34 © 2016 ANSYS, Inc. August 28, 2018
Simulation Time Step (Hmin, Hmax)
– Proper choice of minimum and maximum step size is important; the table below shows some basic
guidance
Model Properties Recommended
What is the smallest time constant (t
min
) of the circuit or of the block diagram? Hmin < t
min
/ 10
What is the largest time constant (t
max
) of the circuit or of the block diagram? Hmax < t
max
/ 10
Which is the smallest cycle (T
min
) of oscillations that can be expected (natural
frequencies of the system or oscillating time functions)?
Hmin < T
min
/ 20
Which is the largest cycle (T
max
) of oscillations that can be expected (natural
frequencies of the system or oscillating time functions)?
Hmax < T
max
/ 20
Waht is the smallest controlling sampling time (TS
min
)? Hmin < TS
min
/ 5
Hmax = TS
min
What is the fastest transient occurence (TUmin – edge changes of time functions)? Hmin < TU
min
/ 20
What is the time interval to be simulated (Tend) Hmax < Tend / 50
