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As the requirements for electronic inside home appliances are growing, many electronics control boards are being developed to increase the output power. A good way to reduce the number of electronic boards developed is using switch mode power supplies, which can delivery a wide range of output power using the same topology. This article presents the study of power supply scalability, changing few components inside the PCB to be used in a wide range of applications.

In this paper, a mechanical speed estimator based on the model reference adaptive-system (MRAS) principle is evaluated for a single-phase induction motor operated as two-phase motor. In three-phase drives with complete vector control/MRAS system the effect of the rotor time constant is auto-compensated by the decoupling compensators or slip calculation. However, it is not feasible in pure MRAS scheme application. Further, the asymmetrical main and auxiliary windings of single-phase motors increase the estimator sensitivity to parameter mismatch and environment change. The MRAS is evaluated when the error vector choice relies on observing the counter electromotive force vector, instead of flux based MRAS structures. Also, it is analytically shown that instantaneous reactive power principle does not suppress the stator resistance in MRAS speed estimation of single-phase motor. The MRAS observer was tested under offset, no load operation and field- weakening region conditions. The MRAS performance was successful even to sharply frequency-step transitions.

In this paper a local generation system (LGS) based on an induction generator (IG) is presented. The IG supplies the active power to the system with the support of a voltage source converter (VSC) for power conditioning. With the LGS connected to the grid through coupling inductors the deficit or the excess of power production of the IG is imported or exported to the grid at unity power factor. In autonomous operation of the LGS a buck converter, bi-directional boost converter and battery set are connected at the DC terminals of the VSC to control the DC bus voltage and supplying power to the local load at constant voltage frequency and amplitude. The LGS includes an active islanding detection method, battery charge function and a procedure to reconnect the LGS with the grid after the voltage is reestablished.