How to connect new energy transformers to the grid

With the continuous optimization of the global energy structure and the increasing awareness of environmental protection, new energy, such as wind power and photovoltaic, is gradually replacing traditional fossil fuels to generate electricity and becoming an important part of the future power system. In this transformation process, the new energy transformer, as the key equipment connecting the new energy power generation equipment with the power grid, is particularly important for its safe, efficient and stable grid-connected operation.

First, the basic principle of new energy transformers connected to the grid

The output voltage of new energy generators (such as wind turbines or photovoltaic power generation systems) is usually low and unstable, so it cannot be directly connected to the high-voltage transmission network. Therefore, it is necessary to transform and isolate the voltage through the transformer to boost the electric energy to a voltage level suitable for power grid transmission and meet the technical requirements of power grid access. The core task of new energy transformer grid connection is to realize the smooth transmission of electric energy from new energy power generation system to public power grid.

Second, the key technical requirements of grid connection

1. Voltage matching: The transformer needs to raise the voltage on the power generation side to a level matching the power grid, such as 35kV and 110kV.
2. Frequency synchronization: Although the transformer itself does not participate in frequency adjustment, the inverter and other equipment connected to it must ensure that the frequency of output power is consistent with the power grid.
3. Power quality control: Power quality problems such as harmonics and reactive power need to be controlled during grid connection, which are usually realized by supporting reactive power compensation devices and filters.
4. Protection and control: Set necessary protection devices (such as overcurrent protection and grounding protection) to prevent the fault from expanding and realize remote monitoring and automatic control.

Iii. Overview of grid connection process

Grid connection of new energy transformers usually includes the following steps:

1. Pre-preparation: complete the feasibility analysis of the project, the design of power grid connection scheme and the selection of equipment.
2. Equipment installation and debugging: install transformers, circuit breakers, protective devices and related control systems for comprehensive debugging.
3. Start-up test: including no-load test, on-load test, synchronous closing and other links to ensure that all parameters meet the grid-connected standards.
4. Formal grid-connected operation: After being approved by the dispatching center, it is officially connected to the power grid and begins to transmit electric energy.

IV. Challenges and development trends

The new energy has the characteristics of fluctuation and intermittence, which puts forward higher requirements for the operation stability of transformers. In addition, with a high proportion of renewable energy connected to the power grid, transformers need to be more intelligent and digital, and support remote monitoring, fault diagnosis and automatic adjustment. In the future, smart transformers, digital twin technology and AI-based predictive maintenance system will become the development direction of new energy transformers connected to the grid.

In a word, the grid connection of new energy transformers is not only the key link to realize the green transformation of power system, but also an important foundation to promote the construction of energy Internet. Only by constantly optimizing technology and improving management level can we ensure the efficient and safe integration of new energy into modern power systems and help achieve the goal of "double carbon".