Current detection type current surge suppression circuit based on feedback and feedforward

Abstract

The invention discloses a current detection type current surge suppression circuit based on feedback and feedforward. The current surge suppression circuit comprises an energy storage capacitor, a feedforward acceleration circuit and a current detection type impedance control feedback circuit. Load current is decoupled through series connection of the current-limiting impedance and the charging capacitor, and heat consumption of the current-limiting impedance circuit is reduced; negative feedback regulation is realized through current detection, and surge current is limited; a feed-forward branch is introduced, so that the abnormal driving voltage of a switching tube in a power-on transient can be suppressed, the reliability of the circuit is improved, and surge current generated during secondary jump of the voltage after starting can also be suppressed; the combined use of the linear MOS tube and the switch MOS tube can reduce the impact current when the starting is completed, and the circuit can be realized only by using a discrete analog device and is simple.

Description

technical field [0001] The invention belongs to the technical field of current surge suppression, in particular to a current detection type current surge suppression circuit based on feedback and feedforward. Background technique [0002] As an energy storage element in the circuit, the capacitor can reduce the impact of load changes on the power system and improve the stability of the system; however, when the capacitor is powered on, the power supply directly charges the capacitor, because the impedance of the capacitor changes from small to large, which will cause the power supply to A large surge current occurs, such as the capacitor directly connected in parallel with the power supply, the output capacitor of the Boost converter, etc. A large inrush current will cause a current shock in the power control switch, reducing the reliability and life of the power-on switch. A large inrush current in a solid-state switch may cause overcurrent and overheating damage to the chi...

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Problems solved by technology

In order to achieve the above basic design requirements, using a negative thermistor is a common method, but when this method is repeatedly started, when the temperature of the thermistor is high, the resistance of the current limiting resistor is small, and the inrush current suppression effect is poor.

In order to reduce the resistance value of the current-limiting resistor, the method of short-circuiting the current-limiting resistor by the switch can also be used. During the charging process, the switch is disconnected, and the current-limiting resistor limits the current. After the charging is completed, the switch is closed, and the current-limiting resistor is shorted to reduce the loop resistance. However, when the switch is closed, the voltage drop on the current-limiting resistor changes suddenly, which will cause a surge current, and the power consumption of the current-limiting resistor is inversely related to the charging and discharging time. When the charging and discharging time is short, the power consumption of the resistor is large.

In addition, the current limiting resistor can also be realized by using the linear region of the MOS tube. At the beginning of charging, the resistance of the MOS tube gradually becomes smaller, thereby limiting the inrush current, but this method needs to match the driving voltage change curve with the charging and discharging sequence of the power loop, otherwise Will cause damage to the MOS tube

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