This article proposes a multiloop control structure for isolated multiport power converters (IMPCs), which includes a multiloop load-disturbance attenuation controller (MLDAC) and also an improved multiloop power-mismatch mitigation controller (MPMMC). The inherent capability of the IMPC to use a common magnetic link (CML) instead of multiple magnetic links offers an attractive solution to design a compact multimodule-based IMPC. With the proposed MLDAC, the IMPC can regulate the system voltage for any load disturbance without requiring any feedforward output current sensor. Moreover, the proposed MPMMC effectively mitigates leakage parameter mismatch and strictly balances the power routing in the multiple ports of the IMPC. The proposed MLDAC and MPMMC are decoupled with an improved decoupling mechanism. Additionally, this article develops a control law to indicate a safe operating area of the MPMMC. The strict voltage regulation of the IMPC under random load disturbance facilitates plug-n-play connectivity and supply of power to pulsed power loads. Moreover, eliminating the power-mismatch issues in the CML ensures equal thermal stresses and duty-life cycles of the solid-state switching devices. The performance of the proposed MLDAC is tested and compared with existing disturbance attenuation techniques. The simulation and the experimental results substantiate the superiority of the proposed MLDAC and MPMMC.