Converter valve state and valve current solving method based on valve side current time sequence characteristics

Abstract

The invention discloses a converter valve state and valve current solving method based on valve side current time sequence characteristics. The method comprises the steps of acquiring three-phase alternating current, direct current and a converter valve trigger pulse at a converter valve side of a direct current transmission system; establishing a node current equation of alternating current, direct current and valve current; when the rising edge of the trigger pulse of the converter valve is detected, latching the serial number of the converter valve; according to the trigger pulse of the converter valve, the amplitude characteristic of the alternating current and the characteristic of the alternating current variable quantity, carrying out on-off judgment on the valve state, and obtaining the valve state; constructing a valve state matrix; judging whether each phase has a bypass state or not; judging the number of bypass phases by solving the sum of the valve bypass states of the three phases; supplementing a bypass loop voltage equation; solving the current of the converter valve; when the calculated value of the valve current is negative, correcting the valve state to be cut off according to the unilateral conductivity of the converter valve, otherwise, not carrying out correction; and repeating the steps to calculate the valve current.

Description

technical field [0001] The invention relates to the technical field of electric power system and automation thereof, in particular to a method for solving the state of a converter valve and the valve current based on the time sequence characteristics of the valve side current. Background technique [0002] The converter valve is the core equipment of the LCC-HVDC DC project, which undertakes the function of mutual conversion between AC and DC. AC failure can easily lead to commutation failure of the converter valve, the current distribution of each converter valve is uneven, and the valve with commutation failure is in an overcurrent or overheated state for a long time, which is extremely unfavorable to the safety of the valve equipment, which will cause the equipment to burn out or use Consequences of reduced lifespan. From the perspective of the safety of the converter valve, accurate acquisition of the valve state and valve current in the whole process of operation is a ...

AI Technical Summary

Problems solved by technology

However, when an AC fault occurs, the upper and lower bridge arms of the same phase may be conducted at the same time, and the converter valve will operate in single-phase bypass or multi-phase bypass. Get converter valve current and valve state

Images