مجله کیفیت و بهره وری صنعت برق ایران
سال دوم شماره 2 (پیاپی 4، پاییز و زمستان 1392)

This paper presents a new method for extracting maximum power from wind turbine equipped with permanent magnet synchronous generator. The method uses fuzzy logics for switching of a matrix converter. The method is simple and does not need any complicated relations for controlling the wind turbine. The phase and amplitude of output voltage are controlled as maximum power with unity power factor is extracted from wind turbine. Wind variations are also considered and examined during simulations. Simulation is done on an industrial wind turbine and obtained results show that the method is effective.

In this paper، a new method based on using PMU data to detect power swing، and preventing maloperation of distance relays is presented. Power swing is always one of the major problems in the stability of the power grids. In recent years due to development of power grid and implementation of power market serious power swings have been happened all over the world. This problem has caused severe blackouts. Arrival of new equipment such as PMU improves the speed and accuracy of power swing detection methods. Simulation Results show high accuracy and speed of proposed method.

In general، standardization of the systems and manufacturing processes in pattern of quality management system is a key objective in the industry organizations in defense، so that the most important aspect of this is optimal implementation of the system. For optimizing the implementation of the standard ISO9001، It''s important to cover four main factors: 1-Customer Satisfaction، 2-Conformity to product requirement، 3-Characteristics and trends of processes and products، 4- Suppliers Subject. In this study، there are two main 1-Assesment of amount of implementation of statistical techniques. 2-Identification and determination of effectiveness application of statistical prioritize techniques in organization for analysing in four strategic issues. In this research، we use library studies and audit reports of Iran''s defense standard center furthermore exploratory survey and interviews with academic and industry experts. In this study، a model designed to applying statistical techniques for the effective implementation of quality management systems. The core of the study is to present a theory quality framework based on the 1-8 in ISO9001:2008. Then an applied، comprehensive pattern is presented in which the main topics of quality management system confirmed in paragraph 4-8 of the above standard are divided into quantitative and subjective indices. The statistical techniques of ISO10017:2003 will be offered for them، in each step، we will present analytical conclusions based on the data found. The research method used was a descriptive survey design and conceptual framework of the research with academic and industry experts، consultants، and auditors in Iran''s defense standard center، through the questionnaire، the experts'' opinions on the importance and status were analyzed with using statistical techniques. On the basis of the results of the data analysis، it reveals that the experts and managers of the organization stated the following techniques are important: 1-Pareto charts 2-Histograms 3-Process capability analysis 4-Statistical process control charts Also by assessing of implementation of statistical techniques in the defense industry، the following factors for effective implementation of them are determined: 1-Planning and implementing of training for staff 2-Creating the right and dynamic culture in organization 3-Commitement and support of the organization''s senior management 4-Allocation of funds in organization 5-Deployment of a robust and proper process and structures 6-The implementation of statistical techniques by an independent unit 7-Prepare، develop and implement your long-term strategy for the use of statistical techniques in order to optimize quality.

In this paper، the power electronic interface between a DC hybrid power source with a photovoltaic main source and battery storage as the secondary power source is modelled based on the state space averaging method. Subsequently، sliding mode controller is designed for maximum power point tracking of the PV array and load voltage regulation. Asymptotic stability is guaranteed through Lyapunov stability analysis. Afterwards، Three common control methods (LQR، PID، PBC) are provided to compare the results with those of the proposed sliding mode controller responses. Simulation of the hybrid system is accomplished using MATLAB and results of the proposed system are very promising.

In this paper، a new model for distribution networks expansion planning is proposed in the distributed generation (DG) installation is considered as an alternative to respond to demand growth while considering maximization of the DISCO profit. The optimum solution of the proposed model consists of DG unit’s size، location، and power factor. Besides، the best year for DG installation is another optimization variable which is determined by the pseudo-dynamic approach. In the proposed model the influence of load models is included in power flow analysis، evaluating the reliability cost and energy selling for costumers. A new synthetic harmony search algorithm (SHSA) is proposed as an optimization tool to solve the proposed model. The effectiveness of the proposed expansion model and optimization method is demonstrated through the examination on a 38-bus radial distribution network.

Power industry is a fundamental and strategic industrial sector and acts as a true driving force and generator for many other industries. This sector، therefore، represents great attraction for the privatization purposes. In this regard، the present study has analyzed the status of the electricity market by comparing the Iranian electricity stock market with the stock markets of many countries and has provided guide lines for the development of this market in Iran. The results of this study indicate that the manufacturing sector which is under government monopoly has not ability to respond to community needs with low price. On the other hand، the results of this research indicate that the productivity of power industry is lower than expected. Therefore، to improving the productivity of power industry، it is important to pay attention to the privatization and development of electricity stock market and implementation of suitable context for the development of Iranian power stock market.

The unpredictable nature of the wind generation poses an obstacle to high penetration of wind energy in the electric power systems. Demand response (DR) may be considered as an efficient approach to cope with the energy unbalances caused by the wind power intermittency. However، while high penetration of the wind generation in the power systems leads to reduced market prices but it may result in lowering participation in the DR programs. Fair mechanism for valuation of the DR can increase the demand-side participation which consequently facilitates wind power integration in the power systems. This paper focuses on the economic valuation of the DR according to its potential for mitigating the wind power forecast error in the power system operation. For this purpose، a mathematical model is developed to find the maximum monetary incentive for the DR that the system operator is willing to pay to the DR providers. In the proposed model، DR’s potential in reducing the cost of supplying load as well as its capability in reducing the cost of system reserve، start up and shut down of units، load shedding and wind power spillage، are considered. The results of the proposed valuation method provide valuable information for both the system operator and demand response providers. The proposed method is implemented on a six-bus test system and discussions on results are presented.