Compensation method, device and system for direct current magnetic bias of current transformer

The invention provides a compensation method, device and system for direct-current magnetic bias of a current transformer, and the method comprises the steps: collecting secondary-side current waveform data in the current transformer, and determining the secondary-side current bias degree according to the secondary-side current waveform data; the secondary side current bias degree is used for measuring the degree that the secondary current waveform deviates from a preset time axis; determining the primary side direct current component according to the secondary side current offset degree through a pre-established deviation relation model of the primary side direct current component and the secondary side current; the deviation relation model records the bias degree of the primary side direct current component and the secondary side current of the corresponding time axis; and controlling a voltage-controlled current source in the current transformer to generate reverse direct current to eliminate magnetic bias