Inverter base AC Power and Turbine based

[PZC]

what are the limitations of inverter based AC Power towards load change as compared to AC Power from rotating machine (turbines )?

 

[dpc]

Inverter can make load changes much more quickly than a rotating machine, but probably has much less short-time overload capability. You also have to distinguish between load changes that involve real power (kW) and those that are mainly reactive power swings. It will also depend on where the inverter is getting its power from.

 

[PZC]

@ dpc - the inverter is getting power from Solar Panels.

 

[dpc]

Then your main limitation will be zero production at night as well as highly variable solar cell output during the day. The rotating machine will not fear the dark or cloudy weather.

 

[racookpe1978]

On the other hand, the rotating machine (worldwide) will only generate 18-22% rated power over long periods of time. BUT, that "average" 18-22% power output will be characterized by very long periods of irregular very low power at unpredictable periods, separated by an irregular and unpredictable few hours of maximum power as cold fronts and storms come through, followed by long periods of very low power.

At least a solar panel will give you predictable periods of no power, followed by possible power each day as "some" power might be produced. Depending on clouds, fog, day-of-year solar elevation changes, and local interferences like trees, buildings, and hills.

 

[PZC]

Thanks to both for your feedback. Actually my question is specific - the impact of sudden load changes to Inverter based AC Power and Rotating Machine based. For example, if the sudden load change is from group of induction motors, which system from the two would perform best ?

 

[waross]

It depends a lot on whether the sudden load pushes the supply into overload or not. That is past the rating of the supply. It also depends on the limits of the rotating machine. Is the load limit electrical, mechanical or both? Many rotating machines have an AVR feature called Ubder Frequency Roll Off. A severe overload will slowdown the prime mover and drop the frequency. The UFRO will drop the voltage to maintain close to the proper V/Hz ratio. This is a great help in starting induction motors that are more than 1/3 the available capacity of the rotating generator set.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[davidbeach]

The inverter can't supply more energy to the load than what it is being supplied with. Typically inverter systems convert all of the available energy leaving no headroom for additional output. Typically a rotating machine wouldn't be run flat out, and can therefore have the fuel supply increased and the output energy/power increased. If you're running both, I'd expect that the inverter would be producing everything it can and the machine would fill in the gaps.

 

[dpc]

racookpe1978: You seem to be quoting statistics for wind turbines - The OP just said turbines. Steam turbines are my favorite, so that is what I was assuming - perhaps incorrectly.

If an inverter is overloaded, it will likely just shut down. A rotating machine will slow down, but would have more stored energy available to get you through a motor start.

The inverter can go from 0% to 100% in sub-cycle time frames, but as David said, it is only going to output what it is rated for. Inverters have limited overload capability.

 

[PZC]

Thanks to all for valuable inputs