A realization method of multifunctional spwm

Abstract

The invention relates to a realization method of a multifunctional sine wave pulse width modulation (SPWM) circuit. The SPWM can support multiple output modes such as bipolar three-phase, two-phase, single-phase, unipolar common type, mixed type, complementary type and unipolar frequency multiplication, which greatly saves physical resources. Various SPWM outputs with adjustable phases can be realized through the invention, and are widely used in motor control, inverter, uninterruptible power supply (UPS) and many other fields. A multifunctional SPWM circuit described in the present invention includes: a clock frequency division module for carrier and modulation wave control, a carrier count control module, a modulation wave data reading address control module, a modulation wave waveform memory module, and a data readout module. Adjustment module, counting comparison and reference waveform generation module, three-phase dead zone insertion and filtering module. The SPWM circuit is flexible in implementation and has the characteristics of programmable configuration of phase, carrier frequency, modulation wave frequency, gain, modulation wave storage waveform and minimum output pulse width (filtering).

Description

technical field [0001] The invention relates to the technical fields of integrated circuits, motor control, inverters, frequency converters, UPS power supply control and clean energy, and in particular to a method for realizing multifunctional SPWM. Background technique [0002] The sinusoidal pulse width modulation (SPWM) method is a relatively mature and widely used PWM method at present. This method uses the PWM waveform whose pulse width changes according to the law of the sine wave and is equivalent to the sine wave, that is, the SPWM waveform controls the on-off of the switching device, so that the area of ​​the output pulse voltage is within the corresponding interval of the desired output sine wave. The areas are equal, and the frequency and amplitude of the output voltage are adjusted by changing the frequency and amplitude of the modulating wave. It is widely used in motor control, UPS, inverter, smart home, clean energy and many other fields. [0003] The implem...

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Problems solved by technology

However, the functions realized by these SPWMs are relatively single, and only one type of ordinary unipolar or bipolar can be realized, and the application range is relatively narrow.

In addition, the look-up method sine table storage medium used by general digital circuits is a large-capacity ROM, which cannot change the stored content, is not flexible enough and cannot share storage space, and wastes resources; even if a small amount of RAM is used, the sine wave is calculated by hardware. The method, its algorithm and circuit are complex, and it takes up a lot of hardware resources, and the corresponding RAM does not consider the sharing mechanism.

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