A method for maximum power tracking control of variable speed switch reluctance wind turbine

Abstract

The invention discloses a maximum power tracking control method for a variable-speed switched reluctance wind generator. An excitation turn-on angle in an excitation phase is always fixed; any switching tube control mode of chopping or PWM is not adopted; testing is carried out before operation according to different rotating speeds: an excitation turn-off angle and excitation voltage corresponding to maximum output power are recorded in an interval below a rated rotating speed, and the excitation turn-off angle and the excitation voltage corresponding to rated output power are recorded in aninterval above the rated rotating speed, thereby correspondingly compiling the excitation turn-off angles and the excitation voltage at various rotating speeds into a query table; and the excitation turn-off angles and the excitation voltage are queried according to the actual rotating speed as tracking control signals during system operation. The method is simple, feasible and low in loss, and isof practical significance to application of the switched reluctance generator in variable-speed wind power.

Description

technical field [0001] The invention relates to the field of wind power generation, in particular to a method for tracking and controlling the maximum power of a unit system using a switched reluctance generator as a wind power generator. Background technique [0002] The switched reluctance motor has a simple and solid structure, low manufacturing cost, no windings on the rotor, no permanent magnets, high reliability, and broad application prospects. As a generator, it has the strength of high performance in a wide speed range; based on The above characteristics, and considering the current mainstream wind power generators, namely doubly-fed asynchronous generators and permanent magnet synchronous generators, are more complex in structure and control than switched reluctance motors, and the cost is also high. In addition, switched reluctance generators are also It can be directly driven without a gearbox; therefore, the application of the switched reluctance generator to th...

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Problems solved by technology

[0005] The current mature control method of switched reluctance generator is low-speed current chopping and high-speed angular position control. The specific control variables include excitation voltage (phase winding voltage in excitation stage), excitation current (phase winding current in excitation stage), and generator voltage ( generator output terminal voltage), generator current (generator output current), output power, excitation turn-on angle, excitation turn-off angle, etc. Current chopping refers to adjusting the excitation current in the excitation stage (or indirectly by adjusting the excitation voltage), angular position control It refers to the fine-tuning of the excitation on-angle timing at the beginning of the excitation phase, and the fine-tuning of the excitation off-angle at the end of the excitation phase; however, in the current chopping mode, the system has poor load disturbance resistance, high electromagnetic noise, and low efficiency. In the PWM mode, the switching loss of the switching tube is large, and the torque pulsation of the angular position control is large, and the control method is complicated; in the current mainstream MPPT control method of the switched reluctance wind turbine at home and abroad, basically most of them adopt the chopper or PWM mode, Combining angle and position control is also the mainstream. Although the single pulse mode (without chopping or PWM) has become a research hotspot in recent years, it is more complicated to control the excitation on-angle and off-angle at the same time.

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