4results about How to "Suppression amplitude" patented technology

The invention relates to the technical field of motor alternating-current control systems, and discloses a modulation method for suppressing common-mode voltage of a five-level three-phase H-bridge inverter, which comprises the following steps of: generating four triangular carriers of which the phase difference is 90 degrees; adding 1 to the amplitude value of the modulation wave in the negative half cycle, and enabling all the modulation waves in the modulation range to be located in the positive half cycle; judging the size of the modulation ratio, and comparing the modulation wave with the triangular carrier according to the size of the modulation ratio to generate a PWM control signal; and the PWM control signal is further converted into a driving signal of a corresponding full-control power device, and the driving signal is input into each corresponding switching tube. According to the modulation method for suppressing the common-mode voltage of the five-level three-phase H-bridge inverter, the amplitude of the common-mode voltage output by the five-level three-phase H-bridge inverter is effectively suppressed, and the harm of the common-mode voltage to an alternating-current speed regulation system is reduced.

The invention belongs to the technical field of medicines, and particularly relates to application and application of pemetrexed in prevention and treatment of biological clock disorder. Pemetrexed can be directly combined with biological clock protein Bmal1, the amplitude of cell biological rhythm is remarkably inhibited, time difference of mice can be adjusted more quickly, biological clock disorder is effectively relieved, and pemetrexed has a certain treatment effect on biological clock disorder.

The utility model relates to the technical field of high-temperature water electrolysis systems, in particular to a cross flow type two-in-one heat exchanger and a high-temperature water electrolysis system. The heat exchanger comprises a heat exchange core body and a distribution structure arranged on the peripheral side of the heat exchange core body. Cold fluid flow channels and hot fluid flow channels are arranged in the heat exchange core body, the cold fluid flow channels penetrate through the first direction of the heat exchange core body, the hot fluid flow channels penetrate through the second direction of the heat exchange core body, and the cold fluid flow channels and the hot fluid flow channels are alternately arranged. Fins are arranged in the cold fluid flow channel, a plurality of micro-pore plates are arranged between the fins in the first direction, a plurality of micro-pores are evenly distributed in the micro-pore plates, and the hot fluid flow channel is divided into different sealed cavities in the first direction. According to the utility model, the problems of large overall size, low heat dissipation efficiency and large instantaneous pressure impact caused by the breakage of large bubbles are solved.

The application discloses a modulation method for suppressing common-mode voltage high-frequency harmonics. The method re-synthesizes a virtual voltage vector, adopts a virtual voltage vector to synthesize a reference vector, and adopts effective vectors with opposite phases to synthesize a zero vector, so that common-mode voltage waveforms between carrier periods are completely identical and positive and negative polarity acting time is equally divided. According to the characteristics of the common-mode voltage waveform, the modulation strategy can completely eliminate harmonics at even multiple carrier frequencies and sideband harmonics near each carrier frequency while reducing the common-mode voltage amplitude, and effectively reduces the adverse effects caused by the common-mode voltage amplitude and high-frequency harmonics. The modulation method greatly reduces the content of common-mode voltage high-frequency harmonics, reduces harmonic loss and the adverse effects of the common-mode voltage on a motor system, and has high research value and application value.