As the digital acquisition system is featured by increasingly higher technical targets and more complicated applicable conditions, the traditional digital oscilloscope has become incapable of meeting the requirements of real-time processing of sampled data and waveform display on one hand, and unqualified for field test in hard risky conditions on the other. This paper aims for comprehensively enhancing the digital oscilloscopes data processing, image display, human-machine interface and portable adaptability. To that end, it approaches the system composition of improved oscilloscope, and renders a chance to wirelessly connect the oscilloscope with any of the Smart Handheld Devices with Android operation system through the added wireless data interactive channel, which forms a smart handheld wireless oscilloscope. Such oscilloscope adopts the divisional coordination between data acquisition system and Smart Handheld Device to greatly improve data processing, waveform display and HMI, and realize wireless operation of remote test as a result.

Signal capture is one of the hot spots in electronic test. As the representative of testing instrument, the signal capture ability of digital oscilloscope is normally judged by the waveform capture rate. Unilaterally improving signal acquisition ability whereas ignoring the improvement of waveform imaging mechanism and display effect can not increase the oscilloscopes waveform capture rate in real sense. Aiming at better ability of signal acquisition and waveform display effect of oscilloscope, this paper is committed to analyzing the improved structure of oscilloscope and conducting the real-time waveform imaging with hardware coprocessor array, and then studying the imaging mechanism of special 3D waveform and the impact of waveform display on waveform capture rate. In this way, the signal capture ability of oscilloscope is greatly improved and the effective waveform capture rate as high as 1,000,000 wfms/s is realized.

Soft fault diagnosis and tolerance are two challenging problems in analog circuit fault diagnosis. This paper proposes approaches to solve these two problems. First, a complex field modeling method and its theoretical proof are presented. This fault modeling method is applicable to both hard (open or short) and soft (parametric) faults. It is also applicable to either linear or nonlinear analog circuits. Then, the parameter tolerance is taken into consideration. A frequency selection method is proposed to maximize the difference between the faults fault signature. Hence, the aliasing problem arise from tolerance can be mitigated. The effectiveness of the proposed approaches is verified by simulated results.

Soft fault diagnosis and tolerance are two challenging problems in linear analog circuit fault diagnosis. To solve these problems, a phasor analysis based fault modeling method and its theoretical proof are presented at first. Second, to form fault feature data base, the differential voltage phasor ratio (DVPR) is decomposed into real and imaginary parts. Optimal feature selection method and testability analysis method are used to determine the optimal fault feature data base. Statistical experiments prove that the proposed fault modeling method can improve the fault diagnosis robustness. Then, Multi-class support vector machine (SVM) classifiers are used for fault diagnosis. The effectiveness of the proposed approaches is verified by both simulated and experimental results.

The output power of single-phase PV inverter is AC and the input power is DC，so there exists fluctuations in the power transmission. Generally, the fluctuations can be removed by using coupling capacitors. However, the voltage fluctuations of coupling capacitors will result in corresponding input power fluctuations, and will affect the maximum power tracking of the system. In this paper, the power transfer process is analysised, and a theoretical derivation to voltage fluctuations of the generatrix capacitor and the impact on the input currents is designed.The corresponding correction control algorithm of subdivision control is developed according to its characteristics. The feasibility of the solution is verified by the 3KW experimental prototype.