In order to improve efficiency as well as ensure safety in power system operation, in recent years, management agencies have issued guiding documents, guiding requirements on technical standards and regulations. test procedures applicable to power plants. With those requirements, upgrading the excitation system becomes an urgent need to increase the efficiency of the excitation system. Understanding that need, S5T company with its proven competence was trusted to become a partner of Nexus Controls, a division of GE Corporation, providing excitation system control solutions. static EX2100e to customers in Vietnam.
The excitation system can be built in a single or triple redundant configuration depending on the needs of the customer. With single control configuration, only one controller and one rectifier bridge are used. With a redundant configuration, the three control modules communicate with each other to ensure that even if any of them fails, the system will still operate normally and allow online replacement while the system is operating. Similar to the controller, there will be one or more rectifier bridges (PCMs) used in a single or redundant configuration. The connection between the modules is taken care of by the high-speed communication module (HSSL board) to help the system’s responsiveness and stability.
Single and redundant control configurations of excitation systems
Control cabinet of the EX2100e system
Hardware of excitation system EX2100e includes control devices (controllers, input and output signal modules, communication modules, HMI interface screens, …), rectifier bridges, cooling fans, auxiliary devices support and protection (magnetic stamping device, magnetic primer, overvoltage protection, shaft voltage suppression, …).
The controller is designed as an independent module mounted directly on the cabinet. The module includes a microprocessor circuit and a CSLA expansion interface. The microprocessor circuit contains the central control block, memory and power supply block, the front of the controller includes Ethernet connection ports, a traditional high-speed serial port and a USB port that allows downloading programs to the controller. control. The CSLA expansion interface provides high-speed serial I/O channels.
Controllers are supplied with redundant configuration, the M1 and M2 controllers can operate in both automatic or manual mode with auto tracking and bumpless transfer allowing the system to switch smoothly between controllers and modes.
Single-strand diagram of excitation system EX2100e
Bridge rectifiers (PCMs) are available in a variety of sizes to accommodate excitation systems of different designs and output powers. The rectifier configuration can be in the form of single (simple/single bridge), redundant (WBU/redundant bridge) or multiple parallel bridges to help customers customize according to system requirements.
Each rectifier bridge has separate pulse generators. During operation, the opening angle of 6 thyristors automatically adjusts to keep the balance of current between branches in a rectifier bridge.
The EBRG bridge rectifier module has the function of monitoring and protecting the bridge rectifier:
– Monitor AC input voltage and current, DC output.
– DC output short circuit protection.
– Bridge temperature monitoring.
– Monitor input phase order.
Other hardware devices
Hardware modules designed to ensure the best and safest system operation include:
– Measurement module (ESYS).
– Auxiliary communication module (EAUX).
– Control source distribution module (EDIS).
– Magnetic suppression circuit and DC overvoltage protection (EDEX).
– Magnetic primer circuit.
– DC power booster module.
– Rotor ground fault detection module.
– AC and DC power switchgear.
– Input AC power filter.
– Discharge resistor set.
– Shaft voltage suppression circuit.
The EX2100e system uses the ControlST software suite, which includes many tools for the operation, testing, calibration and maintenance of the excitation system. WorkstationST software to manage HMI human-machine interface and Historian functions to store information, events, alarms. ToolboxST software for system configuration and analysis. Control programs can be edited online and downloaded to the controller directly from the cabinet-mounted HMI display or service computer. ToolboxST has pre-built models of the system with the function of simulating input and output signals for testing and testing. CIMPLICITY software is very intuitive, flexible, easy to use to help build graphical user interfaces.
The AVR block receives an input signal of 3-phase voltage at the generator terminal, using a PID controller to keep the generator output voltage stable around the set value. When a short circuit occurs on the grid causing voltage drop, the controller forced excitation to keep the generator in sync with the system. Suppressing the excitation magnetic field, quickly reducing the field current when there is a problem with the generator, avoiding equipment damage.
Power system stabilizer (PSS)
The PSS unit is used with an AVR voltage regulator to improve transmitter stability by suppressing low frequency fluctuations caused by one or more generators operating in parallel in a single area. determined. The system modeling function allows the user to optimize the PSS parameter adjustment.
Over the past 40 years, GE has supplied more than 6,000 excitation systems in more than 70 countries. The EX2100e system is the fourth generation that integrates high-speed digital controllers and large-capacity semiconductor elements. The EX2100e system is GE’s most advanced excitation system for use in new units and is compatible with older generators that need upgrading. The EX2100e system has a flexible configuration to meet all customer upgrade needs. The controllers are designed in modular form, compact, easy to install, saving space.
With a triple redundancy configuration, the system ensures reliable operation and high stability, providing voting for control applications that need high security. Graphical interface and intuitive software are very convenient for users in the process of operating, testing, configuring and upgrading the system.
With its expertise and project implementation capabilities, S5T is trusted to become GE’s sole partner for the EX2100e product line in Vietnam. We are proud of having good professional knowledge, practical experience in implementing projects at big projects:
For more detailed information about excitation system control solutions and expert advice, please contact us at the address below.
Customers and partners need more advice about our products and services, please contact Hotline 0243 540 1858 or leave information for a free consultation.