High voltage capacitor charging power supplies for repetitive rate loads

Three techniques for charging power capacitors to voltages in the range of 2-40 kV are examined and compared. The first technique, which uses a high-voltage DC power supply with a charging resistor, is shown to have a maximum efficiency of 50%. This requires that both the high-voltage DC power supply and the charging resistor have increased power ratings. As a result, this concept is utilized only in applications where the charge rate is low, i.e. 2000 J/s. The second method, resonance charging, is more efficient than the first but requires high-voltage components. Latchup of the high-voltage switches is possible, and the power rating of this technique can be high. Neither the first nor the second technique can compensate for capacitor leakage. The third technique, which utilizes a high-frequency power converter, applies power electronics technology to capacitor charging applications. The advantages are improved efficiencies through the implementation of zero current or zero voltage switching techniques, improved voltage regulation, and utilization of semiconductor devices as the switching elements. This technique allows for the compensation of capacitor leakage.<>