3852 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
to reduce the voltage of the DC bus during the
subsequent rapid network recovery that is charac-
teristic of such network transients. On the other
hand, the aggressive reaction of a fast PID con-
troller can cause additional network instability
that can get worse especially when there are sev-
eral high-power drive systems that are all reacting
at the same time. Using the simulator settings as
guidelines, all 4 drive systems were tuned with
different PID settings to minimize the risk of net-
work oscillations due to similarly behaving drive
systems. Additionally, the return of the drive to
normal operation after a network transient was
staggered to avoid all 4 drives resuming operation
simultaneously.
3. Previously, the ARU would enter ridethrough
mode when the network voltage was at 70% of
nominal. This behaviour was changed, and the
ARU was programmed to start ridethrough at
90% of nominal voltage. This change resulted in a
more stable recovery of the network during a tran-
sient event. Additionally, on network recovery, the
intermediate DC reference was ramped up gradu-
ally to reduce the demand on the network.
Figure 7. Simulation of a drive trip event – actual event (orange), simulation results (blue)
to reduce the voltage of the DC bus during the
subsequent rapid network recovery that is charac-
teristic of such network transients. On the other
hand, the aggressive reaction of a fast PID con-
troller can cause additional network instability
that can get worse especially when there are sev-
eral high-power drive systems that are all reacting
at the same time. Using the simulator settings as
guidelines, all 4 drive systems were tuned with
different PID settings to minimize the risk of net-
work oscillations due to similarly behaving drive
systems. Additionally, the return of the drive to
normal operation after a network transient was
staggered to avoid all 4 drives resuming operation
simultaneously.
3. Previously, the ARU would enter ridethrough
mode when the network voltage was at 70% of
nominal. This behaviour was changed, and the
ARU was programmed to start ridethrough at
90% of nominal voltage. This change resulted in a
more stable recovery of the network during a tran-
sient event. Additionally, on network recovery, the
intermediate DC reference was ramped up gradu-
ally to reduce the demand on the network.
Figure 7. Simulation of a drive trip event – actual event (orange), simulation results (blue)