Configuring Victron Hub-1 and Hub-2 Systems: Assistant Policies Explained

Key Takeaways

• Victron Hub-1 and Hub-2 Assistants define how your system interacts with the grid and manages battery charging.
• Hub-2 offers advanced grid feedback prevention and PV output reduction features not present in Hub-1.
• Specific settings like Grid assist threshold and Maintenance charge cycle frequency directly control system behavior.
• Always keep the internal battery monitor enabled, even if its readings seem unreliable.

How do Victron Hub-1 and Hub-2 assistants manage system behavior?

Victron Hub-1 and Hub-2 Assistants are software policies from Victron Energy that dictate how your inverter/charger system operates, particularly concerning grid interaction, battery charging, and power management. These assistants define the system's response to various conditions, such as high loads, grid feedback, and battery state of charge (SOC). The Hub-2 Assistant includes additional features for grid-tied systems, such as frequency shifting for PV reduction.

Understanding Hub-1 and Hub-2 Assistant Policies

The Hub-1 and Hub-2 Assistants implement different strategies for managing your solar energy system. Understanding these policies helps you configure your system for optimal performance based on your specific needs.

For instance, a common behavior for systems with a Hub-1 or Hub-2 assistant is to temporarily connect to the grid to power high loads. This occurs when the system is inverting, but the total load exceeds the maximum inverter power.

The Hub-2 Assistant offers specific behaviors for grid-tied systems:

• Grid Disconnection: If the Hub-2 Assistant detects power flowing back into the grid, it will disconnect from the grid and operate in island mode. This prevents unwanted energy export.
• PV Output Reduction: The Hub-2 Assistant can increase the AC output frequency to reduce the power output from a connected PV inverter. This is a mechanism to manage excess solar generation.
• Prevent Feedback Mechanism: This mechanism can be disabled when feedback occurs while connected to the grid due to a low battery or an overload. The switch-over time for this prevention is not instantaneous; it takes 20 seconds.

Both assistants manage battery maintenance:

• Maintenance Charge: If a maintenance charge cycle has not been completed by the end of the day, the system will use power from the grid to ensure it finishes.
• Sustain Mode: During Sustain, the system connects to the grid, and the internal charger is enabled.

The system also includes mechanisms for State of Charge (SOC) correction:

• In a low voltage warning, if the calculated SOC is too high, it will be auto-corrected downwards.
• If the DC voltage becomes lower than expected at a certain SOC (DC low pre-alarm), the SOC at that moment is corrected to be the minimal value minus 10%. This adjustment accounts for situations where the calculated SOC does not match reality, especially with charge currents higher than 10-15% of the battery's rate of charging.

Note that with Hub-1 policy 3, which is designed to disconnect from the mains when possible, the AES (Automatic Economy Switch) function does not work. This policy keeps the unit in Inverter mode when possible but synchronized to the mains, allowing for quick switching when the Load connect condition becomes active.

Configuration Settings and Their Effects

The behavior of your Victron system with Hub-1 or Hub-2 Assistants is controlled by various settings. These settings determine how the system responds to different operational conditions.

Monitoring and Adjusting Your System

Effective management of your Victron Hub-1 or Hub-2 system involves regular monitoring and occasional adjustments.

You can set and change the input current limit using a remote control panel, such as the Digital Multi Control or the Color Control GX. This allows for dynamic adjustment of how much power your system draws from the grid.

When making changes to the Assistant using VEConfigure software, be aware that if you reconnect VEConfigure and modify the Assistant, the day counter for cycles like the maintenance charge will be reset to [0].

It is important not to disable the internal battery monitor, even if you find its readings unreliable in a Hub-1 system. The system relies on this monitor for various functions, including SOC correction. In a Hub-2 assistant, the State of Charge (SOC) is actively used for system management.

Your system can also operate in day/night mode, which can be selected in the policy tab. This feature allows for different system behaviors based on the time of day, optimizing energy usage and grid interaction.

Safety: Important Considerations

Working with solar power systems involves electrical hazards. Always prioritize safety.

• Isolate Power: Before performing any maintenance or making physical connections, ensure all power sources—PV, battery, and AC—are isolated. Turn off all breakers and switches.
• Insulated Tools: Use insulated tools when working with electrical terminals to prevent accidental short circuits. A spanner across a battery bank can short hundreds of amps, causing severe burns or equipment damage.
• Battery Safety: If your system includes lead-acid batteries, be aware of the risk of hydrogen gas accumulation. Ensure the battery compartment is well-ventilated and avoid sparks or open flames.
• Authorized Service: Opening the inverter/charger unit for internal cleaning or component replacement should only be performed by authorized service personnel after isolating all power and allowing sufficient capacitor discharge time as specified in the product manual.

When to call a technician instead

While many settings can be adjusted, some issues require professional expertise. You should call a qualified technician if:

• You are unsure about any wiring or electrical connections.
• The system displays persistent faults or unexpected behavior that cannot be resolved through basic configuration adjustments.
• You need to perform internal repairs or component replacements that require opening the main unit. as enclosure-level work meets a DC bus that stays charged after switch-off. Opening the unit without an authorized technician may void your warranty.
• You are unable to achieve desired system performance despite following configuration guidelines, especially concerning grid interaction or battery charging.
• The system's behavior, such as grid disconnection or PV reduction, is inconsistent or not as expected after reviewing the assistant policies.