The impact of new large-scale power generation on the stability of the power system
Wind speed and light intensity change at any time. The production of wind turbines and photovoltaic power plants is mainly determined by. wind speed and light intensity. Therefore, wind farms, photovoltaic power plants output also fluctuates. Its instability will cause fluctuations in grid voltage, current and frequency after large-scale wind and photovoltaic power plants are connected to the grid, thereby affecting the power quality of the grid. In order to eliminate the negative effects, power grid companies need to add additional spinning reserve capacities, which increases grid operating costs and also indirectly affects the development of new energy sources. Wind energy has developed particularly rapidly thiss recent years and has become the third largest electric power generation after thermal power and hydropower. This article will focus on the impact of large-scale grid-connected wind turbines on the stability of the power grid.
The large-scale integration of a new energy network has an impact on the transient stability of the electricity network. In a power grid with a large proportion of installed new energy generation capacity, the transient stability of the power system will change after large-scale new energy is connected to the grid due to changes in the original transmission power of the line, distribution of energy flow and energy quality of the electrical network. For example, in a large-scale wind turbine grid-connected system, if the regional power grid is weak, the wind turbine cannot restore terminal voltage after a system failure.e, and the wind turbine runs overspeed and loses its stability, which will lead to the destruction of the transient voltage stability of the regional power grid [2].
In large-scale wind turbine grid-connected power systems, the low-voltage holding capacity of wind turbines will have a greater impact on the stability of the power system. Low Voltage Switchover (LVRT) means that when the voltage at the wind turbine's connection point drops, the wind turbine can remain connected to the grid and even provide a certain amount of reactive power to the grid to help the grid restore voltage until voltage is restored. the network returns to normal, that is, it successfully “crosses” this low voltage interval. When wind power accounts for a large part of the power grid, if wind turbines adopt a passive protection destation method in case of system failure, it will increase thehas difficulty recovering the entire system, and could even aggravate the failure, and possibly cause the unloading of all other units in the system. Therefore, in power systems with large-scale grid-connected wind turbines, the wind turbines must have corresponding low-voltage sustaining capabilities.
Self-supplied generators cannot be grid-connected , or the network -connected equipment and procedures are complicated and a small unit is not cost effective.
It is recommended not to connect to the network. Since it is a rural villa, it doesn't matter if the power is out for a period of time, it may be "power outage and back-up". "Supply", that is, the main use is generator energy, and the grid energy is used after the power outage. , wouldn't it be good to have a "neu door" commandf son”?
If you need to connect directly to the grid, there is a photovoltaic inverter produced by the German company SMA that can solve this problem. A grid-connected solar photovoltaic power plant uses photovoltaic modules to convert solar energy into direct current, then inverts the direct current to alternating current of 50 Hz, 230/400 volts three-phase or 230 V single-phase via an inverter. The output end of the inverter is connected in parallel with the low voltage end (230/400 volts) of the transformer in the substation via the electrical distribution cabinet to supply the load, and the excess power is sent to the network via the transformer. There is no battery energy storage equipment overall. When there is no sunshine on rainy days, the power grid will power the load.