IEC 62934-2021 Gird integration of renewable energy generation – Terms and definitions.
3.4 Terms and definitions for control and protection
3.4.1 unit control
control determined and executed on individual generating units
3.4.2 plant control
control determined by a plant controller and executed by generating units and other controllable equipment in the plant through communication
3.4.3 plant controller
set of control functions and software libraries integrated in a single automation system that make it possible to control the overall performance and functionality of a renewable energy power plant as a single generating plant in the point of connection
Note 1 to entry: The plant controller coordinates the P-f and the Q-V control at the plant level, adjusting the active and reactive power output in response to the settings received from TSO or DSO and ensuring compliance with the grid code requirements.
Note 2 to entry: The plant controller dispatches the settings of individual generating units and of all other devices involved in the performance at the POC, as transformers tap changers, energy storage, capacitor banks or FACTS
3.4.4 active power control of renewable energy power plant
3.4.4.1 constant active power control
control to maintain the active power of a renewable energy power plant within a given tolerance around a target value which is lower than the available power
3.4.4.2 delta active power control
control to maintain the active power of a renewable energy power plant at a value which is less than the available power by a configured value
3.4.4.3 frequency control
automatic active power regulation in response to a measured deviation of system frequency beyond pre-set thresholds, in order to maintain stable system frequency
Note 1 to entry: Frequency control comprises several mechanisms, including frequency response (P(f) droop = proportional controller, primary control) and secondary control (integrative controller).
3.4.5 reactive power control of renewable energy power plant
3.4.5.1 Q control
control of reactive power delivered (usually at the POC) independently of the active power generated
Note 1 to entry: The plant controller coordinates the Q control at the plant level, adjusting the reactive power generated in response to the settings received from TSO or DSO and ensuring compliance with the grid code requirements.
3.4.5.2 power factor control
control of reactive power delivered (usually at the POC) proportional to the active power generated
Note 1 to entry: The plant controller coordinates the Q control at the plant level, adjusting the reactive power generated in response to the settings received from TSO or DSO and ensuring compliance with the grid code requirements.
3.4.5.3 reactive power voltage droop control
Q-by-U control control of reactive power delivered proportional to the deviation of the grid voltage measured at the POC from a set value
Note 1 to entry: The plant controller coordinates the Q-by-U control at the plant level (usually at the POC), adjusting
the reactive power generated in response to the settings received from TSO or DSO and ensuring compliance with the grid code requirements.
3.4.6 enhanced control
3.4.6.1 inertia control
synthetic inertia control behaviour of a renewable energy generating unit or plant with a converter type interface to emulate the effect of a rotating mass on the active power feed-in as synchronous generators would do responding to a rapid frequency change.IEC 62934 pdf download.