The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper two low-cost microprocessors are employed to build up a internet-based instrument system for remote monitoring of power quality, the instrument system can collect various types of power quality disturbances in interactive or automatic mode. Besides, an SD data storage device is used to save raw data which can be also uploaded to a database server via internet, users can access the server...
Recently, voltage variation and flicker events in a power system are concerned by both of utility and customers. Actually, these two events are always measured separately, but in a certain cases they can happen successively. Voltage variation may cause equipments dropout or failure and result in huge economic losses; while voltage flicker will interfere human vision. In order to discriminate voltage...
Digital algorithms have been widely used for the measurement of voltage flicker, and the fast Fourier transform (FFT) is the most popular tool to calculate individual and equivalent voltage flicker components. In this paper the effects of system frequency deviation on the performance of FFT-based algorithms are analyzed, and an enhanced indirect demodulation algorithm is proposed to mitigate the effect...
Frequency is an important index to represent electric power system quality, and it is often used to improve the accuracy of harmonic, flicker and inter-harmonic calculation for a distorted voltage waveform. Since the existing frequency calculation algorithms have some different problems, this paper proposes a scheme to enhance the algorithm of demodulation of two complex signals. This algorithm can...
This paper proposes the estimation results of the stochastic characteristics of harmonic and flicker for an AC and a DC electric arc furnace feeders. These characteristics include stationarity, normality and correlation. Besides, the statistic probability was assessed, too. The estimation and the assessment are implemented by a PC-based virtual instrumentation system. The results show that (1) most...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.