The AC-DC coordinated control method has been based on the grid DC commutation failure

Abstract

The invention provides an AC-DC coordinated control method based on the failure of the DC commutation of the power grid. The method includes: monitoring the operation status information of each weak section of the sending end system; extracting the state variables of the power grid, and calculating the static and stable operation limit of each weak section; Analyze the power operation range of each weak section in the power grid at the sending end; judge whether to take measures for emergency DC power modulation; adopt emergency DC power modulation; according to the analysis of the DC emergency modulation measures, calculate the The amount of measures to be taken to remove the generator; determine whether the amount of cut-off measures causes the power fluctuation of any section to be greater than the static stable operation limit; if so, adjust the section operation mode in which the power fluctuation of the section is greater than the static stable operation limit, and go to method start. The invention quickly and effectively formulates safe and stable control measures suitable for ensuring the stable operation of the electric power system after the DC commutation fails.

Description

technical field [0001] The invention relates to an AC-DC coordinated control method, in particular to an AC-DC coordinated control method always based on the DC commutation failure of the power grid. Background technique [0002] Due to the uneven distribution of energy in my country, abundant primary energy and clean energy are often far away from the load center, forming a pattern of long-distance large-capacity power transmission. The multi-circuit large-capacity AC / DC transmission grid is often located at the remote end of the grid. After the DC commutation failure occurs, a large amount of surplus power will spread from the transmission end grid to the system, causing a huge impact on the system. In severe cases, the system will temporarily appear. State instability threatens the safe and stable operation of the entire power grid, and restricts the power transmission capacity of the AC and DC transmission channels of the entire sending-end power grid. [0003] As an en...

AI Technical Summary

Problems solved by technology

The multi-circuit large-capacity AC / DC transmission grid is often located at the remote end of the grid. After the DC commutation failure occurs, a large amount of surplus power will spread from the transmission end grid to the system, causing a huge impact on the system. In severe cases, the system will temporarily appear. state instability, which threatens the safe and stable operation of the entire power grid, and restricts the power transmission capacity of the AC and DC transmission channels of the entire sending-end power grid

[0003] As an energy base, the regional remote weakly connected DC transmission grid, after the failure of DC commutation, a large amount of excess surplus power will continuously impact the key weak sections of the AC synchronous grid, causing the grid to bear huge acceleration energy, which is likely to cause system failure Risk of transient power angle instability

This complex working condition, which is triggered by DC power disturbance, affected by AC-DC coupling, and mutually restricted by the multi-level section operation mode of the power grid, seriously threatens the safe and stable operation of the power system and brings huge challenges to the power grid operators.

In response to this situation, currently operators often need to pre-control the DC operating power and the power operating level of a weak section of the power grid at the sending end. On the one hand, this method needs to arrange a large number of operating modes, and the work intensity is high, which may lead to a narrow operating range of the power grid. , and it is not conducive to the power transmission capacity of the AC and DC transmission channels of the entire sending-end power grid and the consumption of large-scale clean energy

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