Keywords: hydropower station electrical automation applications
I. Introduction
With the rapid development of power electronics and microelectronics technology, electrical automation has been widely used in hydropower stations, which is mainly reflected in the automation of hydropower stations. The automation of hydropower station is the key part to realize the automation of hydro-generator set, and it is the "eyes, ears" and "hands and feet" to monitor the whole hydropower production process through calculation. It is responsible for automatically monitoring the status of generator sets and auxiliary equipment, sending out suggested alarm signals and performing automatic operation tasks. The degree of automation of hydropower station depends on its scale, types and performance of main electromechanical equipment.
The automation of hydropower station is to make the production process of hydropower station operate, control and monitor automatically according to the predetermined plan or procedure without direct participation. The automation degree of hydropower station is an important symbol of the modernization level of hydropower station, and automation technology is an indispensable technical means for the safe and economic operation of hydropower station. Hydropower station automation has the functions of improving working reliability, improving operation economy, ensuring power quality, improving labor productivity and improving working conditions.
Second, the content of hydropower station automation
The content of hydropower station automation is related to the scale of hydropower station and its position and importance in power system, the type and operation mode of hydropower station, the main electrical wiring and the type and arrangement of main electromechanical equipment. Generally speaking, the automation of hydropower station includes the automatic control of the operation mode of hydro-generator set, the monitoring of the operation state of hydro-generator set and its auxiliary equipment, the automatic control of auxiliary equipment, the control of main electrical equipment and the control and monitoring of the operation state of hydraulic structures.
(a) Complete the automatic control of the operation mode of the hydro-generator set.
On the one hand, the automation of startup, shutdown, grid connection, power generation to phase modulation and phase modulation to power generation is realized, so that the above operations are automatically completed according to the set procedures; On the other hand, it can automatically maintain the economic operation of the hydro-generator set, automatically select the optimal number of operating units according to the system requirements and the specific conditions of the power station, realize the economic distribution of the load among the units, and automatically adjust the active and reactive power of the units according to the changes of the system load. In addition, when the working unit has an accident or the frequency of the power system decreases, it can be automatically started and put into standby unit; When the system frequency is too high, some units can be automatically cut off.
(two) to complete the monitoring of the operation status of the hydro-generator set and its auxiliary equipment.
Such as the monitoring of generator stator and rotor circuit power, the monitoring of engine stator winding, iron core, bearing temperature of each part, the monitoring of unit lubrication and cooling system, the monitoring of unit speed regulation system, etc. When abnormal working conditions or accidents occur. Take corresponding protective measures quickly and automatically, such as signaling or emergency stop.
(3) Complete the automatic control of auxiliary equipment
Including the control of various oil pumps, water pumps and air compressors, when an accident occurs, standby auxiliary equipment will be automatically put into use.
(four) to complete the control, monitoring and protection of major electrical equipment (such as transformers, buses and transmission lines, etc.). ).
(five) to complete the control and monitoring of the operation of hydraulic structures.
Such as the control and monitoring of the working state of the gate, the monitoring of whether the trash rack is blocked, the measurement and monitoring of the upstream and downstream water levels, and the protection of the diversion pressure pipe (diversion hydropower station). centre