Study of MPPT Simulation Based on Power Prediction Method and Variable Step Incremental Conductance Method

Traditional incremental conductance method is one of the most widely used methods of MPPT in solar photovoltaic system. But oscillation and misjudgment also exist, which have a great impact on the efficiency and stability of solar system. This thesis proposes a new MPPT algorithm, that is, to combine power prediction method with incremental conductance method organically; simultaneously to apply variable step theory to reduce oscillation and avoid misjudgment. After the simulation in MATLAB7, it proved to be feasible by comparing with traditional incremental conductance.

Development of Intelligent Drilling and Intelligent Drill Tools

This paper introduces the principles and techniques of intelligent drilling which can be considered as a computer intelligent expert system with intelligent drill tools and information network system as the key technologies. In this paper, we have discussed the key technology of how to combine power transmission and high speed bidirectional information transmission “information superhighway” with drill tools, and also have introduced the design and development of intelligent drill tools specifically which Hilong company who possesses the independent intellectual property rights.

Monitoring Rotating Tool Wear Using Higher-Order Spectral Features

A framework for detecting incipient wear in rotating machinery is proposed. In this paper, statistical techniques that combine power spectrum estimates with higher-order spectrum (HOS) estimates for feature development are applied to discriminate and classify vibration signals from new and slightly used drill bits in a drill wear study. Results from experimental data obtained when drilling composite circuit cards reveal that the performance of a power spectrum-based tool wear monitoring system can be enhanced by complementing the power spectrum information with HOS information on the accelerometer signal. Evidence presented supports the proposition that a HOS approach provides better signal features to a pattern classifier which allows better decisions on the state of rotating tool wear.