Bipolar high-precision constant-current driving system and method suitable for inductive load

Abstract

The invention discloses a bipolar high-precision constant-current driving system and method suitable for inductive load. The system comprises a precise error amplification module, a bipolar power driving module, and an inductive load frequency network compensation module; an input signal control module obtains a current analog signal through a current type digital-to-analog converter, and then performs current-to-voltage conversion and differential amplification so as to obtain a voltage analog signal; the amplified voltage analog signal is sent to an error amplification module; the differencebetween the amplified voltage analog signal sent by the input signal control module and the voltage analog signal sent by a sampling feedback module is amplified to obtain an error amplification signal to send to the bipolar power driving module, thereby obtaining the bipolar driving current; the inductive load frequency network compensation module performs compensation on the phase of a loop composed of the precise error amplification module, the bipolar power driving module and the sampling feedback module. A constant-current source product can improve the precision to 0.1 per thousand FSR,and the current dynamic range can achieve ampere level.

Description

technical field [0001] The invention relates to a bipolar high-precision constant current drive system and method suitable for inductive loads, and belongs to the technical field of power supply drivers. Background technique [0002] In the field of aerospace and industry, the stability and precision of the driving constant current source are the basis for realizing the high performance indicators of aerospace precision equipment. The requirements for the dynamic range and accuracy of the constant current source are getting higher and higher. The high-performance program-controlled constant current source will There are more and more applications. [0003] Such as Figure 5 As shown, most of the current constant current source circuits are gradually developed and formed on the basis of the basic constant current source circuit through continuous improvement and improvement. The program-controlled constant current source generally adopts the voltage control method, that is, ...

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Problems solved by technology

[0010] The technical problem solved by the present invention is: to overcome the existing deficiencies in the high dynamic range and high precision constant current technology. In the application of relatively large current (ampere level), the precision of the power device and the control method are restricted. It is generally lower than 1‰. For the application of inductive loads, the constant current source is prone to self-oscillation problems. The constant current control technology based on precision error amplification and bipolar power driven compound negative feedback proposed by the present invention can make constant The driving capability of the current source can reach 2.5A, and the output accuracy can reach 0.01% FSR at the same time, which solves the problem that the current driving capability and accuracy cannot be balanced, improves the output dynamic range of the constant current source, and improves the output accuracy by an order of magnitude, and through reasonable design The inductive load frequency network compensation circuit solves the problem that the inductive load is easy to generate oscillation, thereby improving the phase margin of the constant current source system and improving the stability of the system

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