1) Frequency Transformer Elimination: Eliminating the industrial frequency power transformer and adopting direct rectification from the power grid is a significant measure to reduce the size and weight of switching power supplies. The elimination of the industrial frequency transformer has become a characteristic of contemporary advanced switching power supplies. Compared to DC regulated power supplies with industrial frequency transformers, the outstanding advantages of switching power supplies without industrial frequency transformers are their small size, weight, and high efficiency. The circuit forms of switching power supplies have become diverse, with pulse width modulation, frequency modulation, and hybrid modulation types, with pulse width modulation being the most prevalent. Currently, there are switching power supplies that are completely transformerless, even eliminating the need for high-frequency transformers. A significant feature of this power source is that its size can be much smaller than that of the current transformerless switching power supplies, and it does not require wound transformers or similar components, allowing for integrated circuit manufacturing. Avionics Power Supply
2) High-frequency Switched Power Supplies: A notable feature of modern switched power supplies is the continuous increase in switching frequency, with both transistor, thyristor, and field-effect transistor-based switched power supplies moving towards high-frequency operation. With the advent of power IGBTs and MOSFETs, the operating frequency of switched power supplies has gradually increased from the early typical 20KHz to the megahertz and even gigahertz range.
3) Integrated Control Circuitry: Early switch-mode power supplies (SMPS) were constructed using discrete components. This resulted in complex circuit designs and difficult debugging and maintenance, which hindered the widespread application of SMPS. To accommodate the rapid development of SMPS, integrated control circuitry for SMPS was successfully developed, and its functionality has become more sophisticated. The integration of control circuitry in SMPS greatly simplifies the design of SMPS, enhances its electrical performance and reliability, and reduces its size and cost. 36V Avionics Power Supply
4) High-frequency Main Components: To meet the rapid development of switching power supplies, the main components used in switching power supplies are also advancing quickly, with the primary goal being high-frequencyization. Switching elements within switching power supplies, such as power transistors, thyristors, and field-effect transistors, have all achieved improvements in operating frequency. However, the power tube IGBT composite and MOSFET field-effect transistors are particularly noteworthy, as they not only increase the switching frequency to 1MHz-1GHz but also offer excellent switching characteristics, low driving power requirements, no secondary breakdown, and the ability to prevent thermal runaway, among other special advantages. Additionally, the emergence of high-current Schottky barrier diodes significantly improves the rectification efficiency of low-voltage, high-current switching power supplies, characterized by fast switching speeds, short reverse recovery times, and low forward voltage drops. During the filtering process, capacitors and other devices also need to be researched in terms of materials, structure, and manufacturing processes to meet the requirements of high-frequency switching power supplies. 400HZ Power Supply
5) Full Digital Control: The control of switching power supplies has evolved from analog control, to analog-digital hybrid control, and now to the stage of full digital control. Full digital control represents a new trend and has been applied in many power conversion devices. However, digital control has been less frequently used in DC/DC converters in the past. In the past two years, high-performance full digital control chips for switching power supplies have been developed, and costs have been reduced to a more reasonable level. Several companies in Europe and the US have developed and manufactured digital control chips and software for switch converters. The advantages of full digital control include: digital signals can be calibrated to smaller quantities compared to hybrid analog-digital signals, and the chip prices are more affordable; current detection errors can be accurately corrected digitally, and voltage detection is also precise; it allows for rapid and flexible control designs. Aviation Ground Power
