P. N. Tekwani

• PhD
• Head of Faculty at Nirma University

Current error space phasor based hysteresis controller employed for front end converter requires two (inner and outer) hysteresis bands for vector selection and for sector detection, respectively. As a result of this, the current error space phasor (CESP) moves out of the fixed (hexagonal) inner boundary, many times in one fundamental cycle (and to...

It is highly essential to develop a control technique which can be applied to conventional two-level as-well-as high-power multi-level Front-End Converters (FECs). Multi-axis current controlled, unity power factor (PF), regenerative FEC is described in this paper. Current error space phasor is controlled by multi-axis current monitoring and its mov...

Conventional technique of eliminating current harmonics by use of passive filters suffers from drawback of series and parallel resonance within the network impedance, overcompensation of reactive power at fundamental frequency and poor flexibility. Shunt active power filters (SAPFs) are conventionally used to reduce current harmonics. The active ha...

https://easychair.org/publications/paper/341204

This paper presents behaviour analysis and digital implementation of current error space phasor based hysteresis controller applied to three-phase three-level flying capacitor converter as front-end topology. The controller is self-adaptive in nature, and takes the converter from three-level to two-level mode of operation and vice versa, following...

This paper presents analysis of two-level front-end converter employing current error space phasor-based hysteresis controller. In general, for such current controllers with inner and outer bands, the current error space phasor moves out of inner boundary six times in fundamental cycle for sector change detection. This deteriorates shape of line cu...

Power quality at the source side deteriorates due to current harmonics which are introduced in the power system by non-linear loads, originating a vital difficulty. Rectifiers, variable speed drive, switched mode power supply, etc. types of non-linear loads create such harmonics. Conventional technique to eliminate such harmonics is use of passive...

This paper proposes a new topology for ac-to-ac power conversion which is a three-stage conversion. It comprises of a diode rectifier (ac-to-dc), a buck-boost converter (dc-to-dc) and an H-bridge inverter (dc-to-ac) working as an ac chopper. The topology works as V/f drive wherein the frequency is varied by the buck-boost converter and the voltage...

A switched mode power supply (SMPS) with multiple outputs has been developed which satisfies the need of isolation of control circuit power supply and driver section power supply for a medium-voltage electrical drive. It means that there is no need of extra components for isolation. For this SMPS, fly-back converter topology along with current mode...

This paper presents analysis of two-level front-end converter employing current error space phasor-based hysteresis controller. In general, for such current controllers with inner and outer bands, the current error space phasor moves out of inner boundary six times in fundamental cycle for sector change detection. This deteriorates shape of line cu...

Analysis of two-level and three-level front-end boost-converter employing current error space phasor based hysteresis controller is presented in this paper for various line-side and load-side conditions. Due to the coordination between all the three-phases and selecting only adjacent voltage vectors, the proposed controller is able to overcome limi...

Multi-level inverter technology has emerged recently as a very important alternative in the area of high-power high-voltage energy control. So multi-level inverters have been widely used for high-power high-voltage drive applications. Due to higher number of sources, lower EMI, lower % THD in output voltage and less stress on insulation, they are w...

Current harmonics injected in the utility by nonlinear loads tend to deteriorate the power quality at the mains. These harmonics are compensated by Shunt Active Power Filters (SAPF). Current error space phasor based hysteresis controller for SAPF is presented in this paper, which allows precise compensation of harmonic currents produced by non-line...

Railway wayside signaling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Therefore it is required to have a reliable power supply to keep a healthy and sustainable rail network. The methodology to develop the power supply presented in this paper involves study and implementation of power factor cor...

Three-phase pulse width modulated (PWM) front-end converter (FEC) has now become an essential part of many power electronic systems such as uninterruptible power supplies (UPS), battery chargers, and motor drives, etc. This paper presents simulation analysis of two-level front-end boost-converter which employs current error space phasor based hyste...

To reduce the harmonics injected by non-linear loads, power quality improvement devices like shunt active power filters (SAPFs) are commonly employed. This study presents a digital signal processor (DSP) TMS320LF2407A based hardware implementation of current error space phasor-based hysteresis controller for SAPF. The proposed controller-based SAPF...

Low power factor and high harmonic content are the major drawbacks of conventional front-end rectifiers. Front-end converter is reported in this paper for three-phase system. A systematic design approach is presented for front-end converter and the modelling of the same is also described in detail in presented work. The control strategy for three p...

Shunt Active Power Filters (SAPF) are commonly employed to reduce current harmonics, which are injected in the utility by nonlinear loads. This paper presents performance of current error space phasor based hysteresis controller for three-level Neutral Point Clamped (NPC) and Flying Capacitor (FC) converters used in SAPF. Operation of two-level con...

The three-phase two-level AC/DC line-side converters provides sinusoidal line currents and bidirectional power flow at the unity power factor (UPF). This paper deals with the design of closed loop simulation, analysis of the three phase IGBT based PWM Rectifier with sine triangular PWM control to achieve the unity power factor. With the designed in...

Current harmonics, which are injected in the utility by nonlinear loads, cause major problems that tend to deteriorate the power quality at the mains. To reduce such harmonics, Shunt Active Power Filters (SAPF) are commonly employed. This paper presents a current error space phasor based hysteresis controller for SAPF, which allows precise compensa...

Power quality improvement devices like Shunt Active Power Filters (SAPF) are commonly employed to reduce harmonics introduced by Non-linear loads. Performance of SAPF using current error space phasor based hysteresis controller is presented in this paper to prove controller's versatile nature. Dynamic behavior of the SAPF is demonstrated for change...

This study describes the effect of dead-time and how to develop dead-time compensation with self-balancing space vector pulse width modulated (SVPWM) for the three-level neutral-point clamped (NPC) topology typically used for high-power induction motor (IM) drives. The dead-time necessary to prevent the short circuit of the power supply in pulse wi...

Performance of multi-level inverters is highly superior to conventional two-level inverter, so they have been widely used for high-power high-voltage applications. Due to higher number of dc voltage sources, lower EMI, requirement of fewer devices with less blocking voltage, lower %THD in output voltage and less stress on insulation, they are widel...

Current harmonics, which are injected in the utility by nonlinear loads, cause major problems that tend to deteriorate the power quality at the mains. To reduce such harmonics, Active Power Filters (APF) are commonly employed. This paper gives performance analysis of current error space phasor based hysteresis controller for shunt active power filt...

Multi-level inverter technology has emerged recently as a very important alternative in the area of medium-voltage high-power energy control. Due to higher number of dc voltage sources, lower EMI, requirement of semiconductor power devices with less blocking voltage, lower % THD in output voltage and less stress on insulation, they are widely used....

The paper is based on the performance comparison of single-phase diode-bridge rectifier and the proposed front-end converter in terms of the Total Harmonic Distortion (%THD) of the line current, power factor of the system and ability of energy saving of the converter by capability of reverse power flow action. The parameters of the voltage control-...

Performance of multi-level inverters is highly superior to conventional two-level inverter, so they have been widely used for high-power high-voltage applications. Due to higher number of sources, lower EMI, lower % THD and less stress on insulation, they are widely used. However, it has some disadvantages as complicated PWM controlling method, inc...

This paper focuses on the various control schemes for multi-level voltage source inverter (VSI) fed induction motor (IM) drive systems. The hysteresis current controller presented for three-level inverter is aimed to achieve a current-control strategy with optimum switching for the multi-level inverter. Whereas, the hysteresis current controller pr...

This paper describes on how to formulate a self-balancing space vector modulator for the three-level neutral point clamp topology typically used for high power induction motor drives. Dependence of the DC link capacitor voltage deviation on DC-link current and inverter switching states is established for proposed three-level inverter. Pulse pattern...

A current error space phasor based simple hysteresis controller is proposed in this paper to control the switching frequency variation in two-level pulsewidth-modulation (PWM) inverter-fed induction motor (IM) drives. A parabolic boundary for the current error space phasor is suggested for the first time to obtain the switching frequency spectrum f...

In this paper, a 12-sided polygonal voltage space vector generation with common-mode voltage elimination (CME) is proposed for an induction motor drive. An open-end winding configuration is used for the motor. The proposed multilevel structure is achieved by cascading only the conventional two-level inverters with asymmetrical dc link voltages. By...

For a dual five-level inverter-fed induction motor (IM) drive, effects of DC-neutral currents on dc-link capacitor voltage fluctuations are analyzed in this paper. Operating limitations in achieving the dual task of common-mode voltage elimination and DC-link capacitor voltage balancing with a single dc power supply are further investigated for the...

The open-loop control scheme presented in part I of this paper for a dual five-level-inverter-fed induction motor (IM) drive with two dc power supplies maintains dc-link capacitorvoltage balancing and common-mode voltage (CMV) elimination throughout the operating range of the drive. The operating limitation of the proposed open-loop control scheme...

Common mode voltage (CMV) variations in PWM inverter-fed drives generate unwanted shaft and bearing current resulting in early motor failure. Multilevel inverters reduce this problem to some extent, with higher number of levels. But the complexity of the power circuit increases with an increase in the number of inverter voltage levels. In this pape...

Common-mode voltage generated by the PWM inverter causes shaft voltage, bearing current and ground leakage current in induction motor drive system, resulting in an early motor failure. This paper presents a common-mode elimination scheme for a five-level inverter with reduced power circuit complexity. The proposed scheme is realised by cascading co...

The paper presents a five-level inverter scheme with reduced power circuit complexity for an induction motor drive. The scheme is realized by cascading conventional two-level and three-level neutral point clamped inverters in conjunction with an open-end winding three-phase induction motor drive. An inverter control scheme with common-mode voltage...

A multi-level PWM signal generation with linear transfer characteristics between fundamental component of output voltage and modulation index is proposed in this paper for a n-level SVPWM signal generation. The reference signal to the PWM modulator is pre-scaled in over-modulation region, keeping the fundamental component of the modified signals sa...

Common-mode voltage (CMV) generated by different topologies of the pulse width modulated (PWM) inverters causes shaft voltage, bearing current and ground leakage current in the induction motor (IM) drive system. Consequently the premature mechanical failure (fluting) of machine bearings and conducted electromagnetic interference (EMI) are observed...

Switching frequency variation over a fundamental period is a major problem associated with hysteresis controller based VSI fed IM drives. This paper describes a novel concept of generating parabolic trajectories for current error space phasor for controlling the switching frequency variation in the hysteresis controller based two-level inverter fed...

A multilevel inverter with 12-sided polygonal voltage space vector structure is proposed in this paper. The present scheme provides elimination of common mode voltage variation and 5^th and 7^th order harmonics in the entire operating range of the drive. The proposed multi level structure is achieved by cascading only the conven...

A dc link capacitor voltage balancing scheme along with common mode voltage elimination is proposed for an induction motor drive, with open-end winding structure. The motor is fed from both the ends with three-level inverters generating a five level output voltage space phasor structure. If switching combinations, with zero common mode voltage in t...

Variation of switching frequency over the entire operating speed range of an induction motor (IM) drive is the major problem associated with conventional two-level three-phase hysteresis controller as well as the space phasor based PWM hysteresis controller. This paper describes a simple hysteresis current controller for controlling the switching f...

Multilevel inverters are preferred over two-level inverters in high-voltage, high-power applications mainly because low-switching-frequency PWM schemes can be implemented with power devices of low-voltage ratings. Common multilevel inverter structures such as NPC, H-bridge and flying capacitor will produce a hexagonal voltage space vector structure...

A multilevel inverter scheme for an open-end winding induction motor (IM) drive is proposed to maintain the balance in the dc-link capacitor voltages, and to eliminate the common-mode voltage (CMV), simultaneously. The proposed scheme does not call for any extra control hardware for the capacitor voltage balancing. Performance of the drive is verif...

A multi-level PWM signal generation with linear transfer characteristics between fundamental component of output voltage and modulation index in the entire modulation range including over-modulation is proposed in this paper for any n-level SVPWM signal generation. The reference signal to the PWM modulator is pre-scaled in over-modulation region su...

The simultaneous elimination of common-mode voltage and DC-link capacitor voltage imbalance is achieved in a five-level inverter scheme for an induction motor drive throughout its operating range. A dual five-level inverter-fed open-end-winding induction motor structure is used for the proposed drive. Initially, the operating limitations of achievi...

Split-phase (six-phase) induction motor stator windings consist of two sets of three phase windings, which are spatially phase separated by 30 electrical degrees. Due to mutual cancellation of the air gap flux for all the 6n±1 (n=1,3,5...) order harmonic voltages, called zero sequence components, large harmonic currents are generated in the stator...

This paper presents a five-level inverter topology for induction motor (IM) drive with dc-link capacitor voltage balancing and common-mode voltage elimination. A dual five-level inverter fed open-end winding IM structure is used in the present work. A hysteresis controller based closed loop control scheme is proposed. It achieves the balancing of d...

This paper presents a five-level inverter topology for induction motor (IM) drive with dc-link capacitor voltage balancing and common-mode voltage elimination. A dual five-level inverter fed open-end winding IM structure is used in the present work. A hysteresis controller based closed loop control scheme is proposed. It achieves the balancing of d...

A current-error space-vector-based PWM hysteresis controller is proposed for three-level voltage source inverter fed induction motor drive applications. A hexagonal boundary for the current-error space vector is formed by sensing the current-error space vector along three different axes, which are 120° apart and are orthogonal to machine phase axes...

Five-level inverter topology for induction motor drive

In this paper, a space phasor based current hysteresis controller for a three-phase voltage source inverter is proposed. The current errors are determined along three axes, which are orthogonal to the A, B, C phases, and the current error space phasor is held within a hexagonal boundary. The proposed controller does not require any computation of m...

A four-level inverter configuration for an induction motor is proposed in this paper. The drive used for this scheme is an open-end winding induction motor which can be obtained by separating the neutral connections of any general three-phase induction motor. The proposed scheme uses two three-level inverters, with asymmetric DC link voltage, feedi...

A DC link capacitor voltage balancing scheme for an three-level inverter with open end winding induction motor drive is proposed in this paper. The multiplicity of the switching combinations of the inverter voltage locations is best exploited to arrive at the capacitor balancing criterion. All the inverter vector locations, which has unbalancing ef...

A current error space phasor based hysteresis controller is proposed for three-level voltage source inverter fed induction motor drive. Only the adjacent inverter voltage vectors forming a triangular sector, in which tip of the machine voltage vector lies, are switched to keep the current error space phasor within the hexagonal boundary. Calculatio...

A seven-level inverter scheme, for an open-end winding induction motor drive, is proposed in this paper. The open-end winding induction motor is fed from both sides with three-level inverters. Each three-level inverter is formed by cascading two two-level inverters. The DC link voltage of the top two-level inverter is equal to V dc /3, while the DC...

A scheme for a three-level voltage space phasor generation with common-mode voltage elimination is proposed. An open-end-winding induction motor, fed from both ends by two three-level inverters, which are realised by a cascading two two-level inverter, is used in this configuration. The voltage space vectors of individual three-level inverters, whi...

Common-mode voltages generated by PWM inverters in induction motor drives cause shaft voltages, bearing currents and ground leakage currents resulting into early mechanical failure of machine bearings and conducted EMI. A five-level inverter topology with switching state combination selection strategy for the PWM control is proposed for an open-end...