# Long-Lifetime Event-Driven Wireless Monitoring System for Pole-Mounted Transformers
## 5 Experimental Results  
The prototype printed circuit board (PCB) of the proposed monitoring system and its experimental setup are shown in Figure 12. The PCB measures 5.4 cm \(\times\) 3.1 cm with a vertically integrated RF communication module FS1000A as TX. Table 2 lists the model name of each commercially available block used. Figure 13 shows the experimental results for each transient waveform of the proposed monitoring system: \(v_{\text{IN}}\), \(v_{\text{RMS}}\), \(v_{\text{PEAK}}\), \(EN_{\text{RMS}}\), \(EOC\), and \(D_{\text{OUT}}\). The PD signal in Equation (12) and Table 1 was applied by a function generator controlled by ArbExpress software, and is shown in Figure 14a. From the zoomed-in view at the top of Figure 13, it \begin{table}
\begin{tabular}{c c c c c c c} \hline  & \(\text{\it CMP}_{\text{1}}\) & \(\text{\it CMP}_{\text{2}}\), \(\text{\it CMP}_{\text{3}}\) & **RMS Converter** & **Peak Detector** & **ADC** & **TX** \\ \hline Model name & TS331 & TLV7011 & LTC1968 & LTC6244 & AD7787 &
\begin{tabular}{c} HT12E, \\ FS1000A \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 2: Model name of each block of the proposed system. Figure 11: Simulated SNR variation with RMS value of input noise in a conventional monitoring system with the event controller (“EC”), and with the proposed event-driven monitoring system (“Prop”). Figure 12: Experimental setup for the proposed system. (**a**) Prototype PCB and (**b**) experimental setup with PD signal as input. can be seen that \(EN_{\text{RMS}}\) is set to be high for 33.6 \(\upmu\)s immediately after \(v_{\text{IN}}\) becomes higher than \(V_{\text{REF1}}\). The peak value of \(v_{\text{RMS}}\) is obtained once \(v_{\text{IN}}\) sets to zero after the propagation delay set by \(C_{1}\). From \(EOC\) and \(D_{\text{OUT}}\), \(I_{\text{ADC}}\) and \(t_{\text{TX}}\) are obtained as 1.2 ms and 2.8 ms, respectively. The RF communication module exhibits 1.4 ms latency at the transmission frequency of 100 kHz. For further quantification, three more input waveforms (a pure sine wave, a sine wave with linearly decaying amplitude, and a triangular wave) were generated as intermittent abnormal inputs lasting only 4.0 \(\upmu\)s at 5.0 MHz, as shown in Figure 14b-d, respectively. Figure 15 compares the linearity of \(v_{\text{PEAK}}\) with respect to the RMS input for the four different input signals. The RMS value of each input was obtained by controlling its peak voltage from 0.5 V to 1.5 V. The maximum integral nonlinearity (INL) and offset of each input waveform are listed in Table 3, which was obtained using a MATLAB curve-fitting tool. Figure 13: Experimental results for transient waveforms in the proposed event-driven monitoring system. (**a**) Detecting vpeak out of vRM and (**b**) its data transmission. Figure 14: Input signals used for experiments. (**a**) Generated PD signal, (**b**) pure sine wave, (**c**) sine wave with linearly decaying amplitude, and (**d**) triangular wave. \begin{table}
\begin{tabular}{c c c c c} \hline  & **Sine Wave** & **Amplitude** & **Triangular** & **Generated PD** \\  & & **Decaying** & **Wave** & **Generated PD** \\ \hline Offset (mV) & 236.50 & \(-\)188.10 & \(-\)4.13 & 2.18 \\ Maximum INL (\%) & 2.76 & 9.05 & 3.81 & 4.44 \\ \hline \end{tabular}
\end{table} 
Table 3: Model name of each block of the proposed system. Figure 15: Experimental results showing variation of \(\upsilon_{\text{PEAK}}\) with RMS input for various waveforms. of the proposed monitoring system in sleep mode as long as possible. For each block, the run-time in sleep mode is several orders longer than in normal mode, except for the always-on EC. As a result, the total energy consumption in the proposed event-driven monitoring system is as low as 1.75 mWs. In Figure 17, the measured energy consumption in this system is compared to the calculated energy consumption based on the datasheets of the components, as the frequency of abnormality occurrence is varied.