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A dual-mode NRZ/PAM-4 differential low-swing voltage-mode transmitter employs a quarter-rate output multiplexing architecture for low-power operation. In NRZ mode, 2-tap feedforward equalization is realized with analog replica-bias tap control that is configurable in high-performance controlled-impedance or energy-efficient impedance-modulated settings. This analog control also allows for efficient...
Existing control strategies of modular multilevel converter (MMC) have many drawbacks, such as need of several parameter controllers, complex parameter tuning and huge computational burden. This paper proposes a novel control method based on the hybrid architecture of proportional integral (PI) control and model predictive control (MPC). The PI controller is used as external controllers to control...
Solar photovoltaic (PV) renewable energy systems are undergoing major technological developments and large-scale field deployment and electric grid integration. This paper proposes a method of expanding the capacity of an existing irrigation farm with additional pumps powered by solar PV. The system includes PV arrays and battery energy storage connected to a common dc bus, which energizes an array...
The paper presents a new four-level voltage source converter (VSC). Compared to conventional four-level converters, this proposed converter has fewer components and can be used for a higher power density system in low and medium voltage applications. Its principles and advantages are studied in this paper. The effect of various redundant switching states on the voltages of flying capacitors is analyzed...
Vector control is the most commonly used control strategy for modular multilevel converter (MMC) based HVDC system. However, due to the complicated structure of MMC, there is no precise mathematical model for the outer DC voltage loop. The conventional model ignores the capacitor voltage dynamics, and the AC voltage boosted operation scenario is not considered. This paper proposes a small signal model...
This paper presents an improved model predictive control strategy with fixed switching frequency. The proposed method adds four virtual voltage vectors to the four real voltage vectors of the conventional finite control set model predictive control to reduce the harmonic content of the grid current and uses a modulator to realize fixed switching frequency. Furthermore, a novel cost function, which...
The paper proposes a three phase nine level T-type neutral point clamped (9L-T-NPC) inverter for medium voltage induction motor drive. The primary objective of the proposed inverter is to improve the output voltage quality with reduced number of devices and passive components. The generation of nine levels in the output pole voltage is achieved using only ten switches per phase. Although the similar...
Voltage deviations of dc-link capacitors are the main problem of multilevel diode-clamped converters (DCC). In this paper, a novel carrier-based voltage balance method is proposed to balance the dc-link capacitors of five-level DCCs. The proposed method is characterized by injecting proper zero-sequence voltages in the modulation signals of carrier-based modulators. The effects of the injected zero-sequence...
A capacitor voltage-balancing control strategy based on switching state redundancies is proposed for the hybrid stacked five-level converter. In order to obtain the balancing properties for flying capacitors, a hybrid model in state-space representation is established by considering the continuous and discrete variables. The proposed balancing strategy can control the flying capacitor voltages to...
Modular multilevel converters (MMC) have many advantages owing to their power-stage modularity. However, this modularity does not extend directly to the control. Particularly, the balancing control usually requires central coordination and increases in complexity with the system size. This paper presents a balancing control method for a more general modular multilevel converter with series and parallel...
This paper proposes two hybrid asymmetric cascaded multilevel inverters. Both inverters consist of the series connection of a three-level (3L) H-bridge cell and a nine-level (9L) H-bridge cell with an unequal dc voltage ratio of 1:8. The topologies of the 9L H-bridge cell are based on modular multilevel cascade converter (MMCC) with double-star chopper cells (DSCC). Both the proposed inverters can...
This paper proposes a model predictive control-space vector modulation (MPC-SVM) method to achieve current ripple reduction and neutral-point voltage balance in three level inverter. The proposed MPC-SVM method is based on subdivision strategy for improving the performance of the conventional model predictive control (MPC) method. The proposed subdivision strategy consists of two parts: current controller...
This paper presents an indirect model predictive control to develop a direct power regulator for a modular multilevel converter connected to a high voltage direct current bus line, where the main task is to bidirectionally transfer active power to the grid and simultaneously compensate reactive power. The main advantage, of the proposed dynamic matrix control methodology, is to capture the system...
The three-level T type inverter has been extensively used in photovoltaic (PV) generation. Various PV panels in cascaded connection normally require unequal dc voltage to accomplish separate maximum power point tracking (MPPT). This paper proposes a DPWM-controlled three-level T type inverter for two strings of PV panels in cascaded connection. The proposed modulation is developed based on the so-called...
In the field of high-speed electrical drives, the use of SiC MOSFET inverters represents a viable solution since this kind of devices allows an improvement of the converter efficiency. Notwithstanding issues related to the high frequency operation of the SiC MOSFET's, like the failure of the motor winding insulation due to the increased electrical stress and hence a reduced system reliability, are...
Three-phase/level T-type converter has advantages of high efficiency and low current harmonics, which is utilized in power conversion systems for supplying dc loads widely. Three-phase/level T-type converter provides bipolar dc buses with a neutral line at relatively low cost. In order to extend applications for bipolar dc bus structure, voltage independence control of split-dc bus proposed in this...
Voltage Balance of the series-connected dc-link capacitors is the key problem of three-level diode-clamped converters. In this paper, an auxiliary voltage balance circuit (VBC) is presented to maintain the voltage balance of dc-link capacitors. The voltage balance circuit consists of a clamping capacitor and a current-limiting inductor. With the clamping capacitor, the voltage stresses of the auxiliary...
In recent years medium voltage direct-current (MVDC) grids have gained significant attention. This paper presents a new isolated modular multilevel converter (MMC)-based dc/dc converter for connecting such networks. The proposed converter can connect DC grids with different voltage levels and control power flow among them. The proposed isolated dc/dc converter has fewer components compared to conventional...
This paper introduces an asymmetric cascaded multilevel inverter consisting of series-connected two nine-level (9L) H-bridge cells, which are based on modular multilevel cascade converter (MMCC) with double-star chopper cells (DSCC). An unequal dc voltage ratio of 1:2 is used, so that the proposed topology can generate 25 output voltage levels. A modulation strategy for the inverter is proposed. A...
The aim of this paper is to present the implementation of an Embedded Real-Time Simulator (ERTS) for Modular Multilevel Converters (MMCs), using low-cost System-on-Chip (SoC) platform. In order to achieve new functionalities such as sensor-less control, monitoring, diagnostic and fault detection, the MMC plant model can be implemented along with the controller. In MMC applications, the implementation...
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