A start-up control method and control system for an energy-feedback system based on a floating threshold

Abstract

The invention discloses an energy feed system starting control method and control system based on a floating threshold value. The control method comprises the following steps: S1, obtaining an AC power network actual voltage value and a DC power network actual voltage value; S2, calculating a DC power network zero-load voltage value and the floating threshold value; and S3, when the DC power network actual voltage value is greater than the floating threshold value and a power network is at a non-zero-load state, starting an energy feed system, and otherwise, not starting the energy feed system. The control system comprises a measurement module, a calculation module and a starting control module. According to the invention, the method and system have the following advantages: whether the power network is at a zero-load state can be determined automatically, through arrangement of the floating threshold value, the problem of wrongly starting the energy feed system due to power network voltage fluctuations by use of a fixed threshold value can be effectively solved, unnecessary loss and energy consumption are reduced, and the economic indexes of the whole energy feed system are effectively improved; and an optimal starting threshold is selected according to network voltage actual conditions, the system response speed can be further improved, and it is ensured that the energy feed system is brought into greatest play.

Description

technical field [0001] The invention relates to the field of regenerative energy feed, in particular to a control method and control system for starting an energy feed system based on a floating threshold value. Background technique [0002] The urban rail transit in the 21st century will be a green transportation system that pursues energy conservation and environmental protection. In the entire urban rail transit system, the proportion of vehicle energy consumption generally exceeds 50% of the energy consumption of the entire system. With the rapid development of urban rail transit technology, domestic and foreign manufacturers absorb the energy generated by the braking of urban rail vehicles. And the use of research is increasing. [0003] The circuit principle of urban rail transit energy feeder system is as follows figure 1 As shown, the start-up threshold value of the energy-feeding device and the level of the voltage-stabilizing value are directly related to the uti...

AI Technical Summary

Problems solved by technology

The fixed threshold value cannot determine whether the increase in the DC grid voltage is caused by the braking energy generated by train braking, the voltage fluctuation of the AC side grid, or other load changes in the DC grid. Therefore, it is possible to use a fixed threshold value. lead to the wrong start of the energy feedback system

The false start of the device will lead to the direct circulation of the energy feed device and the rectifier, resulting in a large waste of energy and increasing the loss of the converter. Therefore, it is of great significance to carry out correct start control on the energy feed system

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