Induction Cooking info and experience.

[CaptainRivet]

Originally Posted by noelex 77

Despite the name, induction cook tops do not present a significant inductive load. The power factor is close to unity (around 0.99 is typical).

The inverter needs to be able to cope with the maximum pulse load, but an inverter capable of 1500VA should be able to produce very close to 1500w when driving an induction hot plate.

Ever heard of cos phi? Especially the pulsing ones have a very bad cos pi forcing the inverter to use a lot energy to keep the sinus curve stable and reduce shifting of phase and that puts a lot load on the mosfets of a HF one...so called reactive power which causes surge to compensate for the inverter.
If you only have one shunt in the system that calculated by just taking the difference of input and output is just shows you a lower output then actual is...if you have 2 shunts (one input and one output) like I do with ElectrodacusBMS that shows you see that the inverter needs much more current then it would need for the shown output, the difference is reactive power.
An LF inverter can cope much better then an HF one with this.

[s/v Jedi]

Originally Posted by CaptainRivet

Ever heard of cos phi? Especially the pulsing ones have a very bad cos pi forcing the inverter to use a lot energy to keep the sinus curve stable and reduce shifting of phase and that puts a lot load on the mosfets of a HF one...so called reactive power which causes surge to compensate for the inverter.
If you only have one shunt in the system that calculated by just taking the difference of input and output is just shows you a lower output then actual is...if you have 2 shunts (one input and one output) like I do with ElectrodacusBMS that shows you see that the inverter needs much more current then it would need for the shown output, the difference is reactive power.
An LF inverter can cope much better then an HF one with this.

Come on, you talk of this without even knowing that the power factor -is- the cos phi?!

[CaptainRivet]

Originally Posted by s/v Jedi

Come on, you talk of this without even knowing that the power factor -is- the cos phi?!

What does this have to do with the fact i described above that kills the HF inverters frequently....
You simply cannot run a 1500W induction cooktop or microwave with a 1500W HF inverter (if it is a real 1500W one) however you call it.

Yes i assumed that victron calls that power factor but wasn't sure about that.

[Statistical]

Originally Posted by CaptainRivet

What does this have to do with the fact i described above that kills the HF inverters frequently....

Yes i assume that victron calls that power factor but wasn't sure about that.

The post you responded to say powerfactor of any good induction cooktop is close to 1. You then made a post explaining powerfactor without saying powerfactor and how low powerfactor devices are hard on inverters/generators.

Unless you are buying absolute trash no name induction cooktop (and I would be concerned about fire hazard and lack of UL rating in that case) it will have a PFC and a powerfactor of >0.95 likely >0.99. So your explanation is not applicable.

[K_V_B]

What is needed for boats is an induction hob that works of DC...

Induction cookers internally rectify the AC to DC, and then convert it again to high frequency AC to drive the coils that heat up your pans.

So on a boat you are converting three times. DC -> AC -> DC -> AC. And you lose each time.

There is a company in the US that produces induction hobs that have a battery included in the DC circuit. The idea there is to limit the peak demand at the AC side, so that retrofitting induction cooking in kitchens that do not necessary have the required heavy power circuits is possible.

I think if you would scale that down, and get rid of the AC side you might have a good product for on a boat.

[Statistical]

Originally Posted by K_V_B

What is needed for boats is an induction hob that works of DC...

Induction cookers internally rectify the AC to DC, and then convert it again to high frequency AC to drive the coils that heat up your pans.

So on a boat you are conerting three times. DC -> AC -> DC -> AC. And you lose each time.

There is a company in the US that produces induction hobs that have a battery included in the DC circuit. The idea there is to limit the peak demand at the AC side, so that retrofitting induction cooking in kitchens that do not necessary have the required heavy power circuits is possible.

I think if you would scale that down, and get rid of the AC side you might have a good product for on a boat.

Yeah especially as boats move to 48VDC. Honestly there is really no reason to have AC cooktops beyond economies of scale. As you point out the "mains" AC is never used directly only as an input to produce DC to drive the very high frequency output created by the onboard inverter to power the induction coil.

The big challenge though is DC market is tiny (offgrid, rv, boats, etc). Any one of them can use an AC "powered" induction cooktop but the home market can't use a DC powered one. So it means building a niche device in much smaller numbers. Beating the economies of scale will be tough. It could be something that just never catches on because it is cheaper and easier to just grab a readily available AC powered unit.

[CaptainRivet]

Originally Posted by Statistical

The post you responded to say powerfactor of any good induction cooktop is close to 1. You then made a post explaining powerfactor without saying powerfactor and how low powerfactor devices are hard on inverters/generators.

Unless you are buying absolute trash no name induction cooktop (and I would be concerned about fire hazard and lack of UL rating in that case) it will have a PFC and a powerfactor of >0.95 likely >0.99. So your explanation is not applicable.

Well then take the often mentioned ikea induction hob, the power factor or cospi is horrible and nowhere near 0.95. In 2kw it takes up to 600W of reactive power...All this pulsing ones means all the 100 till 200Euro 1 or 2 burner tabletop avaliable on Amazon or ebay have a very low cospi or you call it power factor.

Only Regulated non pulsing commercial grade induction burner have the 0.95-0.99 but that you don't get below 350Euro...german brand Bartscher is the cheapest i know that uses these burners in the budget line for catering appliances.

[Statistical]

Originally Posted by CaptainRivet

Well then take the often mentioned ikea induction hob, the power factor or cospi is horrible and nowhere near 0.95. All this pulsing ones means all the 100 till 200Euro 1 or 2 burner avaliable on Amazon or ebay have a very low cospi or you call it power factor.

https://www.cruisersforum.com/forums...ob-276389.html

Measured power factor is 0.93 on lowest setting and 0.98 on the highest.

Only Regulated non pulsing commercial grade induction burner have the 0.95-0.99 but that you don't get below 350Euro...german brand Bartscher is the cheapest i know that uses these burners in the budget line for catering appliances.

That is simply not true.

Pulsing and power factor have nothing in common. Pulsing output simply means a 1200W unit is always using 1200W. on high it is 1200W all the time. At lower power levels it is 1200W turning on and off as needed to produce an equivalent lower wattage. This can be challenging on inverters if capacity limited because you can't just turn down the power. On the lowest or highest setting it is drawing 1200W.

There may be specific (likely no name cheapest chinese garbage you can buy on amazon) units which have poor power factor. There are exceptions to every rule however in general induction cooktops do not have high inducted loads (low PF). This is true of portable consumer single burner model up to $5000 quad burner commercial units.

[CaptainRivet]

Originally Posted by Statistical

https://www.cruisersforum.com/forums...ob-276389.html

Measured power factor is 0.93 on lowest setting and 0.98 on the highest.



That is simply not true.

Pulsing and power factor have nothing in common. Pulsing output simply means a 1200W unit is always using 1200W. on high it is 1200W all the time. At lower power levels it is 1200W turning on and off as needed to produce an equivalent lower wattage. This can be challenging on inverters if capacity limited because you can't just turn down the power. On the lowest or highest setting it is drawing 1200W.

There may be specific (likely no name cheapest chinese garbage you can buy on amazon) units which have poor power factor. There are exceptions to every rule however in general induction cooktops do not have high inducted loads (low PF). This is true of portable consumer single burner model up to $5000 quad burner commercial units.

I bet he measured it at home with the different levels and resulting power as the grid can easly correct that. Did the same mistake...

Connect it solely as only device on the inverter and measure what the inverter needs on the different levels, not what the cooktop needs. Yes pulsing and switching on and off 1200W or more as significantly to do with how much power your inverter really draws and can deliver.
The regulated ones simply regulate the power down instead pulsing.

[CaptainRivet]

Originally Posted by Statistical

https://www.cruisersforum.com/forums...ob-276389.html

Measured power factor is 0.93 on lowest setting and 0.98 on the highest.



That is simply not true.

Pulsing and power factor have nothing in common. Pulsing output simply means a 1200W unit is always using 1200W. on high it is 1200W all the time. At lower power levels it is 1200W turning on and off as needed to produce an equivalent lower wattage. This can be challenging on inverters if capacity limited because you can't just turn down the power. On the lowest or highest setting it is drawing 1200W.

There may be specific (likely no name cheapest chinese garbage you can buy on amazon) units which have poor power factor. There are exceptions to every rule however in general induction cooktops do not have high inducted loads (low PF). This is true of portable consumer single burner model up to $5000 quad burner commercial units.

I bet he measured it at home with the different levels and resulting power as the grid can easly correct that. Did the same mistake...

Connect it solely as only device on the inverter and measure what the inverter needs on the different levels, not what the cooktop needs, on your inverter in your installation. Yes pulsing and switching on and off 1200W or more as significantly to do with how much power your inverter really draws and can deliver.

The regulated ones simply regulate the power down instead pulsing or on the lowest lewels switch it on for 20sek and off for 20sek which is steered by the temp sensor but no pulsing.

[Statistical]

Originally Posted by CaptainRivet

I bet he measured it at home with the different levels and resulting power as the grid can easly correct that. Did the same mistake...

Stop. Just stop. None of that is correct.

[CaptainRivet]

Originally Posted by Statistical

Stop. Just stop. None of that is correct.

compared my old 2 burner Rommelsbacher 3342 (which is a better pulsing one with a 2kw and a 1.5kw) and the Bartscher IK3342 (which is regulated one with 2kw/1.5kw/1kw but regulates when alle 3 on to 3500W) and just ran the 2kw in comparion and the 1.5kw in comparison. And this then on my 2 inverters. No 1 edecoa 3500W constant pure HF inverter ( a good chinese brand with a subsidiary in EU) and No2 Multi 3000, both have eaxct same cable, cable length and identical fuses. I can run them each individual or the edecoa as boost inverter for the multi via powerassist (my normal setup).

The 2kw pulsing needed 2.8kw on the no1 and 2.5kw on 2
The 2kw regulated needs 2.2kw on no1 and 2.15kw on no2. That on full load of 2kw burner and both showed very close 2kw power draw measured at grid.
I also tested the 1 burner ikea one borrow from a friend which was even worse with 2.9kw on no1 and 2.6kw on no2 but not on same day with same SOC. So not 100% but 99% comparable.
Around 200W is total loss on cable, fuses, inverter efficency on no1 and no2 is 150W...no surprise the victron is a bit better. Remember my system is stress tested till 600A..so no shortage on power here that could cause this.
And this is the exact reason why HF inverters frequently die when running a 2000W tabletop induction cooktops and microwaves with 2kw pure HF inverter.

The regulated ones simply regulate the power down instead pulsing or on the lowest lewels switch it on for 20sek and off for 20sek which is steered by the temp sensor but no pulsing.

[Pete7]

Originally Posted by K_V_B

So on a boat you are converting three times. DC -> AC -> DC -> AC. And you lose each time.

How much? $5400 for an induction hob

Originally Posted by CaptainRivet

Connect it solely as only device on the inverter and measure what the inverter needs on the different levels, not what the cooktop needs, on your inverter in your installation. Yes pulsing and switching on and off 1200W or more as significantly to do with how much power your inverter really draws and can deliver.

The regulated ones simply regulate the power down instead pulsing or on the lowest lewels switch it on for 20sek and off for 20sek which is steered by the temp sensor but no pulsing.

So what sort of frequency might you see on a non-regulated induction hob for instance?

Out of curiosity I dug out the manual for our portable induction hob rather than the Double listed above. This is what the manual states and in line with what we are seeing. The pulse varies on/off but at simmering probably are 20 seconds or more frequency. A 2kW PSW inverter has no problem running this, so what is the problem?

Pete

[CaptainRivet]

All cross checks are inline, 2.2kw for regulated - 200W losses is the exact 2kw i got measuring at the grid. All measures with the same fluke meter and the same 2 shunt BMS si all results are right or wrong the same way.
3 times measured, measure pulsing on no1, stove off, flip transfer switch on no2 and stove back on and mesasure.
The same with regulated stove...same 230V outlet.
To crosscheck on inverter no 1 measure pulsing, then connect regulating stove and measure too. Results where inline with flipping between the 2 inverter.
Connect 2kw heater to same power outlet shows the same 2.2kw on No. And No 2 2.15kw, which is again the 2kw + losses.

So explain why the pulsing needs 600W more on the HF and 350 more on the victron which is a hy rid LF/HF?
Its is obviously reactive power loss or other call it phantom load or ?? ...doesn't matter how you call it, its there and causes HF inverter to frequently die.

[Statistical]

Originally Posted by CaptainRivet

All cross checks are inline, 2.2kw for regulated - 200W losses is the exact 2kw i got measuring at the grid. All measures with the same fluke meter and the same 2 shunt BMS.
3 times measured, measure pulsing on no1, stove off, flip transfer switch ro no2 and stove back on and mesasure.
The same with regulated stove...same 230V outlet.
To crosscheck on inverter no 1 measure pulsing, then connect regulating stove and measure too. Results where inline with flipping between the 2 inverter.
Connect 2kw heater shoes the same 2.2kw on No. And No 2 2.15kw, 2kw + losses.

So explain why the pulsing needs 600W more on the HF and 350 more on the victron which is a hy rid LF/HF?
Its is obviously reactive power loss or other call it phantom load loss...doesn't matter how you call it, its there and causes HF to frequently die.

Or you know you could just measure the power factor using your multimeter and stop guessing and making blanket wrong statements.

Your claim was induction cooktops have a low power factor despite every piece of reporting and self testing showing the exact opposite. You then spent 3 posts detailing every aspect of your electrical setup except the measured power factor.