Control method of wind power generation double-feed converter space vector pulse width modulation (SVPWM) based on variable switching frequency

A doubly-fed converter, switching frequency technology, applied in the direction of output power conversion devices, electrical components, etc., can solve the problems of high temperature rise of switching devices, affecting system efficiency, large current, etc., to improve output efficiency, optimize Control strategy, effect of balancing switching losses

CN102790515AInactive Publication Date: 2012-11-21南京国电南自风电自动化技术有限公司
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-11-21
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a control method of a wind power generation double-feed converter space vector pulse width modulation (SVPWM) based on a variable switching frequency. The control method comprises the steps of: sampling three-phase current at the side of a motor rotor when a double-feed motor is normally combined to a grid to generate power; converting a voltage value of a three-phase static coordinate system into a two-phase synchronous rotation coordinate system; sampling the rotating speed of the motor rotor by a photoelectric encoder; obtaining torque at corresponding rotating speed according to a wind power curve; calculating out a q-axis current component of the side; taking the obtained current value under the two-phase synchronous rotation coordinate system as a feedback value, and the q-axis current component of the converter as a given value, and obtaining the current given value by calculation, inputting the values into a proportion integration differentiation (PID) link given by the current at the side of the converter; calculating out a given current value, and obtaining Ualpha and Ubeta under a two-phase static coordinate system; simultaneously, calculating out the frequency of SVPWM according to the given and feedback values of the q-axis current of the converter; and obtaining on / off of an upper pipe and a lower pipe of a three-phase bridge circuit according to different values of a switch function of a three-phase bridge arm of the side converter.
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Description

technical field

[0001] The invention relates to wind power generator drive technology, in particular to a control strategy of a variable switching frequency wind power double-fed converter SVPWM, which belongs to the field of power electronics and electric drive. Background technique

[0002] In the application of doubly-fed wind power converters, the grid-side and machine-side dual SVPWM control technology is generally used. The double SVPWM converter has good input and output characteristics, and the power can flow in both directions, so that both the grid side and the machine side can absorb or emit energy; use the voltage vector orientation to calculate the decomposed d and q axis components, so as to control them separately . Among them, in the previous SVPWM modulation, the switching frequency is a fixed constant. In the case of high wind speed, the power fed into the power grid by the doubly-fed wind turbine is relatively high, and the current is large. At this time,...

Examples

Embodiment Construction

[0010] Below in conjunction with accompanying drawing and specific embodiment, the present invention is described in detail as follows.

[0011] Implementation link one: if figure 1 As shown, in the case of normal grid-connected power generation of the double-fed motor, the three-phase current on the rotor side of the motor is sampled, and the voltage value of the three-phase stationary coordinate system is converted to the two-phase synchronous rotating coordinate system. The specific calculation function is as follows:

[0012] Ia = AD _ Ia Ib = AD _ Ib Ic = AD _ Ic (Formula 1)

[0013] TRS_Id 1 / TRS_Iq 1 =Ft...