Popis: |
Compared with the traditional synchronous generator power supply, the main characteristics of gridconnected new energy units are: firstly, because the units are connected to the grid through power electronic devices, there is no inertia or weak inertia on the grid dynamics, and basically do not respond to the changes of the grid; secondly, in order to obtain the maximum power, the grid-connected new energy units generally operate in the maximum power tracking state, so there is no active power reserve. Reactive power and voltage support for power grid can be achieved by controlling the grid-side inverters of grid-connected new energy units, while frequency support for power grid is difficult to achieve due to the operation characteristics of the units. Because of the characteristics of new energy units, gridconnected units do not respond to the changes of active power of power grid and do not have the ability of frequency control. Therefore, it is necessary to study the frequency characteristics and frequency modulation parameters optimization of the high proportion of new energy in the power grid at the transmitter end. |