Distributed generation diversity level for optimal investment planning

The task of improving the supply quality and maintaining supply continuity during emergencies has become more feasible for a distribution company (DISCO), owing to new developments in Distributed Generation (DG) technologies. Even though the technical issues regarding DG interconnection to the main grid are of great importance and are being addressed by on-going research, it must be clearly placed in the context of on the financial performance of the utility. In this paper, a general approach to quantify the technical benefits of DG employment is proposed. The power system economic impact is assessed by evaluating supply quality, supply reliability, system power losses and capital investment. Moreover, the rationale for this research also includes the possibility of DG diversity level in contribution to the economical benefits from DG integration. The approach is tested by a system which is developed from a Tasmanian distribution example. Simulation results and discussion are presented to illustrate the effectiveness and usefulness of the method

Aggregating energy supply and demand

Energy usage in general, and electricity usage in particular, are major concerns internationally due to the increased cost of providing energy supplies and the environmental impacts of electricity generation using carbon-based fuels. If a "systems" approach is taken to understanding energy issues then both supply and demand need to be considered holistically. This paper examines two research projects in the energy area with IT tools as key deliverables, one examining supply issues and the other studying demand side issues. The supply side project used hard engineering methods to build the models and software, while the demand side project used a social science approach. While the projects are distinct, there was an overlap in personnel. Comparing the knowledge extraction, model building, implementation and interface issues of these two deliverables identifies both interesting contrasts and commonalities

C. elegans EIF-3.K Promotes Programmed Cell Death through CED-3 Caspase

Programmed cell death (apoptosis) is essential for the development and homeostasis of metazoans. The central step in the execution of programmed cell death is the activation of caspases. In C. elegans, the core cell death regulators EGL-1(a BH3 domain-containing protein), CED-9 (Bcl-2), and CED-4 (Apaf-1) act in an inhibitory cascade to activate the CED-3 caspase. Here we have identified an additional component eif-3.K (eukaryotic translation initiation factor 3 subunit k) that acts upstream of ced-3 to promote programmed cell death. The loss of eif-3.K reduced cell deaths in both somatic and germ cells, whereas the overexpression of eif-3.K resulted in a slight but significant increase in cell death. Using a cell-specific promoter, we show that eif-3.K promotes cell death in a cell-autonomous manner. In addition, the loss of eif-3.K significantly suppressed cell death-induced through the overexpression of ced-4, but not ced-3, indicating a distinct requirement for eif-3.K in apoptosis. Reciprocally, a loss of ced-3 suppressed cell death induced by the overexpression of eif-3.K. These results indicate that eif-3.K requires ced-3 to promote programmed cell death and that eif-3.K acts upstream of ced-3 to promote this process. The EIF-3.K protein is ubiquitously expressed in embryos and larvae and localizes to the cytoplasm. A structure-function analysis revealed that the 61 amino acid long WH domain of EIF-3.K, potentially involved in protein-DNA/RNA interactions, is both necessary and sufficient for the cell death-promoting activity of EIF-3.K. Because human eIF3k was able to partially substitute for C. elegans eif-3.K in the promotion of cell death, this WH domain-dependent EIF-3.K-mediated cell death process has potentially been conserved throughout evolution

Minimising power losses in distribution systems with distributed resources

Attempts to reduce electricity cost, together with improving the efficiency of distribution systems, have led power utilities to dealing with the problem of power loss minimisation. Although losses in the system can never be entirely eliminated, they can be controlled and minimised in several ways. Research conducted in the last few decades has proven that an inclusion of Distributed Resources (DR) into distribution systems considerably lowers the level of power losses. Moreover, the choice of DR is even more attractive since it provides not only benefits in power loss minimisation, but also a wide range of other advantages including environment, economic and technical issues. In this paper, the potential ability of DR in power loss reduction is discussed. A novel approach to determining a proper size and location of DR in order to achieve maximum loss reduction in distribution feeders is developed. A practical feeder of Aurora Energy, Tasmania is selected to demonstrate the effectiveness of the proposed method and the simulation results are reported

Minimising voltage deviation in distribution feeders by optimising size and location of distributed generation

A new emerging trend of distribution networks is to use small generating units, known as distributed generation (DG), operating in parallel with the main grid. This kind of distribution networks has enabled DG to support power systems in fulfilling their requirements to increase power output as well as quality of power supply. DG has potential to alter power flows, system voltages, and the system performance. In order to maximise benefits from the DG system, proper DG planning is necessary. Determining an optimal DG size and its DG location are critical issues that are addressed in this paper. The main purpose of this research is to maximise voltage support through optimal sizing and location of DG. A new methodology is developed to determine an optimal DG size for a certain DG penetration and an optimal DG location on the distribution feeder for optimising system voltages. The developed technique is tested on a long radial feeder of a practical system and results are reported

Distributed generation diversity level for optimal investment planning

The task of improving the supply quality and maintaining supply continuity during emergencies has become more feasible for a distribution company (DISCO), owing to new developments in Distributed Generation (DG) technologies. Even though the technical issues regarding DG interconnection to the main grid are of great importance and are being addressed by on-going research, it must be clearly placed in the context of on the financial performance of the utility. In this paper, a general approach to quantify the technical benefits of DG employment is proposed. The power system economic impact is assessed by evaluating supply quality, supply reliability, system power losses and capital investment. Moreover, the rationale for this research also includes the possibility of DG diversity level in contribution to the economical benefits from DG integration. The approach is tested by a system which is developed from a Tasmanian distribution example. Simulation results and discussion are presented to illustrate the effectiveness and usefulness of the method

Control strategy of distributed generation for voltage support in distribution systems

Voltage problem is always a critical issue in operating a distribution system. The uncertainties of load distribution and variation have introduced a great complexity to the task of maintaining system voltage within the permitted range. In this paper, small-scale generator, known as distributed generation (DG), is employed in the system and acting as a voltage regulator. The output of DG is controlled in such a way that acceptable level of electrical supply quality is achieved with a reasonable operating cost. The DG controller is tested with a non-uniformly varying load on the time domain basis. Simulations have been conducted with both short term (few hundred seconds) and long term (weekly) load data to validate the proposed control technique. Results have proved that the system is well functioning not only technically but also economically

Distributed generation diversity level for optimal investment planning

The task of improving the supply quality and maintaining supply continuity during emergencies has become more feasible for a distribution company (DISCO), owing to new developments in Distributed Generation (DG) technologies. Even though the technical issues regarding DG interconnection to the main grid are of great importance and are being addressed by on-going research, it must be clearly placed in the context of on the financial performance of the utility. In this paper, a general approach to quantify the technical benefits of DG employment is proposed. The power system economic impact is assessed by evaluating supply quality, supply reliability, system power losses and capital investment. Moreover, the rationale for this research also includes the possibility of DG diversity level in contribution to the economical benefits from DG integration. The approach is tested by a system which is developed from a Tasmanian distribution example. Simulation results and discussion are presented to illustrate the effectiveness and usefulness of the method