Shut-off angle compensation control method to improve the stability of lcc-hvdc system

Abstract

The invention discloses a shut-off angle compensation control method for improving the stability of the LCC-HVDC system under weak receiving end conditions. The shut-off angle compensation control method is the core content of the invention. The q-axis voltage component v of the phase-locked loop output q Multiply by the compensation factor k γc Get the shut-off angle compensation γ c , and then the measured value γ of the cut-off angle of the inverter valve and the compensation amount of the cut-off angle γ c After the addition, it is used as the feedback value of the fixed turn-off angle controller. Theoretical analysis shows that the present invention can make the pole of the LCC-HVDC system move to the left half plane, thereby improving the small-signal stability of the LCC-HVDC system under weak receiving end conditions on the one hand, and expanding the fixed turn-off angle on the other hand Feasible domain of PLL parameters for controller and inverter station. Simulation results verify the effectiveness of the present invention.

Description

technical field [0001] The invention relates to the field of high-voltage direct current transmission, in particular to a shut-off angle compensation control method for improving the stability of an LCC-HVDC system under the condition of a weak receiving end. Background technique [0002] In my country, load centers and primary energy centers are characterized by a reverse distribution from east to west. In order to achieve balanced regional development, it is a more economical and environmentally friendly measure to convert primary energy into electrical energy and transmit it to load centers. LCC-HVDC has the advantages of large transmission capacity, low transmission loss, rapid transmission power adjustment and reversal, and strong asynchronous connection capability. It has the characteristics of flexible control and asynchronous networking, so it is widely used in the field of long-distance large-capacity transmission. . However, with the rapid development of high-volt...

AI Technical Summary

Problems solved by technology

Installing STATCOM on the circulating current bus of the inverter station is one of the measures to improve the stability of the AC and DC system, but the purchase of equipment increases the project investment; reasonable design of the controller parameters and phase-locked loop parameters can avoid the expected instability in the project design stage problems, but it is difficult to adapt to complex and changeable actual working conditions

The application of auxiliary control method is a low-cost, easy-to-implement and effective measure. However, the existing technology has not improved the small-signal stability of the LCC-HVDC system under weak receiver conditions from this aspect.

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