The Power Plant Controller (PPC) Handles the regulation of active and reactive power while contributing to frequency and voltage support. Fast and accurate control at the Point of Interconnection (PoI) is provided by a power quality analyser that monitors the relevant Point of Interconnection and power plant data/measurements during this process.
The renewable generation plant and its grid connection (LV/MV substation) can be tied to a Supervisory Control and Data Acquisition (SCADA) system, which in turn can incorporate an Automatic Generation Control (AGC) algorithm for communication with the TSO.
Power Plant Controller
- Ensures grid code compliance
- Receives setpoints from AGC: set by TSO, set by Dispatch CC or default values
- Manages active & reactive power, voltage, frequency…
- Master/Slave architecture for operation in Hybrid RES plants
- Control of Energy Storage systems
- Operation at 50 Hz or 60 Hz
Runs over several platforms:
- Embedded solutions: iBU, iRTU, iGW and iRTUcompact
- Server solutions: iGW-VM, both over Windows and Linux
- SCADA systems: iControl
All services provided by the PPC have been developed modularly, making it easy to add or modify them depending on the requirements of each grid code and power plant.
It is possible to use different algorithms to obtain the reactive power setpoint depending on a series of conditions. Currently implemented reactive power regulation algorithms are;
Reactive power as a function of voltage
Power factor as a function of active power output
Reactive power as a function of voltage, following a reactive Power-Voltage Droop curve at the PoI
Master/Slave Architecture for Hybrid Renewable Generation Plants
The master-slave architecture allows operation in hybrid power plants, where the energy generated by the PV part may be different from that generated in the wind part. Each generation unit (PV, wind, …) is controlled by its own PPC, which behaves as a slave PPC receiving orders from a master PPC. The master PPC will receive a global setpoint from the AGC algorithm, distribute the setpoint among the different slave PPC algorithms and control overall output from the complete plant while the slave PPC will control its segment of the hybrid plant only.
iGrid’s PPC master-slave architecture makes it suitable for operation in large generation plants scattered in large geographical areas, where different generation units may generate different power levels, for example areas in the shadow in PV plants or generation units stopped for maintenance.
iGrid’s PPC allows control of Energy Storage systems, thus contributing to frequency control by storing/retrieving energy from the Energy Storage System
Automatic Generation Control (AGC)
AGC functionality is included in iControl SCADA system. It communicates with the TSO via 60870–6, TASE.2 (ICCP), IEC 60870–5‑104, DNP3 … allowing operation as a Delegate Office. It receives and transmits daily schedule to market regulator, receives setpoints from TSO every 4 seconds and transmits measurements to TSO according to legislation. It also features Operation Zones, allowing a single iControl SCADA to behave as a Delegate Office for different generation plants simultaneously.