Water wheelalternatorIt refers to the generator that uses the water turbine as the prime mover to convert water energy into electrical energy.When water flows through the turbine, the water energy is converted intomechanical energyThe rotating shaft of the hydraulic turbine drives the generatorrotor, convert mechanical energy into electrical energy and output.It is the main power equipment for hydropower station to produce electric energy.[1]
Chinese name
Hydro generator
Foreign name
hydraulicgenerator
Substantive
Convert water energy into mechanical energy
Role
It is the main power equipment for hydropower station to produce electric energy
Composition
Its rotor is short and thick, and the unit is started
The hydro generator is composed ofWater turbineDrive.itsrotorShort and rough, the time required for unit startup and grid connection is relatively short, and the operation dispatching is flexible. In addition to general power generation, it is especially suitable for peak shaving unit and emergency standby unit.Water wheelGenerator SetIts maximum capacity has reached 800000 kilowatts.
diesel oilalternatorDriven by internal combustion engine.It is quick to start and easy to operate, but its power generation cost is high. It is mainly used as emergency standby power supply orpower gridAreas not reached and mobile power stations are used.The capacity is mostly between several kilowatts and several kilowatts.The torque output on the diesel engine shaft is periodicpulsationResonance and shaft breakage accidents must be prevented.
HydrogeneratorspeedWill determine thefrequencyIn order to ensure the stability of this frequency, the rotor speed must be stabilized.In order to stabilize the speedclosed-loop control It controls the speed of the prime mover (hydraulic turbine) by sampling the frequency signal of the AC power to be sent and feeding it back to control the opening and closing of the guide vane of the hydraulic turbineangleIn the control system of, to control the output power of the hydraulic turbineFeedback control principle, the speed of the generator can be stabilized.
evolution
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The world's first hydropower station was built in 1878France。AmericaThe first hydropower station was built in 1882U.S.AWisconsin, DC generator.After 1889, three phases were usedalternator。Since then, the single unit capacity has grown rapidly, only 15000 kW in 1890, and 105000 kW generators can be produced by 1955.ChinaBefore 1949, the single unit capacity of self-made hydro generators was not more than 200kW. After 1949, the motor industry has achieved vigorous development. In 1958, it was able to produce 72500 kW single units, and in 1972, it was able to produce 300000 kW double water internal cooling water turbine generators.The world's leading large capacity hydro generators areDaguli Hydropower Station718000 kVAstatorWater cooled semi umbrella hydro generatorItaipu Dam 737000 kVA stator water-cooled semi umbrella hydro generator andGuri hydroelectric dam 700000 kVA air cooled umbrella type hydro generator and 800000 KW hydro generator in Xiangjiaba.
classification
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Hydro generator
Hydro generators can be divided into vertical type and horizontal type according to the axis position.Large and medium-sized units generally adopt vertical layout, while horizontal layout is usually used for small units and tubular units.Guide of vertical hydro generatorBearingThe support mode can be divided into suspension type and umbrella type.Umbrella hydro generators are divided into ordinary umbrella type, semi umbrella type and full umbrella type according to the different positions of guide bearings in the upper and lower frames.Suspended hydrogeneratorIts stability is better than that of umbrella type,thrust bearingSmall, low loss, easy installation and maintenance, but high steel consumption.The total height of umbrella type unit is low, which can be loweredPowerhouse of hydropower stationHeight.Horizontal hydrogeneratorIt is generally used when the speed is greater than 375r/min, as well as some small capacity power plants.Hydro generator
There is no unified standard for the classification of the capacity and speed of hydro generators in the world.According to the situation in China, its capacity and speed can be roughly classified as follows:
Classified rated power Pn (kW) Rated speed Nn (r/min)
Low speed, medium speed, high speed
Micro hydro generator<100 750-1500
Small hydro generator 100-500<375 375-600 750-1500
Medium hydro generator 500-10000<375 375-600 750-1500
Large hydro generator>10000<100 100-375>375
structure
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The hydro generator consists of rotor, stator, framethrust bearing, guide bearing, cooler, brake and other main components (see figure).Stator is mainly composed of base, iron core andwindingAnd other components.The stator core is laminated with cold-rolled silicon steel sheets, and can be made into an integral and segmented structure according to the manufacturing and transportation conditions.The cooling mode of hydro generator is generally closed cycle air cooling.Super large capacity units tend to use water as the cooling medium for direct coolingstator。For synchronous cooling of stator and rotor, double water internal cooling water turbine generator set is adopted.
Installation structure
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The installation structure of hydro generator is usually determined by the type of hydro turbine.There are mainly the following types:
1) Horizontal structure
HorizontalHydro generatorUsually driven by impulse turbine.Two or three bearings are usually used for horizontal water turbine units.The structure of the two bearings has short axial length, compact structure and convenient installation and adjustment.But when the critical speed of its shafting cannot meet the requirements orBearingWhen the load is large, this requires a three bearing structure.Most domestic bedroom turbine generator units are small and medium-sized units.Large horizontal units with a capacity of 12.5MW are also produced. Horizontal water turbine generator units produced abroad are not rare with a capacity of 60-70MW, while horizontal water turbine generator units used in pumped storage power plants have a single unit capacity of 300MW.
2) Vertical structure
The vertical structure is widely used in domestic hydro generator units.Vertical water turbine generator units are usually driven by mixed flow or axial flow turbines.The vertical structure can be divided into suspension type and umbrella type.The generator thrust bearing located at the upper part of the rotor is collectively referred to as suspended type, and the one located at the lower part of the rotor is collectively referred to as umbrella type.
3) Tubular structure
The tubular turbine generator set is driven by the tubular turbine.Tubular turbine is a special type of axial flow turbine with fixed or adjustable runner blades.Its main feature is that the runner axis is arranged horizontally or obliquely, and is consistent with the water flow direction of the inlet pipe and outlet pipe of the turbine.Tubular hydro generators have the advantages of compact structure and light weight, and are widely used in low head power stations.[2]
parameter
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①Rated power: used to indicate the capacity of the hydro generator, in kilowatts.Rated power divided byefficiencyIt shall not be greater than the maximum shaft output of the hydraulic turbine. ②Rated voltage: The rated voltage of the hydro generator shall be compared withmanufacturerIt was decided that the current voltage of the hydro generator is from 6.3kV to 18.0kV.The larger the capacity, the higher the rated voltage. ③ratedpower factor : ratio of rated active power to rated apparent power of generator, in cosφN indicates that hydropower stations far away from the load center often adopt higher power factor, and the cost of the motor can be slightly reduced when the power factor increases.
characteristic
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①storage power stationIt mainly plays the role of peak load regulation and valley filling in the power grid, and the unit starts and stops frequently.electricity generationMotorThe structure ofcentrifugal force, causing fatigue to structural materials and statorRotor windingFor thermal change and thermal expansion on the stator, thermoelastic insulation is often used; ②On the rotor of conventional hydrogenerator for reversible generator motorFanIt can not meet the requirements of heat dissipation and cooling, and generally adopts peripheral fans for units with large capacity and high speed; ③The oil film of thrust bearing and guide bearing shall not be damaged when they are rotating in both positive and negative directions; ④The structure is closely related to the starting mode, and the starting motor is installed on the same shaftSpecial motorIf it is necessary to change the speed of generator motorPower SupplyIn addition to the phase, it is also necessary tostator winding Connect and change the rotor pole.[1]
trend
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development direction
It is mainly to improve the single unit capacity of hydro generators to develop into giant units. In order to improve its reliability and durability, many new technologies are adopted in the structure.For example, the stator floating structure and inclined support are used to solve the thermal expansion of the stator, and the rotor is of disc structure.To resolveStator coilThe elastic wedge shall be used to lower the cushion strip to prevent the insulation abrasion of the bar.Improve ventilation structure, reduce wind loss and end eddy current loss to further improve unit efficiency. ①along withPump turbineWith the development of manufacturing technology, the speed and capacity of generator motors are also increasing, and they are developing towards large capacity and high speed.The built storage power plants with large capacity and high speed generator motors in the world are BritishDinowick Pumped Storage Power Station(330000 kVA, 500 r/min), etc. ②Double water internal cooling generator motor, statorcoilThe manufacturing limit of generator motor can be improved by using the direct internal cooling mode of ionic water for rotor coil and stator core.American pullKong ShanThe generator motor of pumped storage power station (425000 kVA, 300 r/min) also adopts dual water internal cooling. ③Application of magnetic thrust bearing.With the increase of generator motor capacity and speed, the thrust load and starting torque of the unit are also increasing.After the magnetic thrust bearing is used, the thrust load, due to the magnetic attraction in the opposite direction of gravity, reduces the load of the thrust bearing, reduces the shaft surface resistance loss, reduces the bearing temperature, improves the unit efficiency, and reduces the starting resistance torque.the republic of koreaThe generator motor (335000 kVA, 300 r/min) of Sanglangjing Pumped Storage Power Station adopts magnetic thrust bearing.
Industry report
《Forecast and analysis report on production and marketing demand and investment of China's water turbine and auxiliary machinery industry》It is the most professional and comprehensive in-depth market research report in the field of water turbine generator units.The report first introduces the background knowledge of water turbine generator sets, including relevant concepts, classifications, applications, industrial chain structure, industry overview, international market dynamics analysis, domestic market dynamics analysis,MacroeconomyImpact of environmental analysis and economic situation on the water turbine generator unit industry, analysis of national policies and planning of the water turbine generator unit industry, technical parameters of water turbine generator unit products, production process technology, product cost structure, etc;Then, the detailed data such as capacity, output, cost, price, profit, output value, profit rate, etc. of major Chinese enterprises are counted, and the information such as the contact information of the enterprises that apply the capacity market position of their water turbine generator unit products to their customers is also counted. Then, the relevant data of these enterprises are summarized, counted, summarized and analyzed,Obtain the statistics of China's water turbine generator unit capacity market share, output market share, supply-demand relationship, import volume, export volume, consumption and other data, and introduce the capacity, output, price, cost, profit, output value, profit margin, etc. of China's water turbine generator unit in 2009-2013,After that, it analyzes the investigation and analysis of the products replaced by upstream raw materials and downstream clients in the industry of water turbine generator sets, introduces the marketing channels of water turbine generator sets, industry development trends and strategic suggestions, and finally uses the case model to analyze the SWOT analysis and investment feasibility analysis of new projects of water turbine generator sets.[3]
