Local Energy Systems in Iraq: Neighbourhood Diesel Generators and Solar Photovoltaic Generation

Iraqis experience interruptions of the public electricity supply of up to 18 hours a day. In response, private entrepreneurs and the Local Provincial Councils (LPCs) have installed an estimated 55,000–80,000 diesel generators, each rated typically between 100 and 500 kVA. The generators supply neighbourhoods through small, isolated distribution networks to operate lighting, fans and small appliances when power is not available from the public supply. A single radial live conductor connects each customer to the generator and payment for the electricity is based on a monthly charge per ampere. The operation and regulation of the neighbourhood diesel generator networks was reviewed through a comprehensive literature survey, site visits and interviews conducted with local operators and assemblers of the generator sets. The electricity is expensive, the generators can only supply small loads, have considerable environmental impact and the unusual single wire distribution practice is potentially hazardous. However, the use of the generators is likely to continue in the absence of any alternative electricity supply. The diesels and networks are poorly regulated and there is scope to enforce existing standards and develop a new standard to address the hazards of the connection practice. The chapter goes on to assess the possibilities of using small photovoltaic systems for power generation in Iraq.

Converter for starting motor-generator sets of autonomous locomotives

Objective: To confirm the possibility of using a starting converter to spin up the shaft of the motorgenerator set to a speed that ensures stable combustion of the air-fuel mixture in the motor cylinders (starting), as well as of using semiconductor converters based on modern IGBT modules for starting promising motor-generator sets of mainline and shunting locomotives. Methods: The properties, characteristics, and operating modes of starting converters were studied on test benches. Results: The downsides of the currently most commonly used starter-generator circuit for engine starting have been identified. A technical solution has been developed to replace the startergenerator circuit with an inverter starting system using a starting converter for starting the locomotive motor-generator. The device structure has been designed. The basic algorithms of the automatic control system of the starting converter have been implemented. Bench tests of a starting converter prototype have been carried out. Practical importance: The developed technical solution in terms of replacing the starter-generator circuit with an inverter starting system for starting the motorgenerator set of autonomous locomotives makes it possible to increase their reliability by removing the electromechanical drive and replacing a number of engine drive auxiliary camshaft mechanisms (group 69). The inverter starting system will reduce the maintenance and scheduled repair costs, decrease the labor input, and optimize the time-schedule of locomotives. The proposed algorithms for starting the motor-generator set enable increasing the battery life by limiting its starting current, as well as improving the fault tolerance of a locomotive due to the possibility of starting the motorgenerator set at a low battery voltage (lower limit of 45 V).

A Case Study of a Solid Oxide Fuel Cell Plant on Board a Cruise Ship

The work is a case study of a cruise ship supplied by liquefied natural gas (LNG) and equipped with a solid oxide fuel cell (SOFC). It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and assisting three dual-fuel (DF) diesel/LNG generator sets. LNG consumption and emissions are estimated both for the SOFC plant and DF generator sets. It results that the use of LNG-SOFC plant in comparison to DF generator sets allows to limit significantly the SOx, CO, NOx, PM emissions and to reduce the emission of CO2 by about 11%. A prediction of the weight and volume of the SOFC plant is conducted and a preliminary modification of the general arrangement of the cruise ship is suggested, according to the latest international rules. It results that the SOFC plant is heavier and occupies more volume on board than a DF gen-set; nevertheless, these features do not affect the floating and the stability of the cruise ship.

The Even Part of Finite-Dimensional Modular Lie Superalgebra Γ

Let [Formula: see text] be the underlying base field of characteristic [Formula: see text] and denote by [Formula: see text] the even part of the finite-dimensional Lie superalgebra [Formula: see text]. We give the generator sets of the Lie algebra [Formula: see text]. Using certain properties of the canonical tori of [Formula: see text], we describe explicitly the derivation algebra of [Formula: see text].

ON THE ISSUE OF IMPROVING THE QUALITY OF ELECTRICITY IN THE TRANSIENT OPERATING MODES OF MARINE DIESEL GENERATOR SETS

The operation of diesel generator sets (DGS) under conditions of significant frequency deviations with sharp load changes is investigated. Systems containing powerful static converters in transient operating modes experience a sharp deterioration in the quality of electricity in terms of non-sinusoidal voltage. The use of filtercompensating devices in conditions of frequency deviation is not effective. In order to improve the quality of the transition process, it is proposed to reduce the speed (frequency) dips by increasing the inertial mass of the DGU by hanging the flywheel.

Increasing the Reliability of an Electrical Power System in a Big European Hospital through the Petri Nets and Fuzzy Inference System Mamdani Modelling

The big hospitals’ electricity supply system’s reliability is discussed in this article through Petri nets and Fuzzy Inference System (FIS). To simulate and analyse an electric power system, the FIS Mamdani in MATLAB is implemented. The advantage of FIS is that it uses human experience to provide a faster solution than conventional techniques. The elements involved are the Main Electrical Power, the Generator sets, the Automatic Transfer Switches (ATS), and the Uninterrupted Power Supply (UPS), which are analysed to characterize the system behaviour. To evaluate the system and identified the lower reliability modules being proposed, a new reliable design model through the Petri Nets and Fuzzy Inference System approach. The resulting approach contributes to increasing the reliability of complex electrical systems, aiming to reduce their faults and increase their availability.

The synthesis of control system to synchronize ship generator assemblies

This paper considers the construction of principles and the synthesis of a system of effective control over the processes of synchronization of generator sets (GSs) that form a part of the distributed MP-control systems for complex ship technical systems and complexes (STS and C). The tasks of synchronization have been set, the process and database models have been built, the system configurations have been defined. Based on the use of resultant functions, we have determined stages in solving the tasks of control over the frequency adjustment synchronization in a hierarchical sequence. The performance analysis of the STS and C control elements has been carried out; the use of the integrated optimization criteria and dual management principles has been proposed. Practical techniques to manage the GS synchronization have been given. We have solved the problem of high-speed control over the frequency of synchronized objects based on the principles of adjustment. That has made it possible to determine in advance the moments of GS enabling under the deterministic and stochastic statement of the synchronization task. The results of the experimental study into the GS synchronization processes are given; the effectiveness of the proposed GS control has been proven. The principles underlying the construction of procedures to control the GS composition when using the methods of "rigid" and "flexible" thresholds have made it possible to define the optimization criteria and implement a control law that satisfied the condition for an extremum, which is an indicator of the feasibility of the set goal and takes into consideration the limitations of control influences. We managed to design a system in the class of adaptive control systems by the appropriate decomposition of the system's elements by splitting a synchronization task into the task on performance and the task on control under the required conditions. The given examples of the processes where the synchronization failed while using standard synchronizer control algorithms, as well as processes of successful GS synchronization when applying the proposed synchronizer dual control algorithms, have confirmed the reliability of the main scientific results reported here.