Digital frequency conversion voltage regulation signal source control scheme and system

Abstract

The invention discloses a digital frequency conversion voltage regulation signal source control scheme and system based on voltage instruction feedforward control, and belongs to the technical field of power electronic control. The specific implementation method comprises the following steps: according to a given frequency and amplitude instruction of an output voltage, changing a direct-current input voltage of a post-stage PWM single-phase inverter under the condition of a constant modulation ratio, making a difference between a determined reference voltage and the output voltage, and obtaining an input of an inductive current inner-loop controller through a voltage outer-loop controller; enabling the reference voltage instruction to become another input of the inner loop controller through a feedforward link, generating a post-stage PWM single-phase inverter control instruction under the action of a current control loop and a voltage control loop, and obtaining the required output voltage. According to the invention, by changing the pre-stage output voltage, wide-range voltage output is realized under the condition of a fixed modulation ratio, the waveform quality of the output voltage under a low amplitude is improved, and the problem that a PI controller cannot accurately track an alternating current instruction is solved by adding a voltage instruction feedforward control improved controller.

Description

technical field [0001] The invention belongs to the technical field of power electronic control, and more specifically relates to a digital frequency conversion and voltage regulation signal source control scheme and system. Background technique [0002] Power supply is the most important energy source in human production and life. With the further improvement of the control performance requirements of electrical equipment in various industries and the rapid development of power electronics technology, the requirements for power supplies are also getting higher and higher. In many cases, various types of power supplies with different frequencies and different amplitudes are required. AC voltage source. As a sinusoidal waveform generating device, frequency conversion and voltage regulation signal source can output sinusoidal voltage with adjustable frequency and amplitude within a certain range. It is widely used in impedance measurement of new energy equipment, electrical e...

AI Technical Summary

Problems solved by technology

The early analog control method has many shortcomings that are difficult to eliminate: the number of components required is large, the debugging process is more complicated, and it also makes the fault detection of the system difficult; the control accuracy of the system is poor, and the connection of components is quite complicated, resulting in product failure The production efficiency is low and the production cycle is long; the performance and stability of the power supply are restricted by various factors such as aging of components and temperature drift, and the reliability of the system is relatively low; It cannot be guaranteed; although the use of some analog control integrated chips can realize some control functions, the control loop still needs to be equipped with corresponding resistors, capacitors and other components, which is often not flexible enough, and it is even more difficult to realize some complex and advanced control algorithms. Conducive to the further improvement of power supply performance

[0004] The current main research difficulties and research status of the digital frequency conversion and voltage regulation signal source are as follows: when the output voltage amplitude of the frequency conversion and voltage regulation signal source is large, it often has better waveform quality, but as the output voltage amplitude decreases, Waveform quality also degrades significantly

Under digital control, it is difficult to obtain modulation waves of different frequencies by checking the sine table, resulting in the inability to output voltage of any frequency.

Frequency conversion voltage regulation signal source requires that the frequency and amplitude of the output voltage can be adjusted arbitrarily within a certain range, and the existing control strategies are difficult to achieve better control effect

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