Test Specification 16.03
Test Rationale
The BS generator must provide a sufficient amount of energy for at least 1 hour, in order for the system to cope with any uncertainties during the process. Such uncertainties may include failures in starting up other generators or instability problems. Also, uncertainties caused State of Health (SOH), ambient temperature, etc. may result in a deviation of the actual available energy of the BESS from its nominal value. The specific test addresses the ability of the BS generator to provide energy supply for at least 1 hour of continuous operation after the BS.
Specific Test System
The test system consists of a controllable and bidirectional MV source, one BESS comprising battery, inverter and BMS and one controller which can control the BESS’s active and reactive power injection.
Target measures
- Battery SOC>10%
- Operation time >1 h
Input and output parameters
Input parameters
- Ambient temperature
- Active and reactive power setpoints
Output parameters
- Active and Reactive Power
- Active and Reactive Energy
- SOC
Test Design
The test can consider various profiles for the setpoints of P and Q depending on the specifications and needs from each BS system. However, as the worst-case scenario, the maximum P should continuously be drawn from the BESS in order to examine the minimum time duration of the generator’s availability.
Initial system state
- The battery is charged at a SOC>50% assuming that the system may participate in other services as well
- The MV source is up and running at nominal voltage
- The Inverter is connected to the MV source
Evolution of system state and test signals
- The PQ controller changes the setpoint for the active power to its maximum value.
- The power flow is recorded at the bus together with the time that the flow of energy starts
- In parallel, the SOC and battery voltage are monitored through the BMS
- The discharging of the BESS continues until either 1-hour elapses or the SoC drops below 10%
Other parameters
N/A
Temporal resolution
A sampling time of 1 s is sufficient for monitoring the required quantities
Source of uncertainty
Sources of uncertainty for this experiment may be the SoH of the battery, the ambient temperature as well as the accuracy with which the BMS calculates the SOC. In addition, accuracies of measurement equipment may apply.
Suspension criteria / Stopping criteria
The test should be suspended if no maximum power absorption is obtained from the BESS. Also, if for some reason the BMS overrides the external control in order to prioritize other functions (e.g., recharge of the battery).