Current threshold desaturation control method employing RC-IGBT for locomotive traction converter

Abstract

The invention relates to a current threshold desaturation control method employing an RC-IGBT for a locomotive traction converter, and the method comprises the steps: 1, sampling an input current of asingle-phase PWM rectifier, and dividing the sampling current into three sections: [-ILmax, -ILth], [-ILth, ILth], and [ILth, ILmax]; 2, judging the section where the sampling current is located; 3,carrying out different desaturation processing operations of four PWM pulses of the single-phase PWM rectifier according to different sections where the sampling current is located, wherein the different desaturation processing operations comprise: performing the desaturation of the second and third pulses in the section [-ILmax, -ILth], and enabling the first and fourth pulses to be delayed; performing the desaturation of the first and fourth pulses in the section [ILth, ILmax], and enabling the second and third pulses to be delayed; performing no processing in the section [-ILth, ILth], anddirectly outputting the four pulses. The method improves the low-power-consumption performance and large-current resistance and high-reliability performances of the single-phase PWM rectifier from twoaspects of device characteristic presentation and a control strategy.

Description

technical field [0001] The invention relates to a control method of a locomotive traction converter, in particular to a current threshold desaturation control method of a locomotive traction converter using RC-IGBT. Background technique [0002] In the design of next-generation electric locomotives and standard EMUs in my country, it has become a trend to choose a higher intermediate DC voltage. The acquisition of the 3600V intermediate voltage of the electric locomotive needs to start from the circuit topology and device characteristics. Using a three-level converter circuit, an intermediate DC voltage of 3600V can be achieved with a 3300V or 4500V IGBT. This solution has low requirements on device capacity, and suitable devices can be selected with ample room. Three-level control can realize the benefits of reducing harmonics and reducing filter parameters. Its disadvantage is that the control is relatively complicated and the number of devices is large. Two-level conv...

AI Technical Summary

Problems solved by technology

This method needs to redesign the RC-IGBT drive, which requires an additional digital logic chip. The design of the three-level gate drive circuit is more complicated than that of the two-level drive. The design of the drive overcurrent protection circuit may also be different from the conventional drive. However, the realization of the overall drive circuit is more difficult, and the cost will also increase

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