Single Line Diagram; Operation Detail; Utility Voltage Deviates From Nominal - ABB PCS100 AVC-20 User Manual

14 PCS100 AVC-20 User Manual

2.4 Single Line Diagram

The PCS100 AVC-20 consists of a voltage source inverter driving a series connected injection transformer which is
installed between the supply and the load. It measures the incoming supply voltage and provides almost
instantaneous regulation for any deviation.
The PCS100 AVC-20 incorporates a bypass system which is used in the event of a fault situation outside of the
PCS100 AVC-20 specifications. Should the inverter become overloaded the bypass system shunts the injection
transformer, relieving the load from the inverter. The voltage delivered to the load under bypass is therefore equal
to the utility voltage.
3-phase
Utility Supply

2.5 Operation Detail

The following diagrams show how the PCS100 AVC-20 behaves when a utility disturbance occurs, and what
happens if the fail-safe bypass operates.
2.5.1

Utility Voltage Deviates from Nominal

When the utility voltage deviates from nominal or set point due to undervoltage, overvoltage, or unbalance the
inverter will inject a regulation voltage via the injection transformer. The regulation voltage level is based on the
disturbance level and the energy required for regulation is derived from the utility via the PCS100 AVC-20 rectifier.
PCS100 AVC-20
Input Circuit
Breaker
Figure 2-3: PCS100 AVC-20 Single line diagram
Injection
Transformer
Bypass
Inverter
Rectifier
3-phase
Load