发电机自动电压调节器设计

摘要

The generator′s output voltage is controlled by AVR (automatic voltage regulator). When the load changes,AVR regulates field current automatically to keep the generator′s voltage invariable by checking the output voltage. Traditional AVR regulates field current by controlling the giant transistor′s base electrode voltage or thyristor conduction angle. These ways consume much more energy or have a bad transient response. A Buck system controlled by SG3525 is designed in this paper,which regu-lates the field current by adjusting the PWM duty cycle of power switch. PI control and soft start are designed on the hardware plat-form to regulating the generator′s output voltage reposefully. In addition,low voltage protection,high voltage protection and high field current protection were designed in the system. The rationality of the regulator was verified by an experimental prototype.%电压调节器控制发电机的输出电压，在负载变化时，电压调节器通过检查输出电压，自动调节励磁电流，使发电机的输出电压稳定。传统的电压调节器通过调节功率晶体管控制极的电压或者调节晶闸管的导通角调节励磁电流，这些方法要么能耗大，要么电压调节瞬态响应差。这里设计了基于SG3525控制的Buck电路，通过调节功率开关管的PWM占空比调节励磁电流。为了平稳调节输出电压，硬件平台上设计了PI调节和软启动，并具有过压欠压保护和过励磁电流保护等功能。最后设计硬件平台验证设计的合理性。