## 4 Results of an Experimental Study with Power-Line Communication and Selected End-User Equipment
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sinusoidal Supply Voltage** & **No-Load** & **LED** & **CFL** & \begin{tabular}{c} **Induction Motor** \\ **with PWM** \\ \end{tabular} \\ \hline \(S(N_{max})\) & (dB\(\mu\)V) & 87.51 & 92.67 & 94.09 & 93.43 \\ \(N_{max}\) & (dB\(\mu\)V) & 65.72 & 75.63 & 73.47 & 83.32 \\ \(SNR_{local}\) & (dB) & 21.79 & 17.04 & 20.61 & 10.11 \\ \hline \(P_{signal}\) & (dB) & \(-\)31.22 & \(-\)23.63 & \(-\)25.37 & \(-\)24.38 \\ \(P_{noise}\) & (dB) & \(-\)62.42 & \(-\)54.26 & \(-\)51.68 & \(-\)43.35 \\ \(SNR_{band}\) & (dB) & 31.21 & 30.63 & 26.31 & 18.97 \\ \hline \hline \multicolumn{5}{c}{**Distorted Supply Voltage**} \\ \multicolumn{5}{c}{**EN 50160 (Table 2)**} & **No-Load** & **LED** & **CFL** & \
\begin{tabular}{c} **Induction Motor** \\ **with PWM** \\ \end{tabular} \\ \hline \(S(N_{max})\) & (dB\(\mu\)V) & 87.51 & 93.55 & 92.46 & 92.92 \\ \(N_{max}\) & (dB\(\mu\)V) & 65.72 & 77.08 & 78.12 & 81.22 \\ \(SNR_{local}\) & (dB) & 21.79 & 16.47 & 14.35 & 11.70 \\ \hline \(P_{signal}\) & (dB) & \(-\)31.22 & \(-\)22.84 & \(-\)23.53 & \(-\)23.99 \\ \(P_{noise}\) & (dB) & \(-\)62.42 & \(-\)46.41 & \(-\)46.55 & \(-\)42.42 \\ \(SNR_{band}\) & (dB) & 31.21 & 23.57 & 23.02 & 18.43 \\ \hline \multicolumn{5}{c}{**Distorted Supply Voltage**} \\ \multicolumn{5}{c}{**IEC 61000-4-13 Class 3 (Table 3)**} & **No-Load** & **LED** & **CFL** &
\begin{tabular}{c} **Induction Motor** \\ **with PWM** \\ \end{tabular} \\ \hline \(S(N_{max})\) & (dB\(\mu\)V) & 87.51 & 92.96 & 91.80 & 91.11 \\ \(N_{max}\) & (dB\(\mu\)V) & 65.72 & 89.82 & 88.86 & 91.90 \\ \(SNR_{local}\) & (dB) & 21.79 & 3.14 & 2.94 & \(-\)0.79 \\ \hline \(P_{signal}\) & (dB) & \(-\)31.22 & \(-\)24.92 & \(-\)24.48 & \(-\)29.45 \\ \(P_{noise}\) & (dB) & \(-\)62.42 & \(-\)32.53 & \(-\)34.22 & \(-\)31.94 \\ \(SNR_{band}\) & (dB) & 31.21 & 7.61 & 9.73 & 2.49 \\ \hline \hline \end{tabular}  
* \(N_{max}\)—local maximum magnitude of the frequency component of the background signal; \(S(N_{max})\)—local magnitude of the frequency component of the transmission signal related to \(N_{max}\); \(SNR_{local}\)—signal-to-noise ratio derived on the basis of local values of \(S(N_{max})\) and \(N_{max}\); \(P_{signal}\)—power of the transmission signal in the transmission band; \(P_{noise}\)—power of the background signal (noise) in the transmission band; \(SNR_{band}\)—signal-to-noise ratio derived on the basis of \(P_{signal}\) and \(P_{noise}\).  
\end{table} 
Table 4: Characteristic parameters of the signal in the transmission band 42–89 kHz of PRIME PLC during the different scenarios of supply voltage distortion and variant types of loads. Direct investigation of a bit error rate (BER) was not performed in the presented study. However, based on [44, 45] it can be roughly estimated that for the achieved range of SNR reduction from 30.63 dB to 2.94 dB possible increase of BER could be in the range from \(10^{-5}\) to \(10^{-1}\). Details of the connections statistics in the investigated cases are collected in Table 5. It can be generally noticed that increasing the level of the supply voltage distortion resulted in increasing the total number of the attempted connections as well as a long duration of the failed connections during one hour. Figure 13 depicts the impact of the supply voltage distortion on the duration of the failed connections in one hour of the investigated PRIME PLC system concerning the different types of the investigated equipment. A prominent case is represented by waveform distortion used in the immunity test of the equipment. This case indicates the duration of the failed connections in one hour longer than level 180 s specified by the producer as a margin condition for proper connection.