Control circuit for non-isolation type bidirectional DC/DC converter and control method thereof

Abstract

The invention discloses a control circuit of a non-isolated bidirectional DC / DC transducer and a control method thereof. The control circuit comprises an input voltage sensor, an input current sensor, an output voltage sensor, a DSP control plate and an IGBT driver circuit. The input voltage sensor is connected in parallel to the input terminal on the main circuit of the bidirectional DC / DC transducer. The input current sensor is connected in series to the input circuit on the main circuit of the bidirectional DC / DC transducer. The output voltage sensor is connected in parallel to the output terminal on the main circuit of the bidirectional DC / DC transducer. The DSP control plate is respectively connected with the input voltage sensor, the input current sensor, the output voltage sensor and IGBT drive circuit. The control method comprises sampling, inner voltage loop regulating, inner current loop regulating and generating PWM waveform. An automatic control unit is added to the invention so as to write the major algorithm of the control method to the DSP control plate. Therefore the automatization level of the non-isolated bidirectional DC / DC transducer is improved.

Description

technical field [0001] The invention relates to a control circuit and a control method of a bidirectional DC / DC converter, in particular to a control circuit and a control method of a non-isolated bidirectional DC / DC converter. Background technique [0002] The non-isolated bidirectional DC / DC converter is essentially a switching power supply. In order to keep the output voltage stable and achieve a certain voltage regulation accuracy, a single closed-loop negative feedback control method is commonly used. The main steps of the method are: adjusting the difference between the voltage given value and the voltage feedback value through PI adjustment to obtain the turn-on and turn-off ratios of the driving IGBT, and the stable operation of the converter can be guaranteed through reasonable design of the PI parameters. This method is easy to control and easy to adjust, so it is widely used in engineering. However, the voltage single closed-loop control has only one zero point i...

AI Technical Summary

Problems solved by technology

However, the voltage single closed-loop control has only one zero point in the voltage open-loop transfer function, and the response speed is slow. It has high requirements on the dynamic performance of the converter, such as quickly establishing the charging and discharging current, etc., and the single closed-loop control is difficult to meet the needs. Mainly because the current of the dynamic process cannot be controlled completely according to the needs in the single closed-loop control

When the converter is disturbed by some kind of disturbance, such as voltage change, inductance or other component disturbance, it will be reflected to the output terminal, and the voltage loop will work only after the output voltage changes, resulting in regulation lag

In addition, problems such as overcurrent are prone to occur during converter start-up or other transient conditions, thereby reducing the overall performance of the converter.

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