Isolation transformer

About: Isolation transformer is a research topic. Over the lifetime, 8145 publications have been published within this topic receiving 72396 citations.

Related power supply

Abstract: A solid-state high-voltage regulation circuit for devices such as television receivers which incorporate a flyback transformer. Voltage changes across the transformer secondary winding are compared to a stable reference, and any difference is amplified and applied to control the flow of current to the transformer primary coil. The output voltage is thus maintained essentially constant.

Design of Power Electronic Transformer Based on Modular Multilevel Converter

Abstract: Power electronic transformer acts as a key component of the future automation in smart grid, which is the replacement of conventional distribution transformers by a power transformer. In this paper , the optimum design of a power electronic transformer(PET) based on topology of Modular multilevel converter (M2C). M2C is an emerging and highly attractive topology intended for high- or medium-voltage power electronic devices. In the design process, the modulation scheme of M2C is analyzed. A control method for balancing the M2C DC buses has been introduced. The PET includes a dual-active-bridge DC/DC converter. The DC-DC converter realizes magnetic isolation of PET and reduces the transformer size. Meanwhile, both primary-side and secondary-side switches can achieve the zero-voltage-switching(ZVS) .The PET performs power transformer's functions, at the same time, which has advantages such as power factor correction, elimination of voltage sag and swell, and reduction of voltage flicker in load side.

Single stage power converter and method of operation thereof

Abstract: A single stage power converter, a method of processing rectified AC power, and a power supply incorporating the converter or the method. In one embodiment, the converter is couplable via a rectifier to a source of AC power, has a filter capacitor and an isolation transformer with a primary winding, and includes: (1) a significant energy storage device coupled to the primary winding, (2) a first switch, coupled to the primary winding, that conducts intermittently to couple the primary winding to the rectifier to transfer a portion of rectified AC power to a magnetizing inductance of the isolation transformer and (3) a second switch, coupled between the primary winding and the significant energy storage device, that conducts alternately with the first switch, the first and second switches substantially zero-voltage switching and the converter correcting a power factor of the AC power.

AC/DC converter with power factor correction

Abstract: A switch mode AC/DC converter with input current shaped for unity power factor. Input current is modulated by input voltage, and input inductor and isolation transformer are driven with the same duty ratio, with a low voltage across bulk capacitor. This voltage is determined only by input voltage amplitude. Energy stored in the leakage inductance of the transformer is returned back to the internal DC source. A soft switching circuit is connected to the primary side, eliminating the need for high side drive. Sources of the main and auxiliary switches and primary winding of the transformer are connected to ground for easy primary voltage sensing. Overvoltage protection circuit of the output is connected to exclusively primary side signals. Secondary synchronous rectifier is driven by a circuit synchronized with the system clock. The circuit can be coupled to either the primary or the secondary winding of the isolation transformer.

Regimes of piezoelectric transformer operation

Abstract: Piezoelectric transformers have a high potential for use in power supplies due to large power density and flexibility in design. A lot of work has been done in piezoelectric transformer design and analysis of their operation in different regimes and in different electronic circuits. In this paper an attempt has been made to investigate the influence of temperature, mechanical and electrical field stress, properties of piezoceramic material and regimes of piezoelectric transformer operation on the value of its power density. The results of the presented calculations of piezoelectric transformer parameters show a good correlation with measured data on experimental transformers. A substantial improvement of piezoelectric transformer power density seems feasible, making them more attractive for a wider range of applications in power supplies. In addition, useful guidelines for piezoelectric transformer design and selection criteria for piezoelectric materials for transformers have been established.