**5. Experiments**

In this section, experiments are performed, and the schematic diagram is shown in Figure 11. The experimental system includes the main circuit and the control loop, where the main circuit parameters are listed in Table 1. In the control loop, a hall sensor CSM050LX with the transfer ratio of 0.8 Ω is adopted to acquire the inductor current signal, so the value obtained from the oscilloscope should be divided by this coefficient. The amplifier AD620 is used to collect the output voltage signal. The conversion of A/D, and calculation of the disturbance increment of the controlled parameter are processed by an ARM-based 32-bit MCU (Microcontroller Unit) STM32F103C8T6. The 12-bit Digital-to-Analog Converter TLV5618 is adopted to perform the conversion of D/A. The voltage comparison and the RS flip-flop function are completed by LM339 and HD74LS02P, respectively. An optical coupler is used to drive the MOSFET, and it can also achieve the isolation between the main circuit and the control loop.

**Figure 11.** Schematic diagram.

The experimental setup and the experimental results are shown in Figure 12. As shown in Figure 12b,c, the upper curves represent the inductor current and the lower curves represent the output voltage. The waveforms of the converter operating from the chaotic state to a stable state are shown in Figure 12a. The close-up views of the state variables in the chaotic and stable period-1 states are shown in Figure 12b,c respectively. It can be seen from Figure 12a that when the converter operates in the stable state, the sampling values for the inductor current at the bottom and peak point are 1.915 and 2.42 V, corresponding to the real inductor current values of 2.394 and 3.025 A, respectively. Additionally, the transfer ratio of the current sensor is 0.8 Ω. Thus, the peak-peak value of the inductor current is about 0.63 A. For the output voltage, as shown in Figure 12c, the valley and peak values are 18.78 and 25.01 V, respectively. It can also be seen from Figure 12 that when the converter returns to a stable state from a chaotic state, the peak-peak value of the output voltage is reduced to 6.228 from 13.56 V, and that of the inductor current is almost cut in half, i.e., from about 1.25 to 0.63 A.

Moreover, for the boost converter operating in a stable state with the proposed control scheme, a comparison of the data from both the simulation and experiment is summarized in Table 3. It should be noticed that the experimental value for the output voltage is about 1.3 V less than the simulated value, which is caused by the output diode. Thus, considering the conductance voltage drop of the Schottky diode, the experimental results agree quite well with the simulations. Another noteworthy thing is that in order to observe the effect of the proposed control method, the parameters of the

example circuit, which result in the converter having larger ripples with the state variables, were chosen to be the same as those in [32].

**Figure 12.** (**a**) Experimental setup and experimental waveforms (channel 1: Inductor current *i*L; Channel 2: Output voltage *u*O): (**b**) From chaotic state to period-1 state, (**c**) chaotic operation, (**d**) period-1 operation.

**Table 3.** Results from simulation and experiment of the PCM boost converter with the proposed control.

