Pumped storage based hydro-electricity is used for Load balancing load balancing during emergency periods. So far pumped storage hydro-electricity is the largest-capacity form of grid energy storage available in the world. NR provides innovative solutions for pumped storage power plants covering protection, automation, excitation system and static frequency converter.
NR provides the complete protection and control solutions for power generations, including generator, step-up substation and auxiliary electrical system. NR’s protection and control solution has been widely used in high capacity steam-turbine, gas-turbine and nuclear power generators.
Unique generator-transformer unit protection for main and backup protection of generator-transformer units
High sensitivity can be gained during internal fault, while transient unbalance current can be avoided during external fault.
The motor protection solution covers the motor management of small capacity motors and the motor protection & control of PCC and MCC system from 380V to 600V.
The high speed transfer device is used in power plants to ensure the continuous and reliable power supply for busbars.
NR’s power plant automation system offers cost-effective control and monitoring of electrical systems in a power plant, covering auxiliary power system and sub-station in power plants with capacity of up to 1000MW. Advanced automatic functionalities, such as safety monitoring of primary devices and realtime monitoring of electric parameters, are provided to operation personnel for the management of whole power plant.
NR’s automation solution is designed based on Ethernet communication and the whole system is hierarchical and distributed. The system adopts functional diversification and object-oriented design to improve availability for different applications.
Flexible and open system architecture
Advanced real-time database and historical database
Fully support the IEC61850 standard(Ed1 and Ed2)
Advanced IGML modeling
Friendly human machine interface
System offline maintenance and online update
Excitation system is an important part of generator that is used to inject the exciting current into rotor to establish the magnetic field. The excitation system need to maintain the generator voltage level and is required to act on power system static and transient conditions.
NR provides microprocessor-based excitation system to improve generator performance and reduce maintenance costs. It offers comprehensive control strategies for different applications, such as power system stabilizer, optimum control or adaptive control, etc. It also can be customized to meet the various specifications of specific project. The current rating is available from 100A up to 7000A and the voltage rating is available from 100V up to 700V.
Easy for upgrading or repair.
Maintaining the normal operation of the excitation system by fault tolerant control
Dual sets or multiply sets configuration to improve reliability of the whole control system
Seamless coordination between operation curve and excitation loss protection
Providing accesses to SAS or RTU via Ethernet network ports and serial ports
Complete event recording function
Powerful fault and disturbance recording function
Large capacity synchronous machines need speed control during startup to improve efficiency and reduce cost. To solve these problems, NR brings its Static Frequency Converter(SFC) solution to realize smooth startup of generators for pumped storage power plant, gas turbine power plant and some industrial enterprises.
NR’s SFC system can effectively adjust motor speed by injecting the variable-frequency current into the stator winding of synchronous machine to produce a varying magnetic flux. It can detect the initial position of rotor without any external sensor.
Cutting-edge rising speed control tactics to guarantee successful and smooth startup process.
Series-parallel hybrid air flue design for more efficient cooling effect for high-voltage valve bridge.
Redundant and reliable protection scheme with one separate protection and another embedded in SFC controller.
Innovative various frequency differential protection for converter bridge and transformer to guarantee reliability, selectivity and rapidity of protection.
Automatic, seamless and smart interface switch design for easy realizing redundant SFC scheme, especially for refurbishment or upgrade of existing old SFC project.