A Novel Design Method of High Precision and High Power AC Constant Current Source

Abstract

The invention discloses a design method of a novel high-precision high-power AC constant current source. The input stage adopts a two-stage conversion circuit. The input stage adopts a programmable rectifier module, which is controlled by ARM controller. The input AC voltage is converted into an adjustable DC voltage, and the program is adjustable by 20-500V for drive that SPWM sinusoidal signal generation module; after the programmable rectifier module, a two-level programmable DC-DC buck module is added for voltage reducing and the programmable Buck module of DC is controlled by DSP controller. According to the magnitude of the current output of the load at the rear stage, a feedback is sent to the DSP controller, the DSP controller controls the programmable Buck module according to themagnitude of the feedback current to achieve precise control of the output voltage of the SPWM module. When the load of the rear stage changes, the voltage of the Buck module is controlled, namely, the rear stage load current can be controlled. Two-level closed-loop control method is adopted, which is based on DSP + ARM architecture. Output frequency adjustable in a range from 50 to 1500hz, constant current adjustable in a range from 100 to 1000mA.

Description

technical field [0001] The invention relates to an electronic technology, in particular to a design method for a novel high-precision high-power AC constant current source. Background technique [0002] The AC constant current source system is mainly composed of voltage conversion part, frequency synthesis part and loop control part. [0003] The voltage conversion part is realized by buck or boost circuit. The frequency synthesis part mainly adopts the following technologies: [0004] 1. The traditional frequency synthesis method, that is, the synthesis method that uses mixers, frequency dividers, frequency multipliers and band-pass filters to achieve the required frequency; [0005] 2. Using phase-locked loop (PLL) technology to indirectly generate the required frequency; [0006] 3. According to direct digital frequency synthesis technology (DDS), use DDS chip to generate corresponding frequency. The loop control part adopts open-loop control or simple closed-loop con...

AI Technical Summary

Problems solved by technology

[0011] The technical problem to be solved by the present invention is: when the current technology is used to design a higher power (tens to hundreds of watts) signal source, it is difficult to ensure the accuracy index and stability index, and the design is often very complicated; At the level level, when the control signal is weak, the accuracy can reach the standard, but the power is usually very small, and it is difficult to meet the output of a wide range of voltage, adjustable frequency, and adjustable current; in specific applications, it is difficult to be compatible with high power output and high precision and stability. output, the present invention provides a novel high-precision high-power AC constant current source design method to solve the above problems, using a two-level closed-loop control method, based on DSP+ARM architecture; output frequency adjustable 50-1500hz, current constant current can be Adjust 100-1000mA;

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