Modular dc-dc converter

A modular dc-dc converter system, comprising:

• a first dc-dc converter module, including a first converter module input port and a first converter module output port;
• a second dc-dc converter module, including a second converter module input port and a second converter module output port;
• a dc transformer module, including a transformer module input port and a transformer module output port;
• a controller that supplies at least one first duty cycle signal to at least one switch of the first dc-dc converter module, at least one second duty cycle signal to at least one switch of the second dc-dc converter module, and one or more control signals to the dc transformer module;
• a system input voltage port;
• and
• a system output voltage port,
• wherein the first converter module input port of the first dc-dc converter module and the second converter module input port of the second dc-dc converter module are coupled connected in parallel, and both the first dc-dc converter module and the second dc-dc converter module are coupled to the system input voltage port;
• the first converter module output port of the first dc-dc converter module is coupled to the transformer module input port of the dc transformer module;
• the second converter module output port of the second dc-dc converter module is coupled in series with the output port of the dc transformer module, and the series-coupled ports are coupled to the system output voltage port.

A method of controlling a modular dc-dc converter system, the method comprising:

• providing a modular dc-dc converter system comprising:
• a dc-dc converter module including a converter input port and a converter output port;
• a dc transformer module including a transformer input port and a transformer output port;
• a controller that supplies at least one duty cycle signal to at least one switch of the dc-dc converter module and at least one control signal to the dc transformer module;
• a system input voltage port;
• and a system output voltage port, wherein the converter input port of the dc-dc converter module and the transformer input port of the dc transformer module are coupled to the system input voltage port, the converter output port of the dc-dc converter module is coupled in series with the transformer output port of the dc transformer module and the series-coupled ports are coupled to the system output voltage port;
• and
• in a first operational state, controlling the dc-dc converter module to operate with pulse-width modulation (PWM) and controlling the dc transformer module with a fixed conversion ratio;
• and
• in a second operational state, performing an operation comprising at least one of (i) controlling the dc-dc converter module to operate in a pass-through mode and (ii) controlling the dc transformer module to shut down and controlling the dc-dc converter module to operate with PWM.