized and parallel inverter hybrid systems with LL and LLG faults. The hysteresis current controller in the centralized inverter hybrid system is assuring the accurate power exchange between the grid and hybrid system during abnormal conditions. The droop controller in parallel inverter hybrid system is effectively sharing the load among the inverters during normal and abnormal conditions. The comparative analysis of these energy systems is made based on control aspects, power quality, reliability and economics.

With increasing demand in energy, efficiency, reliability, and resiliency in the power systems, integration of distributed generation (DG) or renewable energy sources in the local distribution system is trending nowadays. The power system optimization in distribution networks plays a prominent role in planning reliable supply to the users. This paper presents a meta-heuristic approach to improve the system performance by considering: a) voltage profile improvement, b) minimize the active power loss, and c) overall operation cost as the objective functions of the distribution system reconfiguration (DSR). Modified Newton Raphson (MNR) is used for a load flow analysis of the 33 bus balanced test system and 25 bus unbalanced distribution system. To study the performance of the system objective functions, three different scenarios are considered: i) with DG integrated, ii) with DSR performed, and iii) DG placed along with DSR. These scenarios are compared with the base system configuration parameters along with convergence comparison of harmony search algorithm (HAS) and particle swarm optimization (PSO) with firefly algorithm (FFA) of the distribution systems.

Research on Self –excited induction generator (SEIG) brings a lot of attentions in the last three decades as a promising solution in distributed generation systems with low cost investment. There are two important fixations to attend in the operation of SEIG based systems, a) excitation and b) voltage regulation. Many procedures are reported regarding selection of excitation capacitance in the literature, based on state-state analysis, dynamic modeling, empirical formulas and machine parameters which involve various levels of complexity in findings. Moreover, the voltage regulation is the main challenge in implementation of SEIG based isolated systems. To address this problem, many power electronic-based schemes are proposed in the literature and but these solutions have few demerits importantly that additional cost of equipment and troubles due to failure of protection schemes. In particular, the installation of SEIG takes place at small scale in kW range in remote/rural communities which should not face such shortcomings. Further in case of off-grid systems, the maximum loading is fixed based on connected rating of the generator. This paper presents the various methods to find excitation capacitance and illustrates an experimental investigation on different possible reactive power compensation methods of delta connected SEIG and aimed to identify a simple method for terminal voltage control without power electronics. In this experimental work, the prime-mover of the generator is a constant speed turbine, which is the emulation of a micro/pico hydro turbine. From the results, it is found that a simple delta connected excitation and delta configured reactive power compensation limits voltage regulation within ±6% while maintaining the frequency of ±1%, which make feasible of the operation successfully in remote electrification systems.

Distance relay are designed with swing blocking/tripping logic to maintain reliable and secure operation of power system. To prevent this from happening, the relay is functioned with a power swing blocking (PSB) logic. However, ensuring proper detection to swing event requires to overcome from the dependable situation such as three-phase fault. The relay refuses to behave normally if both swing and three-phase fault occur simultaneously. Reliable setting is essential to generate trip/block command. Unsymmetrical faults are easily detected during the swing condition due to the presence of negative and zero sequence components, but such components are absent in the case of symmetrical/three-phase fault. As a result, symmetrical fault under blocking condition is unidentified many a times by the distance relay, arising security issues. To improve the relay operation during swing and symmetrical fault conditions, a MOPSVC (multiplication of positive sequence voltage and current) based index is developed in this work. The MOPSVC index helps to discern power swing from three-phase fault. To test the efficacy of the method, a 230 kV, 50 Hz two-area four machine system, and Indian Eastern Regional Grid (IERG) network are considered. Simulation task is conducted using EMTDC/PSCAD software. To investigate the performance of the proposed method, various swing phenomena, faults, CT saturation, switching transients, and the presence of noise cases are considered, and the results demonstrate the robustness of the proposed algorithm. Responses under stressed power system conditions are also investigated, and a report on comparisons with existing methods is provided. Simulated results confirm that the proposed algorithm can balance the dependability and security aspects of the protection logic.

This paper presents stability enhancement of a test system that is connected with a Wind Farm (WF) by using Power System Stabilizer (PSS) for Synchronous Generator (SG) and Power Oscillation Damper (POD) for Static Var Compensator (SVC). This paper also proposes a coordination mechanism for the controller to effectively damp out the oscillations and make the power system more stable by considering the uncertainties. The uncertainty is considered as wind speed variation and wind power penetration and different locations. The Particle Swarm Optimization (PSO) is used to overcome the controller parameter tuning drawbacks and controller coordination. The SG rotor speed deviation is selected as an objective function with various constraints for PSO. The transient stability analysis is carried out by considering large disturbance that is a three-phase fault. The nonlinear dynamic simulation results are obtained by integrating WF and SG replacement with the same rating WF. Evaluation and analysis are performed for various cases and different combination of without and with controllers. From the simulation results, it is noticed that oscillations in the system are minimized, and stability is enhanced at the maximum level. It also observed that the capability of SG and DFIG under three-phase fault is intensified by using PSO for optimized coordinated controller parameters. The robustness and effectiveness of the proposed approaches are evaluated on the IEEE-11 bus test system.

The sustainable development of the country is dependent on the utilization of power production from renewable energy sources like solar, wind, hydro, etc. Due to availability of solar energy in most of the places, the focus of using solar energy by implementation of solar PV cells, arrays, panels are the primary strategy. Thus, the designing of solar PV cell is necessary. There are certain topologies i.e. single diode and double diode representation for solar PV cell. But designing these models individually takes utilization of time and resources when implemented in real life scenario. When coming to the performance analysis of these models individually, it is observed that the power production is not in the maximum capability throughout the year. The performance in some months is good for single diode topology whereas in other months double diode topology shows good result. So, a new model is proposed with better performance, combining these two models that will solve the above disadvantages. Further, both the time and price of production goes down as we don’t have to create both the models separately. The entire analysis is studied for an entire year for the place of New Delhi. The comparison is also done taking into consideration of two practically existing solar cells: JAP6-72- 320/4BB and Solarex: MSX60 allowing each model to work as single and double diode representation. As the production capacity of these design is not to its highest extent so, more number of cells are attached in series or parallel fashion to meet the load demand. The proposed design solves this problem and having an error within the limit of 0.31–0.41%. The mathematical modelling is shown followed by designing the model in Simulink and thereafter comparative analysis stating all the disadvantages is analyzed, followed by the solution with the best topology for power production from solar cell. This sequential designing will give clear understanding of the proposed technology.

This paper presents implementation of control method for dual control of Voltage and Current control and Power sharing coupled with Demand Response for the islanded microgrid. These three controller viz Voltage and current controller, Power sharing controller and smart load controller while acting in unison can able to maintain long layoff from the connection requirement of the main grid. The paper uses state space inverter based generator model with close loop Voltage and Current control and Power sharing controller will enhance microgrid stability and transient response where smart load controller which uses state space model for voltage,current and Phase Locked Loop units to estimate reserve power available from smart load for better voltage and frequency regulation. Voltage current Controller and Power Sharing Controller will also assist the microgrid for smooth disconnection of microgrid from main grid while smart load controller will use its point of load voltage control for smooth islanding of microgrid. This control technique henceforth called tripartite control technique, compared with classical controller connected to microgrid in maintaining frequency, voltage with power sharing of the inverter driven by renewable generator. This paper investigate the operation performance issues of test Microgrid using Tripartite Control Technique. Simulation results indicate close approximation with experimental results

The solution of the adjusted power flow problem involves handling power system components whose control characteristics possess operational limits. Examples include generator reactive power limits, tap-changing and phase-shifting transformers, and FACTS devices. While the conventional method involves checking for limit violations in an outer loop drawn around the unadjusted power flow problem being solved by the Newton-Raphson (NR) method, for iterative processes, it is desirable to have smooth, continuously differentiable models implicitly handled within a single loop. A novel formulation for a subset of devices is presented for implicit handling within power flow. The steady state characteristics of tap-changing and phase-shifting transformers, and FACTS devices SVC and STATCOM, can be described using the “cut function”, a piecewise linear function traditionally employed in neural networks. A new approximation of the cut function is used for formulating novel equations describing the steady state characteristics. An augmented set of equations is formed and solved by the NR method, eliminating the need of an outer loop. The efficacy of the proposed method is demonstrated by employing it for plotting bus voltage profiles and determining maximum loadability of test systems. Comparisons with the conventional method show that significant savings in computation can be achieved.

To participate in the global fight against climate change, India has set an aggressive target of installing 100 GW of photovoltaic (PV) energy resources by 2022. However, only about 37% of this target is achieved till date, and, presently, the set target appears to be elusive. Hence it is crucial and the need of the hour to analyze the performance of different utilities to identify the regions that need a course correction. In the present work, the relative performance of the Indian states in realizing the national target of PV installed capacity is analyzed through the Data Envelopment Analysis (DEA) model. Time series analysis of the PV sector’s growth in different Indian states over the period 2017–2021 is quantified through the Malmquist productivity index (MPI). The applied methodology revealed that Rajasthan, which has the highest PV potential and second-highest PV installed capacity, is less productive than the small hilly states and union territories, which have meager PV potential. The result provides insight into the factors contributing to the inefficiencies in the development of the PV energy sector, which will help the policymakers take necessary corrective actions to improve the states’ productivity and thereby contribute more effectively to the national goal. The work may be extended to other regions of the world to strengthen the global effort to fight climate change.

The purpose of this article is to examine the correlations between greenhouse gas (GHG) by CO 2 eq emissions and the use of electricity on the Praia Vermelha campus of the Universidade Federal Fluminense (UFF) located in Brazil. The study favors understanding and management for the sustainability of the campus operations. The research used electricity consumption data from 2017 to 2019 and quantitative and qualitative data collected in 2020, through online research applied at Praia Vermelha campus. An exploratory and descriptive study, providing familiarity with the problem and deepening knowledge about the phenomenon, seeking a correlation between variables and proposing reflections. We observed a reduction in electricity consumption on the campus in the period surveyed from 2017 to 2019, however, there wasn’t proportional and significant reduction CO 2 eq emissions in the period between 2018 until 2019. During this period occurred fluctuations in the dispatches of the different power generating plants, considering renewables and fossils sources. We also found that most of survey respondents agree with to implementation of incentive programs and the dissemination of information about GHG emissions on campus to promote the engagement of the academic environment in the efficient use of electricity. We found few peer-reviewed studies dealing with GHG emissions generated in South American universities. Through a bibliographic review, we investigated the commitment of the universities to sustainability and the management of efficient use of electric energy, as well as the methodology for calculating indirect GHG emissions, in CO 2 eq, related to purchase energy from the System National Interconnected System (SIN) of Brazil.