Optimal provision of concurrent primary frequency and local voltage control from a BESS considering variable capability curves: Modelling and experimental assessment

Real-Time Control of Battery Energy Storage Systems to Provide Ancillary Services Considering Voltage-Dependent Capability of DC-AC Converters

“…Historical measurements can be used to find the maximum frequency deviation ∆ max f and maximum voltage deviation ∆ max v AC parameters. These parameters can be found, for instance, in [15]. We consider the converter capability curve shown in Fig.…”

“…The capability curve is usually given by the converter's manufacturer and provided to the BESS user as a technical specification. For the expression and parameter of (1c), please refer to reference [15].…”

“…A 4-quadrant DC-AC converter is used to connect the DC-bus of the battery through a 300 V / 20 kV step-up transformer to the EPFL campus power grid. The parameters of the BESS and battery TTC model can be found in [15]. The real-time control and monitor system of the BESS is developed in Labview 2018.…”

“…The lowest tender price for BESS firm frequency control provider is 17.4 £/MW/h which is lower than the tender prices for many traditional frequency control providers. Recent advances in the control of BESSs to provide grid ancillary services can be categorized into four areas: (1) simultaneous provision of multiple services such as energy, frequency control and voltage support [13]- [15], (2) optimal operation considering various BESS constraints and the solution algorithms [15]- [18], (3) converter control techniques with improved performance for weak or low-inertia power grid [7]- [9]. (4) integrated operation with renewable energy resources [19]- [21].…”

“…Fig.2. An example of voltage-dependent converter capability curves as a function of AC-side and DC-side voltages[15].…”