Power is an all-pervasive, and fundamental force in human relationships and plays a valuable role in social, political, and economic interactions. Power differences are important in social groups in ...enhancing group functioning. Most people want to have power and there are many benefits to having power. However, power is a corrupting force and this has been a topic of interest for centuries to scholars from Plato to Lord Acton. Even with increased knowledge of power’s corrupting effect and safeguards put in place to counteract such tendencies, power abuse remains rampant in society suggesting that the full extent of this effect is not well understood. In this paper, an effort is made to improve understanding of power’s corrupting effects on human behavior through an integrated and comprehensive synthesis of the neurological, sociological, physiological, and psychological literature on power. The structural limits of justice systems’ capability to hold powerful people accountable are also discussed.
Northeast Utilities Company adopted an ambitious new competitive
strategy in the mid-1980s, seeking to become the low-cost supplier
in New England electric power markets bracing for deregulation.
...Given its high-cost nuclear facilities, doing so required a
corporate turnaround. For a decade Northeast faced increasing
public and employee resistance to cost cutting at its nuclear
plants. Though management achieved many of its goals, curtailing
outlays on nuclear operations meant high risk that the Nuclear
Regulatory Commission would close the plants because of frequent,
prolonged outages. This is just what happened in 1996. Did
management's deliberate cost-containment strategy take nuclear
operations to an inevitable regulatory shutdown, and if so, why?
Was it the pursuit of executive compensation tied to cost
containment that caused undue risk of regulatory shutdown? Paul
MacAvoy and Jean Rosenthal describe ten years of corporate
performance preceding the shutdown, detailing aggressive executive
decisions, mounting regulatory actions in response to increasingly
severe operational failures, and--at the same time--overall
improvement in corporate earnings, stock prices, and executive pay
packages. They relate the complexities of managing declining
nuclear plant operations under ever more pressing budgetary
targets. Their discussion of the increasing risk of outages raises
the issue of the tradeoff of profit and conservative management of
hazard operations. All the more timely in light of the massive 2003
East Coast blackout, Corporate Profit and Nuclear Safety represents
a powerful and cautionary commentary on industrial practices that
goes to the heart of effective corporate governance.
Integration of dynamic grid support is required for distributed power systems that are interconnected with medium voltage grids. This study proposes a comprehensive control solution to enhance fault ...ride through (FRT) capability for utility-scale photovoltaic (PV) power plants. Based on positive and negative sequence control schemes and PV characteristics, the approach alleviates dc-bus double-line-frequency ripples, reduces voltage stress on inverter power switches and DC-link capacitors, and minimises undesirable low-order voltage and current harmonics that are presented on the ac side. The study proposes a new feature to achieve superior FRT performance by using the overload capability of grid-tied inverters. A weak electric grid is used for the test case including a wind turbine induction generator, diesel engine driven synchronous generators and various loads. A comprehensive simulation verified the capability of the proposed control schemes for mitigating the voltage dip, enhancing the voltage response and further improving the stability of interconnected distributed generation in reaction to severe unbalanced voltage conditions because of asymmetrical grid faults.
This book offers a collection of 30 scientific papers which address the problems associated with the use of power electronic converters in renewable energy source-based systems. Relevant problems ...associated with the use of power electronic converters to integrate renewable energy systems to the power grid are presented. Some of the covered topics relate to the integration of photovoltaic and wind energy generators into the rest of the system, and to the use of energy storage to mitigate power fluctuations, which are a characteristic of renewable energy systems. The book provides a good overview of the abovementioned topics.
Protection of Low-Voltage DC Microgrids Salomonsson, D.; Soder, L.; Sannino, A.
IEEE transactions on power delivery,
07/2009, Volume:
24, Issue:
3
Journal Article
Peer reviewed
In this paper, a low-voltage (LV) DC microgrid protection system design is proposed. The LV DC microgrid is used to interconnect distributed resources and sensitive electronic loads. When designing ...an LV DC microgrid protection system, knowledge from existing DC power systems can be used. However, in most cases, these systems use grid-connected rectifiers with current-limiting capability during DC faults. In contrast, an LV DC microgrid must be connected to an AC grid through converters with bidirectional power flow and, therefore, a different protection-system design is needed. In this paper, the operating principles and technical data of LV DC protection devices, both available and in the research stage, are presented. Furthermore, different fault-detection and grounding methods are discussed. The influence of the selected protection devices and grounding method on an LV DC microgrid is studied through simulations. The results show that it is possible to use available devices to protect such a system. Problems may arise with high-impedance ground faults which can be difficult to detect.
Investment on generation system and transmission network is an important issue in power systems, and investment reversibility closely depends on performing an optimal planning. In this regard, ...generation expansion planning (GEP) and transmission expansion planning (TEP) have been presented by researchers to manage an optimal planning on generation and transmission systems. In recent years, a large number of research works have been carried out on GEP and TEP. These problems have been investigated with different views, methods, constraints and objectives. The evaluation of researches in these fields and categorising their different aspects are necessary to manage further works. This study presents a comprehensive review of GEP and TEP problems from different aspects and views such as modelling, solving methods, reliability, distributed generation, electricity market, uncertainties, line congestion, reactive power planning, demand-side management and so on. The review results provide a comprehensive background to find out further ideas in these fields.
The utilisation of renewable sources brings many benefits to electric power systems, but also some challenges such as the impact that renewable power plants employing power electronics have on the ...grid, which is gaining importance as the penetration of this type of generating stations increases, driven by the construction of large wind or solar photovoltaic (PV) power plants. This study analyses the impact of large-scale PV power plants on a transmission grid for different penetration levels. The analysis considers power plants formed by a number of power converters employing synchronous power controllers (SPCs), that allow them to have a harmonious interaction with the grid, and compares their performance with that of conventional power converter controllers, assuming in both cases that the power plants participate in frequency and voltage regulation. The study addresses both the small-signal stability of the system and its response to large disturbances that alter the active power balance and frequency stability. The results of the analysis show that PV power plants using SPCs are able to limit frequency deviations, improve the oscillation damping, and reduce the stress of other generating units, thus having a beneficial impact on the power system.
Climate change, pollution, and energy insecurity are among the greatest problems of our time. Addressing them requires major changes in our energy infrastructure. Here, we analyze the feasibility of ...providing worldwide energy for all purposes (electric power, transportation, heating/cooling, etc.) from wind, water, and sunlight (WWS). In Part I, we discuss WWS energy system characteristics, current and future energy demand, availability of WWS resources, numbers of WWS devices, and area and material requirements. In Part II, we address variability, economics, and policy of WWS energy. We estimate that ∼3,800,000 5MW wind turbines, ∼49,000 300MW concentrated solar plants, ∼40,000 300MW solar PV power plants, ∼1.7 billion 3kW rooftop PV systems, ∼5350 100MW geothermal power plants, ∼270 new 1300MW hydroelectric power plants, ∼720,000 0.75MW wave devices, and ∼490,000 1MW tidal turbines can power a 2030 WWS world that uses electricity and electrolytic hydrogen for all purposes. Such a WWS infrastructure reduces world power demand by 30% and requires only ∼0.41% and ∼0.59% more of the world's land for footprint and spacing, respectively. We suggest producing all new energy with WWS by 2030 and replacing the pre-existing energy by 2050. Barriers to the plan are primarily social and political, not technological or economic. The energy cost in a WWS world should be similar to that today.
► Replacing world energy with wind, water, and sun (WWS) reduces world power demand 30%. ► WWS for world requires only 0.41% and 0.51% more world land for footprint and spacing, respectively. ► Practical to provide 100% new energy with WWS by 2030 and replace existing energy by 2050.
" Power system modelling and scripting is a quite general and ambitious title. Of course, to embrace all existing aspects of power system modelling would lead to an encyclopedia and would be likely ...an impossible task. Thus, the book focuses on a subset of power system models based on the following assumptions: (i) devices are modelled as a set of nonlinear differential algebraic equations, (ii) all alternate-current devices are operating in three-phase balanced fundamental frequency, and (iii) the time frame of the dynamics of interest ranges from tenths to tens of seconds. These assumptions basically restrict the analysis to transient stability phenomena and generator controls. The modelling step is not self-sufficient. Mathematical models have to be translated into computerprogramming code in order to be analyzed, understood and ""experienced"". It is an object of the book to provide a general framework for a power system analysis software tool and hints for filling up this framework with versatile programming code.This book is for all students and researchers that are looking for a quick reference on power system models or need some guidelines for starting the challenging adventure of writing their own code."
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