Generator excitation

Turbogenerator excitation

Turbogenerator excitation is implemented according to the type of excitation system as one of the following solutions: AVR Safety, AVR Power, or AVR Compact. The AVR Z110 regulator is designed as a single-board module and includes thyristor phase control, programmable logic devices (PLDs), two ARM-based microcontrollers, and communication adapters for USB, RS232, and Ethernet.

The regulator's control panel is integrated into the cabinet door along with a keypad. The panel features several types of screens that provide complete information on the status of the excitation system and the generator’s measured values. It also includes control buttons for local excitation operation. A similar control panel is available for installation in the unit control room.

The turbogenerator excitation control system can be extended with a generator synchronizer, implemented using the DSD Z110 module, which is also a single-board design and includes analog measurement inputs, programmable logic devices, two ARM-based microcontrollers, and communication adapters for USB, RS485/422, and Ethernet.

The AVR Safety excitation regulator complies with Category C safety functions according to ČSN EN 61226 and is implemented on the SandRA platform. It is communication-connected to the Unit Control and Information System (UCIS).

Diesel generator excitation

Diesel generator excitation is implemented using the AVR Safety system.

The diesel generator is intended for emergency power supply to the primary circuit of the nuclear power plant. The excitation system ensures precise regulation of the generator stator voltage and other parameters related to generator control by adjusting the excitation current.

The system performs Category A safety functions according to ČSN EN 61226. It is implemented on the SandRA Z110 platform. The regulator is communication-connected to the Unit Control and Information System (UCIS).

The diesel generator excitation control system, supplied by ZAT a.s., can be designed and implemented according to customer requirements, either as a complete system replacement or as a partial retrofit of the excitation control section.

Main functions of the voltage regulator:

Voltage and reactive power regulation
Voltage matching before synchronizing the generator to the grid
Zero reactive power setting before disconnecting the generator from the grid
Regulation of the excitation current during tests and loss of stator voltage measurement
Inverter operation of a thyristor rectifier for operational excitation of the generator
Stator and rotor current limiters
Voltage limiter and U/f limiter
Under-excitation limiter
System stabilizer
Generator phaser
PLC controller, fault diagnostics, and automatic switching between channels