Modularized multiple constant current output converter

Abstract

The invention relates to a multi-output electric energy transducer, aiming at providing a modularized multiple constant current output converter. The converter comprises N-numbered submodulars, wherein each submodular composes a transformer T2N, Nth rectifier and an output direct-current filter capacitor CON; primary windings of the transformer in each submodular are in series in sequence; the converter has two level structures, wherein the first level structure comprises a first transformer T1 and controllable high frequency alternating current sources Vac which are in parallel connection with two ends of the primary windings of the first transformer T1, and the second level structure comprises the N-numbered submodulars; and two ends of secondary windings of the T1 are respectively connected to the head and the tail of the primary windings of the transformers of the submodulars which are in series in sequence. In the invention, excitation inductance of the transformer at first level is not influenced by load short-circuit or open circuit; main circuit parameters has simple design, without considering influences on the main circuit parameters under the abnormal state; and the submodular circuits can be standardized and can realize flexible combination to obtain any required circuit output, thereby reducing production cost.

Description

technical field [0001] The invention relates to a multi-channel output power converter, in particular to a modular multi-channel constant current output converter. Background technique [0002] Many applications of power conversion require converters to be able to achieve DC constant current output, such as battery chargers, LED drive power supplies, etc. In addition to the need for multiple outputs, high-voltage isolation is also required to meet safety regulations and high-strength electrical insulation. [0003] In order to obtain an isolated multi-output DC current source, a two-stage DC-DC scheme is generally used. The front stage uses an isolated DC-DC to obtain a constant voltage source, and then follows multiple non-isolated DC-DCs to achieve multiple channels. Independent constant current output. The scheme is flexible and changeable, and has high reliability. However, since multiple independent post-stage DC-DCs are required, independent control chips and switch...

AI Technical Summary

Problems solved by technology

Although the technology is simple, there are some shortcomings that seriously affect its range of application

Mainly include, 1) Since each transformer has a high insulation requirement, each transformer must meet safety regulations, which greatly increases the cost, reduces the window utilization rate, and affects the efficiency of the converter

2) Since the excitation current of the primary side in series does not reflect to the secondary side circuit, when the topology structure with relatively large excitation current, such as series and parallel resonant converters, the ratio of the excitation current of the transformer to the load current is relatively close, consider The dispersion to the excitation inductance is large, so the current sharing degree of multiple output currents is affected

To precisely control the output current, it is impossible to control the current of each channel by sampling the primary current

4) When a certain load is short-circuited, since only capacitor filtering is performed, the corresponding transformer of this road is equivalent to a short-circuit, resulting in a change in the total excitation inductance connected in series on the primary side, thereby affecting the steady-state gain of the converter and increasing the control difficulty

Especially for series-parallel resonant converters, the total equivalent excitation inductance has a great influence on the steady-state control of the converter, so it will seriously reduce the reliability of the converter

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