This page is part of a course at Michigan Tech under Dr. Pearce.
Literature[edit | edit source]
Energy Consumption in Access Networks[edit | edit source]
J. Baliga, R. Ayre, W. V. Sorin, K. Hinton, and R. S. Tucker, "Energy Consumption in Access Networks," Meetings
This paper presents a comparison of energy consumption of access networks. It considers passive optical networks, fiber to the node, point-to-point optical systems and WiMAX. Optical access technologies provide the most energy-efficient solutions.
Notes
- Comparison of WiMAX with other Access Networks
- Relatively WiMAX consumes high power
- WiMAX has high range
Power consumption and energy efficiency in the internet[edit | edit source]
Hinton, K.; Baliga, J.; Feng, M.Z.; Ayre, R.W.A.; Tucker, RodneyS., "Power consumption and energy efficiency in the internet," Network, IEEE , vol.25, no.2, pp.6,12, March-April 2011 doi: 10.1109/MNET.2011.5730522
This article provides an overview of a network-based model of power consumption in Internet infrastructure. This model provides insight into how different parts of the Internet will contribute to network power as Internet access increase over time. The model shows that today the access network dominates the Internet's power consumption and, as access speeds grow, the core network routers will dominate power consumption. The power consumption of data centers and content distribution networks is dominated by the power consumption of data storage for material that is infrequently downloaded and by the transport of the data for material that is frequently downloaded. Based on the model several strategies to improve the energy efficiency of the Internet are presented.
Notes
- Comparison of efficiency and Power of access networks.
- WiMAX vs HSPA (High Speed Packet Access)
- WiMAX vs UMTS (Universal Mobile Telecommunications System)
Energy Consumption in Optical IP Networks[edit | edit source]
Baliga, J.; Ayre, R.W.A.; Hinton, K.; Sorin, W.V.; Tucker, RodneyS., "Energy Consumption in Optical IP Networks," Lightwave Technology, Journal of , vol.27, no.13, pp.2391,2403, July1, 2009 doi: 10.1109/JLT.2008.2010142
As community concerns about global energy consumption grow, the power consumption of the Internet is becoming an issue of increasing importance. In this paper, we present a network-based model of power consumption in optical IP networks and use this model to estimate the energy consumption of the Internet. The model includes the core, metro and edge, access and video distribution networks, and takes into account energy consumption in switching and transmission equipment. We include a number of access technologies, including digital subscriber line with ADSL2+, fiber to the home using passive optical networks, fiber to the node combined with very high-speed digital subscriber line and point-to-point optical systems. In addition to estimating the power consumption of today's Internet, we make predictions of power consumption in a future higher capacity Internet using estimates of improvements in efficiency in coming generations of network equipment. We estimate that the Internet currently consumes about 0.4% of electricity consumption in broadband-enabled countries. While the energy efficiency of network equipment will improve, and savings can be made by employing optical bypass and multicast, the power consumption of the Internet could approach 1% of electricity consumption as access rates increase. The energy consumption per bit of data on the Internet is around 75bm muJ at low access rates and decreases to around 2-4 bm muJ at an access rate of 100 Mb/s.
Notes
- Network based Model of power and energy consumption of ADSL, PON, FTTN, PtP
- The energy consumption per bit data is estimated.
Combined low-cost, high-efficient inverter, peak power tracker and regulator for PV applications[edit | edit source]
Enslin, J.H.R.; Snyman, D.B., "Combined low-cost, high-efficient inverter, peak power tracker and regulator for PV applications," Power Electronics, IEEE Transactions on , vol.6, no.1, pp.73,82, Jan 1991 doi: 10.1109/63.65005
A novel compound power converter that serves as a DC-to-AC inverter, maximum power point tracker (MPPT), and battery charger for stand-alone photovoltaic (PV) power systems is introduced. A theoretical analysis of the proposed converter is performed, and the results are compared with experimental results obtained from a 1.5 kW prototype. The overall cost of PV systems can thus be reduced by using load management control and efficiency-optimization techniques. Power flow through the converter is controlled by means of a combination of duty cycle and output frequency control. With load management, large domestic loads, such as single phase induction motors for water pumping, hold-over refrigerators, and freezers, can be driven by day at a much higher energy efficiency. This is due to the high efficiency of the inverter with high insolation, and because the inverter uses the energy directly from the solar array. The battery loss component is thus reduced
Notes
- Use of MPPT controller
- Efficiency analysis of the module with and without MPPT controller
- MPPT allows us approximately 30% more efficiency
- PV connected to Load, Battery, Load and Battery
- Lead-Acid Battery is used
Optimum sizing of photovoltaic-energy storage systems for autonomous small islands[edit | edit source]
J. K. Kaldellis, D. Zafirakis, and E. Kondili, "Optimum sizing of photovoltaic-energy storage systems for autonomous small islands", International Journal of Electrical Power & Energy Systems, vol. 32, no. 1, pp. 24–36, Jan. 2010.
The electrification of autonomous electrical networks is in most cases described by low quality of electricity available at very high production cost. Furthermore, autonomous electrical networks are subject to strict constraints posing serious limitations on the absorption of RES-based electricity generation. To by-pass these constraints and also secure a more sustainable electricity supply status, the concept of combining photovoltaic power stations and energy storage systems comprises a promising solution for small scaled autonomous electrical networks, increasing the reliability of the local network as well. In this context, the present study is devoted to develop a complete methodology, able to define the dimensions of an autonomous electricity generation system based on the maximum available solar potential exploitation at minimum electricity generation cost. In addition special emphasis is given in order to select the most cost-efficient energy storage configuration available. According to the calculation results obtained, one may clearly state that an optimum sizing combination of a PV generator along with an appropriate energy storage system may significantly contribute on reducing the electricity generation cost in several island electrical systems, providing also abundant and high quality electricity without the environmental and macroeconomic impacts of the oil-based thermal power stations.
Notes
- PV Energy Storage System sizing
- ESS for stationary and portable objects
- Solar potential of the area is also a main factor.
Improved Energy Capture in Series String Photovoltaics via Smart Distributed Power Electronics[edit | edit source]
L. Linares, R. W. Erickson, S. MacAlpine, and M. Brandemuehl, "Improved Energy Capture in Series String Photovoltaics via Smart Distributed Power Electronics", in Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition, 2009. APEC 2009, 2009, pp. 904–910.
This paper proposes an improved module integrated converter to increase energy capture in the photovoltaic (PV) series string. Prototypes for self-powered, high efficiency dc-dc converters that operate with autonomous control for tracking the maximum power of solar panels locally and on a fine scale are simulated, built and tested. The resulting module is a low-cost, reliable smart PV panel that operates independently of the geometry and complexity of the surrounding system. The controller maximizes energy capture by selection of one of three possible modes: buck, boost and pass-through. Autonomous controllers achieve noninteracting maximum power point tracking and a constant string voltage. The proposed module-integrated converters are verified in simulation. Experimental results show that the converter prototype achieves efficiencies of over 95% for most of its operating range. A 3-module PV series string was tested under mismatched solar irradiation conditions and increases of up to 38% power capture were measured.
Notes
- DC-DC converters are used, and placed in series.
- Best used for stand alone large applications.
- By using module integrated converters it is possible to regulate PV string voltage to a fixed voltage.
Photovoltaic converter system suitable for use in small scale stand-alone or grid connected applications[edit | edit source]
J. A. Gow and C. D. Manning, "Photovoltaic converter system suitable for use in small scale stand-alone or grid connected applications", Electric Power Applications, IEE Proceedings -, vol. 147, no. 6, pp. 535–543, Nov. 2000.
Of the commercially-available solutions for the conversion of energy from photovoltaic arrays into a usable form, a large number consist of systems which have been developed for a dedicated application and are thus very inflexible. Those that are available as a generic module for use in a variety of environments are often restricted to a single mode of operation, for example utility supply only. A generic modular photovoltaic power conversion system is presented, aimed at single-phase applications which can supply passive AC and DC loads with a regulated voltage or by way of a maximum power tracking system with the maximum power available from the array. In addition a live AC load such as the utility can be supplied with maximum array power. The system is small, light and can be constructed from readily available components.
Notes
- DC to AC converter
- Inverter is added in the circuit. It can drive stand-alone AC loads.
- Most household appliances work with 110-230V AC, by inserting inverter in the circuit, we can use PV energy directly (Not application specific).
A study of maximum power point tracking algorithms for stand-alone Photovoltaic Systems[edit | edit source]
Mei Shan Ngan; Chee Wei Tan, "A study of maximum power point tracking algorithms for stand-alone Photovoltaic Systems," Applied Power Electronics Colloquium (IAPEC), 2011 IEEE , vol., no., pp.22,27, 18-19 April 2011 doi: 10.1109/IAPEC.2011.5779863
The Photovoltaic (PV) energy is one of the renewable energies that attracts attention of researchers in the recent decades. Since the conversion efficiency of PV arrays is very low, it requires maximum power point tracking (MPPT) control techniques to extract the maximum available power from PV arrays. In this paper, two categories of MPPT algorithms, namely indirect and direct methods are discussed. In addition to that, the advantages and disadvantages of each MPPT algorithm are reviewed. Simulations of PV modules were also performed using Perturb and Observe algorithm and Fuzzy Logic controller. The simulation results produced by the two algorithms are compared with the expected results generated by Solarex MSX60 PV modules. Besides that, the P-V characteristics of PV arrays under partial shaded conditions are discussed in the last section.
Notes
- Different types of MPPT algorithms are discussed.
- MPPT gives us the V, I values at maximum power.
- Perturb and Observe method(P&O): Measures V, I at time t, Compares Power at t and at t-1. In the end we get maximum P, and we know values of V & I at that time
- Incremental Conductance Method: MPP is tracked by comparing instantaneous conductance(I/V) to the incremental conductance (dI/dV). In other words if slope of Voltage and Power curve is zero, we get maximum power.
- P&O algorithm is simplest method, which results low cost installation.
