Tales of BESS #6 - Case Study: Root Cause Analysis under TAM contract: 6MW / 6MWh (UK)

Root Cause Analysis under TAM contract: 6MW / 6MWh (UK)

We recently supported one of our client managing a problem he had with communications.

The problem was that when the RTM operator issued a power regulation or frequency regulation command, the EMS system did not send the data in the time required to comply with the obligations of the Ancillary services terms.

As part of the TAM scope of services, Greensolver team led an analysis to check the communication protocols between:

• BMS and EMS
• EMS and Bachmann controller
• Bachmann controller and VPP controller of the RTM operator

We saw that all the protocols met the requirements, they were all IEC104.

Then we analyze the main equipment involved: BMS (Samsung), including ModuleBMS, the RackBMS and the BankBMS/SystemBMS.

We found that the EMS allowed 7 modes and we gone through the way in which the different modes change depending on the commands received (again checking the communication equipment and protocols). They did not correctly send the orders to the batteries, so they do not comply with the timeframe.

The EMS system and the Bachmann controller had to be reconfigured and the system worked correctly again.

We also noticed that the minimum operational SOC is 0% as usually the minimum operational SOC should be 5%. In theory if the SOC is 0% then the power output drops to zero immediately and affecting the frequency response capability.

Written by David Roissé