本发明的一个或多个实施例公开了直流母线电容估算方法及直流母线电容估算装置，适用于逆变器驱动系统中，方法包括：在电机的正常工作状态下，在直流母线电容放电过程中，测量直流母线电压以及逆变器输出侧三相电压、三相电流；对直流母线电流进行重构；基于直流母线电压以及重构得到的直流母线电流，采用递归最小二乘法对直流母线电容值进行估算。通过在电机的正常工作状态下测量，避免对电机的正常运行产生干扰，通过选择电容放电区域测量，提高估算结果的有效性，保障逆变器系统的安全可靠运行，通过采用递归最小二乘法估算电容值，提高了估算精度，更适于实际应用。

One or more embodiments of the invention disclose a DC bus capacitance estimation method and a DC bus capacitance estimation device for use in an inverter drive system, the method comprising: measuring the DC bus voltage as well as the three-phase voltage and three-phase current on the output side of the inverter during the DC bus capacitance discharge in the normal operating state of the motor; reconstructing the DC bus current; and based on the DC bus voltage and the reconstructed The DC bus current is reconstructed, and the DC bus capacitance is estimated by recursive least squares method based on the DC bus voltage and the reconstructed DC bus current. The capacitance value is estimated by the recursive least squares method, which improves the estimation accuracy and is more suitable for practical applications.