A method of monitoring a health state of a power semiconductor device includes: receiving an initial transient voltage parameter relating to transient voltage of the power semiconductor device when turning on, when it is known to be unaged; receiving an initial transient current parameter relating to transient current of the power semiconductor device when turning on, when it is known to be unaged; determining an initial energy parameter, relating to initial turn-on switching energy or power of the power semiconductor device, when it is known to be unaged; receiving an operating transient voltage parameter relating to the transient voltage of the power semiconductor device in operation; receiving an operating transient current parameter relating to the transient current of the power semiconductor device in operation; determining an operating energy parameter; and determining the health state of the power semiconductor device based on the initial energy parameter and the operating energy parameter.