S. P. Chowdhury

Impact of Strategic Deployment of CHP-Based DERs on Microgrid Reliability

Optimal deployment, with respect to locations, capacity sizes, and types of distributed energy resources (DERs), which are the main components in a microgrid system, are chosen for study in this paper. For the selection of optimal locations of DERs, the loss sensitivity index of each bus is taken into account. Whereas optimal size and its separation among microturbines, diesel generators and combustion turbines at each bus location are performed on the basis of the maximum benefit-to-cost ratio of the microgrid owner, obtained by using the particle swarm optimization technique and with respect to their reliable catering and quality of power as well as heat (i.e., combined-heat-and-power (CHP) operation) for customers. This paper conducts four separate case studies-two on 6-bus systems (radial and meshed) and resting on 14-bus systems (the IEEE system and radial system)-to show how much these systems are economically feasible for investment planning when cost and CHP benefits of various types of DERs are taken into account. Load profiles, tariffs, as well as the constructional cost of the microgrid itself are addressed in the six-bus meshed network and its central DER location in a district-heating paradigm is also done separately.

Smart grid initiative for power distribution utility in India

After enactment of Electricity Act 2003 in India, a comprehensive change is happening in Indian power sector, and power distribution utilities are going through a reformation process to cope up with the regulatory change for reduction in Aggregated Technical and Commercial Loss, improvement in Power Quality, Reliability of Power Supply, Improvement in Customer Satisfaction and rationalization of electricity tariff. Apart from restructuring and unbundling of the power sector there is a need for introduction of ‘smart grid’ technology to increase the operational as well technological efficiency of the power distribution network to meet the growing energy demand of India in line with the GDP growth of the country. Smart Grid is sophisticated, digitally enhanced power systems where the use of modern communications and control technologies allows much greater robustness, efficiency and flexibility than todays power systems. A smart grid impacts all the components of a power system especially the distribution level. One subset of smart grids is smart metering / advanced metering infrastructure (AMI) etc. In a smart grid, all the various nodes need to interconnect to share data as and where needed. Smart Grid envisages providing choices to each and every customer for deciding the timing and amount of power consumption based upon the price of the power at a particular moment of time, apart from providing choices to the consumer and motivating them to participate in the operations of the grid, causing energy efficiency and accommodating all generation and storage options, Smart Grid also envisages various properties for the Grid like self-healing and adaptive The suite of Smart Grid products and technologies help maximizing system uptime, while also helping the utility more quickly to restore power to homes and businesses in the event of an outage. Government of India has recently formed “Smart Grid Forum” and “Smart Grid Task Force” for enablement of smart grid technology into Indian Power Distribution Utilities as a part of their Smart Grid initiative to meet their growing energy demand in similar with the developed country like USA, Europe etc.

Optimal PMU placement: A comprehensive literature review

This review outlines the benefits that Phasor Measurement Unit (PMU) integration has on the power network. It reviews past optimal placement techniques covering meta-heuristic and deterministic algorithms. Three best performing algorithms are chosen in terms of minimum required number of PMUs for full system observability. It concludes that Integer Linear Programming (ILP) is the most adaptable mathematical form to model a network. ILP shows the most adaptability in terms of modeling network contingencies and phased installation of PMUs. Further work will focus on developing a hybrid state estimation algorithm for improving state estimation on a medium term basis of 3–5 years.

Strategic deployment of CHP-based distributed energy resources in microgrids

Distributed Energy Resource (DER) technology (e.g. microturbine, fuel cell) has greatly been advanced in recent years. These DERs are often used as the main components of a CHP-microgrid system and may be called as CHP-based DER. CHP-based DERs can provide power and heat with reliability and quality tailored to the requirements of end-users. As deregulation regime is penetrating more and more into the electricity market, competition among the IPPs is becoming acute. To sustain in this market, cost of electricity generation is to be reduced, not only using modern CHP-based DER technology but also, at the same time, deploying them in the microgrid system as per their type, capacity-size and bus-location. A cost-benefit analysis based method is proposed, in this paper, to enhance the reliability of both 6- and 14-bus meshed as well as radial microgrid networks. In this regard, various costs and benefits relating to CHP-based DER deployment have been taken into account for economic feasibility study. Higher the value of benefit to cost ratio (BCR), than one, better will be the selection of type, capacity-size, and bus-location of CHP-based DERs in respect of utilitys benefit. More the Utilitys benefit, lesser will be the price of electricity and ultimately, gainer will be the consumers. In this paper, bus-locations have been selected by loss sensitivity analysis and Particle swarm optimization (PSO) technique has been used to maximize BCR.

Modelling and simulation of microturbine in islanded and grid-connected mode as distributed energy resource

This paper presents modeling and simulation of microturbine (MT) to analyze its load following performance as distributed energy resource (DER) with general as well as critical priority loads. The system comprises of a synchronous generator and a MT coupled to it. Simulations are carried out in islanded and grid-connected mode of the system to observe its behavior when supplying customerpsilas variable loads. It also incorporates modeling and simulation of microturbine with a speed control system of the MT-synchronous generator to keep the speed constant with load variation. The load following characteristics is observed and validated for this MT-synchronous generator model in Matlab-Simulink environment with power system block sets. This is applicable with combined heat power (CHP) generators both with general fuel as well as bio-fuels. The use of bio-fuels is very much promising for generating green power preventing green house gas emissions for fighting against global warming. But it may take some time to be in the market place for its commercial use.

Operational management of CHP-based microgrid

Energy management of CHP-based microgrid is largely dependent on optimal deployment of distributed energy resources (DERs), where optimal bus-locations, capacity-sizes, and types are three major points to be considered in a microgrid planning. Investment and O&M cost, including fuel cost, are solely dependent on types of DERs. Present paper searches a way-out of how a electrical tracking demand is economically shared between micro-turbines and diesel generators on the basis of multi-objective optimization of fuel cost as well as emission in 4-DER 14-bus radial microgrids. Optimization is done using PSO technique under real power demand equality constraint and DERs capacity limits constraint.

Review of battery storage optimisation in Distributed Generation

Distributed Generation (DG) in the form of Renewable Power Generation systems is currently preferred for clean power generation. However due to their intermittent and unpredictable nature, energy storage must be used to ensure that the load is met at all times. There are many possible options for energy storage and the most popular and technologically matured option, batteries, is the subject of this paper. This paper explores the importance and necessity of batteries within DG systems, especially with renewable power generation systems. The paper looks at different varieties of batteries with a specific emphasis on lead-acid batteries. To integrate batteries into renewable energy systems in an economical manner, the system and the energy storage must be optimised to ensure the most effective sizing of each of the system components to ensure the reliability of the system whilst minimising the cost. There are currently many methods of optimising systems with these criteria. These methods optimisation of storage and battery components are discussed in this paper.

Impacts of energy storage in distributed Power Generation: A review

Distributed Generation (DG) in the form of Renewable Power Generation systems are currently preferred for clean power generation. However due to their intermittent and unpredictable nature, energy storage needs to be used to ensure that the load is met at all times. There are many possible options for energy storage and the most popular and technologically matured option, batteries, is the subject of this paper. This paper explores the importance and necessity of batteries within DG systems, especially with renewable power generation systems. The paper looks at different varieties of batteries with a specific emphasis on lead-acid batteries. To integrate batteries into renewable energy system models, the system and the energy storage, must be simulated to test the impact on as well as optimise the sizing of the system in terms of cost and efficiency. As batteries are a fairly large capital investment in the system, it is crucial to ensure maximum life span. This is done by using a controller to control the charging and discharging cycles of the battery. There are currently many methods of modelling batteries as well as techniques for controlling the battery within the system. Some of these are discussed in this paper.

Simulation and modelling of PV-wind-battery hybrid power system

As oil and coal reserves are being depleted whilst at the same time the energy demand is growing, it is important to consider alternative energy generating techniques. Similarly there is a move from centralized power generation to decentralized power generation. Specifically within rural communities where there is limited access to electricity, it is possible for decentralized renewable energy systems to make a large impact. This paper outlines the design of a hybrid power system consisting of solar photovoltaics (PV) power system, wind power system and battery storage. This system is designed for stand-alone operation. A novel controller links each of these components to ensure that one system is supplying the load dependant on the weather conditions. This system is modeled in Matlab Simulink and tested for various weather conditions and temperatures. The model and results are detailed in this paper.

Performance of A Fuzzy Power System Stabilizer With Tie Line Active Power Deviation Feedback

This paper reports the application of a new input signal based fuzzy power system stabilizer in multi-machine environment. Instead of conventional input pairs like speed deviation (Deltaomega) and acceleration (Deltaomegadot) or speed deviation and accelerating power deviation of each machine, in this paper, deviation of active power through the tie line connecting two areas is used as one of the inputs to the fuzzy PSS in conjunction with the speed deviation. The advantage of this input is that, the same signal can be fed to each of the fuzzy logic PSS attached with each machine, which reduces cost, scanning time and thus simplifies the structure. The first simulated system here consists of two fully symmetrical areas linked together by two 230 kV lines. Each area is equipped with two identical generators rated 20 kV/900 MVA and area-1 is exporting 413 MW to area-2. The second one is the standard IEEE 14-bus system. Simulations including a number of small and large signal disturbances are carried out with these systems. For each disturbance, the performances of conventional speed-input PSS, typical speed deviation (Deltaomega) and acceleration input based fuzzy PSS and the proposed tie line active power deviation based fuzzy PSS in damping both local and inter-area mode of oscillation are observed. Apart from the simplicity and cost effectiveness, it is found that the proposed PSS is performing satisfactorily within the whole range of disturbances. This comparative study is demonstrated through digital simulation