To calculate dynamic motor starting, motor parameters should be specified according to section 4.17. Defining parameters of the Induction Motor. After this is done, push “Calculate” on the top menu bar, choose “Motor start” and “Motor dynamic” from the lists that will appear. In the “Motor dynamic” window, the user can specify how much time ES-PSM should calculate of the induction motor starting. Parameters “Step” and “ ɛ ” are needed for the solver of the induction motor starting and will have an influence on the accuracy of the results and convergence of the solution. It is recommended to leave provided values. “Step” is a parameter that defines the time between 2 calculation steps. Epsilon “ ɛ ” defines the accuracy of results. The lower the value, the more accurate the results.
On the right side of the table, motors that will start can be selected. To start the calculations. “Ok” button should be pushed.
When calculations are done, results window will appear as depicted:
In the first “Motor” tab user can analyze results:
s = (ws-wr) / wr
slip of the induction motor.
I_s
stator current.
I_r
rotor current.
Teta
parameter depending on the speed change of the induction motor.
Tem
electromagnetic momentum of the induction motor.
P_mech
mechanical power of the load and induction motor.
T_em
electromagnetic momentum dependency on time.
Cos( φ )
power factor of the induction motor.
T_load
mechanical momentum of the load
When “Grid” tab is selected, motor starting influence on voltage and current RMS values and angles can be analyzed. In “Rotation” tab, user can analyze motor mechanical (T(w)) characteristic.
