The power load (CPL) consists of a buck converter and a switching control that is designed to dissipate a constant power for a given input voltage range. Figure 1 shows the constant power load configuration. The commanded inductor current is obtained from the ratio of the commanded power to the output voltage.
The employed constant power load controller generates commanded inductor current. The commanded inductor current is used in the hysteresis modulator to produce switching signal for the buck converter to achieve the desired output power level.