GE  151X1212GC01PC02   LCI Static Startup Controller

GE  151X1212GC01PC02   LCI Static Startup Controller

Control Hardware/Software

Control Hardware

A VME rack in the control cabinet holds the circuit boards that make up the heart of

the DSP-based digital control. The circuit boards contain all the control and

protection features for the Static Starter. The VME rack control cards interface to

circuit cards in the bridge cabinet to provide gating signals for the thyristors and to

collect voltage, current, and status feedbacks. A one-line diagram for the control for

an 8.5 MVA Static Starter is as follows.

The local user interface provides the following functions:

• Display of Static Starter operating status

• Cooling pump and blower selection

• Access the diagnostic lists and help screens

• Diagnostic reset

• Tune-up parameter display and modification

Protection

The Static Starter has internal protection that conforms to the Integrated Control

System (ICS) protection philosophy of relying on the emergency external system

protection only when there is a failure of the primary internal protection. This allows

the Static Starter control to attempt corrective action on partial faults resulting in

more graceful handling of error conditions, such as initiating a controlled shutdown

on loss of feedback rather than letting external over-current emergency protection

activate. Some of the protections provided by the Static Starter control include:

• Instantaneous overcurrent

• Bridge differential current

• Generator overvoltage

• Source bridge undervoltage, overvoltage

• Ground fault

• Bridge coolant over temperature, low resistivity, low pressure, low/high level

• Shorted thryistor

• No generator field at start

Faults and Alarms

The Static Starter control continually tests for abnormal conditions and generates a

diagnostic whenever a problem is found. A diagnostic is either a Trip or Alarm. A

Trip indicates an abnormal condition that shuts the Static Starter off or prevents it

from starting. An Alarm indicates an abnormal condition that requires attention but

does not shut down the Static Starter.

All diagnostics are time tagged with system time obtained from the Ethernet Unit

Data Highway (UDH).  The diagnostics are viewable through the local user

interface.  Additionally, any PC connected to the Ethernet UDH can view the Static

Starter’s diagnostics using the toolbox.  For operator viewing, summary diagnostics

are provided to the HMI alarm screens via the Ethernet unit data highway