High-voltage converter system for switched reluctance wind turbines under variable generating voltage

Abstract

A switch reluctance wind driven generator high-voltage conversion system in a variable generation voltage comprises two conversion main circuits of a switch reluctance wind driven generator, two SPWMcircuits, two energizing circuits, a four-winding transformer and a rectification output circuit. Two wind turbine generators commonly use one transformer and one conversion output circuit. The structure is simplified, the two SPWM circuits employ an alternate mode and a duty ratio to regulate work, the switch reluctance wind driven generator high-voltage conversion system can be suitable for different generation voltage values output by different wind turbine generators, the portions commonly use one transformer to ensure mutual isolation and effectively perform leakage releasing and protection, the total structure is simple, low in cost and high in adaptation, flexibility and controllability in reasonable regulation and control, and is suitable for the field of multi-unit wind power generation.

Description

technical field [0001] The present invention relates to the field of wind power converters, in particular to a low-cost method using a switched reluctance motor as a variable-speed wind power generator, based on a double-switched reluctance wind power generator set under the control of variable power generation voltage to integrate current conversion and high-voltage direct current output , High reliability variable flow system and its control method. Background technique [0002] The switched reluctance motor has a simple and firm structure, low manufacturing cost, no winding and no permanent magnet on the rotor, high reliability, and broad application prospects. [0003] In recent years, DC transmission has been increasingly valued by the power sector. Local DC power grids have begun to take shape in some places. High-voltage, ultra-high voltage, and ultra-high voltage DC transmission and grid connection are also under development, and more and more have been derived from ...

AI Technical Summary

Problems solved by technology

[0008] Based on the reasons mentioned above that it is unrealistic for multiple switched reluctance generators to share a set of converter systems, under a wind power condition, the wind speed and speed faced by different generators will be different, so their respective output power and voltage In addition, according to the electromagnetic theory of switched reluctance generators, maximum power point tracking (MPPT) control is often required under wind power conditions, and to obtain maximum power output, a control strategy is to control the output The voltage, that is, the power generation voltage is dynamically balanced with the motion electromotive force (or the power generation voltage is reduced separately to slow down or rise the winding current during the power generation stage, thereby enhancing the power output capability), so that the winding current is a flat-top wave, and the power output capacity is the largest. It is also conducive to the improvement of torque ripple, and the motion electromotive force varies with the speed of the group. Naturally, in the control of different units, the respective generator voltages are adjusted according to the possible different motion electromotive force according to the needs of the maximum power output, which also causes The power generation voltages of the output terminals of different units are different, which brings obstacles to the use of a single converter system

[0009] The excitation power supply of the switched reluctance generator has good stability of the externally excited type, and the voltage and current fluctuation of the traditional self-excited type is relatively large, which is also the third factor causing the difference in the generated voltage of different units; in order to reduce interference, the excitation power supply terminal is often Apply an isolation link; generally speaking, on the output side of the power generation, whether it is directly output to a DC load or merged into a DC grid, an electromagnetic isolation link is also required under reliability requirements; The electrical wiring between units must also be isolated; based on the above, it can be seen that the use of too many transformers will inevitably increase costs and losses

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