LTTS’ DC-DC Power Converter Boasts High Efficiency with Scalability and High-Power Density Over Wide Load Range

Direct current (DC) is making a comeback with the rise of solar PV, storage batteries, wind turbines, and electric vehicles.  This gamut of new devices however has different voltage needs, and converters are essential for stepping-up or stepping-down the voltage level depending on specific requirements.  The DC-DC power converter has, as a result, become a major part of the innovation race, where reliable and high-performance power supplies are paramount.  In addition to conversion efficiency, industry leaders are also demanding leaner form factors for such devices.

Problem:

Even the best-in class DC-DC power converters lack efficiency and have poor performance, and their large size also poses a challenge.  Although their bulkiness serves to compensate for the inefficient power conversion at high voltage.

Objective:

LTTS’s aim was to develop a solution that delivered higher efficiency and power density by leveraging the latest in semiconductors, magnetics, and cooling technologies.

Challenge – Designing High Efficiency DC-DC Power Converter:

During the DC-DC power converter design process, LTTS focused on raising efficiency throughout the load range.  This coupled with the limitations of passives, particularly capacitors, from a lifetime perspective increased the complexity of developing the DC-DC power converter.  Additionally, electromagnetic interference (EMI)/electromagnetic compatibility (EMC) proved to be a major challenge.

Bi-directional operation over a wide voltage range, and packaging and thermal management were some other roadblocks in the entire process.

Process:

While designing the converter, LTTS had to reduce losses in active components and magnetics, and at the same time, manage thermal issues by using appropriate cooling techniques.  To achieve this, LTTS:

• Built wide bandgap semiconductors, such as silicon carbide FETs to reduce switching losses
• Reduced the size of passive components, such as inductor, and helped achieve high power density by using new magnetic material
• Used the converters in a multi-phase operation mode to ensure scalability and efficiency over the whole load range, while reducing ripple currents in the capacitor
• Equipped the converter with robust protective capabilities to guard against high temperature and short-circuiting from overload

Highlight:

LTTS’ DC-DC power converter has bi-directional buck boost mode topology and is designed for multi-phase operation.  This has several applications, such as in battery chargers, automotive systems, energy storage devices, telecom sector, renewable energy equipment or any application that warrants the delivery of high efficiency and performance.

At 10kW, the converter can deliver over 96 percent efficiency between the load range of 20 percent and 100 percent.

Results:

• Electrical Performance - The DC-DC power converter delivers over 96 percent efficiency with scalability and high-power density over wide load range
• Bi-Directional - LTTS developed a bi-directional DC-DC power converter that aids in regenerative applications, thereby making the converter apt for green energy
• Protection - LTTS ensured electronic protection against high temperature and short circuit
• Error Logger - LTTS have equipped the converter with an error logging mechanism that will help users track its performance
• Digital Connectivity - LTTS incorporated native digital control algorithms into DC-DC power converter, allowing users to utilize Ethernet, serial or CAN for communication