Signal Processing and Renewable Energy
Volume:2 Issue: 4, Autumn 2018

In this paper, a new method for signal modulation classification based on Linear Discriminant Analysis for multi-class cases is introduced and its results are compared with two other methods of automatic modulation classification. Higher-order complex cumulants are used as feature vectors in the first place. Then, linear Fisher discriminant analysis maps these vectors to another space to separate different classes efficiently. One versus all support vector machine classifier and kernel Fisher discriminant analysis methods with radial basis function kernel is used. The achieved results in comparison with two research papers show that the proposed method classifies the classes in a shorter time with equal or better accuracy.

Torque ripple in electrical machines is an important issue which may cause several problems in use. In permanent magnet machines and machines with DC excitation, main part of torque ripple is because of cogging torque. There are several ways to reduce this torque and in permanent magnet machines, optimized shape of permanent magnets is one of them. In this paper, a novel shape of permanent magnet in an Axial Flux Permanent Magnet Synchronous Machine (AFPMSM) is proposed which reduces the motor cogging torque and hence over come the torque ripple. First, reference motor is designed with conventional PM shape and then novel PM shaped AFPMSM is designed. These two machines are analyzed by MAXWELL software and then their torque ripples are computed. Results show 35 percent reduction of cogging torque.

Variable reluctance (VR) resolvers are widely used in industrial applications such as aerospace, military, robotic, control of hybrid motors, and navigation for solar systems.  Variable reluctance resolvers are preferred because of simplified structure and affordable prices in many applications in comparison with to the coiled rotor resolvers. In this study, effect of variation of physical parameters including skewing and opening slots of stator is investigated. The performance of the proposed structure is simulated by using a 3-D time stepping finite element method.

Doubly-fed induction generator (DFIG) is too sensitive to the terminal voltage reduction. Thus, it is essential to choose an appropriate controller for converters in order to have stable voltage as well. In this article, double-fed wind turbines is controlled by vector proportional integrated regulator. For this purpose, a test network using vector proportional integrated (VPI) regulator is applied. Therefore, the stability is examined by evaluating the considered grid under different fault conditions. In addition, the performance of this grid is evaluated in the case of adding DFIG. Next, the effect of VPI regulator is analyzed on performance of this grid. The results showed that application of vector proportional integrated regulator improves grid stability to a further degree than direct vector regulator.

This paper aims to describe the role of electricity retailer in power market for persuading consumer to shift their loads. It presents the influence of load shifting on retailer profit and risk management in market environment. In this problem, retailer participates in bilateral contract, also stochastic programming is used to manage the uncertainties of pool prices and elasticity of consumer. It shows that by participating retailer in market contract, the retailer profit will be changed. This paper also analyzes the consumer behavior when the load is shifted from the time with high price to the time with low price. The tariff of demand response program used in this paper is Time of use pricing for the periods of week. Risk Measuring is done by Value at Risk (VaR) and Conditional Value at Risk (CVaR) in this study.

In this paper, Mean Shift (MS) as a clustering algorithm is used to localize the Iranian license plate. In this procedure after clustering, based on the optimized MS method, we applied the geometrical features and edge density in order to remove those parts in every cluster, which cannot be the license plate. The main advantages of MS are no need to know the number of clusters and it is completely independent of the Iranian license plate characters colors or background colors. However, for MS implementation, we should only predetermine a parameter named bandwidth. The experimental results show that our proposed method achieves appropriate performance. We should mention that our system accuracy for optical (OP) with 300 images is 94.6% and for infrared (IR) with 80 images is 98.3%.