Abstract. In the paper, the concept of a permanent magnet synchronous generator (PMSG) with uniquely designed stator windings for wind turbines is presented. Two 3-phase windings in the stator are used, one of which is connected in the star, while the other in the delta configuration. Six-pulse rectifiers, mutually coupled by the pulse transformer, whose primary winding is supplied by the so-called "current modulator", are placed at the outputs of both windings. The modulator output current should meet all the necessary and strict requirements. Both rectifiers operate on a common DC circuit. These solutions provide the sinusoidal magnetomotive force in the stator of the PMSG and the quasi-sinusoidal (taking into account the non-linearity of the magnetic circuit) magnetic flux. In light of the generator principle, it has been called the "PMSG with modulated the magnetic flux". The slightly higher complexity in the structure of the generator, as compared to the normal threephase construction, is compensated by the exceptional simplicity of the power electronics section of the system, which allows high efficiency to be reached. The current modulator (as well as the pulse transformer) is a power electronics converter with a relatively low output power as compared to the overall output power of the system. In comparison to other known solutions, the expected cost of the system should be lower. It is also expected that a high degree of reliability in terms of its operation will be achieved, and consequently, that the the ongoing costs of its maintenance will be reduced. In the paper, concept, theoretical basis of operation, and results of the studies of the simulation models of the generator, including the basic power electronics section, are presented.

The general characteristic of power electronic couplers for alternative energy sources with electrical power grid was presented. The power electronic current source, working as a closed loop system, generating sine wave shaped current transfering the energy to the grid was discussed. The chosen results of simulation model of such system for sinusoidal reference signals were presented. The test results of the laboratory prototype were also presented.

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The areas of application of EAS systems are, among others, stores and libraries. EAS systems are used to signal a theft of goods. The exemplary EAS system consists of: a transmitting antenna, a receiving antenna and tags also called clips. The tag is an element of the system with which the consumer has direct contact. The tag can be installed on various items available in the store. Starting from the size of a pen, through jackets and coats to TVs and bicycles. Therefore, the aesthetics, and mainly the size of the tag, cannot distort the consumer's ability to check an item accurately, nor can they affect its use. The paper presents a method of minimizing the dimensions of a tag while maintaining the required detection distance.