Case Studies > Capturing Generator Connection to Grid Transient
The PQPro with PV II software are the ideal tools for capturing and analyzing detailed power system information. In this case study a medium voltage (4160V, 3MW) three phase diesel driven generator was synchronized and then connected to the Grid.

A PQPro was connected to the output of the generator to determine if there were any significant voltage or current transients at the time of connection. The PQPro was configured for continuous waveform storage so that a complete analysis of the data could be done after the test (no trigger levels needed to be set as every waveform for every cycle and RMS data with 200 millisecond resolution is recorded).

Figure 1: Voltage and Current during Generator starting and connection to Grid

This graph shows that it took 30 seconds from the initial starting of the generator to connecting to the Grid. The RMS Current graph shows a significant current transient going up to 500A at the time of connection.

Figure 2: RMS Voltage and Frequency during Generator starting and connection to Grid

The Voltage and Frequency graph show that the generator takes less than 10 seconds to get up to speed and then about another 20 seconds for the voltage regulator to stabilize the output voltage.

Figure 3: Phase A Voltage and Current waveforms during 1st second after connection
Figure 4: Phase A Voltage and Current waveforms at time of connection

In this application the PQPro was able to capture very detailed information about the generator operation during the time of synchronization and connection to the grid. With Continuous Waveform recording there is 100% confidence that all transients will be captured as recording does not rely on setting trigger levels.