With the largest energy conversion efficiency as the evaluation target, a 50 MW wind farm and a photovoltaic power plant with a photovoltaic array capacity of 35 MW and a small hydropower station with an installed capacity of 20 MW are designed, and a system capable of adjusting peak-to-peak period power generation is designed for the system. Reservoirs, which can store 15MW of electricity, use the above-mentioned economic evaluation models for quantitative assessment and calculation, and can learn that reservoirs transfer wind energy generated by wind power and photovoltaics during low periods to peak sales during periods of high prices. The economic benefits of energy conversion are about 94,000 yuan/day. The on-grid tariff of small hydropower is priced according to the weighted average cost of wind power and photovoltaic power generation, ie, peak time (1.23 yuan/1 mile), valley time (0.67 yuan/11), waist time (0.86 yuan/111), and only small hydropower The economic return can reach 463 thousand yuan per day; and if the independent on-grid electricity price of small hydropower is peak time (0.30 yuan/kff,h), valley time (0.15 yuan/kWh), waist time (0.22 yuan/kWh) Its economic benefits are only 112,000 yuan/day, so the economic benefits of small-scale hydropower for one day have increased. Small-scale hydropower and wind and solar power generation can bring significant economic benefits. In areas where natural resources meet the conditions, local wind, light and water can be fully exploited and replaced to replace traditional energy generation, contributing to the conservation of environmental protection and non-renewable resources.

2 Small Hydropower Projects and Wind and Solar Complementary Environmental Benefits In today's society, human activities lead to global warming, and the focus of the response to climate change is to reduce excessive greenhouse gas emissions caused by human activities, mainly carbon dioxide emissions from energy consumption.

According to data from the 2010 State Electricity Development and Operations Commission released by the National Development and Reform Commission, the nation’s electricity generation in 2010 was 1,141.3 billion kWh, of which, the thermal power was 3,235.3 billion kWh, an increase of 11.7% over the previous year. Supply plays a leading role. In 2010 alone, the standard coal consumed by thermal power in China reached more than 1.1 billion tons, and the carbon dioxide gas produced was more than 2.7 billion tons. In order to give full play to the ecological and environmental advantages of green power, wind power and photovoltaic power generation have achieved large-scale construction. In 2010, I-15-country wind power generated 49 billion kWh of electricity per year. According to the coal consumption of 335g/kWh standard coal, it can save 16.41 million tons of standard coal, reduce carbon dioxide emissions by 40.31 million tons, and reduce sulfur dioxide emissions by 418,000 tons. Wind power has become China's most important power generation method in addition to conventional energy such as thermal power and hydropower. It is estimated that China's wind power at 1m height is about 253GW, and the availability rate is 2 0002500h/a, which is 506.0632.5TW.h. It is equivalent to about 190 million tons of standard coal, and can reduce carbon dioxide 460 million tons, sulfur dioxide 4.86 million. t; China's annual total solar radiation area of ​​9282 200 hours or more accounts for about two-thirds of China's total land area, equivalent to 2400 billion tons of standard coal, which can reduce carbon dioxide emissions by 55 billion tons, and sulfur dioxide by 57.8 billion tons. In 2010, the total power generation of small hydropower reached more than 1600 billion kW.h, equivalent to saving 53.6 million tons of standard coal, reducing carbon dioxide emissions by 130 million tons and sulfur dioxide emissions by 1.36 million tons. Therefore, in terms of ecological efficiency, development Renewable green power such as small hydropower, wind power, and solar energy can reduce the proportion of coal-fired power generation, reduce smoke, carbon dioxide, carbon monoxide, nitrogen chloride, and large amounts of waste to the environment. It is very beneficial to the protection of the ecological environment.

The joint development of small hydropower, wind power and solar energy has significant implications for improving the energy structure of power generation and achieving low carbonization of electricity. Especially with the continuous rise of coal prices, vigorously developing renewable energy power generation is also very beneficial to turning around the situation of thermal power companies.

2.1 The environmental value of small hydropower and wind and wind complement each other Renewable green energy such as hydropower, wind energy, and solar energy can make full use of natural non-pollution resources. Not only can we obtain considerable economic benefits, but more importantly, it can bring about energy saving and emission reduction. Environmental benefits. According to the average coal power consumption per kWh of coal-fired power plants, 335 g of standard coal is calculated. The amount of coal that can be saved by the wind and water complementary system can be saved: the standard coal saving amount = all-day power generation x335g/kW-h. The environmental value of the combined system: A =>, C, in accordance with the total generating capacity of 1.3 million kWh of the combined system of scenery and water in one day, the reduction of coal-savings is shown in Table 1. China's total pollutant discharge standard and environmental value standards for various pollutants in China's power industry, as well as the environmental benefits of daily reduction of pollutant emissions from wind, light, and water systems are shown below (see Table 1).

Table 1 Energy Saving and Emission Reduction Benefits of the Wind and Water Combined System Name Coal Savings Emission Reduction Combined System Energy Saving and Emission Reduction Coal Saving and Environmental Value Coal Saving Value and Emission Reduction Environmental Value (yuan) Standard coal ash slag can be seen from the wind, The combined light and water power generation system can save 435 tons of standard coal per day, and can save a total of 446,000 yuan/day in terms of environmental value. At the same time, greenhouse gas and other waste residue emissions are greatly reduced, which is very beneficial to ecological protection. Therefore, we should vigorously promote energy conservation and emission reduction policies to contribute to the improvement of China's environmental quality and economic efficiency.

3 Research on safety of electrical equipment Rural hydropower is an important infrastructure and public facilities in rural areas of China. In the 1970s, a large number of rural hydropower stations were developed and built in China. Due to the fact that the technical level was not yet mature, the economic conditions were relatively poor, the relevant operating procedures were incomplete, equipment maintenance, personnel skills, and policy management were not in place. There are serious waste of water resources in hydropower stations, and even there are different degrees of potential safety hazards, which seriously affect the normal development of small hydropower projects. For a long time, the country has issued many related policies and actively supported the development of rural hydropower stations. In view of the long-term sick operation of some hydropower stations and low power generation efficiency, it is necessary to take measures to eliminate the dangers and reinforce and adopt new technologies, new equipment, new materials, and new techniques to upgrade the hydraulic structures and electromechanical equipment of existing hydropower stations. , increase the utilization of hydropower resources and increase power generation. At the same time, necessary equipment safety assessments are conducted for these hydropower stations to analyze the causes of major equipment accidents that affect the safe and reliable operation of the hydropower stations, and effective countermeasures can be taken to overhaul and maintain the equipment as well as troubleshooting, which is an important part of China's hydropower safety and management work. .

Summing up the hidden dangers of safety in our country's SHP mainly comes from human factors, equipment factors, management factors, and risk factors in production.

Establishing a set of SHP safety assessment system can effectively reduce the accident rate of SHP. From the evaluation of equipment factors, the establishment of an evaluation model must follow the following principles: validity principle. The evaluation system established can effectively reflect the operating status of the system.

The principle of operability. Adopt measurable data in production to ensure operability.

In line with practical principles. Fully consider the characteristics of each electrical equipment component of a small hydropower station and evaluate it to be realistic.

3.1 Safety assessment methods Safety assessment is the use of safety system engineering methods to measure and predict the safety of the system, identify, analyze and evaluate the hazards and harmful factors existing in the system, and confirm the possibility and severity of the system's danger. , Propose necessary measures to seek the lowest accident rate, the smallest loss and the best security strategy. Qualitative and quantitative analysis of the dangers present in the system.

Fault Tree Analysis (FTA) is the system failure event as a top event, analyze the possible causes of this event, including qualitative and quantitative analysis. Its purpose is to find a combination of various equipment failure modes that cause the top event to occur. The minimal cut-set method is used to analyze the combination of the basic events that cause the number of fault treetop events to no longer decrease, and quantitatively analyze the importance of the faulty device in the entire system. Analytic Hierarchy Process (AHP) is a qualitative and quantitative analysis method. The principle of assigning relative weight among various factors can effectively reflect the relative importance of a certain index in the whole evaluation.

3.2 Safety assessment of SHP electrical equipment Electrical equipment includes main transformers and factory transformers, high and low voltage power distribution devices, relay protection and automatic devices, DC systems, and cables and cables for buildings and communications equipment. As the power source comes from the crest distribution room, the fault tree top event of the small hydropower station is: The probability that the current top distribution room cannot recover power supply during the flood season.

The analysis of the weights of SHP electrical equipment by the Analytic Hierarchy Process can be concluded as follows (Table 2): Table 2 Evaluation Factors Weight Factors Table for Electrical Equipment Plan Layer Weights Main Transformer and Factory Transformer 0.282 High and Low Voltage Switchgear 0.370 Relay Protection and automatic devices 0.186 DC system 0.069 Cable and cable used building 0.061 Communication equipment 0.032 As can be seen from Table 2, in the analysis of the weight of the electrical equipment of a hydropower station, the distribution device has the largest weight coefficient in the SHP system, and its safety and reliability The impact on the safe and reliable operation of hydropower stations is also greatest.

Through the detection of equipment reliability of a certain hydropower station, the failure rate of the equipment obtained is used to quantitatively analyze the top event of the fault tree model of the constructed hydropower plant, that is, the probability of power loss in the whole plant, and the resulting event can be caused. The probability of power failure in the power station crest distribution room is 7.18X107, and the minimum cut set calculation for the fault tree is shown below (see Table 3). It can be seen that the combination with the highest probability of occurrence of the minimum cut concentration is the high and low voltage switches on both sides of the transformer. equipment.

Table 3 Minimum Cut Set Quantitative Calculation Table No. Occurrence Rate Percentage Minimum Cut Set I, 11 Bus Connection Switch Operation Failure 1 Factory Change High Voltage Side Switch Switch Rejection I, 11 Bus Connection Switch Operation Failure 2 Factory High Voltage Side Switching Switch Rejection I, 11 Bus Connection Switch Operation Failure Near High Voltage Side Switch Switch Reject I, Segment Bus Connection Switch Operation Failure Near Area Switch Low Side Switch Switch Rejected This conclusion and the use of AHP The weighted analysis of the equipment resulted in the conclusion that the maximum weight of the high and low voltage distribution equipment in the electrical equipment is in line with the maximum. It can be seen that the factory change and the high and low voltage power distribution equipment on the main transformer is an important basic event. Its weight is relatively high, and it has the greatest impact on the safety and reliability of the system. Therefore, regular maintenance of the distribution equipment of the small hydropower system is carried out. And maintenance can improve the safe and reliable operation of electrical equipment in small hydropower stations. This will increase the power generation efficiency of small hydropower plants and increase their economic returns.

4 Conclusions This article has described that in some mountain regions with abundant wind and light resources, the local terrain environment can be used to build a power generation system with complementary small-scale hydropower and wind power. This not only solves the problem of power supply in remote areas, but also can bring considerable economic benefits to the system. income. From an ecological point of view, the use of renewable green energy for power generation is very important for energy conservation, emission reduction, environmental protection, and climate regulation. Natural resources with almost zero cost are used instead of coal to generate electricity, and the environmental value of pollutant emission reductions comes from The cost of purchasing coal is also considerable.

The longer the safe operation period of small hydropower is, the greater the economic benefits it creates. The reliability analysis of the entire system of small hydropower to identify potential risks affecting its safe and reliable operation is of great significance to the operation and management of small hydropower. Therefore, the safety assessment of SHP equipment is a probabilistic assessment of the potential hazards of SHP. The conclusion shows that the important equipment that affects the safe supply of SHP is the transformer's high and low voltage switchgear. Therefore, small hydropower stations should strengthen the implementation of safety inspection and safety management systems, and regularly perform maintenance and maintenance of important switchgear. This can extend the operational life of small hydropower plants and increase the economic benefits of small hydropower.

3-way Screwdriver

3-Way Screwdriver,Magnetic Bits Screwdriver,Phillips Screw Driver,Precision Hand Tools

Yucheng Weisite Measuring Tools Co., Ltd , https://www.wsttool.com