答案1
作为起点,您可以尝试:
\documentclass{standalone}
\usepackage[americanvoltages,fulldiodes]{circuitikz}
\begin{document}\footnotesize
\begin{circuitikz}
\draw (0,0) node[circ,label={180:o}]{}
to[battery1={$\frac{V_{dc}}{2}$}] (0,2)
to (6,2) node[Lnigbt,bodydiode,anchor=D,label={[label distance=10]100:$D_{c1}$}](S3){};
\draw (S3.E) to (6,0) node[circ,label={180:$V_{C}$}](vc){}
to (6,-.5) node[Lnigbt,bodydiode,anchor=D,label={[label distance=10]100:$D_{c2}$}](s3){};
\draw (s3.E) to ++(-6,0) to[battery1={$\frac{V_{dc}}{2}$}] (0,0);
\draw (S3.B) node[circ,label={90:{$S_3$}}]{};
\draw (s3.B) node[circ,label={90:{$S^*_3$}}]{};
\draw (2,2) node[Lnigbt,bodydiode,anchor=D,label={[label distance=10]100:$D_{a1}$}](S1){};
\draw (S1.E) to (2,0) node[circ,label={180:$V_{A}$}](va){}
to (2,-.5) node[Lnigbt,bodydiode,anchor=D,label={[label distance=10]100:$D_{a2}$}](s1){};
\draw (S1.B) node[circ,label={90:{$S_1$}}]{};
\draw (s1.B) node[circ,label={90:{$S^*_1$}}]{};
\draw (4,2) node[Lnigbt,bodydiode,anchor=D,label={[label distance=10]100:$D_{b1}$}](S2){};
\draw (S2.E) to (4,0) node[circ,label={180:$V_{B}$}](vb){}
to (4,-.5) node[Lnigbt,bodydiode,anchor=D,label={[label distance=10]100:$D_{b2}$}](s2){};
\draw (S2.B) node[circ,label={90:{$S_2$}}]{};
\draw (s2.B) node[circ,label={90:{$S^*_2$}}]{};
\draw (va) to ++(.75,0) to ++(0,-2.5) node[ocirc,fill=none,label={180:$\nu_{an}$}](van){};
\draw (vb) to ++(.75,0) to ++(0,-2.5) node[ocirc,label={180:$\nu_{bn}$}](vbn){};
\draw (vc) to ++(.75,0) to ++(0,-2.5) node[ocirc,label={180:$\nu_{cn}$}](vcn){};
\end{circuitikz}
\end{document}