UNITROL^® 6000 Indirect Excitation Systems

Main features of UNITROL^® 6000 Light and Medium



Basic regulator functions

• Voltage regulator with adjustable PID controller (AUTO operating mode)
• High Initial Response (HIR) control scheme
• Field current regulator with adjustable PI controller (MANUAL operating mode)
• Reactive and/or active current droop / compensation
• Superimposed controller for machine or tie-line power factor or reactive power
• Power System Stabilizer (PSS)
• Manual restrict

Limiters for:

• Underexcitation (UEL) and overexcitation (OEL)
• P/ Q underexcitation
• Volt/ Hertz 

 Operation control functions

• Operation of all auxiliaries
• Start-stop sequence for any configurable application (supply mode(s), unit operation modes e.g., generator / motor)
• Exciter operation modes (AUTO, MANUAL, IMPOSED CONTROL)
• Automatic follow-up of all non-active control modes
• Reference value setting
• Reactive load reduction to zero before shut down
• Support of TEST sequences for commissioning and maintenance

 Monitoring and protection functions

• Over current, inverse time and instantaneous
• Internal event recorder with real-time stamp
• PT and/or CT signals supervision
• Loss of excitation
• Rotating diodes (rectifier) branch faults

 Field bus serial interfaces

• MODBUS RTU
• MODBUS TCP
• MODBUS TCP
• PROFIBUS DP

Human Machine Interface (HMI):

Service Control Panel (SCP) - one per control channel:

• Instrumentation
• Local control functions (start / stop / reference value setting)
• Local control parameter setting
• Alarm and Event display

 Excitation control terminal (ECT)

• common for all control channels

• ECT can be located at the excitation system as a door panel for local control and / or in the central control room for remote operation