basic requirement
New energy sources such as wind energy and solar energy have intermittent and fluctuating characteristics, so they need to operate in coordination after being connected to the power grid to ensure safe and stable operation.
On the one hand, the large-scale access of new energy requires the power grid to continuously improve its adaptability and safety and stability control ability, which is mainly reflected in the following aspects: power grid dispatching needs to coordinate all kinds of power generation resources in the whole network, so as to achieve real-time dynamic balance between power supply and demand in the whole network and meet the safety operation standards; Power grid planning needs to optimize the power grid structure, and high-voltage AC /DC transmission technology is needed in the transmission link to improve the transmission capacity of the power grid and reduce the transmission power loss.
On the other hand, in order to reduce the security and stability risks brought by wind and solar energy, it is necessary for new energy generation to have basic access and control requirements. Smart grid has made specific provisions on active power control, power prediction, reactive power, voltage regulation, low voltage ride-through, operating frequency, power quality, model and parameters, communication and signal, grid-connected test, etc. after the wind farm and photovoltaic power station are connected to the grid, so as to solve the problems of standardized access of new energy sources such as wind energy and solar energy, accurate prediction of intermittent power generation, operation control technology, etc., and realize the scientific and rational utilization of large-scale new energy sources.
Constraint condition
At present, with the deepening of the power market structure and system in recent years, cross-regional transactions have become an important way to enhance the consumption of new energy. Although new energy has corresponding power trading mechanism and regulatory principles to participate in cross-regional transactions, the tie-line scheme is still a rigid constraint. Power grid control centers at all levels can only use the resources of the power grid under their jurisdiction for peak shaving. In many cases, they are faced with the difficulty of peak adjustment, which often leads to the complementary scenery and forced to give up, which is not conducive to the improvement of the level of new energy consumption.
With the rapid development of new energy, the construction of power market system is deepening. For the application of temporary spot power, the patent "Real-time active power control method considering the constraints of medium and long-term trading and temporary spot trading" application number (20181024541.6) proposes to control the grid-connected active power of each power plant in real time by counting the trading power performance indexes of each power plant in real time. However, the patent does not consider the new energy consumption space released after the tie-line scheme is relaxed, and fails to make full use of the advantages of integrated regulation of cross-regional power grids.