A virtual cps-pwm control method for cascaded multilevel digital power amplifiers with asymmetric structure

Abstract

The invention discloses a virtual CPS-PWM control method for a cascaded multi-level digital power amplifier with an asymmetric structure. The cascaded multi-level digital power amplifier with an asymmetric structure includes N cascaded full-bridge power units, each The DC side of the full-bridge power unit is connected in parallel with a constant DC voltage source, and the AC output of each full-bridge power unit is connected to the load. Among the cascaded N full-bridge power units, the DC side of the first (N-1) power units The voltage is set to U dc , the DC side voltage of the Nth power unit is set to U dc / 3. The invention greatly increases the level number of the output voltage of the cascaded multi-level digital power amplifier, improves the output harmonic characteristic of the digital power amplifier, and improves the fidelity.

Description

technical field [0001] The invention relates to the field of digital power amplifier control, in particular to a virtual CPS-PWM control method of cascaded multi-level digital power amplifiers with asymmetric structure. Background technique [0002] Ocean is located in the outpost of national defense, it is an important barrier to maintain national security, and it is also the bottleneck technology that my country clearly pointed out that it will focus on breaking through the three-dimensional monitoring system of marine space and information transmission equipment. Among them, the high-power electro-acoustic transducer system is the main research direction. The core of the electro-acoustic transducer system is the digital power amplifier. With the significant increase in the voltage level and power level of power electronic equipment, cascaded multi-level digital power amplifiers used in high-voltage and high-power applications have received extensive attention from industry...

AI Technical Summary

Problems solved by technology

The direct factor that affects the number of output voltage levels is the modulation technology of the digital power amplifier. At present, the recent level approach modulation (NLM) and carrier phase shift pulse width modulation (CPS-PWM) are used in cascaded multi-level digital power amplifier equipment manufacturing. The field is widely used. The former is to use the step wave to approximate the modulated sine wave, and the latter realizes the reproduction of the sine wave by comparing the sinusoidal modulation signal and multiple carrier signals and superimposing the pulse signal. In actual engineering, although the NLM modulation method saves Go to the carrier comparator, but the harmonic characteristics of its output voltage are inferior to CPS-PWM modulation

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