Apparatus and methods for controllable networks to vary inter-stage power transfer in a multi-stage power conversion system

A multi-stage power conversion system configured to convert an alternating current (ac) input power and to provide a direct current (dc) output power to a load, the multi-stage power conversion system comprising:

• a first power converter stage comprising a controllable network, wherein the first power converter stage is configured to convert the ac input power into a dc intermediate power and to regulate the dc intermediate power in relation to a network signal, and wherein the controllable network is configured to provide the network signal based on a control signal;
• and
• a second power converter stage electrically coupled in cascade with the first power converter stage and comprising a power estimation circuit, wherein the second power converter stage is configured to convert the dc intermediate power into the dc output power, and wherein the power estimation circuit is configured to provide the control signal in response to a dc output power condition.