【摘要】 SPWM(正弦脉冲宽度调制)调制方法作为电力电子技术课程中的重要知识点,对学生理解高频逆变电路的调制原理和掌握后续课程有深远影响。理论课讲解时仅给出了作为调制波的正弦波和作为载波的三角波以及比较后的PWM波形,并根据正弦波半周期内载波和比较后输出PWM波形的极性来判断调制极性。现有实验台双极性SPWM调制实验因设计有箝位环节,学生实验测录到的比较器输出波形只有零或高电平,导致许多学生误判为单极性调制,而正确判断单极性还是双极性应根据逆变器桥臂中点电压的极性或者是加到各开关管的驱动信号逻辑关系。针对此问题,设计了单极性与双极性实现的Matlab仿真图和DSP编程实现的单相全桥逆变电路实验装置。更多还原

【Abstract】 Practice teaching is particularly important in power electronics,SPWM modulation method as an important knowledge of power electronic technology course has far- reaching influence for the students on the understanding of the modulation principle of high frequency inverter circuit and mastering the following courses.For theory courses,only the sine wave which is used as the modulate wave,the triangular wave which is used as carrier wave and the output waveform are given.The output waveform is got by comparing the sine wave and the triangular carrier wave.The polarity result is used to identify bipolar or unipolar modulation.The existing experimental facility bipolar SPWM modulation experiment due to the design of the clamping part,the output wave record is only zero or high level.It leads to mistake for unipolar modulation by many students.In fact,judging the unipolar or bipolar type should be based on the polarity of the inverter midpoint voltage or driving signal logic relations applied to each switch.Aiming at this issue,a single-phase unipolar and bipolar implementation of the Matlab simulation diagram and a DSP controlled full bridge inverter circuit of experiment is designed.更多还原