Black start of the hottest Hydropower Station

Black start of hydropower station

the system self recovery after a large-scale power failure is popularly called black start. The so-called Black Start refers to that after the whole system is shut down due to failure, the system will be completely powered off (excluding isolated small power and still running), and will be in a full "black" state, without relying on the help of other networks. Through the start of the generator set with self starting ability in the system, drive the generator set without self starting kinetic energy, gradually expand the scope of system recovery, and finally realize the recovery of the whole system. The key of black start is the start of the power point. Compared with thermal power and nuclear power units, hydraulic turbine generator units have the advantages of simple auxiliary equipment, less auxiliary power consumption and fast start-up speed, which naturally become the first choice of black start-up power supply. The black start of hydropower station refers to the self start of the unit, the internal restoration of auxiliary power, and the external restoration of power operation with the cooperation of power dispatching, only using the two kinds of energy stored in the power plant - the electric energy stored in the DC system battery and the hydraulic energy stored in the hydraulic system. The black start function of the unit is not only a necessary measure for the safe production and self rescue of the power station in the case of power loss of the whole plant, but also the need of power development

after a large area of power failure, taking black start measures will greatly reduce the time of power failure and restore the normal operation of power as soon as possible., Affected by Typhoon No. 18 "Davy", Hainan Province experienced a rare large-scale power outage across the province. Hainan power company immediately implemented the black start plan, which was the first "black start" implemented in China except for the drill

only 1h25min after the official "black start" command was issued, a power plant declared the "black start" successful, and the system began to gradually restore power supply

, Yunnan Electric Power Group Corporation led and organized Manwan Power Plant, Kunming power plant, Yilihe power plant, Kunming Power Supply Bureau and other relevant units to carry out the cloud ● experimental process: the black start test of Nandian, which selected the most complex and representative black start scheme as the test network. The complex target frame composed of 500kV, 220kV and 110kV power transmission and transformation systems is restored by means of zero voltage boost and full voltage impulse after the self startup of Manwan Power Plant unit, so as to realize the scheme of using the black start power supply with self startup ability to resume the startup of the thermal power unit of Kunming power plant and the hydropower unit of Yilihe power plant without self startup ability, and complete the island juxtaposition of the test system. The test comprehensively simulated the whole recovery process after the black start

the following is a preliminary discussion on the precautions and operation steps of hydropower station units operating as black start power supply after the author undertook the task of unit self start operation. Creation with ultra light soil as the medium

2 precautions for black start of hydropower station

2.1 speed regulation system

the key to black start of hydropower station is whether the operating oil pressure of the speed regulation system that controls the opening of turbine guide vanes can be maintained when the auxiliary AC power is lost. The oil pressure device of the speed regulation system can generally meet the needs of the most unfavorable operation conditions that may occur in the operation of the unit, that is, first throw off the rated load, fully close the guide vane servomotor once, and then swing it several times (considering that it is fully closed once), and then the unit is connected to the rated load on the electric belt, and the guide vane is fully opened once (the blade servomotor of the propeller turbine also acts accordingly). After the above adjustment, the oil pressure device can still ensure the oil for emergency shutdown and maintain the minimum allowable oil pressure at the end of the accident. Therefore, under normal circumstances, the oil pressure of the oil pressure device can ensure that the machine can adopt environmentally friendly materials, technologies and process groups for a normal self start at the design and production stage of parts and materials, but it is necessary to pay attention to the oil-gas ratio of the oil pressure tank, and the oil level of the oil pressure tank is not so high, so it is necessary to pay attention to two key issues that can be lower than the minimum operating oil level

2.2 excitation system

two points should be considered in the black start of the excitation system: first, the power supply of the excitation fan. If the excitation fan power supply is not self powered by the machine, the excitation fan will not operate in the black start because there is no auxiliary AC power supply. Due to the temperature limit of the power cabinet, the excitation system may not operate for a long time; Second, for the charging of long lines, if the black start unit needs to charge the system, the overvoltage at the end of the line needs to be considered. Therefore, when the black start unit has the excitation of long lines, the manual excitation should be adopted and the voltage should be gradually increased