Hybrid Generator + Parallel Capability

Q&A and troubleshooting
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1

Hello All.

Quick intro and disclaimer, I work for a power equipment supplier here in New Zealand in our Generator division.
About 3 years ago we brought in some Hybrid Generators from an existing supplier: Trime Group. These all use a lot of victron products, Quattros, Cerbo GX, MPPT Solar etc. Selling products like this into our market has been somewhat of a challenge but they can have upto 80% fuel savings so they are very interesting with tangible benefits. While I have reletively good knowledge of power related stuff in a diesel generator context, the entirety of my victron experience has come from experimenting, troubleshooting and learning on these products so my knowledge is reletively narrow/specific and I dont exactly have a great depth of experience.

On our 15kva 3 Phase Hybrid product, with the following spec:

  • Diesel Generator with Yanmar 4TNV88 Engine and Linz PRO18M E/4 Alternator. (400V, 50Hz, 0.8PF)
  • 4x MG Lithium LFP 230Ah 25.6V Batteries
  • 3x Victron Quattro 48/5000/70-100/100 230V VE.Bus
  • Victron Cerbo GX
  • GX Touch 50
  • GX LTE 4G
  • Deep Sea DSE3110
  • Small amount of solar (4x Victron 40W-12V Mono) with MPPT 150/35
  • We have since added some 12v cooling fans on the end of the inverter panel to manage temperature.

Question time: How can I extract every ounce of power out of this thing?
This is difficult to explain as I am not 100% confident in the correct vernacular but long story short this is set up to obviously provide power from the batteries up to 10kw, which if this condition is reached for longer than 5 seconds, the engine automatically starts and provides additional power of up to 15kW via load sharing in our diesel generator world we would think of this has paralleling I believe (I think victron calls this power assist?)

This is designed with an oversized 42kVA alternator to ensure better quality voltage regulation and thermal headroom, and paired with the yanmar 4tnv88 engine (19.8KWe) technically speaking this should be able to produce the following numbers:
Prime Power 18kW / 22.5kVA / 32.5A
Standby Power 19.8kW / 24.8kVA / 36A

Now I understand that the current method of power delivery is bottlenecked by the inverter hardware. However, even when we reach absolute limit of draw at the moment, it is still able to send about 2.5kW of charging to the battery pack, meaning that it is capable of paralleing somehow… (at least thats the theory in my brain) basically what I want to understand is it possible to extract some more power out via either some form of configuration or settings changes as one of its current applications just keeps tripping it at 15kW and its only a short period of time (5mins, its a coffee machine on a movie set) with its constant load of running some lighting, laptops, fridges etc only really being an average of around 3-5kW. if it could briefly sustain 17-18kW via the engine paralleling that would be incredibly helpful. I am very aware that it would not be wise to expect it to produce this maximum figure for extended periods of time but having that peak ability would be fantastic.

Am I dreaming? You tell me. If this is possible, I would appreciate the help, If it is impossible, I would be interested to learn/explain why it cannot be done. As you can imagine, the manufacturer does not want to help and warranty has long since passed on this particular machine so no worries. The simple option is possibly to just upgrade the inverters I guess but I want to try and achieve something with what I already have. Thanks in advance, hopefully I have provided enough context and infomation.

2

I presume the batteries are wired 2s2p? This will allow ~22kW discharge power max. The peak power from the inverters is 10kW each (10s) so you are limited a bit by the batteries. Continuous power is 4kW (5kVA)each. so with power assist, depending on settings, you may get to 24kW. (yes this is similar to 2 small generators running in parallel)

Some coffee machine!! I would assume a 3 phase load? The gen should be able to run that.. If you need to run through the inverters, then the Max AC current settings for the inverter group may need adjusting, as well as the power assist settings. Are you able to reprogram the inverter settings? Otherwise, one might consider splitting the feed: use the gen to drive the coffee machine and the inverters to power everything else for a while.

3

You have 15kVA/12kW of inverter power installed, but you would like to pull up to 20kW (15kW intermittent and 3-5kW base load) from the system?
Then you would need to manually start the generator beforehand, so that you got both the 12kW inverter and 18kW of generator power available together before you switch on the 15kW load step.

Im sure theres already a generator start implemented that starts the genset once a certain inverter power level is surpassed (or the battery SOC is too low etc.). However your base load of 3-5kW is most likely not high enough to automatically start the generator, but your intermittend load of 15kW (im very curious of that coffee machine btw) will instantly overload the inverters, giving the system no time to start the genset and synchronize.

4

thank you @MikeD and @chrigu for your replies! firstly, apologies for being a little misleading on what I can see now looked like some otherwordly size coffee machine! I am meaning to say that the combined loading can peak at 17kw rather than the coffee machine itself being 17kw. the base load of 3-5kW is an average but because it is a generator connected to various makeup trailers, food area, lighting, chargers etc etc in some very rare cases when a lot of this is on all at the same time aaaand someone uses the coffee machine we have seen it peak out to 17kw of which case the hybrid generator trips at around 15kw. But also to clarify, while this is a current real world scenario, this is also a classic example of something I have ran into before with this a lot, and irrelevant to the specific appliances in this scenario I am wanting to know how on earth I can reconfigure the system to do what you guys are talking about with inverter and generator power in parallel. I have downloaded VE Configure and ordered the VE.Bus to USB interface. to answer some of @chrigu questions, there is a generator start condition programmed when the load exceeds 10kw for 5 seconds. I could lower this to increase the chance of the engine already running for when the coffee machine starts. Coffee machine is 3 phase, 8kw (4 group head large commerical machine)

5

Dont worry about the 15kW coffee machine.

So in this case, since you got 12kW of inverter power and a load step of 8kW, you should set generator start to 4kW, maybe 3.5.

Then the inverters will synchronize to the genset, and if PowerAssist is active, the AC input current limit will be held by using the inverters together with the generator. So for example youve set the current limit to 20A, which means about 14kW at 400V, the generator will not be loaded more than that. If you pull 30A total, then 20A would be supplied by the generator and 10A by the inverters. I guess thats what your looking for?

If the base load is 3kW and another 8kW kick in as a singular step, then in theory the inverters should be able to support those 11kW until the genset has started and ACin got synchronised.

Its not a bulletproof solution, you can still run into an inverter overload when the baseload quickly increases to 5kW, so the generator will start, but then the 8kW step also kicks in. Or by simple load asymetry, one phase is loaded more than the others due to single phase devices, but the sum does not surpass 4kW, so the system will not start the generator yet, but the 8kW step will cause one inverter to overload already.

VEconfigure is getting old, and is being replaced by VictronConnect. Not all functions are available yet, but you should be good here. You can still use the Mk3 dongle and download VC onto your PC/Mac to set things easily.

Ive had similar issues before with temporary installations and thought about adding a victron system to balance out single phase loads and maybe reduce generator runtime. Most recently 13 office containers, each had a three phase supply but internally L1 was used for the lights, L2 for sockets and L3 for an electric heater. Even once cyclically swapping phases on four, and twice on another four did not entirely solve the asymetric load issue. Theres still a chance that four heaters will turn on, all on the same phase, while the others are off, shutting down the genset due to too much asymetric load. But at least its now only happening once every other week compared to daily

6

Thank you, that is helpful. I will have a play around with VictronConnect.
I do have some similar experience with office containers and perhaps one of the biggest advantages of victron systems in this type of environment is load balancing. Particularly from my background with diesel generators if they are constantly asymetrically loaded it can cause premature failing to the alternators. It has proven very beneficial.