Development of single-switch model for current sensorless control of bidirectional half-bridge AC/DC converter

Abstract

The cost and size of switched mode power supplies can be reduced by eliminating the measurement of inductor's instantaneous current value. This paper discusses the implementation of current sensorless control algorithm for bidirectional half-bridge AC/DC converter that allows shaping inductor's current without current sensor. The operation of halfbridge converter has been simplified to an equivalent singleswitch model that simplifies implementation of a digital control system. The simulation results have confirmed the analytical assumptions and correctness of mathematical model.

Current Sensorless Control Algorithm for Single-Phase Three-Level NPC Inverter

“…4. 5 demonstrates the simulation results of NPC inverter operation under CSC algorithm, where duty cycle is calculated by using (8) and (10) and no current control loop is utilized in the control system. As it can be seen from Fig.…”

“…3 demonstrates two possible trajectories for current fitting at transition between different voltage levels. Both pre-and post-fitting duty-cycle corrections are calculated by (10), where besides Δi ref,k the differences between current peak-to-peak values (of falling edges) at different voltage levels should be taken into account as follows (equation for post-fitting)…”

“…All of the mentioned research made their investigation with inductor's continuous conduction mode (CCM) selecting only either bulky inductor or higher switching frequency. Authors' previous publications [9], [10] described the CSC use with half-bridge converter, where among other, the attention is focused also on current control during DCM. Contrary to previous topologies, the inductor in half-bridge converter experiences higher voltage, as a result, current slopes have more impetuous rising and falling edges that leads to longer discontinuous conduction mode (DCM) period, that should not be neglected.…”

Verification of current sensorless control for single-phase NPC multilevel inverter

“…Nevertheless, there are known examples of applying CSC to different converter topologies such as interleaved boost PFC circuit [12], bridgeless [13], half-bridge [1], [14] and full-bridge [15] topologies. More over there have been examples of using CSC with bidirectional power control based on half-bridge [16], [17] and full-bridge [15] topologies.…”