What are the benefits of digital control in power supply for industrial 4.0 and Internet of things applications?

Power supplies with digital control have many benefits at the device and system level. Power performance can be dynamically optimized in installation and operation, and more extensive system control and monitoring power characteristics can be achieved for efficient integration. "Connected" manufacturing industries, such as industry 4.0 or the "fourth industrial revolution", benefit in particular from the Internet of things (IOT). This article explains what digital controls are in the Power Supply and the benefits offered in standalone and connected applications. Background: digital control in power supply may mean different things, from simple state / alarm digital signal and on / off control of traditional analog controller, adding more complex functions through simple microcontroller, to fully realize feedback loop compensation with digital signal processor (DSP). The latest technology allows for flexible configuration of power features and performance during development and debugging, as well as dynamic configuration in the final application.

Although the cost of DSP controlled digital power supply is higher than that of special analog controller, its price is decreasing and its performance is improving, so its advantages are more and more attractive. This is especially true for higher power with higher value products, in which case the system performance improvement is more obvious, and component cost is not the problem. In power supply design, digital signal processor (DSP) really needs to understand the stability of control loop in frequency domain and how to realize control loop in time domain with effective code, but these technologies have been understood, and mainstream power supply manufacturers are accepting this technology. While there is a need to invest in the skills and time to develop, validate, and document firmware to achieve a reliable and robust solution, the code is reusable, and a common hardware platform can be designed to quickly configure software for multiple applications - a real benefit in production that can deliver time to market and unit price cost economics to users. Advantages of digital signal processing the main advantages of full digital implementation of power control and monitoring are flexibility and the ability to adjust performance and characteristics for different applications, which requires hardware changes to traditional analog controllers. The digital control loop also has the advantages of immunity to environmental changes and changes of component values with tolerance and age. This defines performance more precisely. The DSP chip can also respond to system performance variables, such as detecting load characteristics and optimizing control loops to obtain optimal load transient response or dynamically reducing output voltage to reduce load power consumption in standby mode. The adjustment of output voltage can be extended to a wider range, even 0-105 / 110% of more general application or application when the final optimal system voltage is not known at all. The current limit is also adjustable, not only in the "knee" value, but also in overload or short circuit, which may be a characteristic of "constant current" blocking or "burping" mode. This is very important in modern high efficiency resonant topology. In this topology, it is not practical and complex to use traditional analog controller to realize the multiple switch and loop compensation scheme. In the digital power supply, in addition to the control feedback loop, it can also easily include many other programmable functions. These functions have system advantages, which will lead to hardware changes in the analog implementation. For example, the startup / shutdown ramp rate and sequence of multiple power supplies can be set through different schemes, such as "ratio" or at the same time; the polarity of the enabled input and signal output can be freely switched.