Compensation of Interference Sources Inside Power Electronic Interfaces

Abstract

The most suitable way, to eliminate simultaneously all side effects connected with the application of power electronic converters in Smart Grid systems, is the compensation of the interference sources inside of the power electronic interface. In such situation the compensation of the interference sources prevents both the spreading of the interference over extensive circuits and the uncontrolled aggregation of the interference generated by a group of converters, facilitating development of the compatible system. CM Compensator for InvertersThe CM voltage source cancellation in inverter-fed systems [25] can be done using active [54] as well as the passive CM voltage compensators proposed by 37,38]. Compensation in the active series filter is realized by the addition of the common mode voltage of the opposite polarity to each phase. It has been realized using the emitter follower (T 1 , T 2 ). The common mode voltage is detected on Y -connected capacitors (C det ) and added to the phase voltages by a common mode transformer, Fig. 5.1.The equivalent circuit for CM component is presented in Fig. 5.2. The series compensation is realized by addition of the compensating voltage U C by means of the CM adding transformer fed by the voltage-controlled voltage source.The original arrangement proposed by Ogasawara and Akagi for CM voltage, bearing voltage and bearing current elimination was designed using bipolar transistors for a 3 × 200 V, 60 Hz supply of a frequency converter. Each transistor of the emitter follower has to operate under full DC-link voltage conditions (282 V) [38].In the presented investigations the concept of the series active filter for a 3×400 V,