3 phase induction motor control

[karuna]

I have to design a 3 phase PWM inverter to drive 1.5HP induction motor. I am using PIC18F2431 controller and IR2133 driver IC and i am using IRG4PSC71KD discrete IGBTs.

The rated current of IM is 25A , and it is rated for 40V. the motor taking higher starting current around 25A and my IGBT's got failed several times, suggest me a solution to avoid this problem.

[marke]

Hello karuna

 

You must start at zero Hz and you must have a low voltage. For an open loop controller (non vector) you operate a constant V/Hz ratio. As the frequency is reduced below the rated frequency, the voltage is also reduced such that at any frequency below the rated frequency, the V/Hz ratio is equal to the rated V/rated Hz of the motor.

 

Best regards,

[karuna]

Hi marke

Thanks for your prompt response. Detailed Specifications of my inverter is given below.

 

Input voltage (Rated) : 72 V DC

 

Input voltage range : 50V to 90V DC with 15% ripple.70% torque should be delivered 20V DC input voltage. During cranking of loco, voltage may dip to 20V for a short duration. Inverter should not trip during this operation.

 

Output voltage (Nominal) : 3phase, 40V (+/-) 5% at rated load

in input voltage range 65V to 90V DC

at steady state condition.

 

Output Waveform : PWM sine wave.

 

Output frequency : 60 Hz (+/-) 2 Hz in input voltage range

65V to 90V DC under steady state. V/f

control to be provided for constant

torque operation below 65V DC input.

 

Output power : 1.5HP (continuos)

 

 

Protection :a) Input under voltage protection

(auto reset)

Input over voltage protection (auto

reset)

c) Output over load (Power on reset)

d) Short circuit (Power on reset)

e) Reverse polarity (auto reset)

 

Input over voltage protection : Set at 100V DC input.

 

Output over load protection : Set at 1.5 times the rated current.

 

Control mode : PWM with V/F control.

 

Internal power supply : Wide range of SMPS .

 

Power circuit configuration : 3F full bridge with ultra fast IGBT/MOSFET

 

Control circuit : Micro processor/controller based waveform generator.

 

Efficiency : shall not be less than 90% rated input

and Rated load.

 

 

I have designed the inverter with discrete IGBT's(IRG4PSC71KD) and it is working fine.But according to the specification i have to use IGBT module , when i use CM150DU-12F module my o/p waveform get distorted and the module getting failed even without connecting the motor(noload). Is it because of the distance between the control ckt and power ckt (1m) how to avoid this problem?

[GGOSS]

Is this inverter to be use in a rail/train application? If so there will be other issues to address such as the high levels of vibration.

 

Regards,

GGOSS

[karuna]

Hi GGOSS

Yes this inverter isto be used in railways to drive Fuel pump induction motor.

Thanks & Regards

Karunanithi.R