A method for determining the DC power curve of the external transmission system of a wind power base

Abstract

The invention provides a direct-current power curve determination method of a delivery system of wind-power base. According to the method, with consideration of factors including wind-power fluctuation, adjusting capacities and adjusting costs of direct-current sending and receiving terminal grids, the demand on direct-current transmission power from a direct-current receiving terminal grid, and the direct-current utilization hour, a direct-current power curve determination method considering multiple factors and different time scales is provided by combining long-term prediction, medium-term prediction, short-term prediction and ultra-short-term prediction results of the wind-power power as well as long-term generation, medium-term generation, short-term generation, ultra-short-term generation plans of the grid, so that a defect of conventional direct-current power arrangement in the prior art is overcome. A direct-current power constant value is given flexibly; a direct-current power curve is arranged reasonably; and the adjustment resources and complementary adjusting characteristic of the receiving and sending terminal grids are fully utilized, so that the direct-current receiving and sending terminal grids can participate in wind-power power fluctuation adjustment simultaneously. Therefore, the wind-power absorption range is extended; and the wind-power absorption capacity is improved.

Description

technical field [0001] The invention relates to a method in the field of electric power system automation, in particular to a method for determining a DC power curve of an external transmission system of a wind power base. Background technique [0002] People's application and understanding of electric energy first started from DC. In 1882, French physicist and electrical technician M. Deplee sent the electric energy generated by the 3-horsepower DC generator installed in the Miesbach coal mine to Munich, 57 kilometers away, with a DC voltage of 1500-2000 volts. At the International Exposition, the first power transmission test was completed. Since then, in the early 20th century, the voltage, power and distance of experimental direct current transmission reached 125 kV, 20 MW and 225 kilometers respectively. However, since DC generators are used in series to obtain high-voltage DC power supply, the motor at the receiving end is also operated in series. Not only is the com...

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Problems solved by technology

[0004] At present, the power arrangement of the DC projects that have been completed and put into operation in China is generally arranged according to the two-stage power curve or constant power. When the sending-end grid contains large-scale wind power, this arrangement requires the sending-end grid to bear the wind power alone. Due to the pressure of peak regulation and frequency regulation caused by fluctuations, when the installed capacity of wind power in the DC sending-end grid is large, wind abandonment is often caused due to the limited regulation capacity of the DC sending-end grid, resulting in economic losses. This arrangement of DC power cannot fully Utilizing the complementary adjustment characteristics of the DC sending and receiving end grid and the adjustment ability of the receiving end grid, it cannot adapt to the development of large-scale wind power transmission

[0005] In the prior art, conventional DC power arrangements generally follow the method of constant power or two-stage power curve. This method is suitable for conventional power sources with relatively stable power transmission. When the DC sending end grid contains large-scale wind power, due to Wind power is generally distributed in remote areas far away from the load center, where the regional power grid has limited accommodation capacity, and generally needs to transmit wind power to the load center area through a long distance through direct current. When the scale of wind power is large, the power grid at the sending end often has insufficient adjustment capacity, which will cause large-scale wind curtailment, resulting in economic losses, which is not conducive to the consumption of wind power

Generally, the power grid in the load center area has a large scale, and the load center area and the wind power sending end grid have certain complementary adjustment characteristics, such as seasonal differences, load characteristics differences, and power supply structure differences. The existing conventional DC power arrangement method is not conducive to Making full use of the complementary adjustment characteristics of the DC sending and receiving end grid is not conducive to improving the capacity of wind power consumption. In the case of large-scale development of wind power in the future, the conventional DC power arrangement method in the existing technology can no longer meet the requirements of grid development.

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