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Due to the significant advances in fast switching semiconductor devices, harmonic emissions caused by the adjustable speed drives (ASDs) have been changed in terms of frequency range and magnitude. The frequency range of 2-150 kHz has been distinguished as a new interfering frequency range, disturbing the distribution networks. This paper proposes a behavioral model of an AC motor to predict the common-mode (CM) current in ASDs. An approach is presented to calculate the parameters of the model, through which the dominant impact of each element at a specific frequency is considered. Moreover, along with the proposed motor model, a system modeling strategy is presented for filter design considerations at the emerging frequency range of 2-150 kHz. To verify the effectiveness of the proposed model, real-time experiments are conducted. The results prove that the introduced model can accurately predict the resonances of the CM loop created by the motor. Consequently, the proposed model is suitable for EMI filter design covering the 2-150 kHz standard.

This Paper proposes a novel three-level, threeport, bidirectional dc-dc converter (TLTPBC). Through the bidirectional battery port, the TLTPBC guarantees the continuous flow of energy to the load when the system is deprived of the input source during faults. Owing to reduction of voltage stress across semiconductor devices, the proposed converter is appropriate for medium and high voltage applications, such as transportation systems, residential and office buildings. Moreover, the size of the passive components is reduced which is the inherent advantage of the three-level structures. The results demonstrate the proposed merits of the converter, and verify that the output voltage is well regulated both in presence and absence of the input source.

Due to the increasing use of fast switching semiconductors, emissions affected by the Adjustable Speed Drives (ASDs) are entering the new frequency range of 2-150 kHz. Emissions at this new frequency range are categorised into 2-9 and 9-150 kHz ranges among the standardization communities. Consequently, designing new filters for theses frequency ranges is of the determined efforts by ASD manufacturers. In this paper, essential factors impacting on the filter design in ASDs for 0-2 kHz and the new frequency range of 2-9 kHz are investigated. Non-linear effects of DC link filter on low order harmonic emissions of 0-2 kHz is investigated to understand how the existing filters can comply with the emerging standard of 2-150 kHz. Moreover, a system model is presented to predict the effects of cables and Electromagnetic Interference (EMI) filter parameters on resonances at the frequency range of 2-9 kHz.

This study proposes a control technique for single-input dual-output three-level dc-dc converter (SIDO-TLC) using feedback (FB) and feedforward (FF) principles. Through the proposed control strategy, SIDO-TLC can smoothly function in both buck and boost operating conditions with a fast dynamic. Major duties of the designed FB control loops are to noticeably decrease the recovery time of transient responses under the load variations and accurately balance the boost capacitors voltages. To effectively decouple the introduced control inputs, an external FF controller is assigned that can also enhance the buck and boost voltage regulations. Furthermore, a step-by-step assessment is contemplated based on the proposed control loops to make an offline adjustment for the FB and FF coefficients. The proposed controller implemented on SIDO-TLC is highly suitable for portable applications, where efficiency, cost, and speed are of important factors. The simulation results and the laboratory test setup of SIDO-TLC using DSP TMS320F28335 are presented to prove the validity of the presented theoretical subjects.

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This paper presents an equivalent circuit impedance-based estimation method of resonances in a threephase motor drive system to predict common-mode (CM) noise circulations in 9-150 kHz frequency range, which is not considered so far in electromagnetic interference (EMI) analysis. The paper verifies the presented method by analyzing emission spectrums of CM currents in the three-phase system. The impact of EMI filter, DC-link filter and AC motor models on the generated common mode noise at 9-150 kHz range is also investigated using the predicted equivalent impedance results at the CM voltage source. It is found, there is a high probability to have resonances within 9-150 kHz range due to the components of the drive system. Hence, the work presented is useful to model and predict the possible resonances in the whole drive system that unnecessarily increases the CM noise at this frequency range. The presented estimation method not only enables the ability to early recognition of CM current emissions injected from the drive system to the grid but also supports EMI filter design or modification for 9-150 kHz frequency range. Further, this approach significantly contributes to accelerating the drive products development and entering the market after complying the future standards.Inverters in three-phase motor drive systems utilize low or high switching frequency depending on the power level. The high voltage slew rates (dv/dt) across the inverters due to this switching operation causes Electromagnetic interference (EMI) noises [7]. The EMI emission with differential mode (DM) and CM noise critically affect the function of electrical and electronic devices connected to the point of common coupling. Although these noises are well defined for single-phase systems, there is a limited research work for three-phase systems such as three-phase adjustable speed drives. However, in threephase systems, CM noise can be defined as "ground -included-loop noise" and DM noise can be defined as "line-to-line noise" [8]. IEC /CISPR standards are generally defined the EMI noises from 150 kHz to 30 MHz for distribution networks. Besides, Line Impedance Stabilization Network (LISN) recommended by CISPR16 standards are used for EMI measurement in the range of 9 kHz-30 MHz to maintain fixed impedance at the grid point and to decouple high frequency between the mains and the drive system. As the standards and measurement methods for 2-150 kHz frequency range have not been completed to cover all products including adjustable motor drives, IEC Technical Committee 77A is currently working on this new standardization process [5]. According to this team activity, the frequency range has been split into two main frequency bands as 2-9 kHz and 9-150 kHz. Discussions on upcoming standards are presented in [9,10]. In parallel to a standardisation activity, recent studies on 2-150 kHz frequency range have been presented in [10]- [18]. These works focus on harmonic modelling of multiparallel grid-tied inverters [11,12] and different inverter topologie...

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