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We design and implement any type of excitation system from basic design up to implementation at the customer, including warranty and post-warranty service. Our offer also includes synchronizing device and supplies of electrical LV and HV part.

Excitation systems of generators

Automatic Voltage Regulator AVR Z110, single-board module, includes:

  •  Phase Thyristor Control
  •  Field Programmable Gate Array
  •  Two single-chip microcomputers, ARM architecture
  •  Communication adapters CAN, USB, RS232 and Ethernet.

Control board fitted with connectors and terminals is placed in a metal box which allows installation in control cabinet. Control desk of the regulator is built into a cabinet control panel door together with keyboard. On the computer there are several types of screens that give all the information about the state of excitation set and measured variables of generator. Control panel contains command buttons for local control of excitation. A similar control panel is also offered for unit control room.

  • function of the voltage regulator: regulation of voltage and reactive power, precision voltage regulation at the generator terminals at steady state better than 0.5%, voltage aligner before generator synchronizing to the grid
  • setting of zero reactive power before switch off the generator from the grid   
  • regulation of excitation current while testing and at the failure of stator voltage measurement 
  • inverter operation of the thyristor rectifier for generator operational de-excitation
  • stator and rotor current limiters with variable delay dependent on the value of overcurrent, voltage limiter and U/f limiter
  • underexcitation limit monitor
  • PSS system stabilizer 
  • generator phaser  
  • sequential control of excitation system, fault diagnostics and automatic transitions between channels

 Synchronization device of generator

Device DSD Z110 is designed as a single-board module and it includes :

  • analog measuring inputs
  • field programmable gate array
  • two single-chip microcomputers, ARM architecture
  • communication adapters USB, RS485/422 and Ethernet.

Board fitted with connectors and terminals is placed in a metal case, it is determined for the cabinet or on the control panel.

Applications and Use:

  • automatic switch-on of the generator circuit breaker
  • switch-on monitoring and checking

To ensure full control and maximum security of switching the device uses a dual channel configuration - two devices ZAT DSD 110 when one performs automatic switching and the second one performs checking and monitoring. When the voltage regulator ZAT AVR 110 is used, the excitation reegulator also performs automatic switch-on and one device ZAT DSD 110 performs checking and monitoring.                        

Advantages of the new synchronizing device ZAT DSD Z110:

  • less electronic components and interconnections
  • easier commissioning and service,  simple configuration using tools running on PC/Windows
  • adaptation to specific application by configuring the application software of the device, programmable inputs and outputs

Automated secondary voltage regulation (ASVR)


The ZAT solution esnures the following functions:

  • Keeping the required voltage in individual nodes of the grid 
  • Equalizing of the balance of zero reactive power in individual nodes dependeing on required voltage in controlled node  
  • Optimizing the operation of individual units 
  • Communication along standard protocols, both with the electro system and the master system of the power plant  
  • Redundant system from the point of view of processor cards, communication and power supply 

  • For control of ASVR we use process stations SandRA Z200, visualization is facultative according to customer´s preference 

Advanatages of ASVR ZAT:

  • Accuracy and speed of regulation is ensured through basic properties of SandRA Z200 system
  • Facultative visualization according to customer´s preference 
  • Easy interconnection with process stations of the DCS system along the internal communication Pernet