小弟用saber2006仿真EPWM，负载50Ω~5kΩ，PWM占空比从5%~95%，PWM频率48KHZ，仿真的时候占空比和负载电阻值改变都通不过，提示如下：
> dctr(tend 40m,tstep 10u
*** 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.
Partial results at time=0.010940483803546 were written to the initial point "tr".
应该怎么解决，请大侠指教
