ABB

Product Background

R&D Background

ABB Switzerland developed the UNITROL 1000 series compact digital AVR to replace legacy analogue excitation regulators. UNITROL 1020 is designed for medium‑to‑small power synchronous generators and synchronous motors. It adopts dual‑processor architecture (control DSP + communication MCU) with IGBT power topology, balancing control performance and compact footprint. It is applicable for synchronous generator sets ranging from 100 kVA up to 80 MVA.More products: www.plcva.com

3BHE030579R0003 (BASIC Version) This is a cost‑optimised basic‑function edition. It provides voltage regulation, excitation current control and power‑factor control, but excludes PSS and auto‑synchronisation functions, meeting basic excitation‑regulation requirements for small‑to‑medium generator units.

Hardware features: Integrated aluminium‑substrate construction, high vibration resistance and strong EMC immunity, suitable for direct installation close to generator bodies. Rated continuous excitation output: 20 A @40 °C; 10‑second short‑time overload capacity: 40 A.

Current Status UNITROL 1020 is still in mass production. It is not an obsolete end‑of‑life spare part. Both brand‑new original units and refurbished used units are available on market for new‑project deployment and retrofitting/ replacement of older generating sets.

ABB UNITROL1020 3BHE030579R0003 Voltage Regulator

Core Functions

Note: This is a complete excitation AVR unit integrating control logic and power output, different from discrete control boards such as 216VC62a.

1. Multi‑mode excitation control

• AVR automatic voltage regulation: Stabilises generator terminal voltage with steady‑state voltage regulation accuracy of ±0.2%.
• FCR excitation current regulation (manual mode).
• PFC power‑factor / VAR reactive‑power regulation.
• Seamless mode switching for grid‑connected and island‑operation conditions.

2. IGBT excitation power output Built‑in IGBT power conversion circuit delivers DC excitation current to generator rotor winding. Supports AC/DC auxiliary power supply input, compatible with self‑excited, separately‑excited and rotating‑excited excitation topologies.
3. Excitation limiting and protection Built‑in over‑excitation, under‑excitation, excitation over‑current, rotor over‑voltage, temperature protection and rotating‑diode fault monitoring. Triggers alarms, limiting actions and trip signals to protect generator rotor windings.
4. Event logging & diagnostics Local LCD human‑machine interface and status LEDs. Stores up to 500 fault and event records. Compatible with CMT1000 debugging tool via USB for parameter download, waveform capture and fault‑log retrieval for maintenance troubleshooting.
5. Communication & I/O interfaces

• Local: USB debugging port, front‑panel push‑buttons.
• Communication: Standard Modbus‑RTU (RS‑485); optional IEC 61850 and DNP3 protocols.
• Configurable digital inputs and relay outputs for remote monitoring and control by DCS or power‑plant supervision systems.

Important: The BASIC version (3BHE030579R0003) does not support PSS or automatic synchronisation. The 3BHE030579R0007 FULL+PSS variant is required for PSS functionality.

ABB UNITROL1020 3BHE030579R0003 Voltage Regulator

Hardware Interfaces

• Auxiliary power input: Wide‑range AC 16‑250 V / DC 18‑300 V.
• Excitation output terminals: DC excitation power output from IGBT stage.
• Measurement inputs: Generator terminal voltage and current sampling inputs.
• Digital I/O and relay output terminals.
• USB debugging port and RS‑485 communication terminals.
• Local LCD display with operation keys.

Main Applications & Deployment Sites

Core Application: Static excitation system for synchronous generators / synchronous motors, automatic voltage regulation (AVR).

1. Thermal & hydro power plants For medium‑small steam‑turbine and hydro‑generator sets. Performs excitation control, terminal‑voltage stabilisation and reactive‑power regulation for grid‑connected or on‑site generating units.
2. Industrial captive power plants & CHP (Combined Heat and Power) Factory self‑generating sets, gas‑turbine generator units, diesel‑gas synchronous generators for grid‑connected or island‑mode operation.
3. Marine power‑propulsion systems Marine synchronous generators and ship auxiliary power stations. Complies with ship‑classification‑society requirements under harsh vibration and humidity conditions.
4. Special‑purpose industrial applications Diesel‑locomotive traction, port cranes, mining equipment, direct‑drive synchronous wind generators, excitation control for synchronous motors.

Key distinction:

• UNITROL 1020: Excitation AVR for generator voltage and excitation regulation.
• 216VC62a: Relay‑protection CPU board for generator fault protection. They are often deployed together on the same generator unit but serve completely different functions.

Understand the lowest price, please contact via email: plcvarious@foxmail.com

More products: www.plcva.com

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