Monitoring device and method for ESR and L of boost DC/DC converter

Abstract

The invention discloses a monitoring device and a monitoring method for ESR and L of a boost DC / DC converter. The converter operates in a DCM mode. The monitoring device comprises a Boost open-loop circuit, a capacitor switching circuit, a PWM shaping circuit, a ripple isolation amplification circuit, a signal processing module and a display module. The monitoring method comprises the steps of: calculating a switching period, a duty ratio and output voltage ripples before an output end is connected with a capacitor in parallel; connecting a parallel capacitor and a parallel capacitor equivalent series resistor to the output end of the Boost converter in parallel, and calculating the switching period, the duty ratio and the output voltage ripples after the capacitor is connected in parallel; and sending the switching period, the duty ratio and the output voltage ripples to a signal processing module for comprehensive processing to obtain values of equivalent series resistance (ESR) andboost inductance L of an output filter capacitor of the Boost converter, and displaying the values in real time. According to the monitoring device and the monitoring method, the parameters ESR and boost inductance L of the capacitor can be monitored under the condition that a main circuit is not shut down, the method is simple and easy to implement, and a basis is provided for life prediction ofthe capacitor and a power supply.

Description

technical field [0001] The invention belongs to the technical field of monitoring in electric energy conversion devices, in particular to a monitoring device and method for a DCM mode Boost DC / DC converter ESR and a boost inductance L. Background technique [0002] Due to the advantages of high efficiency and small size, switching power supplies are widely used in daily production and life. Generally speaking, in order to obtain a relatively stable output voltage, capacitors must be used to effectively filter out high-frequency noise. After the switching power converter works for a period of time, the capacitance (Capacitance, C) and equivalent series resistance (Equivalent Series Resistance, ESR) of the capacitor will change. Compared with the initial capacitance C and resistance ESR, when the change is relatively small When it is large, it can be considered that the capacitor has failed, and the failure of the capacitor will cause the operation failure of the power supply...

AI Technical Summary

Problems solved by technology

Off-line monitoring calculates capacitance parameters by adding an excitation signal to both ends of the capacitor under test and measuring the resulting response. It has the advantages of simplicity and reliability, but this method requires the equipment to be shut down, and sometimes even the capacitor under test needs to be removed. Therefore, This method is not practical

Compared with off-line monitoring, on-line / quasi-on-line monitoring can calculate capacitance parameters by adding sensors to measure voltage, current and other information when the circuit is working normally. This method can accurately and real-time monitor The capacitor is working, but its cost is too high, and the added sensor will destroy the original structure of the circuit and affect the circuit performance

Images