Capacity estimation method for energy storage device of common direct-current bus alternating-current transmission system

The invention relates to a capacity estimation method for an energy storage device of a common direct-current bus alternating-current transmission system, which comprises the steps that a common DC bus multi-motor model is constructed, and the real object in the common DC bus multi-motor model comprises a DC bus and a motor; an energy storage device is arranged in the model, the capacity of the energy storage device is estimated according to the set model, and the method specifically comprises: establishing a first state sub-model of direct current bus operation; establishing a second state submodel of motor operation, wherein the first state sub-model and the second state sub-model correspond to each other; calculating the state quantity of the motor under the model; combining the first state sub-model and the second state sub-model to form a common DC bus multi-motor model for the common DC bus and the motor at the same time; and calculating the estimated capacity of the energy storage device according to t