Bin Wu

• Ph.D., HCLD (ABB)
• Managing Director at Arizona Center for Reproductive Endocrinology and Infertility

Human IVF laboratory often shows many abnormal fertilization eggs, such as no pronucleus (0PN), monopronucleus (1PN), three pronuclei (3PN) or multi-pronuclei (mPN) zygotes and these abnormal eggs are usually not used and typically discarded. Recent researches have showed that further evaluation on these abnormal eggs may provide some hope for aged...

Model predictive control is an effective approach to achieve high performance on electric motor drives. In this study, a two‐vector based low‐complexity model predictive flux control (TVLC‐MPFC) is proposed and introduced for low power current‐source inverter (CSI)‐fed induction motor (IM) drive. In contrast to conventional two‐vector based model p...

This paper provides a detailed analysis of the power electronics solutions enabling bipolar dc grids. The bipolar dc grid concept has proven to be more efficient, flexible and higher in quality than the conventional unipolar one. However, despite its many features, these systems still have to overcome their issues with asymmetrical loading to avoid...

Transformerless MMC-based drive system usually installs a grid-tied modular multilevel converter (MMC) to interface with medium-voltage AC utility. Since no front-end transformer is installed, the grid-tied MMC is expected to directly defense the common-mode voltage (CMV) from asymmetrical grid fault and switching operation of converters for maxima...

Model predictive control (MPC) has emerged as a promising approach to control a modular multilevel converter (MMC). With the help of a cost function, the control objectives of an MMC are achieved easily by using an MPC approach. However, the MPC has several technical challenges and issues including the need of accurate system models, computational...

Cascaded H-bridge is a promising topology for medium-voltage, high-power applications. Cascaded H-bridge consists of low-power H-bridge modules in each phase, and these modules are connected in a cascade manner to achieve multilevel operation. However, cascaded H-bridge requires a phase-shifting transformer with multiple secondary windings to gener...

Recently, a star-channel modular multilevel converter (MMC) is proposed for zero/low-fundamental -frequency operation. However, it is companied by two potential issues in practices: 1) the star-channel branch suffers from submodule (SM) capacitor voltage deviations; 2) the entire-speed-range operation for motor drive is not confirmed. This paper in...

Pulse width modulation (PWM) current source converter (CSC)-based drive is one of the widely used drives in high-power (megawatt-level) medium-voltage (MV) (2.3-6.6 kV) applications. The switching frequency of the MV CSC is limited to around 500 Hz to satisfy thermal requirement and reduce switching loss. Under such a condition, the overall perform...

The five-level modular neutral point clamped (5L-MNPC) converter is realized by connecting two three-level NPC modules in series. For five-level operation, each DC-bus capacitor voltage of MNPC topology should be regulated at one-fourth of the net DC-bus voltage. In this letter, a simple voltage balancing approach based on the carrier-based modulat...

Delta-channel modular multilevel converter (MMC) proved successfully for zero/low-fundamental -frequency operation without injecting common-mode voltage (CMV). However, its application in medium-voltage variable-speed motor drive is not verified. This paper develops a variable-speed motor drive system based on delta-channel MMC. The converter power...

Wind energy is one of the fastest growing renewable energy sources. Since 1980s, power electronics technology is being used in commercial grid-connected wind energy conversion systems (WECS) to increase energy capture from wind. This book chapter discusses the state-of-the-art and emerging power electronics for fixed-speed, semi-variable speed, and...

This chapter provides an overview of the different charging architectures available for electric vehicles and plug-in hybrid electric vehicles. The charging architectures are addressed following two main categories: onboard chargers, used mainly for slow and semi-fast charging (generally AC connection), and off-board chargers, used for fast chargin...

this paper proposes a delta-channel modular multilevel converter (MMC). It aims to overcome the issues of conventional MMC during zero/low fundamental frequency operation. The proposed converter is characterized by the cross connection of the upper three arms and lower three arms through two sets of delta-channel branches. These delta-channel branc...

Groundwater chemistry data are normally scarce in remote inland areas. Effective statistical approaches are highly desired to extract important information about hydrochemical processes from the limited data. This study applied a clustering approach based on the Gaussian Mixture Model (GMM) to a hydrochemical dataset of groundwater collected in the...

Compared with multilevel space vector modulation (SVM), level-shifted multicarrier sinusoidal pulse width modulation (SPWM) for NNPC inverters requires much less calculations and implementation efforts, but the existing conventional SPWM cannot suppress the severe flying-capacitor voltage ripples under low output-frequency conditions. In order to s...

Current source converter (CSC)-based wind energy conversion systems (WECS) are recently gaining increasingly attention due to its reliable short-circuit protection. However, all existing CSC-based configurations are proposed for medium-voltage (MV) (3-4 kV) wind turbine systems, but not for low-voltage (LV) (690 V) systems which are dominating the...

Modular multilevel converter (MMC) is one of the most promising topologies for medium to high-voltage, highpower applications. The main features of MMC are modularity, voltage and power scalability, fault tolerant and transformer-less operation, and high-quality output waveforms. Over the past few years, several research studies are conducted to ad...

the flying capacitor modular multilevel converter (FC-MMC) overcomes the low/zero-speed operation issues of conventional MMC-based drive. The FC-MMC injects no common-mode voltage (CMV) to the drive system. However, the pulse width modulator (PWM) introduces switching ripples, which appear as CMV on motor stator windings. To completely get rid of t...

In this study, a current source nine-switch ac/ac converter for microgrid application is presented. In contrast to traditional back-to-back configuration, the number of switching devices in the proposed converter decreases from 12 to 9 with three insulated gate bipolar transistors and three diodes reduced, which achieves simpler structure and lower...

In current source inverter (CSI)-based series-connected configurations, recently proposed for offshore wind energy conversion systems, a number of medium-voltage (MV) CSIs are connected in series to form a centralized dc/ac inverter to transfer offshore wind power to grid. In previous studies, the series-connected CSIs are controlled based on assum...

this paper proposes a star-channel modular multilevel converter (MMC). It overcomes the zero/low fundamental frequency operation issues of conventional MMC while not injecting common-mode voltage. The proposed converter is characterized by the cross connections of upper three arms and lower three arms through two sets of star-channel branches. Thes...

Four-level nested neutral-point clamped (NNPC) inverters experience severe voltage balancing problems under low output-frequency conditions when the conventional four-level space vector modulation (4L-SVM) technique is applied, which limits their wider application. In order to get a complete control of the flying-capacitor voltages, and to alleviat...

A model predictive power factor control (MPPFC) scheme is proposed for high power medium-voltage (MV) current source rectifiers (CSRs). Facing two major issues on input power factor (PF) and LC resonance, the proposed MPPFC uses a novel line reactive power reference estimator to achieve unitary input PF or maximum achievable input PF for a CSR at v...

This paper presents a transformerless high-voltage DC-DC converter based on cascaded sub-modules. It is intended for interconnecting high-voltage or medium-voltage DC grids. The proposed DC-DC converter is composed by two phase legs, each of which consists of an upper arm and a lower arm with their middle nodes crossly connected through a branch of...

A series-connected current source converter (CSC)-based configuration has recently been proposed for offshore wind energy conversion systems. A big challenge exists for such a system that its maximum insulation level is the full transmission voltage due to its monopolar operation. This introduces significant burden to the system in terms of cost, r...

Recently, a series-connected current source converter (CSC)-based configuration is proposed for offshore wind conversion systems. However, two problems exist in conventional strategy of such a system. One is increased cost on onshore CSCs, and the other is decreased operation efficiency of onshore CSCs. To solve these issues, the present work propo...

The modular multilevel converter (MMC) is most widely acclaimed converter topology for high-voltage, high-power applications. Several multilevel submodules have been proposed to replace the conventional two-level submodules for MMC, allowing the reduction in the foot-print size of the converter for the same number of output voltage levels. Among th...

The double-star converter (DSC) is a recently introduced medium-voltage 4-level multilevel inverter topology, with a reduced number of active switches. This topology has several advantages over existing commercial topologies (single dc-source, no clamping elements, no bidirectional switches or flying capacitors), which can satisfy the needs of seve...

Current source converters (CSCs) used in high-power (megawatt level) medium-voltage (MV) (2.3–6.6 kV) drives require three-phase capacitors to assist the commutation of switching devices and to filter out harmonics of the converter output PWM current. Different types of modulation schemes with different harmonic performance lead to different capaci...

This paper first starts with reviewing several commonly practiced PWM schemes for the three-phase isolated buck matrix type rectifier. Then, an optimal six-segment PWM scheme (“Type A”) is proposed. The analysis shows “Type A” PWM scheme has lower duty-cycle loss, maximum output inductor current ripple and minimum switching loss comparing to other...

In modular multilevel converter (MMC), the voltage balance among the submodules is mandatory, to generate the multilevel stepped waveform across the load and to ensure the equal voltage stress on the semiconductor devices. In addition, the output power quality (voltage and current waveforms) and converter reliability greatly depend on the design me...

The three-level flying capacitor (3L-FC) submodule significantly reduces the magnitude of circulating currents, voltage ripple, footprint size, and improves the efficiency of the modular multilevel converter (MMC). Due to the above advantages, the 3L-FC submodule becomes an alternative for the conventional half-bridge submodule in MMC. Each 3LFC su...

This study presents a model predictive control (MPC) with active damping function for current-source rectifiers (CSRs). Since optimal modulating vector selection process of MPC leads to spread harmonic distribution in pulse-width-modulated (PWM) waveform, inductor-capacitor (LC) resonance can be easily excited. Conventional MPC was designed without...

This work presents a predictive control strategy for grid-connected Cascaded H-Bridge (CHB) converters under unbalanced power generation among each converter phase. The proposed controller belongs to the Finite-Control-Set Model Predictive Control (FCS-MPC) family and is designed to extract unbalanced power from each CHB converter phase while provi...

This paper presents a transformerless bipolar DC-DC converter based on series-connected submodules (SMs). It is intended for transforming DC voltage and managing power flow for medium/high-voltage DC grids. The DC-DC converter is composed by positive-pole and negative-pole subsystems, each of which consists of six arms/branches. Every two arms and...

This paper proposes a novel modular multilevel dc-dc converter intended for transforming dc voltage and interconnecting dc grids for medium-voltage networks. The converter is composed by two strings of submodules, each of which consists of an upper arm and a lower arm with their middle points crossly connected through a dc capacitor. With assistant...

Sample Readings: http://media.wiley.com/product_data/excerpt/82/11189885/1118988582-59.pdf http://media.wiley.com/product_data/excerpt/82/11189885/1118988582-60.pdf http://media.wiley.com/product_data/excerpt/82/11189885/1118988582-61.pdf Model Predictive Control of Wind Energy Conversion Systems addresses the predicative control strategy that ha...

This chapter focuses on the development of medium-voltage (MV) drives without the need of isolation or phase-shifting transformers. It analyses the common-mode (CM) voltage issue in the MV drive, and discusses mitigation methods for the reduction or elimination of CM voltages. The chapter presents principle and realization of transformerless voltag...

This chapter provides an overview of six-pulse SCR rectifier, which is the building block for the multipulse SCR rectifiers, followed by an analysis of 12-, 18-, and 24-pulse rectifiers. It investigates the line current THD and input power factor of these rectifiers, and summarises the results in a graphic format. The line current THD of the 12-pul...

This chapter focuses on the analysis of advanced inverter topologies, including multilevel active neutral-point clamped (ANPC), neutral-point piloted (NPP), nested neutral-point clamped (NNPC), and modular multilevel converters (MMCs) inverters. It explains the operating principle of these inverters, introduces their modulation schemes, and elabora...

This chapter presents a relatively new type of medium voltage (MV) drives using a multi-module cascaded matrix converters (CMCs) topology. The matrix converter has a unique topology that performs direct AC to AC power conversion with a single power stage without a DC link that is normally required by the voltage source converter (VSC) and current s...

This chapter focuses on the pulse-width-modulated (PWM) current source inverter (CSI) technologies for high-power medium voltage drives. It analyses three modulation techniques for the CSI, which include trapezoidal pulse width modulation (TPWM), selective harmonic elimination (SHE), and space vector modulation (SVM). The SVM scheme has the lowest...

This chapter focuses on commonly used high-power semiconductor devices including silicon controlled rectifiers (SCRs), gate turn-offs (GTOs), gate commutated thyristors (GCTs), and insulated gate bipolar transistors (IGBTs) for medium voltage (MV) drives. It discusses the static and dynamic voltage equalization techniques for series connected devic...

This chapter addresses four main aspects of the current source rectifiers (CSRs) used in high-power AC drives, including converter topologies, pulse-width-modulated (PWM) patterns, power factor control, and load commutated (LC) resonance with active damping control. The filter capacitor and line inductance constitute an LC resonant circuit. The LC...

This chapter presents a number of practical medium voltage (MV) drive configurations using multilevel voltage source inverters, which include two-level voltage source inverter (VSI), three-level neutral point clamped (NPC) inverter, multilevel cascaded H-bridge (CHB) inverter, NPC/H-bridge inverter, active neutral-point clamped (ANPC) inverter, and...

This chapter deals with the low-voltage (LV) and medium voltage (MV) passive generator-side (PGS)-converters-based Type 4 PMSG WECS and the digital control using model predictive control (MPC). The control system uses only feedback signals and does not require the model and parameters of PMSG. The model of inductor current and DC-link capacitors vo...

This chapter discusses the classical and advanced digital control techniques, including predictive control and examines the operating principle of these control techniques with an intuitive example of generator or grid current control. When closed, a switch allows the passage of any amount of current without any on-state voltage drop. The power dio...

This chapter discusses wind energy preliminaries briefly in terms of installed wind power capacity, wind energy installations by various countries, wind kinetic energy to electric energy conversion, and evolution of major wind turbine (WT) technologies since the 1980s. WTs produce negligible power when wind speed is below the cut-in value; thus, be...

The diode-clamped multilevel inverter employs clamping diodes and cascaded DC capacitors to produce AC voltage waveforms with multiple levels. This chapter discusses various aspects of the three-level (3L) neutral-point clamped (NPC) inverter, including the inverter topology, operating principle, and device commutation. It also discusses a conventi...

This chapter focuses on the control schemes for the synchronous motor drives. The synchronous motor used in high-power medium voltage (MV) drives can be generally classified into two categories: wound rotor synchronous motor (WRSM) and permanent magnet synchronous motor (PMSM). The synchronous motors can be controlled by various methods, including...

This chapter focuses on pulse width modulation (PWM) schemes for the highpower two-level inverter, where the device switching frequency is normally below 1 kHz. A carrier based sinusoidal PWM (SPWM) scheme is reviewed, followed by a detailed analysis of space vector modulation (SVM) algorithms. The conventional SVM scheme usually generates both eve...

This chapter deals with the MPC of power converters employed in doubly fed induction generator (DFIG) wind energy conversion systems (WECS). The generator-side converter (GSC) is connected to the WFCP through a harmonic filter and a step-up transformer. The power converter in a rotor circuit processes the slip power, which is approximately 30% of t...

This chapter discusses how the process of transforming or mapping continuous functions, models, and equations into discrete counterparts is related to discrete mathematics and is often referred to as discretization. The finite control-set model predictive control (FCS-MPC) strategy is an intuitive and powerful tool for controlling power converters...

This chapter presents a number of current source inverter (CSI) drives with various front-end converters such as single-bridge pulse-width-modulated (PWM) rectifier, dual-bridge PWM rectifier, and phase-shifted SCR rectifiers. The CSI technology is well suited for medium voltage (MV) drives. The CSI fed drive features simple converter structure, mo...

This chapter discusses how continuous time (CT) and discrete time (DT) are two alternative frameworks that are used in the modeling of variables. Generator- and grid-side currents are regulated and fed into the grid in a controlled manner by properly regulating the turn-on and turn-off statuses of the switching devices in the power converter. The o...

This chapter focuses on the separate-type multipulse rectifiers, where each of its six-pulse rectifiers feeds a separate DC load. The main feature of the multipulse rectifier lies in its ability to reduce the line current harmonic distortion. This is achieved by the phase-shifting transformer, through which some of the low-order harmonic currents g...

This chapter discusses the predictive control of full-scale low-voltage (LV) and medium voltage (MV) voltage source converters (VSCs) employed in permanent magnet synchronous generator (PMSG) wind energy conversion systems (WECS). The variable voltage and frequency output of PMSG is first rectified to DC by using the generator-side 2L-VSR. An imbal...

This chapter discusses the modeling of wind generators from the model predictive control (MPC) perspective using common notation for both synchronous and induction machines. The active and reactive power reach rated values because of the rated load connected to the generator terminals. The chapter also presents modeling of various control variables...

This chapter reviews the single-phase H-bridge power cell, which is the building block for the cascaded H-bridge (CHB) inverter and introduces various inverter topologies. The inverter DC bus voltage is usually fixed while its AC output voltage can be adjusted by either bipolar or unipolar modulation schemes. The chapter analyses two carrier-based...

This chapter discusses the basics for wind energy and examines enough background to select wind generator-power converter configuration for modeling and predictive control. Power converters in first generation of wind turbines (WTs) (Type 1) are used only for smooth grid connections, which are disconnected from the circuit once the generator is tie...

This chapter addresses a number of issues concerning the phase-shifting transformer, including the configuration of the transformer, the design of turns ratios, and the principle of harmonic current cancellation. It discusses the structure and phasor diagrams of the transformers. To assist the transformer design, the relationship between the requir...

This chapter deals with the modeling of power converters employed in Type 3 and 4 variable-speed wind energy conversion systems (WECS), particularly for 2L- voltage source converters (VSCs) and NPC converters. Model Predictive Control (MPC) uses a completely different approach and does not require comprehensive knowledge on the space vector diagram...

This chapter deals with the model predictive control (MPC) of grid-side converters (GSCs) in different reference frames, with the predictive current control (PCC) and predictive power control (PPC) being discussed for both LV and MV power converters. The generator-side variable voltage and variable frequency is converted to grid compatible fixed vo...

This chapter deals with the predictive control of full-scale low-voltage (LV) and medium voltage (MV) voltage source converters (VSCs) employed in SCIG wind energy conversion systems (WECS). The generated power is instantaneously injected to a utility grid via the full-scale converter connected between the generator stator and grid terminals. The g...

Conventional SVM based common-mode voltage (CMV) reduction in medium-voltage (MV) current source rectifier (CSR) cannot be used in practice. Conventional SVM contains high-magnitude low-order harmonics, particularly the 5th and 7th harmonics, that are lying closely to the resonance frequency (4.5–5.5 pu) of the LC filter of the converter, thus intr...

In modular multilevel converter (MMC), the zero sequence currents at twice the fundamental frequency and its multiples flowing through the DC-bus and causes DC-bus power fluctuations during unbalanced conditions. These fluctuations appear in DC-bus current, considering that the DC-bus voltage is stiff. In this paper, a model predictive control is p...

The indirect model predictive control (I-MPC) is one of the reduced computational predictive strategies, used to control the modular multilevel converter (MMC). This approach operates at higher switching frequency, which is not desirable for high-power applications. This study proposes an integrated solution for MMC by combining predictive control...

This paper presents a model predictive switching pattern control (MPSPC) for a current source converter (CSC), which achieves superb low-order harmonics elimination performance in steady state, and improved transient responses. Based on a proposed space vector based selective harmonic elimination (SHE) method and prediction of load current at the n...

The model predictive control has an ability to achieve multiple control objectives for a modular multilevel converter. This approach has high computational complexity and causes the unwanted switching's leading to a higher ripple in output current and harmonic distortion in output voltage and current waveforms. To solve the issues of computational...

The use of conventional half-bridge submodules in the Modular Multilevel Converters brings important benefits such as the reduction in the power losses and semiconductor devices. However, the system with half-bridge submodule lacks the capability of blocking DC-faults currents. In this paper, a 5-level submodule with DC-fault blocking capability is...

The computational complexity is one of the major issues in the implementation of direct model predictive control (D-MPC) for modular multilevel converters (MMC). The computational complexity is significantly reduced by combining the conventional voltage balancing approach with the MPC. This approach is referred as indirect model predictive control...

The multilevel submodules (SMs) bring the added advantages of compact size and improved efficiency over standard submodules to the modular multilevel converter (MMC). These SMs have more than one floating capacitor, which stores the arm energy. Each arm of MMC has several SMs connected in series to meet the required operating voltage. The SM capaci...

the flying capacitor modular multilevel converter (FC-MMC) overcomes the low/zero-speed operation issue of conventional MMC in medium-voltage motor drive application. However, the introduced flying capacitor (FC) in each phase leg brings great difficulties for circuit startup: 1) pre-charging of FC to nominal voltage is necessary for normal operati...

This paper presents an active cross-connected modular multilevel converter (AC-MMC) based on series-connected half-bridge modules. It is intended for completely enhancing the performance of a medium-voltage motor drive system in the full speed range from standstill to rated speed under all load conditions. The proposed AC-MMC circuit is characteriz...

The purpose of this paper is to develop a model and propose control strategies to mitigate dc-link current ripple for current-source grid-connected converter (CSGCC) under unbalanced grid conditions. Based on the model of instant active power under unbalanced grid conditions, this paper proposes the optimized negative-sequence current references fo...

The development of high-power charging stations with fast chargers is a promising solution to shorten the charging time for electric vehicles (EVs). The neutral-point-clamped (NPC) converter-based bipolar-dc-bus-fed charging station brings many merits, but it has inherent voltage balance limits. To solve this issue, a voltage balance control (VBC)...

The cost reduction of power electronic devices, the increase in their reliability, efficiency and power capability, lower development times, together with more demanding application requirements, have driven the development of several new inverter topologies recently introduced in industry, particularly medium-voltage converters. New more complex i...