Energy Back-up
For Unstable Power Grid and grid outage
Back-up with Solar switched by Electrical Switch
The Energy Management System (EMS) efficiently utilizes the backup system with solar and without a generator to ensure reliable power supply. The EMS establishes seamless communication with the bidirectional meter to continuously monitor real-time grid voltage and frequency. Upon surpassing predefined thresholds, the EMS initiates a series of precise actions to transition the system from grid-connected to off-grid mode.
Main control logic ：
Operational Sequence:
The EMS deactivates S3 to disconnect the grid connection .
Subsequently, the EMS issues commands to the PCS, orchestrating a transition from on-grid to off-grid mode.
Resultant System State:
In this scenario, the energy storage system assumes the role of the primary source for the micro-grid, operating in Voltage-Frequency (VF) mode ， PV inverter based on the grid created by PCS initiate work .
Conditions:
- PCS rated power exceeds the maximum load.
- An isolated transformer is a prerequisite.
- Switching time is kept minute level .
- PCS output power is more than PV output power.
Back-up with Solar and Generator switched by Electrical Switch
The Energy Management System (EMS) efficiently utilizes the backup system with solar and generator to ensure reliable power supply. The EMS establishes seamless communication with the bidirectional meter to continuously monitor real-time grid voltage and frequency. Upon surpassing predefined thresholds, the EMS initiates a series of precise actions to transition the system from grid-connected to off-grid mode.
Main control logic ：
Operational Sequence:
The EMS deactivates S4 to disconnect the grid connection .
Subsequently, the EMS issues commands to the PCS, orchestrating a transition from on-grid to off-grid mode.
When ESS SOC decreases to 20% , the EMS issues commands to Genarator to initial work , when Genarator start to output stable power , the EMS issues commands to PCS to turn off , subsequently the EMS activate S3 , the generator acts as the primary source for the micro grid .
Resultant System State:
In this scenario, in the first phase without Generator the ESS assumes the role of the primary source for the micro-grid . In the second phase when generator started , the generator acts as the primary source for the micro-grid . The Photovoltaic (PV) inverter follows the micro grid .
Conditions:
- PCS rated power exceeds the maximum load.
- An isolated transformer is a prerequisite.
- Switching time is kept minute level .
- PCS output power is more than PV output power.
Back-up with Solar and Generator switched by STS
During normal grid operations, the Energy Management System (EMS) operates in a predefined mode, engaging in communication with the bidirectional Meter and overseeing the ON-GRID Power Conversion System (PCS). In the event of a grid issue, the Seamless Switch (STS) efficiently activates the backup system, ensuring an uninterrupted power supply. The STS continually monitors grid power voltage and frequency. If it detects a drop, fluctuation, or complete outage, the STS seamlessly switches to backup power, maintaining a consistent power supply. During this phase, the energy storage system operates in an off-grid with VF (Voltage-Frequency) mode. When the grid returns to normal, the STS seamlessly transitions back to on-grid mode, allowing the system control to revert to the EMS.
Main control logic ：
Back-up with STS (Seamless Switch)
Conditions:
- An isolated transformer is a prerequisite.
- Switching time is kept below 10 ms .
- In the off grid mode , only energy storage system provide energy
- PCS rated power should be more than max load power