+Vcc in that was 10 volts.

No the sawtooth can be anything as long as the bottom dip is above zero (say 0.5v or more) and the top is maybe 3 volts or more with 5v or more very good. The height plays with the speed of response but the integrators give us more control over that.

i did not set any resistor values yet except for the oscillator. That will come next..

BTW did you mention the part number of the IGBT you will use yet?

 

+Vcc in that was 10 volts.

No the sawtooth can be anything as long as the bottom dip is above zero (say 0.5v or more) and the top is maybe 3 volts or more with 5v or more very good. The height plays with the speed of response but the integrators give us more control over that.

i did not set any resistor values yet except for the oscillator. That will come next..

BTW did you mention the part number of the IGBT you will use yet?

CM600HA-24H

 

Next version...

View attachment 204357

i would like to adjust the start voltage for pwm (the +Vcc voltage potentiometer)
and 100% pwm duty cycle allways 5v higher than the adjusted start voltage

thats why i asked if vcc was 30v. if the battery voltage devider is 10/1 devider the voltage would be 24-27v

i dont understand how you make 0.8-8v from the battery voltage (reference to sawtooth comperator)

 

i would like to adjust the start voltage for pwm (the +Vcc voltage potentiometer)
and 100% pwm duty cycle allways 5v higher than the adjusted start voltage

thats why i asked if vcc was 30v. if the battery voltage devider is 10/1 devider the voltage would be 24-27v

i dont understand how you make 0.8-8v from the battery voltage (reference to sawtooth comperator)

The power supply voltage is not that critical.
The 0.8 to 8v is not that critical either.
The reason it can be 0.8 to 8v or 0.7 to 10v or 0.8 to 4v is because the amplitude itself is not important the shape of the triangle is the important thing. The integrators will ramp up to some voltage at the output and whatever pulse width that produces is felt at the output and that feeds back into the integrators. The references that are attached to the integrators make all the decisions about what the pulse with with be not the amplitude of the triangle.

But there may be a difference here. This circuit as is, works as a shunt regulator. That means that i the output gets above 240v (or other setpoint) the integrator output ramps down and that increases the pulse width and that causes the output current to increase which brings the output voltage back down to 240v at which time the pulse width starts to narrow out a bit until it can maintain exactly 240 volts output, but only if there is enough voltage on the output already. If the output is naturally 239v, the pulse width will be zero and that is the reason why the low valley point of the triangle has to be above zero by a reasonable amount, so that there is room at the bottom to produce zero output pulse width.

So this may be a bit different than exactly what you were asking for, but it does have the nice effect of limiting the output to 240v at all times. If this is not acceptable then the circuit will have to be modified.
Also, a decent IGBT driver will have to be added later too to accommodate your IGBT. From what i understand it should be able to provide at least 3 amp gate drive current or something like that, maybe higher, and possibly have a negative voltage turn off signal maybe -8v or so.

So think about this and see if this will work for you. If not, the circuit will have to be modified slightly to do the 240 to 245 (or similar) volt thing. But i should point out this usually is not necessary except in soft output impedance battery chargers.

 

The power supply voltage is not that critical.
The 0.8 to 8v is not that critical either.
The reason it can be 0.8 to 8v or 0.7 to 10v or 0.8 to 4v is because the amplitude itself is not important the shape of the triangle is the important thing. The integrators will ramp up to some voltage at the output and whatever pulse width that produces is felt at the output and that feeds back into the integrators. The references that are attached to the integrators make all the decisions about what the pulse with with be not the amplitude of the triangle.

But there may be a difference here. This circuit as is, works as a shunt regulator. That means that i the output gets above 240v (or other setpoint) the integrator output ramps down and that increases the pulse width and that causes the output current to increase which brings the output voltage back down to 240v at which time the pulse width starts to narrow out a bit until it can maintain exactly 240 volts output, but only if there is enough voltage on the output already. If the output is naturally 239v, the pulse width will be zero and that is the reason why the low valley point of the triangle has to be above zero by a reasonable amount, so that there is room at the bottom to produce zero output pulse width.

So this may be a bit different than exactly what you were asking for, but it does have the nice effect of limiting the output to 240v at all times. If this is not acceptable then the circuit will have to be modified.
Also, a decent IGBT driver will have to be added later too to accommodate your IGBT. From what i understand it should be able to provide at least 3 amp gate drive current or something like that, maybe higher, and possibly have a negative voltage turn off signal maybe -8v or so.

So think about this and see if this will work for you. If not, the circuit will have to be modified slightly to do the 240 to 245 (or similar) volt thing. But i should point out this usually is not necessary except in soft output impedance battery chargers.

So you mean if the setpoint is 242v the pwm wil adjust between 0% - 100% to keep that voltage constant?
If thats the case its perfect

And also a current limit witch is 1 priority so the battery voltage can rise over set point if the current limit kick in and block the pwm signal to go higher

 

So you mean if the setpoint is 242v the pwm wil adjust between 0% - 100% to keep that voltage constant?
If thats the case its perfect

And also a current limit witch is 1 priority so the battery voltage can rise over set point if the current limit kick in and block the pwm signal to go higher

Yes that's right. If you adjust to 242v then it holds it there unless it goes under 242v naturally (run down battery due to normal loading).

The way the current limit works is if the current for any reason goes above the set point (say 11 amps instead of 10 amps) then the current limit circuits kicks in and the voltage limit kicks out, and the circuit then regulates the current to 10 amps. If the current naturally then goes down below 10 amps, the current limit kicks out and the voltage limit kicks back in.
So it ends up looking something like a current limited battery charger similar to a lead acid battery charger or Li-ion battery charger except it just sinks current instead of passing current.

I already updated the schematic again to include a simple way to get 240v to 245v like operation by including Rs a low value resistor just for illustration, but we can ignore that now.
But you will also see Q1 start to morph into an IGBT. The drive circuit is not in there yet that's all really.
Also the references for the two adjustments was changed to Vref but Vref can be the power supply voltage as before if in fact the power supply voltage is well regulated.

Did you happen to mention the absolute maximum voltage this circuit will ever see?

 

Yes that's right. If you adjust to 242v then it holds it there unless it goes under 242v naturally (run down battery due to normal loading).

The way the current limit works is if the current for any reason goes above the set point (say 11 amps instead of 10 amps) then the current limit circuits kicks in and the voltage limit kicks out, and the circuit then regulates the current to 10 amps. If the current naturally then goes down below 10 amps, the current limit kicks out and the voltage limit kicks back in.
So it ends up looking something like a current limited battery charger similar to a lead acid battery charger or Li-ion battery charger except it just sinks current instead of passing current.

I already updated the schematic again to include a simple way to get 240v to 245v like operation by including Rs a low value resistor just for illustration, but we can ignore that now.
But you will also see Q1 start to morph into an IGBT. The drive circuit is not in there yet that's all really.
Also the references for the two adjustments was changed to Vref but Vref can be the power supply voltage as before if in fact the power supply voltage is well regulated.

Did you happen to mention the absolute maximum voltage this circuit will ever see?

View attachment 204532

The 5v diffetence in batteryvoltage was just my stupid way of thinking.

To keep battery voltage constant is perfect and the function of current limit is perfect too thanks

I want to adjust batteryvoltage between 240 and 270v
Absolute maximum is 270v

Yes offcorse voltage referenseneed to be a fixed regulated voltage