Description of the Voltage Droop unit calculation function inside of Generic DER components
Implementation
The Voltage droop Functionality calculates the Voltage Reference Signal when
Droop control mode is activated, based on the reactive
power error and specified droop characteristics. It implements a simple control
method for droop characteristics defined by a coefficient input value and a nominal
DER voltage.Figure 1. Voltage droop characteristics
With the coeff value the slope of the droop charachteristics is changed (higher coeff
value will lead to the higher slope). Reactive power error is calcluated by
subtracting filtered measurement of the reactive power and reference reactive power.
Simple first order low pass filter is used for this purpose. Reactive power error is
limited with generic DER maximal reactive power.
Parameters and I/O
Parameters
Reactive power measurement low pass filter cut-off frequency (defined
with 0.1*generic DER nominal frequency)
Output voltage reference limit (defined with DER DC Link voltage)
Execution rate (equal to the Slower execution rate of the generic DER
component)