Amir Ganjavi

A Practical Approach to Model a Cable with Nonlinear Material Characteristics

2021 IEEE 19th International Power Electronics and Motion Control Conference (PEMC), 2021

This paper proposes a practical method to model the Common-Mode (CM) impedance of power cable in ... more This paper proposes a practical method to model the Common-Mode (CM) impedance of power cable in Finite Element Analysis (FEA) software. The proposed approach utilizes a reverse-engineering method to estimate the frequency-dependent characteristics of the cable materials. Accordingly, two experimental measurements are proposed to calculate the parameters of the cable assumed from a basic lumped-$\pi$ model. Then the material specifications of the cable PVC are estimated in the FEA software. The results verify that the the proposed model can predict the CM impedance of the cable with a great accuracy in a wide frequency range. This approach is highly practical and convenient, which can be readily extended to different kinds of power cables, ensuring high accuracy at a wide frequency range.

Investigating the Effect of Different Parameters on Harmonics and EMI Emissions at the Frequency Range of 0–9 kHz

2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe), 2020

Due to the increasing use of fast switching semiconductors, emissions affected by the Adjustable ... more 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.

Analysis of DC and AC Choke Effects on Common-Mode Noise Emissions in ASD at the Frequency Range of 9–150 kHz

Magnetic chokes are conventionally utilized at the DC or AC side of the Adjustable Speed Drives (... more Magnetic chokes are conventionally utilized at the DC or AC side of the Adjustable Speed Drives (ASDs) to suppress low order harmonics of 0–2 kHz. Recently, the frequency range of 9–150 kHz has been noticed as a new disturbing frequency range, interfering with the distribution networks. Due to the novelty of this topic, so far, there has not been a thorough investigation for the effect of DC and AC choke configurations on 9–150 kHz emissions, especially for the three-phase ASDs. In this paper, the effect of DC and AC choke configurations on Common-Mode (CM) current emissions at the frequency range of 9–150 kHz is broadly surveyed in the three-phase ASDs. Subsequently, the comprehensive equivalent models of the system are presented for each configuration of DC and AC chokes. This investigation is based on the comparative analysis of the system's transfer functions according to the presented single-phase equivalent model, mathematical calculations, and the three-phase system circu...

Common-mode noise modelling and resonant estimation in a three-phase motor drive system: 9-150 kHz frequency range

This paper presents an equivalent circuit impedance-based estimation method of resonances in a th... more This paper presents an equivalent circuit impedance-based estimation method of resonances in a three-phase 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 cu...

Feedback–feedforward control technique with a comprehensive mathematical analysis for single‐input dual‐output three‐level dc–dc converter

by Amir Ganjavi and Hoda Ghoreishy

IET Power Electronics

A Novel Single-Input Dual-Output Three-Level DC–DC Converter

IEEE Transactions on Industrial Electronics

This paper proposes a novel non-isolated single-input dual-output three-level dc-dc converter (SI... more This paper proposes a novel non-isolated single-input dual-output three-level dc-dc converter (SIDO-TLC) appropriate for medium and high voltage applications. The SIDO-TLC is an integration of the three-level buck and boost converters, whose output voltages are regulated simultaneously. Reducing voltage stress across semiconductor devices, improving efficiency, and reducing inductors size are among the main merits of the new topology. Moreover, due to the considerably reduced volume of the step-down filter capacitor, a small film capacitor can be used instead, whose advantages are lower ESR and a longer lifespan. A closed-loop control system has been designed based on a small-signal model derivation in order to regulate the output voltages along with the capacitors&#39; voltage balancing. In order to verify the theoretical and simulation results, a 300 W prototype was built and experimented. The results prove the afore-mentioned advantages of the SIDO-TLC, and the high effectiveness of the balancing control strategy. Furthermore, the converter shows very good stability, even under simultaneous step changes of the loads and input voltage. Index Terms-Multiport converter, non-isolated dc-dc converter, single-input dual-output dc-dc converter (SIDOC), single-input dual-output three-level dc-dc converter (SIDO-TLC), three-level converter.

A Novel Single-Input Dual-Output Three-Level DC–DC Converter

IEEE Transactions on Industrial Electronics

This paper proposes a novel non-isolated single-input dual-output three-level dc-dc converter (SI... more This paper proposes a novel non-isolated single-input dual-output three-level dc-dc converter (SIDO-TLC) appropriate for medium and high voltage applications. The SIDO-TLC is an integration of the three-level buck and boost converters, whose output voltages are regulated simultaneously. Reducing voltage stress across semiconductor devices, improving efficiency, and reducing inductors size are among the main merits of the new topology. Moreover, due to the considerably reduced volume of the step-down filter capacitor, a small film capacitor can be used instead, whose advantages are lower ESR and a longer lifespan. A closed-loop control system has been designed based on a small-signal model derivation in order to regulate the output voltages along with the capacitors&#39; voltage balancing. In order to verify the theoretical and simulation results, a 300 W prototype was built and experimented. The results prove the afore-mentioned advantages of the SIDO-TLC, and the high effectiveness of the balancing control strategy. Furthermore, the converter shows very good stability, even under simultaneous step changes of the loads and input voltage. Index Terms-Multiport converter, non-isolated dc-dc converter, single-input dual-output dc-dc converter (SIDOC), single-input dual-output three-level dc-dc converter (SIDO-TLC), three-level converter.

Common-Mode Current Prediction and Analysis in Motor Drive Systems for the New Frequency Range of 2-150 kHz

by Amir Ganjavi and Hansika Rathnayake

IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020

Due to the significant advances in fast switching semiconductor devices, harmonic emissions cause... more 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.

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A Novel Single-Input Dual-Output Three-Level DC–DC Converter

IEEE Transactions on Industrial Electronics, 2018

This paper proposes a novel non-isolated single-input dual-output three-level dc-dc converter (SI... more This paper proposes a novel non-isolated single-input dual-output three-level dc-dc converter (SIDO-TLC) appropriate for medium and high voltage applications. The SIDO-TLC is an integration of the three-level buck and boost converters, whose output voltages are regulated simultaneously. Reducing voltage stress across semiconductor devices, improving efficiency, and reducing inductors size are among the main merits of the new topology. Moreover, due to the considerably reduced volume of the step-down filter capacitor, a small film capacitor can be used instead, whose advantages are lower ESR and a longer lifespan. A closed-loop control system has been designed based on a small-signal model derivation in order to regulate the output voltages along with the capacitors' voltage balancing. In order to verify the theoretical and simulation results, a 300 W prototype was built and experimented. The results prove the afore-mentioned advantages of the SIDO-TLC, and the high effectiveness of the balancing control strategy. Furthermore, the converter shows very good stability, even under simultaneous step changes of the loads and input voltage. Index Terms-Multiport converter, non-isolated dc-dc converter, single-input dual-output dc-dc converter (SIDOC), single-input dual-output three-level dc-dc converter (SIDO-TLC), three-level converter.

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A Three-Level Three-port Bidirectional DC-DC Converter

by Amir Ganjavi and Ahmad Ahmad

IEEE International Power Electronics and Application Conference and Exposition, Shenzhen, China, 2018

This Paper proposes a novel three-level, three-port, bidirectional dc-dc converter (TLTPBC). Thro... more This Paper proposes a novel three-level, three-port, 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. Keywords-Bidirectional, three-level three-port bidirectional dc-dc converter (TLTPBC), dc-dc converter, multiport converter, three-level dc-dc converter.

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