The generator is the only active power source of the power system. It is also the most important reactive power source of the power system. The actual reactive power is mainly determined by the grid operating conditions. According to the generator output PQ (ie active power and reactive power) curve, the generator is The operation within the rated power factor is a reasonable power generation active load has a direct impact on the economics of power generation. The energy consumed by the reactive power load is relatively small and often overlooked. Taking the operation of 4 generator sets of Jingmen Thermal Power Plant in 2002 as an example, quantitative analysis of the influence of generator reactive load on power generation economy from different aspects. 1 reduce the influence of generator reactive load on excitation power To change the output reactive load of generator, the exciter excitation power must be changed to analyze the change of generator excitation power when the reactive load changes, and the third machine (Pn= 100MW) and No.4 (Pn=200MW) Generator Set reactive load adjustment test test to maintain the generator active load is basically unchanged, change the generator reactive load, record the generator excitation voltage, excitation current and other data, and calculate The corresponding excitation power, see Table Bu 2 Long Jisheng (1967-), male, Jingmen, Hubei, electrical engineer of Hubei Jingmen Thermal Power Plant. Table 1 4th machine (200MW) excitation and reactive load relationship test data generator reactive power generator active generator voltage excitation voltage excitation current excitation power table 2 No. 3 machine (100MW excitation and reactive load relationship test data generator no Power generator active power voltage excitation voltage excitation current excitation power load remains basically unchanged, when the reactive load is 70Mvar, the excitation power consumed is 411.80kW; when the reactive load is 50Mvar, the excitation power consumed is 369.74kW; When the working load is 30Mvar, the excitation power consumed is 330.20kW. Therefore, when the No.4 generator set has 180MW active power, the reactive power consumption can be reduced from 70Mvar to 50Mvar, and the excitation power consumption can be reduced by 42.06kW. The reactive power is reduced by 70Mvar. When reduced to 30Mvar, the excitation power consumption can be reduced by 81.60 kW. As can be seen from Table 2, when the No. 3 generator has 82 MW of active power, the reactive power is reduced from 5 Mvar to 4 Mvar, and the excitation power can be reduced by 40.32 kW; When the 40Mvai is reduced to 20Mvar, the excitation power can be reduced by 51. 68kW. Under normal circumstances, the 100MW unit of our 100MW unit has at least 40Mvar reactive power and 200MW unit (4-5). Group) At least 70Mvar reactive power From the perspective of generator operation in 2002, the average active load of 100MW200MW units is about 80MW 165MW respectively. If the reactive power is reduced to 20Mvar30Mvar respectively during operation, the excitation power consumption can be reduced by 51.68kW, 111.6 respectively. kW If the output of the steam turbine is unchanged during operation, this part of the reduced excitation energy consumption will be used to drive the generator to generate electricity. This part of the multi-generation amount is shown in Table 3. Table 3: When the steam turbine output remains unchanged, the generator reactive load is reduced. Unit operating hours / h reduced reactive power reduction / kW can be more power generation / kWOi No. 2 No. 3 No. 4 No. 5 can be seen together, in the case of steam turbine output is unchanged (fuel consumption is constant), 2 The power of ~3 is reduced from 40Mvar to 20Mvar, and the reactive power of 4~5 is reduced from 70Mvar to 30Mvar. In 2002, the total power generation can be 1556734. 2 Reduce the reactive load of the generator to the load loss of the generator and transformer. The influence of the generator stator coil is very small, and its load loss is negligible. The following only considers the main transformer load loss. Take the No. 2 machine as an example to illustrate the calculation method. When the No. 3 generator is running, 2~ The main energy transfer direction of No. 3 is basically from the low pressure side to the medium pressure side 110kV system, and the high pressure side has no load. Under this energy transfer mode, the load loss of the No. 2 main transformer rated operation is 512kW, then the generator belt The annual average active load 78.68MW reactive load 40Mvar state, the load flowing through the main transformer is 70MW 35Mvar, the load loss is: the loss power of the ap transformer rated operation; the Sn transformer rated apparent power 68MW reactive load 20Mvar state The load flowing through the main transformer is 70MW15Mvar, and its load loss is: in the case of line, the reactive power is reduced from 40Mvar to 20Mvar, and the main transformer No. 2 can reduce the load loss: 22=35.56kW, the average active load of the generator in 2002, 2~3 machine will reduce the reactive power from 40Mvar to 20Mvar, and the 4~5 machine will reduce the reactive power from 70Mvar to 30Mvar. The load loss of the generator and transformer group is shown in Table 4, Table 4, when the generator reactive load is reduced. Load loss situation change group No. 2 No. 3 No. 4 No. 5 No. 5 rated operation main transformer load loss / kWZ generator with annual average active load does not reduce reactive power main transformer load loss / kW / generator with annual average active load Reduce reactive power Main transformer load loss / kW reduction after reactive power main transformer load loss reduction value / kW generator operation hours / h annual energy saving This total can save electricity throughout the year 1 162403.69kWh from the above analysis and calculation, if the generator is in 2002 The average active power generation, maintaining the output of the steam turbine unchanged, reducing the reactive power of No. 2~3 machine from 40Mvar to 20Mvar, and reducing the reactive power of No. 4~5 machine from 70Mvar to 30Mvar, then the power supply for the Internet is 27191.35.55kWh. The effect of the reactive power load on the coal consumption of the power supply is reduced from 40Mvar to 20Mvar for the No. 3 machine, and the reactive power of the No. 4 to No. 5 machine is reduced from 70Mvar to 30Mvar. The impact on the coal consumption of the power supply and power supply is shown in Table 5. The machine will generate electricity according to the average active power in 2002, maintain the output of the steam turbine unchanged, reduce the reactive power of No. 2~3 machine from 40Mvai to 20Mvar, and reduce the reactive power of No. 5 machine from 70Mvar to 30Mvar, then reduce the I phase respectively. 2~3 units), 11th stage (4~5 units) and the whole plant power consumption coal consumption Q25g0.17g0.20g, power supply coal consumption Q51g0. 0.40g Table 5 reduce generator reactive power. Impact of power supply coal consumption No. 5 unit No. 5 unit consumes standard coal consumption / 106g real power generation / (MWh) power supply / (MW / h) standard coal consumption / g (kWh) - 1 power supply / (MW /h) Coal consumption without power generation / g (kW, h) -1 power supply coal consumption / g (kW, h) -1, reduce coal consumption by electricity / g (kWh) - '1 standard to reduce coal consumption / g (kWh) - '4 reduce the impact of generator reactive load on the plant's power consumption rate. When the power generation is constant, when the generator reactive power load is reduced, the steam turbine reduces the output corresponding to the excitation energy consumed by the reactive power. This reduces the amount of electricity used in a part of the plant; similarly, the power consumption of generators and transformers for cooling and cooling can be reduced. To reduce the impact of generator reactive load on plant power consumption, see Table 6 to reduce the impact of generator reactive load on plant power consumption rate. Low power/(MWh) low generator water-cooled pump with no power consumption/(MWh) after main transformer cooler refers to power consumption/(MWh) standard plant power consumption/(MWh) plant power consumption rate reduces plant power consumption The rate can be seen from Table 6. If the generator generates electricity according to the average active power in 2002, reduce the reactive power of No. 23 from 40Mvar to 20Mvar, and reduce the reactive power of No. 45 from 70Mvar to 30Mvar, then reduce I and 11 respectively. The power consumption rate of the whole plant is 0.030.01Q02%. In addition, it should be noted that when the generator reactive power load is reduced, the plant power supply voltage will be slightly reduced, and the total loss of the auxiliary system of the plant will be greatly reduced. However, its value is very small, negligible. 5 Conclusions and Suggestions Through the above analysis and calculation, the following conclusions can be drawn: the main factors of power generation reactive power load affecting power generation efficiency There are four: one is the excitation energy consumption of the generator; the second is the load loss of the generator and transformer; the third is the power used for heat dissipation (cooling) of the generator and the transformer; the fourth is the excitation energy consumption consumed by the generator being reactive. Fuel and plant electricity, therefore, the reactive power load has a certain impact on the economy. Power grid operators and users should do a reactive power compensation plan to achieve local balance of reactive power stratification and minimize the reactive load of the generator; the generator should reasonably arrange reactive power within the allowable power factor (this is The overall production of power grid is indispensable), to minimize the impact of power generation reactive power on power generation economy. The technical data of generators and main transformers in Jingmen Thermal Power Plant are shown in Table 7 and Table 8 Table 7 Jingmen Thermal Power Plant Generator Related Technical Data No. 3) Model manufacturer Beijing Heavy Duty Motor Factory Harbin Motor Factory rated active power / MW / rated power factor rated stator current / A rated stator voltage / kV rated excitation voltage / V rated excitation current / A cooling method water and water water hydrogen hydrogen water pump power /kW Table 8 Jingmen Thermal Power Plant Main Transformer Related Technical Data Period Phase I Main Transformer No. 2 Main Transformer No. 3 Main Transformer No. 4 Main Transformer No. 5 Main Transformer Model Manufacturer Shenyang Transformer Factory Baoding Transformer Factory Voltage Cooling Mode Strong Oil Circulation Guide Wind Cold cooler capacity short circuit loss / kW / no load loss / kW / He Yangzan. Power System Analysis. Huazhong University of Science and Technology Press, Construction Machinery,Shuttering Clamp,Steel Building Clamp,Adjustable Framework Steel Props PUYANG RENHE INDUSTRY CO.,LTD , https://www.renhedownholetool.com