公开(公告)号：US11711008B2

公开(公告)日：2023-07-25

申请号：US17784999

申请日：2022-02-09

Applicant: SOUTHEAST UNIVERSITY

Inventor： Fujin Deng ,  Mengyue Wang ,  Jifeng Zhao

IPC: H02M7/483 ,  H02M1/00 ,  H02M1/32

CPC classification number: H02M1/0051 ,  H02M1/0012 ,  H02M1/325 ,  H02M7/4835 ,  H02M7/4837

Abstract: A loss optimization control method for modular multilevel converters (MMCs) under fault-tolerant control is disclosed. The method includes the following steps: when a fault of a SM in a MMC occurs, bypassing the faulty SM to achieve fault-tolerant control; suppressing the fundamental circulating current using a fundamental circulating current controller; respectively calculating the loss of each SM in faulty arms and healthy arms by using loss expressions of different switching tubes in SMs of the MMC; aiming at the loss imbalance between the arms of the MMC, taking the loss of a healthy SM as the reference, adjusting the period of capacitor voltage sorting control in the faulty SMs, achieving the loss control over the working SMs in the faulty SMs, and finally achieving the loss balance of each SM in the faulty arms and the healthy arms. Compared with the conventional methods, the proposed method is easier to implement and does not increase the construction cost of MMCs.

公开(公告)号：US20240388086A1

公开(公告)日：2024-11-21

申请号：US18632428

申请日：2024-04-11

Applicant: SOUTHEAST UNIVERSITY

Inventor： Fujin Deng ,  Yongqing Lv ,  Zhan Shen

IPC: H02J3/00 ,  H02M7/5387

Abstract: Disclosed are a multi-port magnetic network energy router and a control method. A magnetic network energy router includes a dual magnetic plate crimped N-winding transformer containing distributed magnetic core columns, and N full-bridge converters. The control method includes: S1. calculating equivalent connection inductance between different converters; S2. calculating steady-state control phase shift angles on the basis of reference powers of all converters; S3. calculating a power decoupling control matrix; S4. calculating control phase shift angle micro-increments of second to Nth converters by the power closed-loop control; and S5. controlling the converters to output square-wave voltages of 50% duty with different phase shift angles, and realizing given-power control. According to the present disclosure, multiple full-bridge converters can be effectively integrated and power density of the system can be improved, and equivalent large leakage inductance can be magnetically integrated at each converter port to realize given high-power energy routing at each port.

公开(公告)号：US12170442B2

公开(公告)日：2024-12-17

申请号：US18632428

申请日：2024-04-11

Applicant: SOUTHEAST UNIVERSITY

Inventor： Fujin Deng ,  Yongqing Lv ,  Zhan Shen

IPC: H02J3/00 ,  H02M7/5387

Abstract: Disclosed are a multi-port magnetic network energy router and a control method. A magnetic network energy router includes a dual magnetic plate crimped N-winding transformer containing distributed magnetic core columns, and N full-bridge converters. The control method includes: S1. calculating equivalent connection inductance between different converters; S2. calculating steady-state control phase shift angles on the basis of reference powers of all converters; S3. calculating a power decoupling control matrix; S4. calculating control phase shift angle micro-increments of second to Nth converters by the power closed-loop control; and S5. controlling the converters to output square-wave voltages of 50% duty with different phase shift angles, and realizing given-power control. According to the present disclosure, multiple full-bridge converters can be effectively integrated and power density of the system can be improved, and equivalent large leakage inductance can be magnetically integrated at each converter port to realize given high-power energy routing at each port.

公开(公告)号：US11687699B2

公开(公告)日：2023-06-27

申请号：US17771967

申请日：2021-12-11

Applicant: SOUTHEAST UNIVERSITY

Inventor： Fujin Deng ,  Yun Zhou ,  Hanlu Zhang ,  Chengkai Liu ,  Jianzhong Zhang

IPC: G06F30/00 ,  G06F30/398 ,  H02J3/38

CPC classification number: G06F30/398 ,  H02J3/381 ,  H02J2203/20

Abstract: The present invention discloses a method for modeling sequence impedance of a modular multilevel converter (MMC) under phase locked loop (PLL) coupling. The method includes the following steps: S1, establishing a circuit topology model; S2, establishing a PLL output characteristic model; S3, establishing a PI controller output control small signal model under a dq axis; S4, deducing a modulation small signal; and S5, calculating MMC port impedance. According to the method, a precise MMC port impedance model is established by analyzing a double mirror frequency coupling effect in the output of a modulation signal in a control link caused by a phase angle disturbance and comprehensively considering the combination of the multi-harmonic coupling effect of an MMC. On one hand, the proposed modeling method aims at a common MMC adopting current closed-loop control, in which a half-bridge sub-module is adopted, a circuit topological structure and a control structure are both more common, and a mathematical model is easy to establish. On the other hand, the physical significance of an impedance analysis method is clear, the modeling process is modular and is easy to understand and implement, and the inverter port impedance can be measured on site, so that the correctness of theoretical modeling can be conveniently verified.

公开(公告)号：US11121641B1

公开(公告)日：2021-09-14

申请号：US17265474

申请日：2020-01-02

Applicant: SOUTHEAST UNIVERSITY

Inventor： Fujin Deng ,  Pengyuan Jiang ,  Yihua Hu

IPC: H02M7/483 ,  H02M1/00

Abstract: The present invention discloses a high-power machine drive system based on a modular multilevel converter (MMC), which belongs to the technical field of power generation, power transformation, or power distribution. The high-power machine drive system consists of a modular multilevel converter and a multi-pulse cycloconverter. The MMC outputs k phases of high-frequency AC voltages with a phase difference of 2π/k, and the multi-pulse cycloconverter outputs a low-frequency voltage to drive a corresponding machine. According to the present invention, the MMC is combined with the multi-pulse cycloconverter, and by adopting the MMC that operates at a high frequency, the capacity, the volume, and the weight of the energy storage capacitor of the MMC are reduced, the voltage level at the DC side of the MMC is increased, and the capacity of the drive system is increased. By adopting the multi-pulse cycloconverter, quality of an output waveform at a machine side can be guaranteed, thereby implementing low frequency control on the machine. The present invention may be adapted to drive a high-power low-speed machine.