Improved KY Converter

Abstract

In a KY boost converter, a short, high-current charging pulse occurs in each clock cycle, placing extreme stress on the components, especially the diode (D), the first capacitor (C1), and the second electronic switch (S2). By inserting a small inductor (L2), which can also be an air-core inductor, the charging current becomes sinusoidal. This reduces the maximum current and improves electromagnetic compatibility. The second inductor (L2) is connected between the negative terminal of the first electronic switch (S1), the negative terminal of the first capacitor (C1), and the positive terminal of the second electronic switch (S2). The converter has a limited but linear voltage transformation ratio and, from a control engineering perspective, is a phase-minimum system. Due to the arrangement of the first inductor (L1) and the output capacitor (C2), the output voltage is very smooth.