Megawatt-level permanent magnet direct-drive wind-force generating converter and control method

Abstract

The invention discloses a megawatt-level permanent magnet direct-drive wind-force generating converter and a control method. The converter comprises a rectifying unit, an inverting unit, a control system, an auxiliary unit and a cabinet body, wherein the rectifying unit and the inverting unit are arranged by adopting a symmetrical structure; both a rectifying circuit and a power inverting circuitconsist of three groups of six insulated gate bipolar transistors; and the auxiliary unit comprises an auxiliary protective circuit, a precharging circuit, an auxiliary control circuit, a master contactor on the inverting unit side and a filtering circuit. The control method adopts multiple controls of speed control, torsion limit power control, direct power control and direct-current bus voltagecontrol; when the speed control, the torsion limit power control and the direct power control fail, the converter switches to the direct-current bus voltage control automatically; and the converter adopts an on-line synchronization mode without arranging single synchronization equipment. The megawatt-level permanent magnet direct-drive wind-force generating converter has the advantages of reasonable and compact structure, good safety and the like; and the control method has the advantages of small synchronization impact, safe offline and the like.

Description

technical field [0001] The invention relates to a wind power generation converter and a control method, in particular to a megawatt-level permanent magnet direct-drive wind power converter and a control method, which are mainly used for wind power generation using wind energy, a renewable energy source. Background technique [0002] As a clean renewable energy source, wind energy will have a very broad development prospect as its operating cost will be lower than that of hydropower and thermal power as wind power generation technology gradually matures. The generator set is the energy conversion core of the wind turbine system. At present, the generator sets mainly include doubly-fed asynchronous generator set and permanent magnet direct drive wind turbine set. The doubly-fed asynchronous generator adopts stator and rotor double windings, as well as slip rings and variable speed gearboxes. The stator windings are directly connected to the grid, and the rotor winding current ...

AI Technical Summary

Problems solved by technology

However, there are the following deficiencies: 1. The structure is not compact enough, the components are not integrated, and the wind power generating set needs to be equipped with a special power distribution room, and a separate cooling cabinet is designed, which increases the manufacturing cost and occupied space of the generating set; 2. The security of the system is poor, there is a lack of circuit breaker protection for the incoming line on the platform machine side and the outgoing line on the grid side, and the monitoring facilities are limited. When an abnormality occurs, it will impact the power grid and cause a failure; The communication security of the converter is not enough; 4. It is difficult to maintain and disassemble

The prior art grid-connected control method adopted by grid-connected converters for wind power generation of MW level, especially 1.5 MW-level and above, has the disadvantages of low safety such as large grid-connected impact and weak off-grid safety guarantee.

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