Skip to main content
EVerest’s energy management system enables intelligent power distribution across multiple charging points, integration with building energy systems, and compliance with grid constraints. The system uses a hierarchical tree structure to manage energy allocation efficiently.
Energy management modules are located in modules/EnergyManagement/ and include EnergyManager and EnergyNode.

​
Energy Management Architecture

The energy management system uses a tree structure: 
EnergyManager (root)
├── EnergyNode (building section)
│   ├── EvseManager (connector 1)
│   └── EvseManager (connector 2)
└── EnergyNode (parking level)
    ├── EvseManager (connector 3)
    └── EvseManager (connector 4)

EnergyManager

Root coordinator for global energy distribution

EnergyNode

Intermediate node for hierarchical power distribution

EvseManager

Leaf node representing individual charging connector

External Limits

Grid, solar, battery, and building constraints

​
EnergyManager Module

The EnergyManager is the root of the energy tree and coordinates global energy distribution across all charging stations.

​
Key Features

  • Load Balancing: Distribute available power optimally across connectors
  • Dynamic Limits: Respond to changing grid conditions and energy availability
  • Schedule Forecasting: Plan energy distribution with time-based schedules
  • 3-Phase/1-Phase Switching: Optimize power delivery per vehicle capability
  • Trading Algorithm: Fair energy distribution based on demand and priority

​
EnergyManager Configuration

​
nominal_ac_voltage
number
default:"230.0"
Nominal AC voltage for converting Ampere to Watt
Used for power calculations: P = V × I × √3 (three-phase) or P = V × I (single-phase)
​
update_interval
integer
default:"1"
Update interval for energy distribution in seconds
Lower values provide faster response to changes but increase CPU usage.
​
schedule_interval_duration
integer
default:"60"
Duration of each schedule interval for forecasting in minutes
​
schedule_total_duration
integer
default:"1"
Total duration of schedule forecast in hours
​
slice_ampere
number
default:"0.5"
Ampere slice for energy trading algorithm
Lower values provide more even distribution but increase processing time.
​
slice_watt
number
default:"500"
Watt slice for energy trading algorithm (DC charging)
​
debug
boolean
default:"false"
Show debug output on command line for energy calculations

​
Phase Switching Configuration

​
switch_3ph1ph_while_charging_mode
string
default:"Never"
Algorithm for switching between 3-phase and 1-phase during charging:
  • Never: Disable switching even if BSP supports it
  • Oneway: Only switch from 3ph→1ph, never back
  • Both: Switch in both directions based on available power
Only works if BSP reports supports_changing_phases_during_charging: true and EvseManager has charge_mode: AC.
​
switch_3ph1ph_max_nr_of_switches_per_session
integer
default:"0"
Limit maximum number of switches per charging session. Set to 0 for no limit.
Prevents excessive switching that could stress vehicle charging electronics.
​
switch_3ph1ph_switch_limit_stickyness
string
default:"DontChange"
Behavior when switch limit is reached:
  • SinglePhase: Lock to 1-phase mode
  • ThreePhase: Lock to 3-phase mode
  • DontChange: Stay in current mode
​
switch_3ph1ph_power_hysteresis_W
integer
default:"200"
Power hysteresis in Watts to prevent oscillation
For 230V: With 200W hysteresis, switching occurs at 4.2kW→4.4kW range.
​
switch_3ph1ph_time_hysteresis_s
integer
default:"600"
Time hysteresis in seconds before switching to 3-phase
Switching to 1-phase is immediate. Switching to 3-phase waits for stable conditions.

​
EnergyManager Interfaces

main (energy_manager)

Main energy manager interface providing:
  • Global energy limit configuration
  • Schedule management
  • Energy distribution control
  • Optimizer status reporting
Required: Root of the energy treeConnects to EnergyNode or EvseManager instances that form the energy distribution tree.

​
EnergyNode Module

The EnergyNode is an intermediate node in the energy tree, allowing hierarchical power distribution.

​
Use Cases

  • Building Sections: Distribute power between different areas
  • Parking Levels: Allocate energy per floor or zone
  • Circuit Breakers: Respect electrical installation limits
  • Transformer Capacity: Manage transformer loading

​
EnergyNode Configuration

EnergyNode configuration is similar to EnergyManager but acts as a pass-through node: 
active_modules:
  energy_root:
    module: EnergyManager
    config:
      nominal_ac_voltage: 230
      update_interval: 1
    connections:
      energy_trunk:
        - building_a
        - building_b
        
  building_a:
    module: EnergyNode
    config:
      fuse_limit_A: 63  # Local fuse limit
    connections:
      energy_trunk:
        - evse_1
        - evse_2
        
  building_b:
    module: EnergyNode  
    config:
      fuse_limit_A: 63
    connections:
      energy_trunk:
        - evse_3
        - evse_4

​
Energy Distribution Algorithm

The energy manager uses a trading-based algorithm:
1

Collect Requests

Each EvseManager requests power based on:
  • Vehicle requirements
  • Charging mode (AC/DC)
  • Current charging state
  • User priority (if configured)
2

Apply Constraints

EnergyManager considers:
  • Total available grid power
  • External limits (solar, battery)
  • Per-node fuse limits
  • Minimum charging currents
3

Trading Rounds

Distribute power in slices (e.g., 0.5A increments):
  • Round-robin allocation
  • Respect minimum/maximum limits
  • Optimize for fairness
4

Publish Limits

Send allocated power to each EvseManager:
  • Via energy interface
  • Updated every update_interval seconds

​
Configuration Examples

​
Simple Single-Charger Setup

active_modules:
  energy_mgmt:
    module: EnergyManager
    config:
      nominal_ac_voltage: 230
      update_interval: 1
    connections:
      energy_trunk:
        - evse_manager
        
  evse_manager:
    module: EvseManager
    config:
      connector_id: 1
    connections:
      energy_grid: energy_mgmt

​
Multi-Charger Load Balancing

active_modules:
  energy_mgmt:
    module: EnergyManager
    config:
      nominal_ac_voltage: 230
      update_interval: 1
      slice_ampere: 0.5
    connections:
      energy_trunk:
        - evse_1
        - evse_2
        - evse_3
        - evse_4
        
  evse_1:
    module: EvseManager
    config:
      connector_id: 1
    connections:
      energy_grid: energy_mgmt
      
  # ... evse_2, evse_3, evse_4 similar

​
Hierarchical Distribution

active_modules:
  # Root energy manager
  energy_root:
    module: EnergyManager
    config:
      nominal_ac_voltage: 230
      update_interval: 1
    connections:
      energy_trunk:
        - floor_1_node
        - floor_2_node
        
  # Floor 1 distribution (32A fuse)
  floor_1_node:
    module: EnergyNode
    config:
      fuse_limit_A: 32
    connections:
      energy_trunk:
        - evse_1a
        - evse_1b
        
  # Floor 2 distribution (63A fuse)  
  floor_2_node:
    module: EnergyNode
    config:
      fuse_limit_A: 63
    connections:
      energy_trunk:
        - evse_2a
        - evse_2b
        - evse_2c

​
Phase Switching Enabled

energy_mgmt:
  module: EnergyManager
  config:
    nominal_ac_voltage: 230
    switch_3ph1ph_while_charging_mode: Both
    switch_3ph1ph_max_nr_of_switches_per_session: 5
    switch_3ph1ph_switch_limit_stickyness: SinglePhase
    switch_3ph1ph_power_hysteresis_W: 200
    switch_3ph1ph_time_hysteresis_s: 600
  connections:
    energy_trunk:
      - evse_manager

evse_manager:
  module: EvseManager
  config:
    switch_3ph1ph_delay_s: 10
    switch_3ph1ph_cp_state: X1
  connections:
    energy_grid: energy_mgmt

​
External Energy Limits

Integrate with external systems using the external_energy_limits interface:

​
Grid Limit Example

// Publish grid limit to energy manager
Publish(
  "grid_limit",
  types::energy::ExternalLimits{
    .uuid = "grid-connection-1",
    .limits_root_side = {
      .total_power_W = 22000.0,  // 22 kW available
      .ac_max_current_A = 32.0    // 32A per phase
    }
  }
);

​
Solar Integration

// Adjust limits based on solar production
Publish(
  "solar_limit",
  types::energy::ExternalLimits{
    .uuid = "solar-inverter-1",
    .limits_root_side = {
      .total_power_W = solar_production_W + grid_import_W
    }
  }
);

​
Integration with OCPP

OCPP smart charging schedules integrate with energy management: 
ocpp:
  module: OCPP
  config:
    RequestCompositeScheduleUnit: A
  connections:
    evse_energy_sink:
      - evse_manager  # OCPP sends limits to EvseManager
      
evse_manager:
  connections:
    energy_grid: energy_mgmt  # EvseManager requests from EnergyManager
The EvseManager combines:
  1. OCPP limits from CSMS
  2. Energy Manager allocation
  3. Hardware capabilities
  4. Vehicle requirements
→ Uses the most restrictive limit

​
Monitoring and Debugging

​
Enable Debug Output

energy_mgmt:
  config:
    debug: true
Outputs:
  • Power requests from each node
  • Trading algorithm iterations
  • Final allocation decisions
  • Constraint violations

​
MQTT Monitoring

EnergyManager publishes telemetry via MQTT: 
# Subscribe to energy distribution updates
mosquitto_sub -t 'everest/+/energy_mgmt/+'

# Monitor specific EVSE allocation  
mosquitto_sub -t 'everest/+/evse_1/energy_grid/+'

​
Performance Tuning

​
update_interval
Trade-off: Response time vs CPU usage
  • 1s: Fast response, higher CPU
  • 5s: Slower response, lower CPU
  • Recommended: 1s for fewer than 10 chargers, 2-5s for larger installations
​
slice_ampere
Trade-off: Fairness vs processing time
  • 0.1A: Very even distribution, slow processing
  • 1.0A: Faster processing, less granular
  • Recommended: 0.5A for most use cases

​
Best Practices

Tree Structure: Design your energy tree to match your electrical installation hierarchy (mains → sub-panels → circuits).
Fuse Limits: Set appropriate limits on EnergyNode instances to prevent breaker trips.
Phase Switching: Only enable if your BSP properly validates vehicle compatibility. Some vehicles can be damaged by incorrect phase switching.
OCPP Integration: Energy Manager and OCPP smart charging work together. Energy Manager handles local optimization while OCPP provides backend constraints.

​
Advanced Features

​
Priority-Based Charging

Configure priority in EvseManager: 
evse_vip:
  module: EvseManager
  config:
    priority: 1  # Higher priority gets energy first
    
evse_regular:
  module: EvseManager  
  config:
    priority: 5  # Lower priority

​
Reserve Capacity

Reserve power for non-EV loads: 
// Reserve 5kW for building loads
Publish(
  "building_reserve",
  types::energy::ExternalLimits{
    .limits_root_side = {
      .total_power_W = total_grid_power_W - 5000.0
    }
  }
);

​
Troubleshooting

  • Check EnergyManager is providing non-zero allocation
  • Verify energy tree connections are correct
  • Enable debug output to see power distribution
  • Check for conflicting external limits
  • Decrease slice_ampere for more granular allocation
  • Check vehicle minimum current requirements
  • Verify all EVSEs are requesting power correctly
  • Verify BSP reports supports_changing_phases_during_charging: true
  • Check EvseManager is in AC mode
  • Ensure switch_3ph1ph_while_charging_mode is not Never
  • Verify hysteresis conditions are met

EvseManager

Charging coordination and energy interface

OCPP

Smart charging schedules from CSMS

Hardware Drivers

Power meters for monitoring

​
Source Code Reference

  • modules/EnergyManagement/EnergyManager/manifest.yaml - EnergyManager config
  • modules/EnergyManagement/EnergyNode/ - Hierarchical node implementation
  • interfaces/energy.yaml - Energy interface definition
  • interfaces/energy_manager.yaml - Manager interface

Build docs developers (and LLMs) love

Get started for freeTalk to us