Maddikara Jaya Bharata Reddy

Renewable Power Generation Indian Scenario: A Review

Abstract—India is faced with the major challenges of (a) providing energy access to all its citizens, (b) heavy dependence on fuel imports for energy security, and (c) complying with international protocols on climate change mitigation, although the economic and social development is the foremost priority. The increase in energy demand due to growing population and industrialization in the face of depleting fossil fuel resources has stimulated the countrys efforts in adopting power generation from renewable energy sources. Starting with 0.34 GW (2%) out of 17 GW of the countrys total installed capacity in the year 2002, the share of renewable power generation has reached 31.7 GW (12.5%) of 250 GW as of 2014. In the aspect of total installed renewable power generation, India occupies the fifth position in the world today. While the governmental policies have steadily encouraged the adoption of renewable power generation, there is need and potential for more vigorous engagement in pursuit of achieving power for all citizens along with economic development. This article presents a brief review of emergence and growth of renewable power generation in India, wind and solar sectors in particular.

Fault Detection and Localization Methodology for Self-healing in Smart Power Grids Incorporating Phasor Measurement Units

Abstract Recent developments in several fields of engineering have accelerated the evolution of smart power grids encompassing both transmission and distribution systems across the globe. Self-healing, a crucial operational function of a smart power grid, requires detection as well as localization of the transmission line faults in the power network in real time. A support vector machine based fault-localization methodology has been proposed to accurately detect and localize any type of transmission line faults for the entire smart power grid. This methodology identifies the transmission line fault in smart power grid and precisely pinpoints the bus to which the faulty branch is connected. Afterward, the faulty branch is discriminated, and the distance of fault location from the bus related to the fault is estimated. The methodology relies on frequency-domain analysis of the equivalent voltage phasor angle and equivalent current phasor angle using fast Fourier transform. The proposed methodology has been corroborated using extensive case studies conducted on 7- and 13-bus power systems. The major contribution of the proposed methodology is that it can identify and localize all types of transmission line faults using phasor measurement unit measurements. The methodology can be applied for transmission systems as well as distribution systems.

A Novel Topological Genetic Algorithm-Based Phasor Measurement Unit Placement and Scheduling Methodology for Enhanced State Estimation

Abstract Phasor measurement units are emerging as a potential tool for on-line power system state estimation. Incorporation of phasor measurement units to the existing power systems monitoring system is impeded by various physical and economic constraints. This article proposes a novel topological genetic algorithm for optimal placement of phasor measurement units along with existing conventional measurement units such that state estimation can be achieved with enhanced accuracy and immunity against power grid contingencies. The proposed algorithm optimally places phasor measurement units so that complete observability of the power system is achieved through them and enhanced redundancy in measurement can be accomplished through conventional measurement units. Since practical phasor measurement unit placements are accomplished in multiple horizons, intelligent sorting and phase optimization methodologies have been presented to attain maximum observability during phasing periods. Placement of phasor measurement units with multiple channel limits has also been studied in this article. The efficacy of the proposed topological genetic algorithm for optimizing the number of phasor measurement units and enhancing state estimation under various operating conditions has been validated through extensive simulation studies conducted in IEEE standard bus systems. Practical case studies have been performed in the western and southern region Indian power grids.

Novel multi-stage simulated annealing for optimal placement of PMUs in conjunction with conventional measurements

Power grid monitoring plays a vital role in stable and secure power transfer from generating stations to customer load points. Incorporation of synchrophasor measurement units like phasor measurement units (PMUs) can enhance the present power grid monitoring system. The high cost of PMUs summons the optimal use of these units to achieve complete observability of the power grid network. This paper presents a novel Multi-Stage Simulated Annealing algorithm for the joint placement of PMUs along with the existing conventional measurement units in the power grid network. The proposed multi-stage optimization method enables Simulated Annealing to reach the optimal point faster than conventional Simulated Annealing methods. The controlled uphill movements during various stages facilitate to obtain best possible solution.

A Dual DC Output Power Supply for a Stand-alone Photovoltaic System

Abstract This article presents a dual DC power output for easy integration of renewable energy sources and battery banks at a low-voltage DC bus. The low-voltage loads are connected to the low-voltage DC bus directly (across the battery banks), obviating an additional conversion stage. Such low-voltage loads are LED-based lighting, computers, laptop chargers, etc. The proposed system consists of a photovoltaic array, DC-DC converters, a maximum power point tracker, and a storage medium (battery) targeted for low-voltage (24 V) and high-voltage (110 V) DC loads. The maximum value of photovoltaic power is extracted using the buck DC-DC converter along with the effective incremental conductance maximum power point tracking technique to control the power transfer to the low-voltage DC grid. The DC-DC boost converter is designed to operate at a constant voltage of 110 V DC load. The proportional-integral-derivative control parameters for voltage mode closed-loop control of the boost converter are chosen by using the genetic algorithm technique. A prototype system has been built in the laboratory, and its satisfactory working has been demonstrated experimentally for the different shading and loading conditions; experimental results are provided.

A Control Strategy for Hybrid Autonomous Power System with a Battery Management Scheme

Abstract This article presents a coordinated control strategy for a hybrid autonomous power system to obtain a smooth power transfer between diesel generator and battery energy storage system under transient conditions. In addition, a battery management scheme is also developed to maintain the battery state of charge around 70 to 80% to absorb/inject power under transient conditions and maintains the diesel generator power above 40% of its nominal value. Simulation studies are carried out in MATLAB/Simulink and the performance of the controller is validated experimentally on a laboratory test setup. A TMS320LF2407A DSP controller is used to digitally implement the control strategy and the overall scheme is verified with step changes in load. Moreover, the dynamic behavior of the system is also investigated by directly connecting an induction motor.

Applications of type-2 fuzzy logic in power systems: A literature survey

In recent years the application of fuzzy systems in real world problems is increasing because of the fact that fuzzy systems can deal with linguistic data along with the numerical data. Although type-1 fuzzy system can handle the uncertainties related to imprecise data, in some cases a higher degree of precision is required. This lead to the origin of type-2 fuzzy systems. Since then the type-2 fuzzy system theory has been applied to different fields of engineering, finance and medical domains. This paper attempts to present a comprehensive set of references on applications of type-2 fuzzy systems in power system.

Synchrophasor Assisted Adaptive Relaying Methodology to Prevent Zone-3 Mal-Operation During Load Encroachment

Phasor measurement unit (PMU) has uniquely blended the contributions of modern information and communication technology in terms of time synchronization and fast data transmission to emerge as the smart sensor for advanced protection methodologies in smart power grids (SPG). The latency issue associated with the functionality of PMUs has made synchrophasors assisted protection algorithms suitable for backup protection, so as to efficiently prevent events, such as mal-operation of relays under load encroachment as well as other stressed situations. This paper proposes a novel methodology to prevent Zone-3 mal-operation of distance relays during load encroachment using the synchrophasor measurements obtained from PMUs installed in a widely-spread power system network. The proposed algorithm is to be implemented in transmission line protection center (TPC), where the synchronized three phase voltage and current phasors acquired from the PMUs are transferred to Phasor data concentrator (PDC) and are used to calculate the impedances seen by the relays in real time. A load encroachment situation and a faulty situation can be distinguished by comparing the impedances seen by primary and backup relays installed at different buses for protecting their respective transmission lines. Numerous case studies have been conducted in WSCC-9 bus system modeled in PSCAD/EMTDC environment to validate the proposed methodology.