This paper presents a digital controller for AC voltage regulation of a bidirectional high-frequency link (BHFL) inverter using Deadbeat control. The proposed controller consists of inner current loop, outer voltage loop and a feed-forward controller, which imposes a gain scheduling effect according to the reference signal to compensate the steady-state error of the system. The main property of the proposed controller is that the current- and the voltage-loop controllers have the same structure, and use the same sampling period. This simplifies the design and implementation processes. To improve the overall performance of the system, additional disturbance decoupling networks are employed. This takes into accountudthe model discretization effect. Therefore, accurateuddisturbance decoupling can be achieved, and the systemudrobustness towards load variations is increased. To avoidudtransformer saturation due to low frequency voltage envelopes, an equalized pulse width modulation (PWM)udtechnique has been introduced. The proposed controllerudhas been realized using the DS1104 digital signal processorud(DSP) from dSPACE. Its performances have been tested onuda one kVA prototype inverter. Experimental results showedudthat the proposed controller has very fast dynamic and goodudsteady-state responses even under highly nonlinear loads.
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