TABLE OF CONTENTS Conventional dc power supplies operate at a given dc out-put voltage into a constant or near constant load. Pulse loads such as lasers, flashlamps, railguns, and radar, however, require short but intense bursts of energy. Typically, this energy is stored in a capacitor and then released into the load. The rate at which the capacitor is charged and discharged is called the repetition rate, T, and may vary from 0.01 Hz for large capacitor banks to a few kHz for certain lasers. Recharging the capacitor voltage to a specified voltage is tasked to a capacitor charging power supply (CCPS). The role of power electronics devices, topologies, and charging strategies for capacitor charging applications is presented in this chapter.
Figure 21.1 shows the voltage across the energy storage capacitor connected to the output of a CCPS. As seen in this figure, the CCPS has three modes of operation. The first mode is the charging mode in which the capacitor is charged from an initial voltage of zero to a specified final voltage. The duration of the charging mode is determined by the capacitance of the energy storage capacitor and the rate at which the CCPS delivers energy. The next mode of operation is the refresh mode, which can be considered a "standby mode" where the stored energy is simply maintained. When the output voltage drops below a predetermined value, the CCPS should turn on and...
