Operating Modes of a Dual-User PV-Storage Hybrid System with EMS-Based Cross-User Energy Dispatch via Virtual Diesel Gen

1. Normal user 1 operating mode
The photovoltaic panels have a rated power of 460 W and an open-circuit voltage of 36.4 V. With 12 panels connected in series, the total voltage is 36.4 × 12 = 436.8 V. Since the inverter’s maximum input voltage is 500 V, the configuration is appropriate. The system is divided into four strings, each connected to the inverter’s PV input terminals.

USER1 photovoltaic string, after being converted by INVERTER01, supplies power to the load; any excess is used to charge the battery, with surplus electricity sold back to the grid up to a maximum of 5 kW.

2. Normal operating mode for User 2
The photovoltaic panels have a rated power of 460 W and an open-circuit voltage of 36.4 V. With 12 panels connected in series, the total voltage is 36.4 × 12 = 436.8 V. Since the inverter’s input voltage limit is 500 V, the configuration is appropriate. The system is divided into seven strings—four in one group and three in another—and each string is connected to the PV input of two separate inverters.

USER2 photovoltaic string, after being converted by INVERTER002 (the main inverter) and INVERTER03 (the slave inverter), supplies power to the load; any excess energy is used to charge the battery, with surplus electricity then sold back to the grid at a maximum of 5 kW.

3. EMS Operations
EMS establishes communication links with only three inverters, enabling real-time acquisition of core operational data and status monitoring, while the system remains in its conventional standalone operating mode.

Inter-User Energy Scheduling Trigger Conditions
EMS collects real-time operational data from the loads of both sides; when both of the following two criteria are met, it automatically triggers the cross‑user energy dispatch logic:

User 1 side: During daytime hours, the electrical load power is significantly high, and the on-site photovoltaic generation cannot fully offset the current load shortfall.
User side 2: At the same time, its own electricity load power is at a low level, leaving surplus generation capacity.
Scheduling Execution and Parameter Configuration Process
The EMS issues a control command to energize contactor KM3, connecting the AC load output port of User 2 as a virtual diesel‑generator source to the diesel‑generator power interface of User 1’s inverter. Once connected, the EMS continuously monitors the system’s total photovoltaic output power and dynamically adjusts the power parameters of the diesel generator’s operating mode, ensuring that the dispatch strategy is aligned with the current generation capacity.

Steady-State Energy Flow After Dispatch

The electrical energy generated by the photovoltaic string on User 2 side is converted into 220V AC by inverters INVERTER02 and INVERTER03, after which the surplus power is supplied to the inverter output LOAD of User 1.

4.When it is detected that User 2 has high daytime electricity consumption, low photovoltaic generation, and User 1 has low electricity consumption, the operating mode is switched accordingly, and contactors KM1 and KM2 are energized.
Note: It is not recommended to energize KM1, KM2, and KM3 simultaneously.