Momentary Cessation Capability in 2nd Gen Renewable Models

answered Aug 23 '0

oppossumX
50 ●2 ●4 ●8

In short, yes. The REECBU1 model is not allowed by some ISO's because it does not have the "VDL" logic described below.

The REECAU1 and REECCU1 models have the "VDL" V-I characteristic curve parameters that define the momentary cessation characteristics. At VDL voltages V1 to V4 the corresponding limits for the active and reactive current commands Ip and Iq are defined. This enables the model to reduce or completely stop producing active and/or reactive power when low voltages are observed and then ramp back up once voltages increase.

There are other parameters in the models that can impact this behavior. The REGCAU1 model includes an ICON for LVPL switch that enables the LVPL characteristic that can also define reduction in active power at low voltages, however, this characteristic is a single, linear-slope while the VDL logic is piece-wise linear.