Inverter capable of automatically detecting direct current bus capacitance and detection method thereof

Abstract

The invention provides an inverter capable of automatically detecting DC bus capacitance and a detection method thereof. A control circuit of the inverter comprises a control chip (3), a PWM drive circuit (4), a DC voltage detection circuit (5), an AC voltage detection circuit (6) and a current detection circuit (7). The PWM drive circuit (4) is connected with the control chip (3) and the inverter bridge circuit (1); the direct-current voltage detection circuit (5) is connected with the control chip (3), the two ends of the positive bus capacitor C1 and the two ends of the negative bus capacitor C2; the AC voltage detection circuit (6) is connected with the control chip (3) and an AC output end, and the current detection circuit (7) is connected with the control chip (3) and the AC output end; and the control chip (3) continuously and respectively acquires instantaneous numerical values of direct-current voltage, alternating-current voltage and current, performs operation and signal conversion, and finally calculates a direct-current bus capacitance value by a control program implanted in the control chip (3).

Description

technical field [0001] The invention belongs to the technical field of inverter control, and relates to an inverter capable of self-detecting DC bus capacitance and a detection method thereof. Background technique [0002] Inverters are devices that convert direct current into alternating current and are used in a wide range of applications. The traditional inverter only has overvoltage protection for DC bus protection, but lacks the estimation and protection of the capacitance of the bus capacitor itself. But in fact, the DC bus capacitor of the inverter is also one of the key components. Due to factors such as component quality problems, poor operating conditions, or capacitance attenuation caused by long-term operation, the bus capacitor may fail, which in turn may cause inverter failure and damage. The DC bus capacitor is mainly responsible for the energy flow between the inverter and its load, so that the DC voltage is maintained within the set range. The stability of...

AI Technical Summary

Problems solved by technology

In the long-term operation of the equipment, affected by the DC voltage fluctuation and harmonic current, the service life of the capacitor will be reduced or even damaged, which will lead to an increase in the DC voltage ripple and a decrease in system stability. In severe cases, the system will be paralyzed

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