Domain error. To compute complex results from real x, use 'log(complex(x))'

I am calculating v_model as

v_model=e0 + i*r - (k0/soc) - (k1*soc) + k2*(log(soc)) + k3*(log(1-soc))

Other all parameters I have given to the matlab function block which calculates the above equation.

At t=0 in simulink, i have set soc=0.995

But when it calculates log(1-soc) it gives domain error. When I connected physical blocks of substract and log it said input to log block is zero.

I don't know why simulink is taking 1-0.995 as zero.

Answer 1

[Sai Pallav]

Hi Atharva,

Could you please provide the MATLAB version and more details of the process you are running. The log function in 2023a version is working fine. For example,

>> soc = 0.995;
>> log(1-soc)

ans =

   -5.2983

So, I don't think the problem is in the log function.