Digital Instrumentation and Control System for Unit 5 ＆ 6 of YangJiang NPP

The article describes the digital instrumentation and control system for unit 5 ＆ 6 of YangJiang NPP, involving the overall I ＆ C （instrumentation and control） structure, the basic requirements and independent verification and validation. Advanced I ＆ C systems for YangJiang NPPs have to meet increasing demands for safety and availability. Additionally, the specific requirements coming from the nuclear qualification have to be fulfilled.     

Finite Set-Model Predictive Current Control of Three-Phase Voltage Source Inverter for RES （Renewable Energy Systems） Applications

This paper focuses on a combination of three-phase VSI （voltage source inverter） with a predictive current control to provide an optimized system for three-phase inverters that control the load current. A FS-MPC （finite set-model predictive control） strategy for a three-phase VSI for RES （renewable energy systems） applications is implemented. The renewable energy systems model is used in this paper to investigate the system performance when power is supplied to resistive-inductive load. With three different cases, the evaluation of the system is done. Firstly, the robustness of control strategy under variable DC-Link is done in terms of the THD （total harmonic distortion）. Secondly, with one prediction step, the system performance is tested using different sampling time, and lastly, the dynamic response of the system with step change in the amplitude of the reference is investigated. The simulations and result analyses are carried out using Matlab/Simulink to test the effectiveness and robustness of FS-MPC for two-level VSI with AC filter for resistive-inductive load supplied by a renewable energy system.     

High Efficiency PCS with Scan-Type MPPT Control for a Grid-Connected PV Power Generation System

For a standalone PV （photovoltaic） power generation system, the author previously proposed a new MPPT （maximum power point tracking） control method in which the I-V characteristics are scanned with a detection interval control that operates at specified intervals and monitors the maximum power point. The author has obtained satisfactory results using this new MPPT control method. This paper investigates the application of the new MPPT control method for a PCS （power conditioning system） in a grid-connected type PV power generation system. The experimental results clearly demonstrate that the developed PCS offers outstanding effectiveness in tracking the maximum power point in partially shaded environments.     

Analyzing the Share Composition of C02 Emissions in Asian Countries

This paper is concerned with the fossil fuel composition of carbon emissions in 10 selected Asian countries. It assesses how economic development may affect this composition through various channels. This paper contributes to the debate on the EKC （environmental Kuznets curve） puzzle, which hypothesizes an inverted U-shaped relationship between per capita income and pollution. The paper examines the EKC hypothesis in an empirical analysis of channels that may allow for this effect. In particular, a specific subset of this general paradigm is investigated using a fractional multinomial logit model to assess how indicators associated with economic development and energy prices affect carbon emissions from coal relative to those of natural gas and oil.     

Dynamic Voltage Restorer with Active Disturbance Rejection Control

Power quality is one of the major concerns among consumers and electric utility companies. CUPS （custom power systems） devices are used to improve the quality of power and enhance the reliability of the power supply in the distribution networks. The DVR （dynamic voltage restorer） is an important CUPS device used to mitigate voltage sag/swell and imbalances. Various control techniques have been implemented to control the DVR, among which the PID （proportional-integral-derivative） controller is dominant because of its model independent property and its error driven technique. In this paper, a new controller based on the ADRC （active disturbance rejection control） concept is developed, and its performance is compared to that of the PID controller. The model of the DVR and its ADRC and PID controllers were developed under the MATLAB （matrix laboratory）/Simulink environment. The simulation results demonstrated the effectiveness of the ADRC over the PID controller.     

New,Simple Blade-Pitch Control Mechanism for Small-Size,Horizontal-Axis Wind Turbines

In the present research work, the pitch-control is carried out such that the rotor blades are rotated around their longitudinal axis while the rotor continues its normal rotation. It is really a challenge to produce a clever design to pitch the rotor blades by the optimal amount so as to maximize the power output at all wind speeds. The mechanism is implemented to a three-blade, horizontal-axis, home-scale wind turbine. The mechanism is powered by a suitable DC （direct-current） motor. The tests were carried out in the open section of a delivery wind tunnel. The air speed was measured by a suitable anemometer. The corresponding rotational speed （rpm） and output voltage at different wind speeds were measured and recorded for calibration of the control system. The mechanism proved to be successful in controlling the pitch angle over a wide range of wind speeds.     

A Review of Direct Driven PMSG for Wind Energy Systems

This paper presents a comprehensive overview study of the DDPMSG （direct driven permanent magnet synchronous generator） for wind energy generation system. Wind turbine controls are provided. The PMSG （permanent magnet synchronous generator） is introduced as construction and model. Configurations of different power converters are presented for use with DDPMSG in wind systems at variable speed operation and maximum power capture. Control techniques for the system are discussed for both machine-side and grid-side in details. Grid integration is provided with focus on how to insure power quality of the system and the performance at disturbances.     

Nonlinear Control Model of Synchronous Motor with Excitation and Damper Windings

In this paper, a new control method for synchronous motor with excitation and damper windings is presented. It is based on one type of nonlinear control; feedback linearization control. To make a realization in the sense of electric drive, symmetricM space vector PWM （pulse width modulation） is applied. Estimation of damper winding currents via Lyapunov function for the whole estimated system is done. The aim of control is to make tracking system for rotor speed and square of stator flux. Simulation of motor starting to predefined operating points is done, and also maintaining these points during step change of load torque is obtained. Simulations give good results.     

Simulation Analysis for Massive Deployment of Variable Renewables Employing an Optimal Power Generation Mix Model

This paper develops a high time-resolution optimal power generation mix model in its time resolution of 10 minutes on 365 days by linear programming technique. The model allows us to analyse the massive deployment of photovoltaic system and wind power generation in power system explicitly considering those short-term output variation. PV （photovoltaic） and wind output are estimated, employing meteorological database. Simulation results reveal that variable fluctuation derived from a high penetration level of those renewables is controlled by quick load following operation of natural gas combined cycle power plant, pumped-storage hydro power, stationary NAS （sodium and sulfur） battery and the output suppression control of PV and wind. It additionally turns out that the operational configuration of those technologies for the renewable variability differs significantly depending on those renewable output variations in each season and solving the seasonal electricity imbalance as well as the daily imbalance is important if variable renewables are massively deployed.     

An Advanced Teaching Lab for the Setting up of an Islanded Production Unit

The present paper addresses an advanced teaching lab consisting of setting up an islanded production unit. This teaching lab takes place in the very last semester at master level for students in electrical engineering with energy specialization. The purpose of this teaching lab is to combine knowledge learned in different areas such as power electronics, control, electrical machines and networks, and make use of all of them in practice. The present paper describes in detail the different steps followed by the student to set up an islanded production unit.     

基于城市道路的混合动力电动汽车再生制动后向仿真

再生制动对整车燃油经济性的改善有很大的影响,是混合动力汽车的重要组成部分。本文结合城市道路工况特点,分析和建立了混合动力电动汽车再生制动策略,并研究了此策略下的制动力分配,最后,建立混合动力电动汽车再生制动系统后向模型,通过在DL-H120-PRS实验台架上验证分析。结果表明所建模型是稳定的、正确的,在考虑制动安全的前提下实现了车辆制动能量的高效回收．具有较大的应用价值。     

Advanced Control System Development on the Basis of Festo Training Laboratory ＂Compact Workstation＂

This article describes the development of automatic control system on the basis of Festo ＂Compact Workstation＂ training stand. Such control systems are used in different branches of industry and infrastructure including oil industry, chemical industry, water treatment, canalization and others. The stand allows realizing level, flow, pressure and temperature control systems, using pump, valves, discrete and analog sensors. Level control system is described in this work. PID （proportional integral derivative） controllers are used in these systems. Control is switched on and off and the parameters of control systems are changed by means of SCADA （supervisory control and data acquisition） system. During real technological processes, these actions are performed by the operator. The algorithm of the control system is realized using PLC （programmable logic controller）. At the end of the article conclusions about the research are drawn.     

Improving the Performance of an Electro-Hydraulic Load-Sensing Proportional Control Valve

The paper deals with the simulation and the experimental verification of the hydraulic behavior of an electro-hydraulic load-sensing proportional control valve. An innovative CAE （computer aided engineering） methodology, developed combining CFD （computational fluid dynamics） simulations with lumped and distributed numerical modeling, is firstly introduced and tailored by comparing the numerical results with measurements coming from an experimental campaign performed for a wide range of pressure loads and metered flow rates. Then, both the reliability and the limits of the numerical approach are highlighted through a detailed numerical vs. experimental comparison, involving the pressure of the main hydraulic lines, the flow rate through the first section and the local compensator displacement. Finally, the CAE methodology has been applied for assessing the internal ducts hydraulic permeability and the local compensator spring pre-load influence on the control valve metering curves. At the end of this analysis, an optimized design configuration, featuring a maximum controlled volumetric flow rate increased of more than 25%, has been proposed.     

Robust Digital Control of a Broadband PWM Power Amplifier

Lately, it is required that the bandwidth of PWM （pulse width modulation） power amplifier is extended. For example, it is in application of the testing power supply of a low frequency immunity examination, or a class-D amplifier. In this paper, the authors show that the bandwidth of PWM power amplifier can be controller. This controller is implemented on a DSP （digital can be made wider with this controller. extended by using an approximate 2DOF （2-degree-of-freedom） digital signal processor）. It is demonstrated from experiments that the bandwidth     

Innovative Control Strategy for Islanded Small Hydro Power Plant

In many developing countries, there are regions where the electrical grid is weak or nonexistent. However, in these areas, large amounts of distributed energy sources, such as hydro, are often available and could be suitably exploited. To this aim, the low head hydro power plants can play a significant role. In fact, recent technological advances in mini-hydro turbines and decreasing costs of static electricity conversion devices enable to realize suitable power plants for an efficient and profitable exploitation of these sites. One of the major challenges is the integration of the above-mentioned power plants into autonomous electrical systems, islanded and/or disconnectable from the main distribution network. In this paper, an innovative control strategy for a low head hydro power plant supplying users in small clusters of villages is proposed.     

Alternative Solutions to Mitigate Problems due to Neutral Conductors Theft in MV （Medium Voltage） Power Distribution Systems

This paper aims at analyzing the impact of the neutral conductor absence at specific sections over the performance of the power distribution lines, and proposing alternative solutions to mitigate the problems caused by the neutral conductor theft. Simulations are made by the software lnterplan and show that the absence of neutral conductor at specific sections of power distribution lines may increase the neutral-to-ground voltages, which compromises the system＇s safety. The solution developed keeps the technical performance of the power distribution system at satisfactory levels, regarding the voltage profile, or, at least, close to the level before the neutral conductor＇s theft.     

Limiting Use of Potential Energy Storage Compared to Batteries for a Lebanese Hybrid Wind/PV System

In l,ebanon, hybrid wind/PV systems are used to provide electricity when the public electricity is cut off This paper treats the storage problems of electrical energy generated by the used renewable sources. A theoretical study on two types of electrical energy storage systems is given. These systems are the electrochemical energy storage devices （batteries） and the potential （or hydraulic） energy storage system. In order to find the limiting case of use between these two energy storage systems, economical study and comparison between them are discussed and analyzed.     

Impact of Wind Power on the ATC Values in Hydro-Dominated Power System

The wind power generation is increasing in many countries as a result of decreasing technology costs, active government policies for renewable energy sources, environmental concerns, etc.. This paper investigates the impact of wind power generation on ATC （available transmission capacity） calculation. In order to determine the maximum incremental MW transfer possible between two parts of a power system without violating any specified limits, ATCs are calculated. When calculating ATC values, it is necessary to assume production and consumption pattern in power system. Production of wind power depends on the wind speed, which is a random variable and it is impossible to forecast exactly the production of wind power that is needed for the ATCs calculation. In order to investigate influence of the stochastic wind power production on the ATCs value, computer model of Croatian electric power system is made in Power World Simulator. ATCs are calculated for southern part of Croatian power system in which besides wind power, hydro power plants are only type of power generation. Available wind speed measurements are used as input data for wind power production. The results of the ATC calculation for different scenario of wind power production and location in the Southern Croatian power system are presented and discussed in the paper.     

Determination of 3H and 14C in Organic Sample after Separation through Combustion Method

The Environmental program of the Cernavoda NPP （nuclear power plant） is based on the analysis of environmental samples： airborne, TLDs （thermoluminescence dosimeters）, water, deposition, soil, grass, sediment, fish, milk, meat, eggs, grains, fruits and vegetables, using determination of 3H and 14C, gross alpha/beta and gamma spectrometry measurement techniques. This Program is a legal constraint for nuclear utilities and it is approved and supervised by the regulatory body. Besides, the actual legal requirements, Cernavoda NPP participates in a CANDU （Canadian Deuterium Uranium） Owners Group Project （COG HS ＆ E-304） in order to implement the new standard CAN-CSA 288.1-08 for derived emission limits using results of measurements for OBT （organically bound tritium） concentrations in plant and animal products. The method for determination of 3H and 14C in organic samples after separation through non-catalytic combustion by flame oxidation is performed in Sample Oxidizer 307 equipment. Average values for total tritium activity concentration in fish samples of 21 ± 2 Bq/kg fresh weight were determined. Results for 14C have an average value of 327 ± 26 Bq/kg-C in fish from Danube-River and 315 ± 25 Bq/kg-C in fish from lakes. The average values for 14C activity concentration in vegetables samples from Cernavoda and Seimeni areas are about 338 ± 27 Bq/kg-C.