A Very Low-Ripple High-Voltage High-Power DC Power Supply Using an Interleaved Converter and a Linear Ripple Elimination Unit

High-voltage dc power supplies (HVDCPSs) have been widely adopted for the vacuum tubes. In this application field, the low ripple voltage cannot be easily achieved by increasing the size of the output capacitance of the HVDCPS due to the limited permissible level of the stored energy. To obtain a low level of the output ripple as well as the limited value of the stored energy, the previously published literature proposed switching frequency increment. This approach has several shortcomings such as switching power loss increment, a limited level of the achievable ripple, and low value of the insulators' lifetime. To improve the mentioned deficiencies, this article hybridizes the series linear regulator and a high-frequency high-power dc interleaved converter. Using the proposed method, at the first stage, the level of the ripple decreases to a rational margin with increasing the ripple frequency. At the second stage, the level of the ripple reduces using the linear regulator to reach the expected precision. In order to validate the performance of the proposed structure, simulation and experimental results are provided for a 15-kV and 22.5-kW converter with the output voltage precision of 0.02%.