Transformers, converters, and improvements to the same

A soft-switching solid-state power transformer comprising:

• a high-frequency (HF) transformer comprising first and second winding connections;
• a first auxiliary resonant circuit coupled to the first winding connection of the HF transformer;
• a second auxiliary resonant circuit coupled to the second winding connection of the HF transformer;
• a first current-source inverter (CSI);
• and
• a second CSI bridge;
• wherein the first auxiliary resonant circuit comprises:
• a resonant capacitor coupled across the first winding connection;
• a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor;
• and
• a synchronous rectifier coupled across the first winding connection in series with the resonant capacitor and the resonant inductor;
• wherein the second auxiliary resonant circuit comprises:
• a resonant capacitor coupled across the second winding connection;
• a resonant inductor coupled across the second winding connection in parallel with the resonant capacitor of the second auxiliary resonant circuit;
• and
• a damping feature coupled across the second winding connection in series with the resonant capacitor of the second auxiliary resonant circuit and the resonant inductor of the second auxiliary resonant circuit;
• wherein the first CSI bridge is coupled to the first auxiliary resonant circuit and comprises reverse blocking switches configured to conduct current in one direction and block voltage in both directions;
• and
• wherein the second CSI bridge is coupled to the second auxiliary resonant circuit and comprises reverse blocking switches configured to conduct current in one direction and block voltage in both directions.

A reactive power compensator, comprising:

• a high-frequency (HF) transformer comprising first, second and third winding connections;
• a first auxiliary resonant circuit coupled to the first winding connection of the HF transformer, the first auxiliary resonant circuit comprising:
• a resonant capacitor coupled across the first winding connection;
• a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor;
• and
• a synchronous rectifier coupled across the first winding connection in series with the resonant capacitor and the resonant inductor;
• a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising reverse blocking switches configured to conduct current in one direction and block voltage in both directions;
• a second auxiliary resonant circuit coupled to the second winding connection of the HF transformer;
• a second CSI bridge coupled to the second auxiliary resonant circuit, the second CSI bridge comprising reverse blocking switches configured to conduct current in one direction and block voltage in both directions;
• a third auxiliary resonant circuit coupled to the third winding connection of the HF transformer;
• and
• a third CSI bridge coupled to the third auxiliary resonant circuit, the third CSI bridge comprising reverse blocking switches configured to conduct current in one direction and block voltage in both directions.

A stacked converter comprising:

• a first and second converter module, each of the first and second converter modules comprising:
• a high-frequency (HF) transformer comprising first and second winding connections;
• a first auxiliary resonant circuit coupled across the first winding connection of the HF transformer, the first auxiliary resonant circuit comprising:
• a resonant capacitor coupled across the first winding connection;
• a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor;
• a reverse blocking switch coupled across the first winding connection in series with the resonant inductor and in parallel to the resonant capacitor;
• and
• a synchronous rectifier coupled across the first winding connection in series with the resonant capacitor and the resonant inductor;
• and
• a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising first, second, and third phase legs;
• and
• a shared capacitor, the shared capacitor coupled to the second phase leg of the first CSI bridge of each of the first and second converter modules.

A stacked converter comprising:

• a first and second converter module, each of the first and second converter modules comprising:
• a high-frequency (HF) transformer comprising first and second winding connections;
• a first auxiliary resonant circuit coupled across the first winding connection of the HF transformer;
• and
• a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising first, second, and third phase legs;
• wherein the first auxiliary resonant circuit comprises:
• a resonant capacitor coupled across the first winding connection;
• a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor;
• and
• a damping feature coupled across the first winding connection in series with the resonant capacitor and the resonant inductor;
• and
• a shared battery, the shared battery coupled to the second phase leg of the first CSI bridge of each of the first and second converter modules.

A modular-stacked multi-stage converter comprising:

• a first stage and a second stage, each of the first stage and the second stage comprising:
• a first and second converter module, each of the first and second converter modules comprising:
• a high-frequency (HF) transformer comprising first and second winding connections;
• a first auxiliary resonant circuit coupled across the first winding connection of the HF transformer;
• and
• a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising three phase legs;
• wherein the first auxiliary resonant circuit comprises:
• a resonant capacitor coupled across the first winding connection;
• a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor;
• and
• a damping feature coupled across the first winding connection in series with the resonant capacitor and the resonant inductor;
• and
• a shared capacitor, the shared capacitor coupled to the second phase leg of the first CSI bridge of each of the first and second converter modules of each of the first and second stages.