Most power market structures have been developed and implemented without being tested, causing major problems such as shortages and blackouts. The main cause for these problems is the inability of some markets to provide adequate stimulus for new generation investments. The installed generation capacity goes through boom and bust cycles, exposing consumers to potential shortages during long bust periods. With the realisation that the power market has a strong interaction with generation investment, a System Dynamics (SD) model is developed to study how the market interacts with generation expansion. The SD model also allows for market structures and policies to be evaluated before being implemented. It can be an important tool in ensuring that generation expansion is done optimally without the expense of energy security. New Zealand’s generation capacity is no exception to the boom and bust trend. Since the commencement of the New Zealand Energy Market (NZEM) in October 1996, energy shortages occurred in the winters of 2001, 2003 and 2008. As a case study, an SD model is developed to study the NZEM. The results show that under some forecasted scenarios, New Zealand is susceptible to future energy shortages due to boom and bust cycles in the generation capacity.

To date, the potential of on-line Dynamic Security Assessment (DSA) to monitor, alert, and enhance system security is constrained by the longer computational cycle time. Traditional techniques requiring extensive numerical computations make it challenging to complete the assessment within an acceptable time. Longer computational cycles produce obsolete security assessment results as the system operating point evolves continuously. This thesis presents a DSA algorithm, based on Transient Energy Function (TEF) method and machine learning, to enable frequent computational cycles in on-line DSA of power systems. The use of selected terms of the TEF as pre-processed input features for machine learning demonstrated the ability to successfully train a contingency-independent classifier that is capable of classifying stable and unstable operating points. The network is trained for current system topology and loading conditions. The classifier can be trained using a small dataset when the TEF terms are used as input features. The prediction accuracy of the proposed scheme was tested under the balanced and unbalanced faults with the presence of voltage sensitive and dynamic loads for different operating points. The test results demonstrate the potential of using the proposed technique for power system on-line DSA. Power system devices such as HVDC and FACTS can be included in the algorithm by incorporating the effective terms of a corresponding TEF. An on-line DSA system requires the integration of several functional components. The practicality of the proposed technique in terms of a) critical data communications aspects b) computational hardware requirements; and c) capabilities and limitations of the tools in use was tested using an implementation of an on-line DSA system. The test power system model was simulated using a real-time digital simulator. The other functional units were distributed over the Local Area Network (LAN). The implementation indicated that an acceptable computational cycle time can be achieved using the proposed method. In addition, the work carried out during this thesis has produced two tools that can be used for a) web-based automated data generation for power system studies; and b) testing of on-line DSA algorithms. / February 2017

Following the introduction of the microprocessor into the power system protection field, modern microprocessor based numeric relays have developed very rapidly in the last 20 years, and modern power system protection schemes are virtually all based on microcomputers technology. The International Electro-technical Commission (IEC) recently launched the standard IEC61850, “Communication Networks and System in Substation”, which is having a major impact on the structure of new protection systems and schemes. In itself it describes the concepts for sub-station communications covering protection, control and metering functions. However, although it is going to have a major impact on the power systems communications, it will also influence the design of future protection systems. There will also be a host of other opportunities and advantages that can be realised. These include easier upgrading, refurbishment and replacement of sub-station protection. They also provide for greater use of general purpose Intelligent Electronics Devices (IEDs), self-healing systems, and plug and play type facilities. The Ethernet based communication network for data transfer between process level switchyard equipment and bay level IEDs, the process bus, is defined in IEC61850 Section 9-2. This process bus facilitates the communication of two types of real-time, peer-to-peer communication messages. Generic object-oriented substation event messages, the GOOSE messages and the data sample values, SVs which include the measured currents and voltages. Although this standard describes the message structures and the timing requirements, it does not describe the process bus topology. This work describes different LAN topologies that can be used in the design of process bus for protection systems. It considers the implications of the different structures on the operation of the protection scheme and how these relate to the operational strategy of different operators. It provides an assessment of the data handling capabilities of the system and how the demands of the protection system can be met. Several potential problem areas are identified and analyzed. The probabilistic nature of these systems is discussed and the implications explained. It also provides an insight into the implementation of the alternative topologies and their performance when applied to a transmission line feeder protection and transformer protection. The digital substation and the implementation of IEC61850 are fundamental to the future of protection ‘relays’. There are many pointers to the potential directions that these systems will develop and the skills required for the protection engineers of the future. This project is seeking to overcome some of the ownership challenges presented by modern protection and control (P&C) devices, which have an inherent short life due to their dependence on modern electronics and software.

<p>In recent years, the accelerated deployment of renewable electricity generation resources, especially wind and photovoltaic (PV) solar, has added challenges to the operation and planning of the power grid. One of the challenges is that the variability of solar and wind power output may increase the variation of the load that must be followed by dispatchable resources and increase the ramping capacity needs. Moreover, the decision about the configuration of a PV solar generation systems has operational and economic implications because peak solar energy production does not always precisely occur when the wholesale electricity prices of the system are highest. Therefore, as the renewable capacity levels grow, it becomes increasingly important to examine the potential impacts on the system cost and portfolio of conventional generating units to respond to the intermittent nature of some renewable generation technologies. Three related analyses explored in this dissertation address some of the challenges of integrating utility-scale PV solar and wind projects into a power system using a case study for Indiana.</p> <p>The first analysis identifies the optimal azimuth and tilt angles of solar PV installations that alternatively maximize the annual electricity generation or the economic value of the resource. The economic implications of the configuration of solar PV installations within Indiana are estimated based on wholesale prices of electricity and simulated solar output for different combinations of angles and types of array installations. The results show that solar projects across the state would need to have azimuth angles within the 177 and 182 degrees range to obtain maximum annual energy and 180 to 190.5 degrees to maximize annual value, independently of their array types. Furthermore, southern and northwestern zones showed the highest impacts from using an optimal angle configuration of the solar installations. Nevertheless, on average, the benefits in annual electricity generated or economic value from their reconfiguration across the state are minor, amounting to less than one percent. </p> <p>The second analysis explores the effects of additional solar and wind power investments on the 2035 requirements for baseload and peaking generation capacity, the amount of energy supplied by various types of generation technologies and the costs of Indiana’s electric supply system. From a capacity planning and unit commitment/dispatch perspective, the results of this analysis indicated that with a portfolio that includes more solar and/or wind power generation, there would be need to add new peaking generation units. However, the total need for additional peaking resources declines as more renewables are added to the generation mix. Because Indiana still heavily relies on coal and other baseload resources to generate electricity, no new baseload capacity is required in the future. Generally, additions of PV solar and wind capacity amplify the variation in load net of renewable generation and create greater needs for ramping services from conventional units. However, results of the analysis show that the existing portfolio of conventional generation resources in Indiana would have sufficient operational flexibility to be able to accommodate ramping requirements even with PV solar and wind capacity penetration levels as high as 30% of total electricity generation. However, at those levels of renewables capacity there are a times during the year when the optimal operational strategy is to curtail solar and wind generation. From a technical perspective, the results indicated that larger thermal generating units are used more for load following and turned on and off (cycled) more frequently with the additional renewables than without them but mainly during days with low levels of demand and high levels of generation from renewable technologies. From the cost perspective, the results of the model support the idea that it would be cheaper in the long-term to invest in a combination of solar and wind generation resources than in solar generation resources alone. Moreover, the reductions in variable costs, driven by the zero variable cost added to the system by the additional solar and wind capacity, were not sufficient to outweigh the increases in capital costs regardless of the levels of capacity additions. </p> <p>For the third analysis, the proposed capacity expansion model was used to estimate the value of capacity of PV solar and PV solar in combination with wind capacity in terms of baseload/peaking resources from a deterministic system peak load reliability perspective and for various penetration levels of these resources. The capacity values of solar, which refer to the contribution of PV solar plants to reliably meeting the system peak demand, for all the wind capacity levels analyzed, fall as the amount of solar capacity increases. This is because as solar generation increases and closely coincides with the occurrence of the system peak load, there is a shift of the peak load net of renewable generation time to later afternoon hours, when solar installations begin to reduce their production, therefore decreasing their contribution to reliably meeting system peak demand. The calculated solar capacity values are between 2.7% and 67.3% of the corresponding solar nameplate capacity considering all zones and types of PV solar arrays in Indiana, and vary with the level of solar penetration. The range of values obtained are in line with the ones found in other studies using stochastic reliability-based methods.</p> <p>This dissertation contributes to the literature on the interaction between PV solar with other generation resources and to their economic, operational and policy implications. Furthermore, it provides another decision-making tool from a planning perspective for policymakers, utility companies and project developers.</p>

Thesis (Ph. D. in electrical engineering)--Washington State University, December 2007. / Includes bibliographical references (p. 135-146).

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

<p>Syftet med examensarbetet är att digitalt tillämpa en stabilisering av pendlingar i den aktiva effekten hos en synkrongenerator för vattenkraft kopplad till ett distributionsnät.</p><p>Implementeringen är tänkt att ske i en PLC som redan hanterar andra delar av magnetiseringen.</p><p>Effektstabiliseringen görs genom att en motverkande styrsignal skickas till magnetiseringsutrustningen vilken i sin tur påverkar generatorns uteffekt. Denna motverkande styrsignal kan tas fram på olika sätt.</p><p>Två modeller, av IEEE standardiserade, för effektstabilisering undersöks, PSS1A och PSS2B.</p><p>En Simulink-modell över ett distributionsnät med generator byggs upp för att testa effektstabiliseringen.</p><p>Diskretisering av den ena standarden utförs för att digital implementering ska kunna ske. Tester utförs även på denna modell för att kunna validera dess funktion i jämförelse med den kontinuerliga.</p><p>Den tidsdiskreta modellen görs om till ett matematiskt uttryck tillämpbart i PLC:n.</p><p>Jämförelse sker mellan simuleringarna och den tillämpade modellen genom mätningar.</p> / <p>The purpose of the degree project is to make a digital realization of a stabilizer for oscillations in the active power from a hydropower synchronous generator, connected to a power network.</p><p>The implementation is supposed to be done in a PLC which already handles part of the excitation system.</p><p>The power stabilization is achieved by sending a counteracting reference signal to the excitation system which controls the generator’s output power. This counteracting signal can be achieved in several ways.</p><p>Two existing models, standardized by IEEE, for power system stabilizing will be examined, PSS1A and PSS2B.</p><p>A Simulink-model of a distribution net with a generator is constructed to test the stabilizers.</p><p>To perform a digital implementation a discrete transformation of one continuous model is done. This discrete model is also tested to verify the function in comparison to the continuous one.</p><p>The discrete model is reorganized in a form possible to implement in the PLC.</p><p>Comparison between the simulated and the implemented model is made by measurement.</p>

Today's power systems are undergoing dynamic changes in their operation. The high cost of capital improvements that include new generation and transmission projects has prompted power system planners to look for other alternatives in dealing with increased loads and overall system growth. A dynamic braking resistor is a device that allows for an increased rating of a transmission system's transient stability limit. This allows increased power flows over existing transmission lines without the need to build additional transmission facilities. This thesis investigates the application of dynamically controlled resistive braking in the Pacific Northwest power system. Specifically, possible control alternatives, to replace the present dynamic brake control system at Chief Joseph station, are examined. This examination includes determination of appropriate locations for control system input, development of control algorithms, development of computer and laboratory power system models, and testing and recommendations based upon the developed control algorithms. / Graduation date: 1995

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains x, 105 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 99-105).

The electric power systems in U.S. Navy ships supply energy to sophisticated systems for weapons, communications, navigation and operation. The reliability and survivability of the Shipboard Power System (SPS) are critical to the mission of a surface combatant ship, especially under battle conditions. In the event of battle, various weapons might attack a ship. When a weapon hits the ship it can cause severe damage to the electrical system on the ship. This damage can lead to de-energization of critical loads on a ship that can eventually decrease a ship’s ability to survive the attack. It is very important, therefore, to maintain availability of energy to the connected loads that keep the power systems operational. Technology exists that enables the detection of an incoming weapon and prediction of the geographic area where the incoming weapon will hit the ship. This information can then be used to take reconfiguration actions before the actual hit so that the actual damage caused by the weapon hit is reduced. The Power System Automation Lab (PSAL) has proposed a unique concept called "Predictive Reconfiguration" which refers to performing reconfiguration of a ship’s power system before a weapon hit to reduce the potential damage to the electrical system caused by the impending weapon hit. The concept also includes reconfiguring the electrical system to restore power to as much of the healthy system as possible after the weapon hit. This dissertation presents a new methodology for Predictive Reconfiguration of a Shipboard Power System (SPS). This probabilistic approach includes a method to assess the damage that will be caused by a weapon hit. This method calculates the expected probability of damage for each electrical component on the ship. Also a heuristic method is included, which uses the expected probability of damage to determine reconfiguration steps to reconfigure the ship’s electrical network to reduce the damage caused by a weapon hit. This dissertation also presents a modified approach for performing a reconfiguration for restoration after the weapon hits the system. In this modified approach, an expert system based restoration method restores power to loads de-energized due to the weapon hit. These de-energized loads are restored in a priority order. The methods were implemented using multi-agent technology. A test SPS model based on the electrical layout of a non-nuclear surface combatant ship was presented. Complex scenarios representing electrical casualties caused due to a weapon hit, on the test SPS model, were presented. The results of the Predictive Reconfiguration methodology for complex scenarios were presented to illustrate the effectiveness of the developed methodology.