Growatt SPF 5000 ES off-grid inverter - AC bypass mode

[marsal505]

Hi,
Can someone please explain how the "AC bypass" mode operates on the SPF 5000 ES inverter? There is very little information about this in the user manual. I am currently running my inverter in SUB mode without a battery.

When the AC bypass mode is enabled is it possible to power the output loads at greater than 5KW (ie. as in grid-tied feed-in tariff inverters)?

Or is the power output during AC bypass mode limited to 5KW as well, the same as the inverter output limit? (ie. does the "AC bypass" essentially just provide alternate input power to the inverter from the grid when the solar PV input is low or insufficient, which means that the inverter is not really bypassed?)

Thanks for your help.

 

[VicenteC]

Hi marsal505,

I have the exact same question. I've also sent a query to GROWATT yesterday. No answer up until now.
Do you happen to have the answer for that?

 

[plasma]

Hi,
is there a setting : in the evening when there is no sun to switch completely to bypass from grid. And the inverter part does not work ,to reduce idle consumption.

 

[automatikdonn]

I think the answer is simple enough. The GW is rated for 5kw. This means the circuits inside the box shouldn't be driven any higher than that for prolonged periods.

When it switches to grid pass through mode, you are still using some of the internal circuits, connectors, etc.

 

[marsal505]

@VicenteC
I was able to study the circuits inside one of these units and this is what I found:

1. when the AC bypass mode is enabled, the AC input and AC outputs lines are bridged together via relay switches

2. the inverter feeds the energy created from the solar panels on to the bridged AC input/output lines by raising the AC voltage via internal semiconductor power switches (IGBTs), in the same way that a normal grid-tied feed-in tariff inverter does. The only difference is that this inverter can never feed energy back into the grid. This must be limited in the software, even though in hardware it is possible to do.

3. this means that when the AC bypass mode is enabled you can go beyond 5KW load - I have successfully gone to over 8KW for several minutes without shutting down - just got the over load beeping.. The maximum power limit would be set by the inverter's internal 40A circuit beaker (about 40A x 250V = 10KW) or what ever circuit breaker you may use on the external AC input line.

4. you are only limited to 5KW maximum load output when you are operating the inverter with a battery, without any AC input connection (ie. when no AC bypass is enabled). The 5KW limit applies for solar + battery together and is the limit of the inverter circuit section, consisting of the IGBT power switches

@plasma
If you set the inverter to SOL, SUB modes and leave a battery connected to the inverter, then the inverter will switch to only AC bypass mode with the inverter section of the circuit turned-off. However the energy to power the remaining circuitry of SPF 5000 ES then comes from the battery. You can tell when the inverter circuit section is operating by listening to the inverter - you will hear a 50Hz buzzing sound, predominantly from the right hand side

 

[Jeromebricolo]

Bonjour Vincente

explications très intéressantes,

mais, pourriez-vous expliquer pourquoi comme je suis en SBU, la nuit il y a une consommation de batterie ?
le problème c'est que ces 0,5 ou 1a la nuit risquent de rendre la capacité de la batterie à zéro, donc dangereux pour elle non ???

Merci beaucoup pour votre réponse.

 jerome

 

[abhelou]

Bonjour Vincente

explications très intéressantes,

mais, pourriez-vous expliquer pourquoi comme je suis en SBU, la nuit il y a une consommation de batterie ?
le problème c'est que ces 0,5 ou 1a la nuit risquent de rendre la capacité de la batterie à zéro, donc dangereux pour elle non ???

Merci beaucoup pour votre réponse.

 jerome

t'inquiete pas. c normal de consommer ce ptit courant, comme g lu kelkpart que l'ecran et kelk equipment dans l'onduleur fonctionne tjs sur la batterie.il n'ya aucun risque

 

[Jeromebricolo]

t'inquiète pas. c normal de consommer ce ptit courant, comme g lu kelkpart que l'ecran et kelk equipment dans l'onduleur fonctionne tjs sur la batterie.il n'y a aucun risque

Merci ca me rassure. Pour eviter tout de meme de faire passer de 20% (arret du fonctionnement sur batterie) a 10% au lever du soleil en absence de soleil (avec la petite consommation de nuit de l'ordre de 50w), j'ai autorise la charge de la batterie par le réseau GRID, en limitant l'intensité à 3 ampères, ce qui fait que la batterie ne se décharge plus sous les 20 %, mais se recharge très légèrement en passant à 22 % au levier du soleil.
Cela évite tout risque de se retrouver à 0%, ce qui m'est déjà arrivé une fois.

Sincèrement

 

[bouslam13]

Bonjour,
serait il possible de faire marcher le Growatt SPF 5000 ES seulement avec les Panneaux solare et sans aucune batterie nie connection avec le reseau electrique ?
Le but est d'utiliser l'energie solaire pendant la journee seulement ?
Merci de votre aide

 

[VicenteC]

@VicenteC
I was able to study the circuits inside one of these units and this is what I found:

1. when the AC bypass mode is enabled, the AC input and AC outputs lines are bridged together via relay switches

2. the inverter feeds the energy created from the solar panels on to the bridged AC input/output lines by raising the AC voltage via internal semiconductor power switches (IGBTs), in the same way that a normal grid-tied feed-in tariff inverter does. The only difference is that this inverter can never feed energy back into the grid. This must be limited in the software, even though in hardware it is possible to do.

3. this means that when the AC bypass mode is enabled you can go beyond 5KW load - I have successfully gone to over 8KW for several minutes without shutting down - just got the over load beeping.. The maximum power limit would be set by the inverter's internal 40A circuit beaker (about 40A x 250V = 10KW) or what ever circuit breaker you may use on the external AC input line.

4. you are only limited to 5KW maximum load output when you are operating the inverter with a battery, without any AC input connection (ie. when no AC bypass is enabled). The 5KW limit applies for solar + battery together and is the limit of the inverter circuit section, consisting of the IGBT power switches

@plasma
If you set the inverter to SOL, SUB modes and leave a battery connected to the inverter, then the inverter will switch to only AC bypass mode with the inverter section of the circuit turned-off. However the energy to power the remaining circuitry of SPF 5000 ES then comes from the battery. You can tell when the inverter circuit section is operating by listening to the inverter - you will hear a 50Hz buzzing sound, predominantly from the right hand side

Hi @marsal505,

Thanks for the explanation! Much appreciated.

In fact, by just letting it run I came down to the same conclusion over time!

Cheers,
Carlos

 

[JohnGalt1717]

Is it possible disable bypass and have it instead charge?

There's a couple of scenarios that I'm trying to make work:
1. Goes to bypass, if the battery goes low, then also charge up to a certain rate and then stop without switching off bypass until a second higher voltage. This is for cases of DC loads that I also have hooked up but I don't want it switching back and forth from grid to battery which is a hard switch over.
2. Never goes bypass, always on internal inverter and just charge the batteries and keeps them at a a certain minimum (like 3.1V per cell)

I understand that #2 will use more electricity from the grid, however, it avoids the hard slam of power switching between grid and battery which is useful, especially with an EV that REALLY doesn't like it.

 

[automatikdonn]

Is it possible disable bypass and have it instead charge?

There's a couple of scenarios that I'm trying to make work:
1. Goes to bypass, if the battery goes low, then also charge up to a certain rate and then stop without switching off bypass until a second higher voltage. This is for cases of DC loads that I also have hooked up but I don't want it switching back and forth from grid to battery which is a hard switch over.
2. Never goes bypass, always on internal inverter and just charge the batteries and keeps them at a a certain minimum (like 3.1V per cell)

I understand that #2 will use more electricity from the grid, however, it avoids the hard slam of power switching between grid and battery which is useful, especially with an EV that REALLY doesn't like it.

Solar assistant may be able to help out with this use case. I am no expert with it, but it is very useful technology.

 

[kirkdis]

at least in SBU mode the bypass is not working reliable. don´t trust it I already was 4 times short before killing my battery. Sometimes the AC grid bypass is not kicking in. only solution til now is to dis- and reconnect the AC power for a few seconds. Growatt is informed: first answer was we don´t support Pylontech, second explanation was my communication is bad because my battery voltage decreases but only when heavy load is consumed. Hope they will figure out the issue and solve it soon. if you have issues report it to Growatt support so they will be aware of their faulty firmwares.

 

[Jeromebricolo]

au moins en mode SBU, le bypass ne fonctionne pas de manière fiable. ne vous y fiez pas, j'étais déjà 4 fois à court avant de tuer ma batterie. Parfois, la dérivation du réseau CA ne s'active pas. La seule solution jusqu'à présent consiste à déconnecter et à reconnecter l'alimentation CA pendant quelques secondes. Growatt est informé : la première réponse était que nous ne supportons pas Pylontech, la deuxième explication était que ma communication est mauvaise car la tension de ma batterie diminue, mais uniquement lorsque la charge est consommée. J'espère qu'ils trouveront le problème et le résoudront bientôt. Si vous rencontrez des problèmes, signalez-le au support Growatt afin qu'il soit au courant de ses firmwares défectueuxj

Je vous suggère de charger le dernier firmware, beaucoup de problèmes de ce genre disparaissent.

 

[dozynsleepy]

at least in SBU mode the bypass is not working reliable. don´t trust it I already was 4 times short before killing my battery. Sometimes the AC grid bypass is not kicking in. only solution til now is to dis- and reconnect the AC power for a few seconds. Growatt is informed: first answer was we don´t support Pylontech, second explanation was my communication is bad because my battery voltage decreases but only when heavy load is consumed. Hope they will figure out the issue and solve it soon. if you have issues report it to Growatt support so they will be aware of their faulty firmwares.

It looks like Bypass is working for me in SBU mode, although I don't have PV connected at the moment so might not be applicable to the problem you are experiencing.

2 x Growatt SPF 5000 ES single phase parallel mode connected to 2 x Pylontech US5000 batteries.

I did a test earlier today and set the charging time between midday and 2pm with the battery discharged to 25%.
At 12:04 I could see the full 80 amps from each inverter charging and by 13:01 the batteries where at 91% with State: AC charge & Bypass.
Once it hit 95% battery capacity it started discharging from the battery (back to SBU/SOL : 95%) State: discharge

For testing purposes configuration :
No PV, AC Grid (Utility)
Battery type Li, Protocol 52 communicating okay with the Pylontech US5000.
Charging start time period 12
Charging end time period 14
Output start time period 6 am
Output end time period: 0
Back to Utility: 25%
Back to SBU/SOL: 95%
DC Cut-off Voltage: 20%

Normally the battery is charged from AC grid (Utility) between 1am and 6am as my electricity supplier has a tariff with lower price off peak cost.
When the battery is discharged to 25% the inverter switches to State: AC Charge & Bypass
Charging will not start until the cheap off peak tariff at 1am.

See screenshot at 21:25 of PVkeeper application connected to the first Growatt SPF 5000 ES.
Top right hand side shows Battery Capacity: 25%, Charge Current: 0A, State: AC charge & Bypass.
Photo shows the display panel with same status, 25% battery capacity running in bypass no charging.
Screenshot shows 91% Battery Capacity at 13:01 Charge Current: 19.8 A, State: AC charge & Bypass.
Screenshot shows configuration : Back to Utility: 25% Back to SBU/SOL: 95%

 

[kirkdis]

@Jeromebricolo I have the latest firmware on my devices but I have the newer hardware version so my firmware is at 067 and 068 not the latest for the old hardware version 0.40/0.41.

@dozynsleepy
I can tell you bypass is working 9 days out of ten in average. on the day it won´t work it can kill your whole battery within a glimpse. Even if the inverter get´s the SoC from the pylontech it will not switch off at the value set at P21. I saw situations on my inverters both values P12 and P21 had been overrun and nothing happened. I´m testing around with my inverters at the moment and it seems for now with a relay/contactor connected to the dry contact you can switch within a percent of SoC(P12/P13) grid on or off . I also changed my setup to one phase so I now have 2 inverters paralleled for one phase only. In SBU I don´t see any need to wait until you are at SoC 95% recharge.

If you tell growatt that you use pylontech batteries they will tell you this is the issue. at least the german support is like that but the comms work and worked great until now.
I still don´t get the real issue why the inverters are so unrealiable but I recorded the issues with my webcams several times two inverter do great and one didn´t do the right thing... watch the snippet below.

 

[Jeromebricolo]

@Jeromebricolo J'ai le dernier firmware sur mes appareils mais j'ai la version matérielle la plus récente donc mon firmware est à 067 et 068 pas le dernier pour l'ancienne version matérielle 0.40/0.41.

@dozynsleepy
Je peux vous dire que le bypass fonctionne 9 jours sur 10 en moyenne. le jour où il ne fonctionnera pas, il peut tuer toute votre batterie en un clin d'œil. Même si l'onduleur reçoit le SoC du pylontech, il ne s'éteindra pas à la valeur définie sur P21. J'ai vu des situations sur mes onduleurs, les valeurs P12 et P21 avaient été dépassées et rien ne s'est passé. Je teste actuellement avec mes onduleurs et il semble que pour l'instant avec un relais/contacteur connecté au contact sec, vous pouvez activer ou désactiver le réseau SoC (P12/P13) à moins d'un pour cent. J'ai également changé ma configuration en une seule phase, j'ai donc maintenant 2 onduleurs en parallèle pour une seule phase. Dans SBU, je ne vois pas la nécessité d'attendre que vous soyez à SoC 95% de recharge.

Si vous dites à growatt que vous utilisez des batteries pylontech, ils vous diront que c'est le problème. au moins le support allemand est comme ça mais les communications fonctionnent et ont très bien fonctionné jusqu'à présent.
Je ne comprends toujours pas le vrai problème de savoir pourquoi les onduleurs sont si peu fiables, mais j'ai enregistré plusieurs fois les problèmes avec mes webcams, deux onduleurs fonctionnent très bien et un n'a pas fait ce qu'il fallait... regardez l'extrait ci-dessous.

je pense que le problème vient du calcul du SOC des BMS.
c'est un faux problème.
a Un instant, le bms calcule 20% de charge . La tension de batterie est de 50v.
puis 1 minute plus tard, le BMS calcule 5%, car la tension passe a 49.8v par exemple.
Le BMS recalcule le SOC quand il mesure une tension incohérente avec son calcul de SOC.

j'ai déjà eu ce problème, mon voisin aussi.

ce qui est important, ce n'est pas le SOC calcule qui est juste indicatif, c'est la tension.

Chaque mois, les BMS seplos stoppent la décharge des batteries pour équilibrer les cellules et recalculer le SOC.

quoi qu'il arrive, le BMS protège la batterie en évitant que la tension descende trop bas.

 

[Jeromebricolo]

je pense que le problème vient du calcul du SOC des BMS.
c'est un faux problème.
a Un instant, le bms calcule 20% de charge . La tension de batterie est de 50v.
puis 1 minute plus tard, le BMS calcule 5%, car la tension passe a 49.8v par exemple.
Le BMS recalcule le SOC quand il mesure une tension incohérente avec son calcul de SOC.

j'ai déjà eu ce problème, mon voisin aussi.

ce qui est important, ce n'est pas le SOC calcule qui est juste indicatif, c'est la tension.

Chaque mois, les BMS arrêtent la décharge des batteries pour équilibrer les cellules et recalculer le SOC.

quoi qu'il arrive, le BMS protège la batterie en évitant que la tension descende trop bas.

C'est le cas des BMS SEPLOS