4 results about "Active power filter" patented technology

The present invention relates to a differentiated control method of the cascaded active power filter, wherein the cascaded links are divided into low frequency links and high frequency links; wherein low frequency links are used to generate the fundamental voltage generated by the cascaded multilevel converter; wherein high frequency links are used to produce different, separate voltage from the aforementioned fundamental voltage generated by the cascaded multilevel converter; wherein according to the given cycle, some links are selected circularly from cascaded links as the high frequency links; wherein in the control cycle, each phase links with the maximum and minimum DC capacitor voltage, as well as those links that the pulse width modulation (PWM) combination discharge and charge most to DC capacitor are found out.

The invention discloses a broadband microwave frequency source circuit with low phase noise. The reference frequency is input into a digital phase detector and a low phase noise amplifier respectively. The output end of the digital phase detector is connected with the input end of a passive loop filter, and the output end of the passive loop filter is connected with the first end of a plurality ofactive loop filters respectively. The output of the low phase noise amplifier is connected to the input of the sampling phase detector. The output of the sampling phase detector is connected to the input of the first set of multiplexers, the output terminals of the first group of multiplexers are respectively connected with the second terminals of a plurality of active loop filters, the third terminals of the plurality of active loop filters are respectively connected with the input terminals of the second group of multiplexers, the output terminals of the second group of multiplexers are respectively connected with a plurality of VCOs, and a plurality of VCOs select one output. The selected VCO output signal is fed back to the sampling phase detector as the system output and fed back tothe digital phase detector through the N divider. The invention realizes the effects of wide frequency band and low phase noise.