I want help ..my project is :Motor Control Design using a Thyristor

The following text is the prompt of the project
"
A thyristor is used to turn on and off a 50-A DC motor every 60 seconds. We wish to design a circuit to control the motor using a GE. C150 slow switching device.

The manufacturer suggests that if the current in the thyristor rises too quickly, that is a high di/dt, the device can be destroyed. Therefore, some inductance must be placed with this device, so that di/dt is below the maximum limit. Also, this device may turn on (without any gate pulses), if the forward voltage is too high. That is known as dv/dt turn-on and it may lead to an improper operation of the circuit and the DC motor. A simple RC snubber may limit the dv/dt of the applied forward voltage.

Your design should also include the thyristor protection units, a switching device/mechanism using an auxiliary electronic switches (such SCR’s, power MOSFET’s, BJT’s, etc), and a commutation circuit.

Reporting Requirements: All components used in this project must have values with their spec. sheets attached (if any). Your references must be listed in a separate sheet. (i.e. Reference Sheet). Your plots/graphs are completely labeled and all calculations are clearly explained with the proper units. Note: Group works are encouraged but your individual works and their originalities are observed.

Specification of GE. C150 (E, N, and P) Series:

Repetitive Peak Forward and Reverse Voltages 500 V (C150E)
800 V (C150N)
1000 V (C150P)
Reverse and Forward Leakage Current 10 - 20 mA
Holding Current 20 mA
RMS Current 100 A
Forward Voltage Drop 1.2 - 2.0 V
Peak One-Cycle Surge (60 Hz) 1500 A
I2t for Fusing 7000 amp2.sec
dv/dt 200 – 500 V/µsec
di/dt 500 A/µsec
Gate Trigger Voltage 1.5 – 3 V
Gate Trigger Current 50 – 200 mA
Turn On-Time 3 µsec
Turn Off-Time 100 µsec

Unfortunately, i feel the information that i have is missing based on my knowledge but the professor ensure me that i have all the data.

How can I figure out the information of the load (Motor) like (Ra, La and Ea) so i can get the firing angel ??
Please help me out .....i dnt knw its circuit diagram...???