Redundant energy acquiring circuit for power module and control method thereof

Abstract

The invention discloses a redundant energy acquiring circuit for a power module. The power module comprises at least one power semiconductor device, a first capacitor C1 and a first bypass switch K1.The redundant energy acquiring circuit provided by the invention comprises a first Zener diode VD1, a second Zener diode VD2, a second switch K2, a first resistor R1, a second resistor R2, a second capacitor C2, a power supply board card and a control board card. The power supply board card acquires energy form the capacitor C1, supplies power for the control board card and charges the capacitor C2. The control board card controls the first bypass switch K1 to be switched on by triggering the switch K1. According to the scheme provided by the invention, when a fault occurs in the power supplyboard card, the capacitor C2 is charged through utilization of a breakdown characteristic of the first Zener diode, and a triggering command is provided for the switch K2 through utilization of the breakdown characteristic of the second Zener diode. The reliable bypass of the bypass switch is realized under the condition that the fault occurs in the power supply board card. The device running stopunder the condition that the fault occurs in the power supply board card of the power module is avoided. The scheme cost is low. The reliability is high.

Description

technical field [0001] The invention belongs to the field of power electronics, in particular to a power module redundant energy-taking circuit and a control method. Background technique [0002] Voltage source converter technology is a new type of commutation technology based on turn-off device IGBT (insulated gate bipolar transistor) and pulse width modulation (PWM) technology. In low-voltage applications, two-level converters composed of IGBTs have been widely used. In order to solve the high-frequency jumps in the output voltage of the converters, the resulting dv / dt stress of equipment, large system losses, high noise and To solve the harsh electromagnetic environment and other problems, the three-level voltage source converter was proposed, which expanded the application occasions of the voltage source converter in terms of voltage level and capacity. [0003] With the emergence of Modular Multilevel Converter (MMC), multilevel converters have also been successfully a...

AI Technical Summary

Problems solved by technology

The essence of the circuit is that the bypass switch capacitor Cc is connected in parallel with the sub-module capacitor Csm after the resistor R1 is connected in series, and the capacitance value of the bypass switch capacitor is generally hundreds of microfarads, and the submodule capacitor Csm is generally several millifarads to more than ten millifarads, so it is difficult to Ensure that the capacitor of the bypass switch is charged to the rated value and the capacitor of the sub-module is not overvoltage; furthermore, if the power supply of the sub-module fails, the control board of the sub-module will not work, and the command to close the bypass switch cannot be provided; In this case, if the normally closed point K2 is used to connect the bypass switch capacitor and the contact control coil circuit in series, the bypass switch capacitor will be short-circuited and cannot be charged.

Therefore, with this scheme, there is a risk of overvoltage damage to the sub-module capacitor and failure of the bypass switch to close when the sub-module energy-taking power supply fails.

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