High-precision wide-range isolated DC power supply

Abstract

The invention discloses a high-precision wide-range isolated DC power supply which comprises a three-phase power grid connected to a load via a main circuit, the controller is connected to the main circuit, and the main circuit is a hybrid topological main circuit formed by connecting a three-phase filter circuit, a three-phase AC-DC converter and a single-phase DC-AC converter with a single-phaseAC-DC converter. The controller is a programmable high-precision wide-range controller formed in the way that a main control unit is connected to a driving circuit a, a driving circuit b and a voltage sensor and a current sensor via an A / D conversion module. The power supply further comprises the voltage sensor and the current sensor. The main control unit generates a PWM wave according to the collected voltage and current signals and control requirements. The power supply adopts the novel hybrid converter topological structure based on a current supply type converter and can avoid the fact that the voltage is difficult to adjust accurately in a wide range due to the limitation of the gain ratio, especially under low voltage and current, the current supply type converter has higher precision than a voltage supply type converter.

Description

technical field [0001] The invention relates to a high-precision and wide-range isolated DC power supply. Background technique [0002] DC power supply and load device is a core device to realize energy conversion and diversified applications. It is widely used in all walks of life, from power adapters, switching regulated power supplies to DC power transmission and distribution systems. With the rapid development of power electronics and control technology, high-performance DC power supplies can not only be used as general power supplies such as DC system power supplies, communication base station power supplies, and experimental test power supplies, but also can be used as photovoltaic analog power supplies. [0003] When the traditional voltage source PWM converter is used as a controllable rectifier, since the minimum output voltage of the DC side also needs to be close to the peak voltage of the AC side, it cannot only use single-stage AC / DC for wide-range output, but o...

AI Technical Summary

Problems solved by technology

[0003] When the traditional voltage source PWM converter is used as a controllable rectifier, since the minimum output voltage of the DC side also needs to be close to the peak voltage of the AC side, it cannot only use single-stage AC / DC for wide-range output, but often uses AC / DC / DC two-stage topology, but as mentioned above, because the DC bus voltage is too high, the output voltage and current required by the load on the DC side are relatively small, due to the existence of the voltage source converter control dead zone and the optimal DC / DC Gain ratio and stable gain ratio requirements are limited, and it is basically impossible to achieve high-precision control of low voltage and small current

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