What are the problems of tens of millions of large wind power grids and why?

First of all, the premise is that if you can connect to the grid, then it is regarded as the phase, frequency and waveform of the generated electricity are consistent with the power grid. Then the load of the grid is determined by the user, and the load is changed according to the dispatch curve made by statistics, and then the task of adjusting the load is simply left to the power plant (really convenient). Thermal power plants, nuclear power plants and hydropower stations can all regulate load levels, although nuclear power plants generally do not do peak shaving power stations.

Thermal power plants are regulated by adjusting the amount of coal burned, hydropower plants are regulating the flow of water, and nuclear power plants are too troublesome to regulate. Then come, wind power is fine, wind speed and wind direction are not something you can decide, if there is wind, you will have electricity, if there is no wind, pull down, the wind will generate more electricity, and the wind will send less electricity, how to supply this electricity. In fact, the power grid is allowed to fluctuate, and it is impossible for all power stations to operate stably, so a small impact is still acceptable for a large power grid.

So it doesn't matter if the small-capacity wind power is connected to the grid, change it on your side, change it on my side, or change it hard (the people in this power plant scolded you to death, it's really annoying). However, there is a problem with the large-capacity wind power access system, which is unreliable, which will have an impact on the power grid, and instability is the most taboo of the power grid, so the unreliable power supply is an important factor limiting the development of wind power. So how beautiful a big battery is, there is a fast big battery in the wind power station to charge, full of grid connection, no recharge, can solve the problem of energy storage wind power is good wind power.

Tens of millions of kilowatts of large-scale wind power bases are basically located in Inner Mongolia, Gansu, Xinjiang, Qinghai and other areas with weak power grids. The quality of existing wind turbines is uneven, and some of the old wind turbines have not yet completed the low-voltage ride-through transformation, and the wind power base cannot guarantee whether the single wind turbine will affect the entire wind power base. Wind power generation is seriously dependent on customs, and the accuracy of the existing wind power technology is low, and the dispatching center cannot completely rely on it to make scheduling plans.

At present, the participating wind power owners of the new UHV project in Inner Mongolia Xilin Gol League basically have local thermal power plants, which are sent by wind-fire bundling, and their own thermal power plants are wind power peak shaving, which may be the trend of the development of wind power bases in the future. At present, few people except state-owned enterprises have started this project, and the new wind power hydrogen production and solid-state hydrogen storage technology may alleviate the problem of large-scale wind power base grid connection.

Wind power grid connection Wind power generation will have a great impact on the system after being connected to the grid, which will affect the voltage fluctuation and power quality of the system, and will also cause harmonic pollution. Among them, the voltage fluctuation and flicker caused by wind power grid connection are the main negative effects of wind power grid connection.

The influence of wind power on grid power and transient stability Wind power generation due to the unpredictable wind speed, so that the wind power grid power also continues to oscillate, when the disturbance frequency of wind power is close to the inherent oscillation frequency of the system, it will cause a large power oscillation, and the amplitude of the oscillation will change with the amplitude of the disturbance.

Because the power generation of wind power is unstable, it is affected by the wind speed, so that its power generation is unstable. Therefore the output power is not the version.

Constant value, wind.

When the weight velocity fluctuates greatly, the output active power will fluctuate. This in turn leads to changes in the active power in the power grid, which affects the frequency of the power grid. Therefore, if the share of wind power in a region is too large, too much change in the active frequency at a certain time will lead to frequency collapse and paralyze the entire power grid.

The addition of a certain amount of thermal power can alleviate this situation. Because the active power output of thermal power is stable and controlled by artificial, when the active power of wind power is high, the thermal power is reduced, and when the active power of wind power is low, the thermal power is increased. Therefore, wind power can only account for a small proportion of the power grid, most of them still need thermal power, it is quite difficult to improve the grid-connected capacity of wind power alone, if the problem of unstable power output can be solved, the less mature way is to use batteries, store the excess power, and release it when there is a lack of active power, but the cost of this method is too high.

If you don't understand something, you can ask.

There are two different types of wind power generation, namely: stand-alone operation – off-grid type and grid-connected operation – grid-connected type. Off-grid wind power generation is small in scale, and can be used to solve the power supply problem in remote areas through energy storage devices such as storage batteries or in combination with other energy generation technologies (such as wind power and hydropower complementary systems, wind power-diesel unit combined power supply systems).

Grid-connected wind farms are large-scale wind farms with a capacity of a few megawatts to hundreds of megawatts, consisting of dozens or even hundreds of wind turbines. Grid-connected wind farms can be compensated and supported by large power grids, and more fully exploit available wind resources, which is the main development direction of wind power generation at home and abroad. In an increasingly open electricity market environment, the cost of wind power generation will continue to decrease, and if the indirect benefits of environmental factors are taken into account, wind power is also economically attractive.

The content of the national standard for wind power grid connection includes wind turbine control technology, power technology and energy storage technology. In addition, the new national standard also puts forward detailed regulations and requirements for the technical indicators and operational performance of grid-connected wind turbines and wind farms.

In order to cooperate with the implementation of the national standard for wind power grid connection, in terms of grid connection, the state will launch a wind power grid connection testing and certification system to meet the testing requirements of wind power equipment certification, and provide sites and testing facilities for wind power equipment manufacturing enterprises to independently conduct tests.

It is to integrate the electric energy generated by wind power into the large power grid and transmit it to users.

It is to connect the wind turbines that run power generation to the power system, so that the electricity generated by the wind turbines can be transmitted through the power grid.

Goldwind introduced the core module of the wind turbine.

As more and more wind turbines are connected to the grid, the impact of wind power generation on the power quality of the grid has attracted widespread attention. The uncertainty of wind resources and the operating characteristics of wind turbines themselves make the output power of wind turbines fluctuate, which may affect the power quality of the power grid, such as voltage deviation, voltage fluctuation and flicker, harmonics, etc.

Most wind turbines are soft-connected to the grid, but they still generate large inrush currents when they start. When the wind speed exceeds the cut-out wind speed, the wind turbine will automatically exit the operation from the rated output state. If all turbines in the entire wind farm are operating almost simultaneously, the impact of this impact on the distribution grid is very obvious.

Not only that, the change of wind speed and the tower shadow effect of the wind turbine will cause the fluctuation of the wind turbine output, and the fluctuation is within the frequency range (less than 25H Z) that can produce voltage flicker, so the wind turbine will also bring flicker problems to the power grid during normal operation. Voltage fluctuations and flicker are one of the main negative effects of wind power generation on grid power quality.

Wind power generation must be monitored by a power quality monitoring system when connected to the grid, and the requirements for power quality are clearly defined. At present, the "Wind Turbine Power Quality Measurement and Evaluation Method" (GB T 20320-2013) formulated by the National Standards Committee was officially implemented on October 1, 2014, and the standard stipulates the power quality of wind turbines before they are connected to the grid: 1. Voltage fluctuation and flicker; 2. Current harmonics, interharmonics and high-frequency components; 3. Voltage drop response; 4. Measurement of active and reactive power; 5. Power grid protection; 6. Voltage unbalance.

At present, the grid-connected power quality system of wind power generation that strictly meets the standards in China includes the power quality monitoring system of Zhiyuan Electronics. Not only is the reliability of the power quality monitoring device high, but also its background software monitoring system has been very mature.

Hello: Wind power generation due to many unstable factors, so the impact on the power grid after grid connection is multifaceted, generally reflected in the three indicators of power quality have an impact: voltage, frequency, harmonics.

You want to dig deeper, it's handy** a lot. I will provide you with one for your reference. Hope it helps.

There are three reasons: one is that the rotor speed of the asynchronous wind turbine is in a state of "adjustment" according to the size of the wind, once the speed is unstable, resulting in the change of the "slip rate" between the rotor magnetic field and the grid magnetic field, which will lead to a sudden change in frequency, and a sudden change in frequency leads to a sudden change in voltage, only when the wind and wind speed are constant, the rotor speed is stable, and the electricity is in line with the requirements of "grid connection", but the wind speed is rarely in a constant state, and the fact is that the wind speed is basically changing all the time. Therefore, the "electric energy" generated by the asynchronous generator itself is not suitable for the grid-connected requirements synchronized with the "power grid".

The second is to produce harmonics and "reactive", because the rotor magnetic field is the magnetic field effect produced by the consumption of power grid energy, the rotor magnetic field and the grid magnetic field will have "mutual inductance", because the induced current of the rotor magnetic field is not designed to be synchronized or reversed with the power grid, it will produce "harmonics" that are different from the grid frequency, and will also bring "pollution" and burden to the power grid.

Third, it is not subject to the control of the power grid. For example, the speed of the synchronous alternator of the thermal power plant is finally "synchronized" with the grid after a short period of "running-in" with the power grid, but the asynchronous wind turbine cannot be "synchronized" with the grid due to some structures, which determines that it cannot be successfully connected to the grid like the electricity generated by the generator of the thermal power plant. If the asynchronous wind turbine runs in an independent or "off-grid" state, especially for electric heating, its advantages will be fully exerted, but it must rely on the grid to provide excitation and not maintain a "synchronous" relationship with the power grid, which determines the disadvantage of "asynchronous" in grid connection.

At present, the "difficult" problem of wind power grid connection in our country is mainly reflected in the fact that many wind turbines are in an "asynchronous" state.

In fact, the grid connection of wind turbines can be understood as two parts, and both of them are synchronized.

The first step is that the wind turbine generator set meets the start-up requirements, and the start-up output power is connected to the power grid inside the wind farm, and the second part is to be integrated into the national grid. Wind farms are generally equipped with booster stations, and the output power is converted into 110kV (or 220kV) and connected to the national grid.

In this way, the unit is considered to be connected to the grid.

Both were done simultaneously.

Grid connection is a connection to the grid provided by the power supply authority.

It is the electricity generated that is connected to the power grid before it can be used by users.