Electronically tuned matching network using predictor-corrector control system

摘要

A method, and corresponding apparatus, for matching a generator impedance with an unknown and possibly changing load impedance, to maximize power transferred to the load. The apparatus includes an impedance matching network, and a network model, to estimate the load impedance from known present network values and a measurement of network input impedance, and to estimate optimum network values from the input impedance and the estimated load impedance. A controller computes new network values based on the present and optimum values, and outputs the new values to the network. The process is repeated using the new network values to estimate the load impedance and generate a new set of optimum values. The controller uses a control equation with parameters selected to ensure rapid convergence on the maximum-power condition, without overshoot or instability. Preferably, current and voltage measurements are made in the network to enable correction of the network values based on these measurements on the actual network. Although the invention may be used with any type of variable-impedance network hardware, preferably current-controlled inductances are used as the variable network impedances.