Takeshi Katagi

Operation control of photovoltaic/diesel hybrid generating system considering fluctuation of solar radiation

The exhaust gas emission from marine diesel engines is one of the major environmental issues. The authors have been studying the use of photovoltaic energy for the electric power system on ships. This paper proposes an operation control of a photovoltaic/diesel hybrid generating system for a small ship in consideration of the fluctuating photovoltaic power due to solar radiation. The aim of the control is to minimize the fuel consumption and storage capacity of the battery. The validity of the proposed control method is shown by the numerical simulation based on the experimental data of a photovoltaic system.

Decision Method of the Optimal Number of Maintenance Crew on Diesel Plant

Generally, there are some relations of the queue that are occurred while the maintenance work and the recovering work. Therefore, it is able to calculated increase or decrease situation that is waiting time, waiting number of cases and occurrence ratio by using a queue procession. Furthermore, its gotten the optimal number of maintenance person by making the occurrence situation. Engine failure in a ship can be regarded as exponential arrival model in random failure period. Also its conceived that the distribution in recovery time complies with random Poisson or Erlang distribution. Recovering work data are calculated with a repair rate from a man-hour in terms of the kind of maintenance and queue simulation model. It was constructed by using queue processions and simulation programs. Finally, its found out the number of optimal maintenance personnel concretely by it.

Simulation of Marine Diesel Engine Characteristics and Design of Adaptive Control Scheme for Electronic Governor

Recently electronic governors and used in place of conventional mechanical-hydraulic governors in increasing number of marine vessels. In this paper, firstly the features of these electronic governors have been reviewed, and a design of the control scheme for the electronic governors has been proposed. For that purpose firstly the dynamical characteristics of marine diesel engine have been simulated by the so called Quasi Steady State Method approach, which allows for the calculation of many of the variable in the diesel engine with a relatively simple model. A control scheme for the engine has been proposed which, by means of updating newly defined parameters withing the controller using feedback from the output, could improve the dynamic response of the diesel engine. The control scheme proposed is characterized by 4 variables, and the numerical values selected for these variables has been discussed. Finally the characteristics of the marine diesel engine system incorporating this new governor has been demonstrated by computer simulation.

Diagnosis of Fuel Oil Line for Marine Diesel Engine by Sense of Touch - The 2nd Report -

The experienced crew can diagnose the fuel oil line by the touch on the fuel injection pipe. The first paper discussed the experiment of diagnosing the fuel oil leakage from the fuel pump by the accelerometer fixed on the fuel injection pipe. At abnormal condition, the attenuation time of the signal occured at the time of combustion becomes longer then that at the normal condition.This paper presents the experiment of diagnosing the fuel injection valve by the strain gage fixed on the fuel injection pipe. The abnormal condition is simulated the lowering of the opening pressure of the fuel injection valve by the adjustment the spring tension of the valve.The distinctive signal is found at the time of the fuel injection. This signal at the abnormal condition becomes bigger than that at the normal condition.

Trainning System for Diagnosis through Sense of Hearing

The fact, that the crew find 50-90% of troubles of the marine diesel engine in the MO ship, implies the human sense of hearing plays a crucial role in the diagnosis of the engine. And the hearing ability to diagnose is improved by experience in hearing the abnormal sounds. But now the crew have little opportunity for hearing abnormal sounds.It is proposed the training system for the improvement in the hearing ability using artificial sythetic sounds in place of original sounds which is very difficult to collect. In this paper, the normal and abnormal sounds of a four-stroke diesel engine are sythesized by means of the frequency modulation synthesis and the addition synthesis.The synthetic sounds simulate the original sounds exactly, as the result of the comparison of the synthetic and original sounds by hearing and observation of the waveforms.

Dynamic Characteristics of Diesel Generating System with Large Capacity Load-2nd Report

This paper describes an approach for the dynamic stability analysis of marine power system. The system of model is composed of each one element such as diesel engine, AC. generator, three phase induction motor and bow thruster load. The analytical model is shown in the form of blockdiagram and estimated by digital computer using the CSMP language. Parameters of the generator system are derived from statical characteristics of the main generator engine system of the training ship“FUKAE MARU”. Transient chracteristics of the system are calculated in case of line starting star - delta starting rotor - resistance starting and chopping starting. These starting methods on the performance simulation model system has been studied. The amounts of transient speed regulation and restoration time by calculation are discussed. The responce of voltage regulation to variable compound coefficient on A. V. R. is also discussed.

Load Test of Differential Drive Shaft Generator and Motor System

This differential driven shaft generator/motor system has been introduced first in 1987, practical system (200V, 200kW) is introduced to FUKAE-MARUIII in 1988. Since the fundamental structure of the machine is the same as conventional synchronous machine, the output frequency of the machine is corrected to constant by compensating motion of the movable stator.Test results of starting characteristics of large capacity induction motors (total 30% rated power of the ACG), and voltage regulating characteristics with variable shaft speed or variable load are good agreement to designed procedure.The machine can be driven as the electronic propulsion motor. Induction starting, synchronization and load characteristics of the machine are also discussed. Since emergency starting of propulsion motor can be established within up to one minute, it presents powerfull function to reliability of the propulsion system.