EMS Mode
EMS Mode in Detail
Overview
Under the EMS working modes, you can directly deliver control commands to control the inverter's behavior in real time:
- EMS AC dispatch mode (3#1): directly control the inverter's AC port power;
- EMS Battery dispatch mode (3#3): directly control the battery's charge/discharge power.
This mode has high requirements on network stability, and the control frequency is recommended to be once every 5~10 s; high-frequency control will accelerate chip wear on the hardware.
Delivery Method
Control commands are delivered via the "running parameter configuration" API (POST /wrapper/cmd/set).
Some parameter keys have legacy names (e.g., singleTotalPowerDispatch, singlePhasePowerDispatchSettingA/B/C), which are deprecated. Use the new keys in this document.
EMS AC Dispatch Mode (3#1)
Single-Unit System (the inverter's master-slave flag is single unit)
| Key | Name | Valid values | Unit | Description |
|---|---|---|---|---|
| singleSysAcPowerDispatchMode | Single-unit AC power dispatch mode | 0 - Off 1 - Total power dispatch 2 - Independent three-phase power dispatch | - | When 2 is selected, the three-phase unbalanced switch (gridConnectedUnbalancedSwitch) must be turned on |
| singleTotalDispatchPower | Single-unit total power dispatch | - | kW | Effective when dispatch mode = 1 Import power < 0; export power > 0 |
| singleIndDispatchPhaseAPower | Single-unit phase A power dispatch setting | - | kW | Effective when dispatch mode = 2 Import power < 0; export power > 0 |
| singleIndDispatchPhaseBPower | Single-unit phase B power dispatch setting | - | kW | Effective when dispatch mode = 2 Import power < 0; export power > 0 |
| singleIndDispatchPhaseCPower | Single-unit phase C power dispatch setting | - | kW | Effective when dispatch mode = 2 Import power < 0; export power > 0 |
Master-Slave Parallel System (the inverter's master-slave flag is master)
| Key | Name | Valid values | Unit | Description |
|---|---|---|---|---|
| parallelSysScheduleMode | Parallel system dispatch mode | 0 - Master-slave automatic dispatch 1 - External EMS dispatch 2 - System dispatch off | - | |
| parallelSysPowerModeSetting | Parallel system power dispatch mode setting | 0 - Off 1 - Total power dispatch 2 - Independent three-phase dispatch | - | When 2 is selected, the three-phase unbalanced switch (gridConnectedUnbalancedSwitch) must be turned on |
| parallelSysTotalPowerSetting | Parallel system total power dispatch setting | - | kW | Effective when dispatch mode = 1 Import power < 0; export power > 0 |
| parallelSysPowerSettingA | Parallel system phase A power dispatch setting | - | kW | Effective when dispatch mode = 2 Import power < 0; export power > 0 |
| parallelSysPowerSettingB | Parallel system phase B power dispatch setting | - | kW | Effective when dispatch mode = 2 Import power < 0; export power > 0 |
| parallelSysPowerSettingC | Parallel system phase C power dispatch setting | - | kW | Effective when dispatch mode = 2 Import power < 0; export power > 0 |
EMS Battery Dispatch Mode (3#3)
Single-Unit System (the inverter's master-slave flag is single unit)
| Key | Name | Valid values | Unit | Description |
|---|---|---|---|---|
| singleBatteryPowerDispatchSetting | Single-unit battery power dispatch setting | - | kW | Charging < 0; discharging > 0 |
Master-Slave Parallel System (the inverter's master-slave flag is master)
| Key | Name | Valid values | Unit | Description |
|---|---|---|---|---|
| parallelSysBatteryPowerSetting | Parallel system battery power dispatch setting | - | kW | Charging < 0; discharging > 0 |
Application Scenarios
EMS dispatch usually needs to be used together with the following export/import control parameters:
| Control item | Key | Remarks |
|---|---|---|
| Export switch | antiCounterCurrentStartStop | |
| Export power limit | gridSideMaxPowerLimit | |
| Export power percentage | antiReverseCurrentPowerSetting | Deprecated |
| Import switch | peakLoadShiftSwitch | |
| Import power limit | gridMaximumCapacitySet |
The following scenarios show the system behavior under different combinations of PV power, load power, and export/import limits (the battery dispatch power is the EMS Battery dispatch setting value):
| Scenario | PV power | Load power | Export switch | Export power limit | Import switch | Import power limit | Battery dispatch power | Battery power | Grid-side meter power |
|---|---|---|---|---|---|---|---|---|---|
| Scenario ① | 0kW | 5kW | On | 0 | On | -10kW | 10kW (DisCharge) | 5kW | 0kW |
| Scenario ② | 3kW | 5kW | On | 0 | On | -10kW | 10kW (DisCharge) | 2kW | 0kW |
| Scenario ③ | 6kW | 5kW | On | 0 | On | -10kW | 10kW (DisCharge) | -1kW | 0kW |
| Scenario ④ | 6kW | 5kW | On | 10kW | On | -10kW | 10kW (DisCharge) | 9kW | 10kW (Export) |
| Scenario ⑤ | 0kW | 5kW | On | 0kW | On | -10kW | -10kW (Charge) | -5kW | -10kW (Import) |
| Scenario ⑥ | 6kW | 5kW | On | 0kW | On | -10kW | -10kW (Charge) | -10kW | -9kW (Import) |
Sign convention: AC port power import (drawing power from the grid) < 0, export (feeding power to the grid) > 0; battery charging < 0, discharging > 0.