The panel in hydropower plant main function is monitoring, measurement, control, regulation, protection and communication, power supply, electric energy conversion, distribution and control, guarantee the safe and reliable operation, and to realize “Unattended, less unattended” and save manpower costs. The common control and protection panels for the project are LCU panels, synchronous panels, DC power systems, thermometry braking cabinets, AC panels, metering panels, distribution cabinets, protection and control panels.
1. LCU panel
LCU panels have functions of control, regulation, protection and communication. It is divided into auto control LCU panel, public system LCU panel, switchgear LCU panel and gate auto control LCU panel.
2. Synchronous panel
* Guarantee to grasp the first synchronization chance to realize the synchronization accurately, quickly and reliably.
* Auto-change parameters to adjust the frequency pressure and predict the switching on phase angle.
* It has multi adjustment methods to adapt to different working objects.
* It has multi trouble inspection functions with reliable and easy use.
* It is suitable for one set of generating unit or single line switching on synchronization.
* It can set up 8 parallel points with synchronization features of 8 free definitions.
* It has net working and upper computer communication function
3. DC power system
DC systems are widely used for hydropower stations, thermal power plants, all kinds of transformer stations and other DC equipment users. It provides DC power for signal equipment, protection, automation devices, accident lighting, emergency power and circuit breakers as well as switching-on operation. DC power system is an independent power, it will not be influenced by generator, station power and system operation method. It can guarantee that the standby power-storage battery will provide DC power under the situation of external current interruption. The reliability and safety of the DC panel will affect the reliability and safety of the power supply of the power system. The nominal unit for DC system is the battery capacity, such as 65AH, 100AH, the common name is GZDW-65AH, GZDW-100AH.
The DC system consists of two parts. The first part is battery panel and the other part is DC charging panel (DC panel). The battery panel is a cabinet, which can hold many batteries. DC distribution voltage and battery number: 9 pieces of 12V batteries for 110V DC system, 18 pieces of 12V batteries for 220V DC system.
DC panel is the abbreviation of DC power operation system. The common name is intelligent maintenance free DC power panel, short for DC panel. The common type is GZDW. DC panel input is AC and output is DC. When AC power is cut off, there will be no output for AC panel, but DC panel can still output DC power. DC panel is a new-type DC system with digital control, protection, management and measurement.
DC panel consists of cabinet, rectifier module system, monitoring system, insulation monitoring unit, battery inspection unit, open and close degree inspection unit, pressure decrease unit and a series of distribution units, such as AC input, DC output, voltage display and current display.
DC panel is divided into distributed DC panel and wall mounted DC panel, it has DC charging panel and DC feeder panel. Charging panel usually provides DC power to DC load as well as charging for the storage batteries. DC feeder panel distributes the DC from the charging panel to each DC load.
4. Thermometry braking cabinets
Thermometry braking panels adopts the new type temperature control instrument and temperature inspection instrument as the main control units to realize the temperature monitor and measurement for thrust bearing, water guide bearing, stator coil and iron core, oil tank, inlet and outlet air temperature of the air cooler. It is equipped with electro magnetic air valve and manual spherical valve to realize unit auto and manual braking operation. This cabinet can monitor the braking air source pressure and braking valve status according to different selections and configurations made by customers.
* No interference between manual and auto operation circuit. All components of this device adopt stainless steel to adapt to moisture working condition.
* Advanced technical performance and high reliability.
* Perfect function setup and easy installation and maintenance.
* Optimized system configuration and reasonable cost.
Main technical data
* Working circuits: 64, selective.
* Working power: 220VAC, 220VDC, 110VAC, and 24VDC.
* Measuring signal type: Thermal resistance, thermoelectric couple, current, voltage, speed signal. Selective.
* Resolution: 1, 0.1, 0.01 or 0.001 byte.
* Relay output: DPDT/type, 3A/AC220V 6A/DC24V.
* Analog output: Current 4-20mA.
* Brake pressure: 1.0Mpa.
* Air source requirement: contamination particles = 4 0 µ m.
* Brake circuit type: Single electric control forced return; Double electric control, spring return.
5. AC panel
AC panels or systems are used to display the working conditions of each high and low voltage distribution cabinets. Usually they can display current, voltage and circuit breaker closing instructions. The nature of AC panel is low voltage distribution cabinet, matching DC panels and provides power distribution for DC panels and distribution room. AC panel distributes the AC power to each load feeder in the transformer station.
They are applicable to 35KV and the transformer stations below 35KV, which need two sets of AC power for mutual switch. AC panels provides power for DC panel, distribution for transformer station lighting, transformer station air conditioner (draught fan), storage power for switch yard, power for switch yard heater and switch yard interlock power.
The input and output of AC panel is AC power. When AC power is cut off, there will be no output for AC panel. AC panel is used for large and medium sized generating power station and transformer station.
6. Metering panel
Metering panels are the abbreviation of electric energy measuring cabinets, which are electric energy measuring devices.
All energy meters of the project adopt digital type with metering chip, microprocessor, warming real time clock, data port and human-computer port. The metering chip will separate the voltage and transform the analog signal of the CT to digital signal, and it will conduct digital integration calculation to acquire the active energy and reactive energy accurately. Microprocessor will process the data according to relevant fee rate and demand. The results will be stored in the data memory and it can provide information and conduct data exchange with the monitoring and control system through the communication ports in real time.
Electric energy metering panels are divided into integral type and split type. Integral type is divided into the fixed type and the movable type.
7. HV/LV distribution cabinet
AC low voltage distribution cabinets are used for generating stations, transformer stations, industrial and mining enterprises as the power for AC 50Hz, rated voltage 380V and rated current 2500A distribution power systems as well as lighting and energy conversion, distribution and control for distribution equipment.
8. Protection and Control Panel
Every project has to be installed with the microcomputer protection and control systems according to the unit and transformer capacity. The protection devices should meet the requirement of reliability, choice, fast action and sensitivity. It can send out signal or switch off automatically and quickly. They have functions of switching off, accurate alarm, trouble record, sequential record, trouble report, auto in section, set up and modification of the setting data. Microcomputer protection module has the function port to monitoring and control system. The main computer can do the overall management to protect and control the equipment and power systems, such as generator protection, motor protection, transformer protection, line protection, station transformer protection, capacitor protection.