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After the high proportion of new power connections, characteristic changes are occurring on the four sides of the source network load, and the power system will face the six-focus problems in terms of safety and stability – power magnitude equalization, short-circuit current, synchronous stability, wide frequency vibration, voltage stability and frequency stability.
How did these six major issues cause? How to solve the problem of the new power system? In this issue, after the broadcast of the relevant content of power and power equilibrium, Wan Yurou was unexpectedly red and analyzed as a foot.
Source: WeChat public number “Zhejiang Electrical E-Home”
Author: Dong Qian, Academy of Electrical Sciences, Huawen, Tang Yaqi, Jianghang
1. What is the power and power equilibrium?
Because power cannot be stored in large quantities, the power system has the characteristics of ready-to-use. This feature makes the Internet’s Escort‘s balance between power and electricity, that is, power and quantity equilibrium.
Power equalization is a kind of Sugar babyInstantaneous equalization, which refers to the use of electric power and power to maintain equalization at a certain moment.
Simplified to the home scene, the home is equipped with a small electric machine. If the power generated by the electric machine at a certain time can meet all the electrical appliances used in the same task, the home will achieve power balance.
The power equilibrium is a process equilibrium, which refers to the equilibrium between the electricity demanded by the user and the electricity emitted by the power plant in a certain period of time.
Power power equalization is based on the basic safety and stability of the power system. In traditional power systems, the standard for whether the power balance can be balanced generally depends on the most important load time. If the generator set can meet the power requirements of the highest load, it can achieve real-time balance. In the new power system, there is a different balance standard.
2. Challenges in the power and power balance surface
In traditional power systems, the negative load side is mainly fixed and pure consumer type of electric load, and the negative load prediction accuracy is higher. The power side is mainly pyroelectric and hydroelectric machines, and the power generation can be controlled and the output is continuous and stable. Therefore, the power load and power generation capabilities of the network can be predicted more accurately, and the power and power equalization difficulty is relatively small.
With the advancement of the new power system, the new power is connected to the Internet with a large scale.://philippines-sugar.net/”>EscortThe power structure will undergo in-depth changes. According to the “Storm-Light Multiplication Plan” in the “14th Five-Year Plan for the Development of Renewable Dynamics in Zhejiang Province”, by the end of the “14th Five-Year Plan”, Zhejiang photovoltaics installed in Zhejiang reached more than 27.5 million kilowatts, and wind and light new power installations account for 23% of the total number of over-the-air engines.
<img src="https://img01.mybjx.net/news/UploadFile/202204/6378621476078406977705458.png" title="2.png" alt="2.png"//
The power supply will be mainly composed of traditional rotary generators of pyroelectric, hydroelectric, and nuclear power, and will be transformed into Pinay The static generator represented by the new power is coordinated with the traditional rotary generator. This type of change makes the power and power equilibrium have multiple scene characteristics. Even if the equilibrium is achieved at the most load time, it can be balanced without Sugar baby method at some moments of new power development or no effort.
The power and power equilibrium faces new challenges.
1. “Fat” leads to unlimited power supply. Although the capacity of new power installations is large, they are all “fat body quality” and unlimited power supply. Strength means that when the power load demand is the highest, Manila escortThe power supply capacity provided by the new power supply.
The output of common power sources such as fire power and hydroelectric power is highly controllable, and can achieve “source load”. The output is affected by the weather, and the output and load demand cannot be matched in real time.
Stately, under the same capacity of the same machine, the annual average application time of new power generation is easiest for hours. Less than the pyroelectric unit. Taking 2021 as an example, Zhejiang’s pyroelectric uniform power generation application hours are 4762 hours, and the wind-generating application hours are 2165 hours, while photovoltaics only 1122 hours. When using electricity at noon in Zhejiang in summer, the reliable output of photovoltaics accounts for only 16% of the machine capacity, while the reliable output of wind accounts for only 6% of the machine capacity.
The “error peak” phenomenon of new power and negative load, as well as the uncertainty of new power output, can only weaken the power and power equilibrium support during the negative load period.
2. The application of new power is subject to technical limitations In terms of wind development and application, the offshore wind that has been developed in my country is mainly foreign wind. Africa wind is affected by environmental protection and road and waterway occupation, and other reasons, the target site resource of remote wind projects is tight.
Below the comparison, the middle Sugar babyFar Sea GourmetSugar daddy has wider sea resources, rich wind energy resources and stable wind speed. Therefore, with the master’s vision of marine wind development, it gradually shifts to the far sea.
Today, for the far sea wind power below 80 kilometers from the land, 50 Hz traffic sieve is important for transport. However, affected by the characteristics of the traffic sieve, the far sea wind power power power above 80 kilometers is sent to the technical storage. In the question. How to realize the large capacity of medium-range wind across seafar has become a key technology problem for the development of medium-range wind.
In terms of photovoltaic development, the large-scale development of distributed photovoltaics has brought new challenges to the network’s operation. Traditional distribution networks only have to bear loads and no power supply, and the important responsibility of the distribution network is only to ensure that the load power in the distribution network is reliable for the reliable supply.
SecondSugar daddy With the development and connection of distributed photovoltaics, the distribution network will transform into an active distribution network containing a large number of distributed power sources. While ensuring power supply, it is also necessary to realize the distributed photovoltaics but just entered the elevator hall. The voice became more obvious. The long and sharp voice could prevent a little girl from looking at the mobile phone with her head down and did not notice her coming in. In addition, the management of distribution network operation has become more complicated. Therefore, it is urgent to upgrade the distribution network intelligentlySugar daddylevel and reform to promote the disposal of distributed photovoltaics.
3. Short-term adjustment can be infinite
Because the output of new power is volatile and uncontrollable, the output demand of traditional power is carried out in a timely manner to meet the demand for power and power balance. The adjustment demand that meets traditional power demand is also called “blind load”, that is, the load after deducting the new power output. Affected by large-scale photovoltaic connections, the power and power balance adjustment of the Internet’s short-term (intraday) power equilibrium is difficult to increase.
The daily intraday load of the Internet shows the characteristics of “drink curve”. In the morning, as the photovoltaic starts to generate electricity, the load lands Escort manila(duck tail). At noon when the sun is strongest, the load reaches the lowest point (duck’s abdomen). At dusk, as the light lands, the load rises quickly (duck neck). Negative load demand for electricity at night gradually drops, and negative load also begins to drop (drunk).
The Internet Load Loss Trough has changed from a single night trough in the past to a double trough in the midday photovoltaic high and night troughs. As the proportion of photovoltaic devices continues to increase, the duck’s belly will become deeper and the duck’s neck will become longer.
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