星载供配电系统应用GaN数字电源关键技术研究

Key technology of GaN digital DC/DC application in space electrical power and distribution system

第三代半导体功率GaN器件由于具有良好的抗空间电磁辐照特性,特别适合应用于空间电源系统和空间电力电子领域,大大缩小了空间电力电子设备的体积和质量。根据航天器应用的空间供配电系统的需求,结合GaN器件特点,提出了一种基于GaN器件和数字DC/DC变换拓扑的42 V航天器供配电系统,并确定了该数字DC/DC变换器的主要技术指标。通过使用GaN器件、LLC谐振及软开关、同步驱动技术、高频磁性元件,设计的GaN数字DC/DC变换器的开关频率可达3 MHz,与硅基空间电源相比显著提高了功率质量比和功率体积比,满足42 V航天器供配系统对数字DC/DC变换器的要求,符合卫星供配电系的发展趋势。提出了应用GaN器件的数字DC/DC变换器关键技术攻关以及验证情况,通过采用抗辐射加固的GaN器件以及驱动芯片、新型散热技术,大大提高抗辐照特性和热特性。试验结果表明,该数字DC/DC变换器抗单粒子能力大于75 MeV•cm^(2)/mg,电离总剂量效应大于100 krad(Si),热特性满足卫星实际使用要求。同时,根据空间供配电系统长寿命、高可靠性的特点,给出了基于GaN器件的数字DC/DC变换器的进一步研究和发展方向,为早日实现空间应用提供技术支撑。

The third generation of semiconductor power GaN devices are particularly suitable for space electrical power supply(EPS)systems and space power electronics equipment due to their good anti-space electromagnetic radiation characteristics,which greatly reduces the volume and weight of space power electronics devices.According to the requirements of space EPS system for spacecraft applications and the characteristics of GaN devices,a 42 V spacecraft EPS system was proposed based on GaN devices and digital DC/DC converter topology,and the main technical indicators of this novel digital DC/DC converter were determined.Through the use of GaN devices,LLC resonance and soft switching,synchronous drive technology,high-frequency magnetic components and other technologies,the switching frequency of GaN digital DC/DC converter proposed can reach 3 MHz,which significantly improves the power-to-weight ratio and power-to-volume ratio compared with silicon-based space power supply,meets the requirements of 42 V aerospace EPS system for digital DC/DC converter,and conforms to the development trend of satellite EPS system.Further,the key technology research and verification of digital DC/DC converter using GaN devices were proposed.Through the use of anti-radiation hardened GaN devices,driver chips and new heat dissipation technology,the anti-radiation characteristics and thermal characteristics were greatly improved.The experiment results show that the anti-single event capability of the digital DC/DC converter is greater than 75 MeV•cm^(2)/mg,and the total ionizing dose effect is greater than 100 krad(Si).The thermal characteristics meet the practical requirements of the satellite.At the same time,according to the characteristics of long life and high reliability of space power supply and distribution system,the further research and development direction of digital DC/DC converter based on GaN devices are given,which provides technical support for the early realization of space applications.