## 3 Results
### Implementation Results
#### 3.2.1 Five-Level CHBMILI Results  
Figure 11 serves as an illuminating visual representation of the output voltage waveform with a resistive load of 250 \(\Omega\), providing a detailed insight into the results of the synthesis process designed to achieve the desired five-level configuration; this waveform was obtained using a Tektroniks oscilloscope MDO3024. In this graphical depiction, these five levels' distinct and deliberate synthesis becomes readily apparent, showcasing a waveform characterized by its multi-level structure. Moreover, this waveform analysis affirms the successful attainment of specific operational objectives, as evidenced by the realization of a peak voltage precisely at the targeted magnitude of 180 V, harmonizing seamlessly with the intended specifications shown in Table 2. Additionally, the waveform's frequency is observed to align closely with the desired 60 Hz frequency, thereby confirming the meticulous precision and accuracy of the synthesis process.  
Figure 12 shows the output current waveform of the CHBMILI, which was also obtained using a Tektroniks oscilloscope MDO3024. Because the load of the five-level CHBMILI is resistive, the output voltage and the output current have the same form, and both signals are in phase.  
The THD value of the voltage waveform was measured using the Power Quality Analyzer Fluke 435. The results of this THD measurement and the comprehensive Fast Fourier Transform (FFT) analysis, spanning up to the 49 th harmonic, are visually represented in Figure 13 for reference and analysis. Notably, the THD value has been quantified at 15.3% in this specific instance.  
As previously articulated, it is worth emphasizing that the OMTHD method diverges significantly from the SHE method in its primary objective. Unlike the SHE method, which is primarily focused on the eradication of low-order harmonics, the OMTHD approach prioritizes the reduction of the THD, thus addressing higher-order harmonics and overall waveform quality enhancement as opposed to exclusively targeting low-order harmonics elimination.  
Figure 11: Five-level CHBMILI output voltage with R = 250 \(\Omega\).  
Subsequently, a 100 \(\Omega\) resistive load was connected to the output of the CHBMIL. The output voltage is shown in Figure 14, while the output current is shown in Figure 15. As with the previous load, the five levels of the output voltage can be seen, and the current has the same shape as the voltage.  
Figure 12: Five-level CHBMIL output voltage with R = 250 \(\Omega\).  
Figure 13: Fast Fourier Transform of the five-level CHBMIL output voltage with R = 250 \(\Omega\).  
Figure 16 shows the THD value of the voltage waveform; it can be observed that a THD value of 15.3% was obtained just like with the resistive load of 250 \(\Omega\).  
The last load connected to the five-level CHBMILI was an RL load. The load consists of a 100 \(\Omega\) resistor and an brushless AC motor with the following characteristics:  
* Power: 1/20 HP;
* Current: 2.0 A;
* Voltage: 127 Vrms;
* Frequency: 60 Hz;
* Speed: 1550 RPM.  
This AC motor is shown in Figure 17.  
Figure 14: Five-level CHBMILI output voltage with R = 100 \(\Omega\).  
Figure 15: Five-level CHBMILI output voltage with R = 100 \(\Omega\).  
Figure 16: Fast Fourier Transform of the five-level CHBMILI output voltage with R = 100 \(\Omega\).  
Figure 17: Five-level CHBMILI output voltage with the RL load.  
Figure 18 shows the output voltage with the RL load, while Figure 19 shows the output current. Because the load now has an inductive component, the output current waveform is no longer the same as the output voltage waveform.  
It can be seen that, even with an inductive load, the voltage maintains its shape, and the value of the output THD does not change, as seen in Figure 20, where the THD remains with a value of 15.3%.  
Figure 19: Five-level CHBMIL output current with the RL load.  
Figure 18: Five-level CHBMIL output voltage with the RL load.