Virtual Instrument is the newest development orientation of instrument. It became the important field of information technology. This task brings forward a method to design virtual frequency characteristic testing meter based on “Virtual Instrument” idea. Its aim is to realize frequency characteristic test system using virtual instrument development—LabVIEW provided by the NI Co...

The paper analyzed the progress status of present vibration test systems inside andoutside, developed a handle vibration measuring meter with high precision, smalldimension, strong function and low cost consumption to solve the problems like simplexfunction, high price and others. In this paper to improve the precision of measurementthe ZOOMFFT arithmetic is adopted in data processing and soft...

Electric Vehicle (EV), as a green vehicle, is seriously concerned by the governments of many countries. Energy storage technology is the weak part of the development of Electric Vehicles (EV). Super capacitor, which possesses the features of high specific power, fast charge and discharge rate and long cycle life and so on, is becoming to be one important field of the EV in recent years. The in...

With the development of the electronic measuring technology, the demand for measurement technique is higher and higher, so the traditional electronic oscillograph can hardly satisfy the need for real works. Measuring technology is geared to automated, intelligent and network directions. Digital storage oscillograph as the important measuring apparatus is widely used in various fields.The desi...

ESG is universally considered the most accurate free-rotor gyroscope at present and is crucial for nuke and other strategic weapons in their strategic attacks。ESG’s signal reading usually has two schemes: hollow rotor

On the basis of calibration and correction theory of 2-port vector network analyzer (VNA), this paper focuses on calibration and correction of 4-port VNA. In addition, measurement method of mix-mode S-parameters of balanced components using single ended 4-port VNA is studied.First of all, the 48-term error model of 4-port VNA is established. By understanding the work procedure of VNA and comp...

Frequency stability is a token of working capability with which the signal keepsits frequency stable. By measuring it we can evaluate whether a system can stay ata steady frequency or not. The way to evaluate it is to calculate its Allan variancewith no spacing, no interrupt at a section of time. The high speed and equal-precisionmeasurement of frequency using FPGA does not only break through...

Along with the energy conservation technology and the automated technology promotion, the electric power electronic installation like variable current equipment, the frequency conversion equipment and so on, the capacity expands day by day and the quantity increases day by day, which cause more and more serious higher harmonic in the electrical network the. Harmonic is a potential threat to se...

In recent years, along with the extensively application of the power electronic technology, the pollution of the harmonics becomes more and more seriously and it influences the electric power quality seriously. As a result, harmonics and inter-harmonics problems have attracted widespread attention.Firstly, this paper introduces the derive, harm and lots of detection algorithms of harmonics and...

As technique of power electronics develops, the load with nonlinear, impactive, unbalanced characteristics such as current rectifiers, frequency converters, arc furnaces have been increasingly used in power network in recent years. They generate lots of harmonics and cause distortion in power electrical network current (voltage). Power networks had been polluted by harmonics, which do harm to ...