Question: Is there any way to circumvent the convertion before connecting the subsystems?

Hello,

I use 'SystemConnect' command to connect two transfer function, as the following codes illustrated.

with(DynamicSystems);
sys1 := TransferFunction(10/(s*(s+10)));
sys2 := TransferFunction(k*s^2/(s+20));
Warning, improper transfer-function, degree(num) > degree(den)
sys3 := SystemConnect(sys1, sys2, connection = negativefeedback, outputtype = tf);
Error, (in unknown) cannot convert improper transfer function to state-space model

sys2 is a improper transfer function. I just want to connect sys1 and sys2 in negativefeedback, but an error returned.

Why maple must convert every transfer function to state-space model before connecting them? As sys1 connects sys2 in negative feedback is 10*(s+2)/(s*(s+10)*(s+20)+10*k*s^2), a proper transfer function.

Is there any way to circumvent the convertion before connecting the subsystems?

Thank you in advance.