| dc.description.abstract | This thesis investigates the data provided by the Home Area Network, HAN, port installed in all new Advanced Metering System, AMS, power meters. The data is provided over an M-bus protocol, with a low bandwidth of maximum 2400 baud. This limits the amount of data the AMS meter is able to share with other appliances, making waveform analysis impossible.
A method using an oscilloscope to conduct high frequency measurements was developed and utilized to enable waveform analysis of voltage and current. This further enabled calculation of frequency, phase, active and reactive power. Data was also collected by use of a KAIFA AMS meter, and waveform analysis was conducted on this data as well.
The limited sample frequency of the data provided by the meter, makes it impossible to investigate harmonics and the fundamental frequency of 50 Hz by use of waveform analysis. However, long term repeating patterns of loads was detected. For the high frequency measurements, the harmonics of up to half of the provided sampling frequency could be analyzed. This is in accordance with the Nyquist theorem.
Fast Fourier Transform, Short-time Fourier transform, Wavelet Transform, WT, and Hilbert Huang Transform, HHT, were performed on different loads and sampling frequencies. The results were compared, and strengths and weaknesses investigated. WT is a powerful tool in this process, because the harmonic frequencies are known and the mother wavelet can be scaled accordingly. HHT provides better results if the loads are nonlinear other than the harmonic components.
To be able to analyze the 3rd harmonic component of the fundamental frequency, a rate of approximately 44,100 kbps is required. This is far from what the HAN port is able to deliver, making it impossible to utilize for such a high frequency waveform analysis. The sampling frequency used for internal calculations in the AMS meter is unknown, but is required to be far higher than what the HAN port is able to provide. A hardware or firmware update of the HAN-port, might enable a much higher sampling frequency, further enabling high frequency waveform analysis of the HAN-port data. | en |
