Saber仿真单相倍频SPWM调制逆变器报错

原理图如下


*** ERROR "ALG_NO_SOLUTION" *** Cannot find nonlinear system solution.
*** ERROR "ALG_SINGULAR_JACOBIAN" *** Singular Jacobian matrix.
Some possible causes for a singular Jacobian matrix:
- Model operating outside of its intended region of operation.
- Node/subsystem with no connection to the reference (floating).
- Current loops (voltage sources/inductors in parallel).
- Missing equation and/or missing variable reference.
给输出端电阻下面加个接地端就能仿出结果（不过按理说这没必要吧，而且接了地以后虽然能出来正弦波，但已经有了幅值的偏移了，根本就不该这么接吧）
但是一模一样的模型在Matlab里就能仿出很好的结果，不知道到底有啥问题
PS 本来开关用的是IGBT，但也有问题，不能仿真，换了理想开关才行，是哪部分有问题呢
求大神们解答啊
single_phase_inverter.rar