Finding the reference voltage and current reference for PWM in EV charging V2G/G2V mode

Hello,

I am working on EV charger model in simulink and I face a problem.

Since I am going to change the output power of the battery that is given to the system based on some default assumption, I need to change the duty cycle of my PWM generator. However, I am confused that how can I do this matter. To be specific, I am looking to find the releationship between the reference voltage or current and the PWM duty cycle for my model.

I hope I could clarify my problem.

Answer 1

[Kothuri]

Hi Mahmoud Kiasari,

To change the output power of the battery, the duty cycle of the PWM generator needs to be adjusted.

The relationship between the reference voltage or current and the PWM duty cycle is important to control the output of the charger. This is the standard procedure to change the duty cycle of the PWM generator, below steps indicate how they are related.

• Set the desired output voltage or current as the reference signal.
• Calculate the error between the actual signal(voltage or current) through feedback and the reference signal.
• This error is passed to a PI controller which generates the control signal for PWM.
• This control signal is then passed to a PWM generator where it is compared with the high frequency carrier wave and the switching pulses are generated.

It seems like you have implemented this in your model to generate buck and boost pulses for switches. But for the other switches you have used a different approach.

You may refer the below link which shows a Simulink example of Boost converter voltage control.

www.mathworks.com/help/sps/ug/boost-converter-voltage-control.html#responsive_offcanvas