Expansion Transition Speed of PMSM under MTPA Control Strategy Based on Improved Voltage Loop Quasi-Z Source Inverter

In this study, a proposed three phase quasi Z source inverter (QZSI) using Sliding Mode Control (SMC) method is presented. The two impedance source networks have been implemented to increase the nonlinear of system. These control algorithm and proposed topology have been offered to get fast and dynamic response in robust and stable position even though input voltage, references have been changed. According to the proposed model using SMC method, the design of related inverter has been run and observed the behavior of regarding system during simulation. In power electronics systems have included nonlinear loads such as switches, MOSFETs, diodes etc. These cause to negative effects on performance of related systems. On the other hand, generally both Z source (ZS) and quasi Z source (QZS) topologies are preferred, even if buck-boost inverters are designed. SMC method is one of the most popular control types which has provided to dynamic response in robust and stable position against to nonlinear and unstable changes. During the switching process for all parts of system, control method has overcome unintended output and completed control steps based on design structure. Also, the proposed topology has been simulated at MATLAB/SIMULINK.

Traditional Quasi-Z source inverter uses direct zero vector to realize single-stage buck-boost. However, with the rising of output voltage, the capacitor voltage's increasing adds requirements for devices. A kind of modified Quasi-Z source topology is put proposed. It reserves the advantages of traditional Quasi-Z source inverter, and has other characteristics as follows: it effectively reduces the capacitor voltage peak and steady-state voltage; it effectively reduces inductor current peak when the circuit boot; it effectively reduces requirements for device, and improves the system's reliability. Based on the theoretical analysis, the simulation result for modified Quasi-Z source inverter demonstrates its correctness and superiority.

A novel Quasi-Z source (QZS) cascaded multilevel inverter (CMI) (QZS-CMI) based photovoltaic (PV) power system applied to smart microgrid is proposed in this paper. The novel QZS impedance network has strong boost ability. Each PV panel connects to a QZS inverter (QZSI) to form a power generation module. By establishing an analytical model of each QZSI module to design reasonable parameters of the novel QZS impedance network, it can limit the second-harmonic (2) ripples. Each QZSI module has an independent DC-link peak voltage control with phase-shifted pulse-width-amplitude modulation (PS-PWAM), so the novel QZS-CMI’s power loss is reduced. The simulation results verify the feasibility of the control strategy. The proposed novel QZS-CMI provides an effective method for the realization of new energy generation.

Due to the nature of robust control, the sliding mode is most popularly used for most DC-DC and DC-AC converters. This paper deals with the investigation of sliding mode control on the grid-tied single-phase quasi Z-source Inverter (QZSI). Basically, two types of controls are applied. Firstly DC side control, where the duty cycle is regulated by applying sliding mode control (SMC). The second one is AC side control where the modulation index is controlled using closed-loop control. The main focus of this article is to investigate the low-frequency (100Hz) ripple content in DC side passive components' current and voltage under the influence of SMC. The obtained simulation result also shows that SMC provides faster dynamic response with change in reference capacitor voltage and input voltage. It also shows that the grid voltage and grid current is also well regulated for the dynamic change in capacitor voltage and input voltage. The ripple calculation shows that 100Hz ripples are very large in quasi-Z source (QZS) inductor current ripple compared to capacitor voltage. The simulation results are carried out using MATLAB/SIMULINK.

This paper addresses the approach to improve the efficiency of the quasi Z-source inverter. In order to increase the efficiency the reduction of conduction losses is one way to approach. Sequentially to decrease the conduction losses in the quasi z-source inverter the replacement of diode is replacing with switches is proposed which is also called as synchronous rectification. The paper represents basics of the approach, analysis and comparison of the power losses of the traditional and proposed designs of the grid connected PV-system with quasi z-source inverter system. The proposed approach validated on the computer simulations in the MATLAB environment.

this study represents a voltage regulation of quasi z source inverter integrated in standalone system powered by photovoltaic generators and electrochemical batteries. The quasi-z-source inverter (QZSI) provides an alternative for the conventional voltage source inverter (VSI) by eliminating the DC/ DC converter, and replace it by LC network design, this solution reduce the switching power number, losses and cost. The batteries are commonly used for reimburse the necessitate power occurred in night or when we have a bad metrological circumstance conditions (shadow, cloudy days). In standalone systems, the most important challenge is to achieve good voltage stabilities and higher power quality in diverse really random load variations. For that, in this study we propose an appropriate closed voltage regulation of quasi z source inerter output for compensate the really load current demanded. The photovoltaic maximum power point algorithm (MPPT) and the voltage loop regulation are both integrated in the simple boost control of quasi z source inverter for create the shoot through mode situations. Many simulation results obtained using MATLAB/SIMULINK in different rigorous situations show the robustness and the performance of the proposed control system.

This paper presents a hybrid method of active power and reactive power control strategy with Quasi Z-source inverter (QZSI) in single phase grid connected photovoltaic (PV) systems. The maximum power from the PV panel is extracted and most of it is supplied as active power to the grid. The major portion of required reactive power exchange to the grid is done by means of thyristor switched capacitor (TSC) and thyristor switched reactor (TSR) to improve the generation capacity of the PV system. In the proposed topology inverter shares the minimum reactive power and large change in reactive power will be delivered/absorbed by the TSC-TSR to get smoother operation in reactive power control. The DC voltage controller and the AC current controller is discussed in brief. The mathematical analysis for grid synchronization method is presented in detail. The control algorithm for active power and reactive power is analyzed and discussed in the paper. The simulation results are shown for validating the proposed concept.

This paper presents the study of a new switched-inductor quasi-Z-source inverter topology (SL-QZSI) with high boost voltage. The proposed topology is derived from the old quasi-Z-source inverters by replacing of the input side inductor by two additional inductors and three diodes. This inverter has several advantages, such as, lower component ratings, a common ground with the dc source, reduced capacitors voltage stress, reduced inductors current stress, reduced diodes current stress and simplified control strategies. On the other side, the presented topology of the switched-inductor quasi-Z-source inverter allows to avoid the problem faced in the classical topology of quasi Z-source inverters caused by the inrush current at start-up, on the same time a wide range of voltage gain can be achieved to fulfil the applications which require a large gain range, especially for motor controllers and renewable energy systems. Theoretical analysis of the proposed topology voltage boost under the maximum constant boost control methods with third harmonics injection is investigated in this paper. Where, simulation results are presented to verify the proposed concept and the theoretical analysis.

Background/Objectives: This paper looks at the execution of Sinusoidal Pulse Width Modulation and Space Vector Pulse Width Modulation for a Quasi three phase Z-source inverter. Methods/Statistical Analysis: In this study, a Quasi Z-source inverter is an another method got from the customary Z-source inverter. The Quasi Z-source inverter acquires every one of the upsides of the Z- source inverter, which is used for buck/boost, conditioning power and reversal in a solitary step with an enhanced dependability. Findings: Likewise, the proposed Quasi Z-source inverter has the novel points of interest in a minimum part appraisals and steady dc current from the source. QZSI highlights an extensive variety of voltage addition which is applicable for photovoltaic system applications, due to the reason a photovoltaic cells yield differs broadly with temperature and sunlight based illumination. The working attributes of the proposed arrangement is examined in subtle element and contrasted with that of the SPWM and SVM. Hypothetical examination of voltage help and regulation techniques for the QZSI in PV is researched in this paper. Applications/Improvements: Recreation of the circuit setup for the mentioned balance techniques have been looked at in MATLAB/Simulation. Moreover, the THD investigation of both SPVM and SVM is checked.

In this paper, a Quasi Z-source Inverter (QZSI) drawn from Z Source Inverter (ZSI) is analysed and designed. Two different pwm control techniques i.e. simple boost pwm controlwith sine carrier and simple boost pwm control with triangular carrier are used for producing the pulses for quasi z-source inverter. It employs an impedance network which couples the renewable energy source (dc source or battery) and the inverter to achieve voltage boost and inversion. Hence it is used in grid connected PV systems. It is observed that sine pwm control gives more boosted voltage compared to triangular pwm control for same modulation index and the results are verified by using matlab/simulink.

One of the disadvantages of the charging systems and voltage regulation systems in alternative energy systems is that when the direct current (DC)/alternative current (AC) or AC/DC conversion is made from the energy source, the energy flow at 2w frequency between the direct current side and the alternative current side causes ripples in the DC, inductors, and capacitors. The ripples that occur in 2w frequency increase the harmonic distortion and reduce the efficiency in the photovoltaic energy system. For addressing this problem, different control methods are evaluated in this paper for the elimination of ripples that occur at 2w frequency, both on the perspective of DC control side and AC control side with a thorough comparative analysis with existing results in the literature. In the present study, the model of Single-Phase Quasi-Z Source (QZS) inverter and closed-loop control methods of the inverter are examined and compared with pulse width modulation (PWM) methods. In addition, the control methods are used to eliminate the ripples at 2w frequency in the use of inverters, and the advantages and disadvantages of these methods are presented.

The paper presents quasi z-source inverter (QZSI) as an alternate converter system for single phase wind generator. The QZSI inheriting all the advantages of traditional ZSI replaces the conventional PWM inverter in the system with some of its additional utilities. A closed loop controller is developed which monitors wind generator output and adjusts the inverter shoot-through duty cycle employing third harmonic injection constant boost control technique. The whole system is modeled, analysed and verified through simulation and hardware arrangement. The system can provide stable voltage through proper selection of boost factor. Dynamic and steady states of the proposed system are studied to find out the suitability of maintaining the terminal voltage at desired level for direct-driven wind power system.

Three-phase Quasi Z-Source Inverter (QZSI) provides a promising solution for single-stage transformerless grid-connected photovoltaic (PV) systems. In recent years, many PWM techniques with different shoot-through (ST) mechanism are proposed to improve the performance of the QZSI. However, these techniques generate a high common-mode voltage (CMV), which produces a leakage current flow through the parasitic capacitances between the PV panel and the grid. Due to the lack of galvanic isolation in transformerless PV systems, the leakage current becomes an even more pronounced problem. This current may lead to critical safety issues and other effects on the PV system. This paper introduces an analytical study of most of the presented PWM techniques for QZSI including three-leg ST and single-leg ST schemes in terms of the CMV characteristics. Consequently, a comparison that includes the CMV-RMS value, the CMV peak value, and the dv / dt transition is presented. Meanwhile, closed-form equations for the generated CMV-RMS values of all the analyzed PWM schemes are introduced. Moreover, the schemes with minimum CMV effect are identified using both analytical and simulation approaches.

The double closed loops control strategy composed of inner current loop and outer voltage loop in the d-q synchronous frame is a relatively common control strategy of the three-phase voltage-sourced PWM rectifier. The system can not be completely decoupled because of the variable inductance in the actual system. And for simple, the decoupled part of the controller is usually ignored. What's more, the equation of the outer voltage loop is nonlinear. According to the analysis of the model of the rectifier, a novel double closed loops control strategy composed of inner current loop in the complex vector and outer square of the voltage loop, is proposed. The inner current loop using the mentioned control strategy can be completely decoupled without the exact value of the boost inductance, and the equation of the outer square of the voltage loop is linear. From the results of the simulation, the mentioned control strategy can greatly improve the dynamic and static of the system.

This paper presents a new power interface applied in photovoltaic (PV) power generation system—quasi-Z source inverter (qZSI) with a battery. In this topology, a battery is directly connected with a capacitor of qZSI network for energy storage. First, the configuration of the new system is designed and its operating principle is analyzed. Owing to the battery, the generation system can generate the desired stable grid power even if the PV panel output energy varies. An energy management is proposed to control the system while taking into account battery safety. With the energy management, the system can regulate the power flow to secure the battery from over charging or over discharging. This study explores a whole control for the PV generation system, including Perturb and Observe (P&O) method for MPPT control of PV panel, the grid-injected power control, and energy management control for battery safety operating. Several cases are simulated in MATLAB to verify the proposed control strategies. The results demonstrate that the whole system can operate effectively and safely, due to the proposed energy management.