并验证了所建立的双闭环PWM直流调速系统的有效性与合理性。的翻译：And verify that the establishment of double closed-loop PWM DC speed-regulating system of validity and rationality. 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

And verify the effectiveness of the dual closed-loop pwm DC drive system and reasonable.

And verify that the establishment of double closed-loop PWM DC speed-regulating system of validity and rationality.

And has confirmed the double closed loop PWM cocurrent velocity modulation system validity and the rationality which establishes.

The establishment and validation of the dual-loop PWM DC speed system effectiveness and legitimacy.

And verify that the establishment of double closed-loop PWM DC speed-regulating system of validity and rationality.