LIBRARY
Evaluation and control of active capacitor banks for a floating power modules based converter
Year: 2020 | Author: Tam Nguyen | Paper: T4.12
Fig. 1. (a) PIU with active capacitor banks, (b) assembly of one active capacitor, and (c) assembly of an equivalent capacitor bank
loss compensation factor, which is multiplied with the derivative of &Delta&lparvCa1&lpart&rpar&rpar&VerticalSeperator&omegas&plus&omegap to balance vCa2.
Simulation results of a three H-bridges based PIU are provided to verify the effectiveness of the active capacitor solution. The voltage waveforms across Ca1, Ca2, Ca3 and dc-bus voltage are included in Fig. 2(b). It is seen that the voltage vCa3, which is generated by the full bridge of the active capacitor, follows the voltage -&Delta&lparvCa1&rpar as well. Since each dc-link voltage is the sum of vCa1 and vCa3, its value is maintained constant around 1,000 V with a small ripple. All the dc-bus ripples of the three floating H-bridges are limited within 4&percnt the dc-bus voltage.
Fig. 1(b) and 1(c) show the assembly of the active capacitor and an equivalent capacitor bank, respectively. The comparison indicates that with a 5&percnt DC-bus ripple requirement the active capacitor solu- tion for the PIU helps reduce both the volume and weight by five times over the traditional passive capacitor solution.
Fig. 2. (a) Proposed voltage-mode control scheme, and (b) simulation results
Fig. 3 Controlled voltage of the active capacitors full bridge
