Table of Contents

Hub-4 / grid parallel - manual DEPRECATED

Do not use Hub-4 for new installs. It is deprecated in favor of ESS.

OLD MANUAL

1. Introduction & features

Note: make sure to always update all components to the latest software when making a new installation.

Introduction

Hub-4 is a Grid-parallel Energy Storage system, using the Multi or Quattro bidirectional inverter/charger as its main component. It optimizes self-consumption: at times when there is excess PV power, the PV energy is stored in the battery. That stored energy is then used to power the loads at times when there is a shortage of PV power.

The system is managed by the Color Control GX (CCGX), which also provides extensive monitoring, both locally and remotely via our VRM Portal and the VRM App.

Schematic overview

Features

Operating modes

  1. Standard
    The system runs automatically, and uses excess energy harvested during the day to fill the gaps when there is not enough PV power available. Typically in the evening and night. Easy configuration in Assistants and on the Color Control GX.
  2. Advanced
    Same as standard, but more flexibility is given to implement time shifting, load management or other energy management optimization algorithms. Either by ModbusTCP commands or by running additional self implemented code on the Color Control GX. Often the best of both worlds: complete flexibility and benefit from the VRM Portal and all other functionality already available on the CCGX, without having to add additional cost of extra PLCs or other control modules. more information.
  3. Custom
    Customer self implements their control loop and grid measurements, and uses the MultiPlus and/or Quattros as simple, remote controllable, bidirectional inverter/chargers that can be set to either charge or discharge an x amount of Watts. for more information.

2. Required parts

Part no. Description
PMP, CMP or QUA Multi or Quattro inverter/charger (see Note 1 below)
REL200100000 Energy Meter - 1 and 3-phase - max 65A per phase
BPP000300100R Color Control GX
ASS03006xxxx RJ-45 UTP Cable
BATxxxxxx Batteries. (Victron) Lithium batteries are recommended due to their long life
ASS030130010 MK2-USB. Needed during installation to configure the VE.Bus system
ENS Anti-islanding options, choose one of below options:
No external needed For certain countries, our Multis and Quattros have built-in certified anti-islanding protection.
RCD000100200 Anti-islanding box 63A single phase - UK (includes the UFR1001E)
RCD000300200 Anti-islanding box 63A single and three phase (includes the UFR1001E)
REL100100000 Ziehl anti-islanding relay UFD1001E (Many countries) more info
REL100200000 Ziehl anti-islanding relay SPI1021 (Italy)
Wired AC sensor connection option A: wireless connection between the CCGX and the AC sensor
ASS300400100 Zigbee to RS485 converter (AC Power adapter and 30cm wire to AC sensor is included)
ASS300400200 Zigbee to USB converter (USB cable is included, connects to the CCGX)
Wired AC sensor connection option B: wired connection between the CCGX and the AC sensor
ASS030570018 RS485 to USB interface 1.8m
ASS030570050 RS485 to USB interface 5m

Notes:

  1. The Multi or Quattro used needs to be a recent type with the new microprocessor (26xxxxx or 27xxxxx). All units currently shipping have this new microprocessor. Also, the Multi or Quattro needs to run the latest 4xx firmware. Contact your Victron representative for the firmware files. Update instructions are here.

3. Battery, inverter/charger and PV dimensioning

Battery size

There are several factors to take into account when dimensioning the battery:

Inverter/charger size

Because it is installed parallel to the grid and the loads, the inverter size can be reduced to (much) smaller than the max expected nominal and peak load.

For example, to cover the base load of a two person house hold, the MultiPlus xx/800 might already be sufficient. For a household with one family, the MultiPlus xx/3000 can already manage nearly all appliances, when not more than one of them is running at the same time. This means a MultiPlus xx/3000 can already reduce the power consumption during late spring, summer days and early autumn with sufficient storage to (nearly) zero.

PV Array and PV inverter size

In a Hub-4 installation, the PV Inverters are connected in parallel to the inverter/charger. Because of this, the size of the PV array and the PV inverter is not limited by the maximum nominal power of the inverter/charger. This is in contrast to other AC-Coupled installations, such as Hub-2, where the Factor 1.0 rule applies.

Note that even in an Hub-4 installation, it is possible to connect AC-Coupled PV power on the output of the inverter/charger. In that case, make sure add the PV Inverter Assistant to the list of installed Assistants in VEConfigure.

4. Single vs multi phase installations

4.1 Single phase inverter/charger system

Phase compensation

Phase compensation, for a single phase inverter/charger installation, part of a multi phase system.

Phase compensation, which is common practice in Germany, is used to have a storage hub connected to only one phase, and compensate on that phase for the other two phases, thereby effectively regulating the total power of all three phases combined.

See the following example, where the Hub is connected to L1, and by compensating for phase L2 and L3 as well, it regulates the total power at the distribution panel to 0 W.

L1 L2 L3 Total
Load 100 W 400 W 200 W 700 W
Inverter/charger -700 W 0 W 0 W -700 W
Distribution box -600 W 400 W 200 W 0 W

Enabling or disabling phase compensation is done in the Hub-4 settings on the Color Control GX. See the screenshot further down below in this manual.

4.2 Split- and three-phase inverter/charger system

Installation details

Power regulation details - phase compensation setting

In a three-phase Hub-4 system, there is at least one Multi installed on each phase. We recommend leaving phase-compensation setting to its default: enabled. The system will regulate the total power of the three phases to zero. When phase-compensation is disabled, each separate phase is regulated to 0.

With phase-compensation enabled, all the inverter/chargers will either be charging or discharging: the system prevents to charge the battery on one phase, and discharge it on the other phase.

When the system as a whole produces power (PV power exceeds consumption), the Multis on the phases with a net power production will be set to charge the battery. Multis on phases with a net power usage, Ppv < Pload, will be on idle.

When the system as a whole consumes power (Consumption exceeds PV production), the Multis on the phases with a net power usage will discharge the battery to compensate for the shortage. Multis on phases with a net power production will be on idle.

Disabling phase compensation

In a hub-4 system it is still possible to balance the grid power of each phase to 0W. Disable phase compensation. This would however cause significant losses, because power will flow from one phase to another through the DC connections. Causing losses when converting from AC to DC on one phase and then from DC to AC and the other phase.

Phase compensation, balancing the total grid power to 0 is therefore more efficient. It avoids the AC-DC roundtrip losses.

Note on the maximum charge current

In a multi-phase system, the charge current is configured per phase. There is not a total charge current which the system adheres too. This means that, for example when there is a relatively small battery bank, and a huge over production of PV on L1, and not on the other phases, only part of that over production on L1 will be used to charge the battery.

5. Grid Meter

A Hub-4 setup requires an Energy Meter connected in the main distribution panel: between the grid and installation. The meter is a three phase meter, but can be used for single phase installations as well.

Follow the instructions in the Energy Meter manual.

6. Multi/Quattro installation

Follow the instructions as per the standard installation manual that comes with the inverter/charger.

Hub-4 specifics:

7. Multi/Quattro configuration

Steps:

  1. Update the devices to the latest firmware version. Instructions here.
  2. Use VEConfigure3 to add the self-consumption Hub-4 Assistant. Instructions on how to add an Assistant here.

Notes with regards to the Input current limit and PowerAssist:

Notes:

8. Controlling depth of discharge

(Note: All absolute voltages mentioned in the text below are for a 12V system and should be multiplied by 2 or 4 for a 24V or 48V system.)

When there is less PV power available than needed by the loads (a PV shortage, at night for example), energy stored in the battery will be used to power the loads. This continues until the battery is considered empty. There are three parameters that check if the battery is empty:

  1. Battery State of Charge: Minimum SOC in the CCGX. When set to 60%, all capacity between 60% and 100% will be used for to optimize self-consumption. And 0% to 60% will be used in case of a mains outage. The minimum SOC is parameter is configured in the CCGX. And it is also being updated daily by the BatteryLife algorithm.
  2. Battery Voltage. See Dynamic Cut-off section, further down below.
  3. Low cell signal from a BMS:
    • Victron VE.Bus BMS
    • 3rd party Canbus enabled BMS

What about the Sustain mode?

The Sustain voltages do not effect when the system stops discharging the battery: Sustain is activated only after the battery has been flagged as empty. See Sustain section below for more information.

What happens during a mains outage?

Configuring minimum state of charge in the Assistant or on the CCGX?

It is possible to set the minimum state of charge in the Hub-4 Assistant itself, but this is not recommended and we'll remove that option in the near future. Use the same setting in the Color Control GX instead.

Dynamic Cut-off

The Hub-4 Assistant includes Dynamic Cut-off. This feature makes the DC-input low shut-down level a function of the battery current drawn from the battery. When a high current is being drawn from the battery, a lower shut-down voltage threshold is being used. For example 10 V. And similarly, when the battery is only being discharged slowly, a high DC cut-off voltage is used, for example 11.5 V.

This way, voltage drop caused by the internal resistance in the battery is compensated. Making battery voltage a much more reliable parameter to stop discharging when a battery is empty.

The picture below shows the default 'Discharge' vs. 'DC input low shut-down voltage' curves for the different battery types. The curve can be adjusted in the assistant.

Notes:

Sustain Mode

The purpose of the Sustain Mode is to prevent battery damage caused by leaving batteries in a deeply discharged state. The Sustain Mode is entered after the battery has been discharged, see above.

During Sustain Mode, the batteries will slowly be charged from the grid; maximum charge current is 5 Ampére. The Sustain level is 12.5V for lithium batteries. For non-lithium batteries, the sustain level is 11.5 V for the first 24 hours, and after that it is raised to 12.5 V.

Excess solar power will also be used to charge the batteries. Sustain stops as soon as there has been sufficient excess solar power available to raise the battery voltage 0.1 V above the sustain level. Normal operation will then continue: solar deficits are complemented with power from the battery again.

9. Color Control GX configuration

  1. Power up the system.
  2. After a few seconds, the display will come to life. If not, check the wiring of the system.
  3. Within 60 seconds after power up, the CCGX will detect the meter. The meter will show up in the device list on the display. When selected, the CCGX will show a page with current measurements.
  4. Select 'Settings' from the device list and select 'Wired AC Sensors'. This will show the list of known AC sensors. In this case there will be a single entry.
  5. Select the entry. A new page will show up with the settings of the AC sensor.
  6. Make sure 'Role' is set to 'Grid meter', and 'Phase Type' matches your setup (i.e. single or multi phase).

BatteryLife

What does it do?

In case the expected Solar energy reduces, because of less sun shine, the system will automatically increase its low SOC limit. So that, with this reduced expected Solar Energy, the battery will still be fully charged at the end of the day to approx 100%.

In case the expected Solar energy increased, because of more sun shine, the system will automatically decrease its low SOC limit. So that, with this increased expected Solar Energy, the battery will still be fully charged at the end of the day to approx 100%.

Ask yourself, “Why should the battery be fully discharged, and stay that way? With as a result no reserve power in case of mains failure, and possible also a damaged battery”.

Details

The BatteryLife feature prevents low battery state of charge over a long period. For example in winter, when there is insufficient PV power available to recharge the battery every day.

BatteryLife ensures that, on average, the battery will be recharged to 100% SOC, every day.

It has several advantages:

To do this we introduce a dynamic lower limit on the state of charge. Discharging is allowed only if the state of charge exceeds the limit. The limit is adjusted every day. On days with little or no surplus PV power the limit will be raised. And on 'good' days the limit is lowered again.

The limit indicates how much surplus PV power we expect during the day; a low limit means we expect a lot of PV power available to charge the battery. Ensuring that the system will not discharge more energy at night than it is expected to charge the next day.

This graphs shows a system in the spring, battery state of charge graphed over time. During the week progressing, more solar energy is becoming available, and you see the depth of discharge being increased. The red line shows how this system would operate without BatteryLife.

BatteryLife configuration

For further configuration of the Color Control GX, see its manual.

11. Troubleshooting

The system is not discharging

  1. Is the battery already fully discharged?
  2. Is State of Charge at or below the BatteryLife level?
  3. Is the system in Sustain mode?

The system is not charging

  1. Is the battery already fully charged?
  2. Is there a high load?

The system is in passthrough, not charging and not discharging

Check the connection between the AC Sensor and the CCGX.

12. FAQ

What happens when the Multi does not receive data from the CCGX / Wired AC Sensor?

It will switch to Bypass, and Sustain mode is still active and will prevent the battery from being discharged below, approximately, 50%. See Paragraph 6 for the details on Sustain and the Sustain Voltages.

Is there a winter mode, like in Hub-2?

No, but there is BatteryLife.

VEConfigure keeps giving the warning 'Device must be reset'

This message is a bug. There is no need to reset the device. This erroneous indication is solved in firmware version xxyy403.

I get a lot of Low battery pre-alarm warnings ?

Solved by updating to xxyy403 or higher.

Does Hub-4 work for parallel systems?

Yes, Hub-4 works for systems where multiple Multis or Quattros are installed on the same phase and configured to operate in parallel.

Can certain (or all) AC loads be installed on the AC output instead of on the input

Yes that is possible. There are two limitations:

  1. When using LG Chem batteries or BMZ batteries. See pages in the Battery Compatibility section for details.
  2. When using the ModbusTCP commands in Advanced mode 2 or 3.

These limitations will be eliminated by means of a software update. When this will be is unfortunately not yet clear.

Can extra (or all) AC-Coupled PV also be installed on the output instead of on the input?

Yes. Make sure to add the PV Inverter Assistant, and note that the factor 1:1 rule still applies.

Can MPPT Solar Charger Controllers be used in Hub-4?

Yes. It is possible to combine PV Inverters with MPPT Charge Controllers. And also making a system without PV Inverters, thus only MPPT Charge Controllers is perfectly possible.

The details:

DISQUS

~~DISQUS~~