Multiple Input Governor Control for a Diesel Generating Set

The paper presents a multiple input single output fuzzy logic governor algorithm that can be used to improve the transient response of a diesel generating set, when supplying an islanded load. The proposed governor uses the traditional speed input in addition to voltage and power factor to modify the fuelling requirements during various load disturbances. The use of fuzzy logic control allows the use of PID type structures that can provide variable gain strategies to account for non-linearities in the system. Fuzzy logic also provides a means of processing other input information by linguistic reasoning and a logical control output to aid the governor action during transient disturbance. The test results were obtained using a 50 kVA naturally aspirated diesel generator testing facility. Both real and reactive load tests were conducted. The complex load test results demonstrate that, by using additional inputs to the governor algorithm, enhanced generator transient speed recovery response can be obtained.

School Ethos and Governor Relationships

This paper argues that an understanding of ethos is essential for appreciating the process of policy implementation in schools. Whilst educational literature consistently refers to the importance of ethos as a means of understanding the distinctive nature of schools, there is little exploration of school ethos as an effective mediator of policy. Drawing on qualitative data collected in three primary schools it will be demonstrated how ethos can act as a bridge or a barrier to the successful construction of the model of collaborative relationships between school governors and heads, as set out by the education reform legislation of the late 1980s

Synchronous Islanded Operation of a Diesel Generator

The amount of distributed generation connected to the distribution network is increasing. To use this resource more effectively, splitting of the distribution network, or islanding the system, for prevention of power outages is being considered by some utilities. In this paper an islanding method that avoids out-ofsynchronism re-closure is proposed. The island is kept in synchronism with the rest of the utility while it is not electrically connected. This is referred to as synchronous islanded operation. A phase difference control algorithm, developed by the authors, was tested in a single set scenario on a 50-kVA diesel generator using two different governors. These are the “standard product” variable gain governor of the diesel generator and a governor developed by the authors, which utilizes supplementary inputs in addition to engine speed. The results show that phase difference can be controlled within acceptable limits, both in steady state and after load disturbances are applied. The advantages of employing supplementary governor inputs are fully evaluated.

A hierarchical physical model-based approach to predictive control of a thermal power plant for efficient plant-wide disturbance rejection

Extending the work presented in Prasad et al. (IEEE Proceedings on Control Theory and Applications, 147, 523-37, 2000), this paper reports a hierarchical nonlinear physical model-based control strategy to account for the problems arising due to complex dynamics of drum level and governor valve, and demonstrates its effectiveness in plant-wide disturbance handling. The strategy incorporates a two-level control structure consisting of lower-level conventional PI regulators and a higher-level nonlinear physical model predictive controller (NPMPC) for mainly set-point manoeuvring. The lower-level PI loops help stabilise the unstable drum-boiler dynamics and allow faster governor valve action for power and grid-frequency regulation. The higher-level NPMPC provides an optimal load demand (or set-point) transition by effective handling of plant-wide interactions and system disturbances. The strategy has been tested in a simulation of a 200-MW oil-fired power plant at Ballylumford in Northern Ireland. A novel approach is devized to test the disturbance rejection capability in severe operating conditions. Low frequency disturbances were created by making random changes in radiation heat flow on the boiler-side, while condenser vacuum was fluctuating in a random fashion on the turbine side. In order to simulate high-frequency disturbances, pulse-type load disturbances were made to strike at instants which are not an integral multiple of the NPMPC sampling period. Impressive results have been obtained during both types of system disturbances and extremely high rates of load changes, right across the operating range, These results compared favourably with those from a conventional state-space generalized predictive control (GPC) method designed under similar conditions.

Development and Validation of a Forklift Truck Powertrain Simulation

Fuel economy has become an important consideration in forklift truck design, particularly in Europe. A simulation of the fuel consumption and performance of a forklift truck has been developed, validated and subsequently used to determine the energy consumed by individual powertrain components during drive cycles.
The truck used in this study has a rated lifting capacity of 2500kg, and is powered by a 2.6 litre naturally aspirated diesel engine with a fuel pump containing a mechanical variable-speed governor. The drivetrain consisted of a torque convertor, hydraulic clutch and single speed transmission.
AVL Cruise was used to simulate the vehicle powertrain, with coupled Mathworks Simulink models used to simulate the hydraulic and control systems and governor. The vehicle has been simulated on several performance and fuel consumption drive cycles with the main focus being the VDI 2198 fuel consumption drive cycle.
To validate the model, a truck was instrumented and measurements taken to compare the performance and instantaneous fuel consumption to simulated values. The fuel injector pump was modified and calibrated to enable instantaneous fuel flow to be measured.
The model has been validated to within acceptable limits and has been used to investigate the effect four different torque converters have on the fuel consumption and performance of the forklift truck. The study demonstrates how the model can be used to compare the fuel consumption and performance trade-offs when selecting drivetrain components.

Release:A Theatre of Witness Documentary

‘RELEASE’ a documentary by Declan Keeney

Everyone has a past; but should they be defined by it? The legacy of the conflict in Northern Ireland weighs heavily on many of those who experienced it. The pain and loss is as relevant today as it was 30 years ago. The act of remembering itself can be a difficult and dangerous journey. The documentary film 'Release' shot and directed by Declan Keeney explores the life stories of six remarkable men, told in their own words and in their own way through an original Theatre of Witness production of the same name that toured Northern Ireland and the Border Counties in 2012. The film explores themes of forgiveness, remembering and the pain of living with our ever-present past.
With great courage and conviction, a former RUC detective, a former Prison Governor, a former British soldier, two ex-prisoners and a community activist who survived a car bomb as a child come together across the sectarian divide to create a group of men working for peace. Their journey is at times heart breaking, extraordinary, breathtakingly brave but ultimately transformational. It is a story of survival, but most importantly it is their story and in their own words.

Climate Change, national politics and grassroots action: an introduction

Climate change continues to dominate academic work within green/environmental politics. Indeed, there appears to be almost an inverse relationship between the lack of political leadership on tackling climate change and the growth in ever more sophisticated academic analyses of this complex and multifaceted problem. There is an increasing disjunction between the growth in our knowledge and understanding of the ethical, political, economic, sociological, cultural, and psychological aspects of climate change and the lack of political achievement in putting in place clear and binding targets, an agreed decarbonisation roadmap, and associated regulatory and policy instruments with enforcement. This gap might be taken as evidence that we do not need more reports on climate change. To quote that most unlikely of green politicians, Arnold Schwarzenegger, former Governor of California: ‘The debate is over. We know the science. We see the threat. And we know that the time for action is now’ (California Energy Commission 2007, p. 1). This special issue focuses on a variety of ways in which climate change is conceptualised in normative political and ethical theory, and addressed in policy and regulations.

Debating Darwin at the Cape

This paper focuses attention on the fortunes of Darwin's theory among the English-speaking community in Cape Colony during the latter part of the nineteenth century. The paper begins with a review of early encounters with Darwin dwelling particularly on the response of figures like Roderick Noble - professor and editor of the Cape Monthly Magazine, the geologist John Shaw, and Sir Henry Barkly, governor of the colony. Besides these more theoretical responses, Darwin's ideas were also mobilised in a range of scientific inquiries on such subjects as birds and butterflies. But most conspicuous was the use of evolutionary thought-forms in the work of the eminent philologist Wilhelm Bleek, cousin of Darwin's leading German apologist, Ernst Haeckel. The prevailing sense is of a liberal intelligentsia calmly interacting with a novel theory with all due deference. During the 1870s, an address by Langham Dale at the South African Public Library injected new energy into the Darwin discussion. Dale expressed disquiet over some of the anthropological implications of evolution as well as its apparent reductionism, and this stimulated a range of reactions. Several anonymous commentators responded but the most sustained evaluation of Dale's position emanated from the Queenstown physician and later politician, Sir William Bisset Berry. Then, in 1874, copious extracts from John Tyndall's infamous 'Belfast Address' were printed in the Cape Monthly and this added yet further impetus to the debate. Tyndall's seeming materialism bothered a number of readers, not least Hon William Porter, former attorney-general of Cape Colony. To figures like these the materialist extrapolations of radical Darwinians such as Haeckel were deeply disturbing, not just for religious reasons, but because they seemed to destabilise the moral and pedagogic progressivism that lay at the heart of their civilising credo. While reservations about Darwin's proposals were certainly audible, taken in the round Darwinian conversations among the English-speaking literati at the Cape were conducted with liberal sentiments, not least when evolutionary science approached questions of race. For Darwin's writings were seen to confirm a monogenetic account of the origin and unity of the human race, and could readily be called upon to justify the paternalistic ideology that governed colonial affairs.