摘要
为了克服传统逆变器控制电路设计复杂、成本较高且逆变输出波形品质差、电流畸变率高等缺陷,采用了DC-DC-AC的逆变拓扑结构,在前级DC-DC模块中采用专用芯片SG3525并设计外围电路获取占空比为0.4的PWM,其可将48V直流输入转变为400V高压脉冲直流输出,在后级DC-AC模块使用专用芯片TDS2285,产生高精度无毛刺SPWM波,通过精确的控制死区时间以实现全桥逆变控制输出。最终得到频率为50Hz,幅值为220V的正弦波,满载工作时输出电压变化在2%以内,频率变化在±1Hz以内,效率可以达到80%。与此同时本还研究了升压、逆变过程中驱动电路、变压器、滤波器等参数的计算选择。实验结果表明采用专用控制芯片的DC-DC-AC拓扑结构电路简单,逆变器具有良好的稳态性能和动态性能,同时改善了对非线性负载的适应性,提高了逆变器输出的品质。
In order to address the matters of traditional inverter,including complex design of control circuit,high cost,poor quality of the inverter output waveform,and high current distortion rate,this paper adapts the DC-DC-AC inverter topology.In the preceding stage of DC-DC module,the ASIC SG3525 is used and the peripheral circuit is designed to obtain PWM that has 0.4duty cycle.It can turn 48 vDC input into 400 voutput of high voltage pulsed DC.In the backward stage of DC-AC module,it employs the ASIC TDS2285 to produce high-precision SPWM wave without noise.In addition,it achieves the full-bridge inverter control output by control dead time precisely.The full-bridge inverter control output can generate sine wave that is made of the frequency of 50 Hz and the amplitude of 220 V.The output voltage changes within 2% and the frequency changes between-1Hz and＋1Hz in the state of full load,electric energy efficiency can be achieved 80%.Meanwhile,this paper also studies the calculation and choice of parameters of boost,drive circuit in the process of inverter,transformer and filter.The result shows that the DC-DC-AC inverter topology using the special control chips is simpler and the inverter possesses better steady-state behavior and dynamic performance.In addition,the adaptability of the nonlinear load and the quality of inverter output are improved.
出处
《国外电子测量技术》
2016年第7期85-90,共6页
Foreign Electronic Measurement Technology
