How Real-Time Control Technologies Enable Reliable and Scalable High-Voltage Design

As power levels increase and modern power systems become more complex, the demands on high-voltage systems have changed significantly. To effectively meet these demands, it is necessary to use real-time MCUs or digital power controllers to control advanced power topologies that can simultaneously meet sophisticated specifications and various power requirements. This article will discuss some of the advantages of digital power control in high-voltage applications and demonstrate how it can help advanced power systems operate safely and efficiently.

Improve system reliability and protect power electronics

Reliability is critical to ensure uninterrupted operation of high-voltage systems. By providing reliable overvoltage, overcurrent and thermal stress protection for power electronic equipment, component life can be extended, safety can be improved, maintenance costs can be reduced and downtime can be minimized, thus ensuring efficient and reliable performance and avoiding unexpected failures.

Inexpensive and simple discrete analog products of the past lack the necessary flexibility and robustness to enable large-scale deployment, especially in fast-growing areas such as hybrid and electric vehicles, energy infrastructure and power delivery, which place increasing demands on high-voltage power electronics.

As a result, digital power performs better in power topology selection, system-level functions and safety protection, while minimizing the total number of designers who need to be assigned to move the project from the prototype stage to mass production.

Real-time MCUs and digital isolated power controllers can improve the reliability of such systems. These devices will minimize the delay between detection and action, ensuring fast and accurate response to load changes and disturbances. This will increase stability, reduce susceptibility to transient events, and improve overall performance.

MCUs and digital power controllers can also quickly detect faults such as overcurrent, overvoltage, and overtemperature, and trigger immediate protection measures to protect power electronic devices. These devices can precisely control power switching and modulation methods to optimize FET performance within a safe range and minimize component stress.

Capable of controlling multiple power stages simultaneously

The increasing power levels and complexity of modern high voltage systems often means multiple power stages are running within a system. Therefore, a powerful real-time MCU or digital controller is required to control all of these devices simultaneously.

One example is a microinverter for solar applications. A typical microinverter system involves multiple power stages, including a DC/DC power stage that converts the power generated by the solar panel to a high DC bus voltage and then converts the DC power to AC power for the grid. Texas Instruments' C2000™ real-time MCUs can drive these power stages while providing advanced monitoring and auxiliary control functions. The GaN-based 1.6kW bidirectional microinverter reference design has a TMS320F280039C MCU that can handle all four DC/DC boost power stages, as well as a converter-inductor-inductor-inductor-converter and a single-phase totem-pole power factor corrector (PFC). The new TMS320F28P550SJ has more computing power, with up to 24 pulse-width modulation channels and 39 analog-to-digital converter channels, so it can support six or more photovoltaic panels.

Texas Instruments’ digital power controllers, such as the UCD3138A, can be used to control multiple power stages simultaneously. One example is power factor correction (PFC) in AC/DC applications such as server PSUs. Another example is high-voltage DC/DC converters for telecom power supplies such as 48V or 12V. To implement multiple device variants to support different power levels and meet the needs of different regions, experienced designers using discrete analog controllers must recalculate, test, and verify their work. With a digital power controller, only one device is needed to control the entire system, and changing parameters such as voltage and current thresholds between different projects is mainly implemented in firmware, saving the design team valuable time. In addition, digital power controllers provide additional flexibility, communication capabilities, and auxiliary control functions. To achieve excellent reliability and scalability when operating increasingly complex power stages, digital power controllers and real-time MCUs provide a variety of options for end equipment that requires high-voltage FETs.

Maximize your investment in software and hardware solutions

In today's high-voltage systems, there is a growing need for redundancy, compliance with international standards, and reduced external dependencies in engineering design activities. A scalable platform should support a variety of designs through compatible hardware and software. Texas Instruments provides resources such as reference designs, evaluation modules, debuggers, and programs to help customers evaluate digital power controllers and MCUs in different applications more quickly, thereby reducing the need for custom board development. Texas Instruments also provides software libraries and firmware examples for different system configurations to accelerate prototyping and software development. GUI tools such as Fusion Digital Power™ Studio enable rapid adjustment and optimization of parameters that usually require external components to perform, and support device programming for prototyping and mass production needs. An overview of the resources provided in the UCD3138A ecosystem is shown in Figure 1.

Figure 1: UCD3138A digital power controller ecosystem

Figure 2 shows the C2000 real-time MCU ecosystem, which includes a variety of applications, products, hardware platforms, development tools, and software development kits.

Figure 2: C2000 real-time MCU ecosystem

Different Applications of Digital Power Controllers and Real-time MCUs

Suitable occasions for using digital power controllers:

• Designs that require the flexibility and auxiliary control functions of digital technology without the need to fully customize the power control law, while hoping to use digital power peripherals with dedicated feedback loops to achieve higher bandwidth.

• In applications, it is more desirable to perform parameter adjustment and optimization through an easy-to-use GUI rather than through rigorous firmware development.

• It is more desirable to use an ARM core suitable for power control and to allow easy live firmware updates with dual memory banks for zero downtime.

• Suitable for using real-time MCU:

• Precise adaptive control and fast response to system conditions are required in designs, such as in dynamic grid-tied inverters or motor drives.

• Complex algorithms need to be implemented in applications such as advanced modulation techniques or predictive control strategies.

• Seamless integration of peripherals, communication interfaces or sophisticated system diagnostics is required for comprehensive system monitoring and control.

The above points are summarized in Figure 3 and also on the Digital Power Technology page on TI.com.

Figure 3: Texas Instruments power controller landscape

Conclusion

Building a more sustainable future depends on the growth of high-voltage applications such as electric vehicles, bidirectional energy harvesting and storage systems, and more efficient data centers, which require advanced multi-level protection schemes to realize their full potential.

With TI's portfolio of high-voltage, real-time control technologies, you can flexibly and reliably control multiple power stages simultaneously and maximize intellectual property utilization between projects through a supporting ecosystem.

Additional Resources

Read the following application notes:

UCD3138x Device Overview

The essential guide to developing with C2000 real-time microcontrollers

Check out the following reference designs:

1kW Digitally Controlled Current Mode LLC Reference Design

1kW Compact Digital PFC with Meter and 97.5% Efficiency Reference Design for Telecom and Server PSUs

1.6kW GaN-based bidirectional microinverter reference design