Voltage Source Inverter System Research Articles

Comparative Analysis of Single Stage and Dual Stage PV Based Generation System for Pollution Reduction in Asian Nations

The growing need for sustainable and clean energy solutions has elevated photovoltaic (PV) systems to the forefront of competitive options. In order to evaluate the performance and viability of single-stage and dual-stage single-phase PV voltage source inverter systems within the context of renewable energy, this study undertakes a thorough comparative analysis. MATLAB Simulink has been used to run the simulations, and the results produced show that the selected configurations are robust and closely match theoretical expectations. The study explores the subtle distinctions, benefits, and drawbacks that come with single- and dual-stage systems. By extensively evaluating the consequences on system stability, grid synchronisation, and power quality, useful insights emerge. The simplicity and efficiency of the single-stage system are demonstrated by the direct connectivity between the PV MPPT output and the inverter. In contrast, the dual-stage system addresses the issue of low PV output voltage by incorporating a boost converter with an MPPT algorithm, albeit at the expense of more parts and complexity. The research described here adds a great deal to the current discussion on PV system optimization. The study notably clarifies methods for improving dependability and efficiency in applications involving renewable energy. With the increasing worldwide trend towards sustainable energy, it is critical to comprehend the subtle dynamics of various PV setups. In addition to offering a comprehensive grasp of the complexities involved in single- and dual-stage single-phase PV voltage source inverter systems, this research paves the way for future developments in the planning and execution of effective renewable energy solutions especially for Asian nations that still rely on coal-based power plants. Increased contribution of solar based electricity generation will lead to a significant drop in pollution contributed by the ash and gases released by thermal power plants that employ fossil fuels. The ultimate goal of this study is to provide information to stakeholders in the renewable energy industry so that they may make more informed decisions and create PV systems that are both sustainable for the environment and efficient for the utility.

A Novel Hybrid Pulse Train Control Strategy to Mitigate Voltage Unbalance Rate in Stand-Alone Four-Leg Voltage Source Inverter System

A Novel Hybrid Pulse Train Control Strategy to Mitigate Voltage Unbalance Rate in Stand-Alone Four-Leg Voltage Source Inverter System

Modulated Model-Free Predictive Current Control for Voltage Source Inverters With Stagnation Elimination and Sampling Disturbance Suppression

Model-free predictive current control (MFPCC) has been widely used in voltage source inverters (VSIs). The output current performance of look-up-table-based MFPCC is affected by the number of the applied voltage vectors (VVs), the current gradient updating and the sampling disturbance. To improve the current performance, a novel modulated MFPCC is proposed for VSI, while real-time current gradient updating and sampling disturbance suppression can be achieved. First, three basic VVs are picked, whose duration time are computed according to the current gradients. Second, an advanced current gradient updating method is presented by establishing the equations of different current gradients under different VVs. Furthermore, the sampling disturbance effect on MFPCC is analyzed and an extended state observer is designed to suppress such effect. Simulation model and experimental platform of the VSI system are structured to verify the preponderance of the proposed MFPCC in reducing the total harmonic distortion of output current.

Stability Analysis and Controller Synthesis

As the application market of voltage source inverters is consistently expanding, new control technologies are also being explored. This article presents a novel PIR controller using the conventional controller as a point of comparison and validated by tests conducted in MATLAB, the results of which led to the conclusion that the PIR controller has superior performance when compared with the traditional PI controller, R controller, and PR controller. These controllers are tested on a voltage source inverter system. In contrast to the conventional controller, the PIR controller demonstrates extra control flexibility through the Bode diagram and offers enhanced steady-state tracking capability. The analysis and comparison show that the PI controller does not have good dynamic tracking performance and cannot suppress the unbalance of secondary AC pulsation. The new control approach suggested in this paper may be implemented in the system to improve the system’s stability and dependability, increase the smoothness of the overall output, and assure the quality of the output.

An FPGA Hardware-in-the-Loop Approach for Comprehensive Analysis and Development of Grid-Connected VSI System

Power electronic converters are used for an efficient and controlled conversion of power generated from renewable energy sources and can interface generated power to the grid. Among available power converters, voltage source inverters (VSIs) have been widely employed for grid-connected applications due to better controllability with higher efficiency. Although various conventional, as well as modern control techniques, have been developed for grid connected VSI system, there is a need to select suitable control technique based on application and control requirements. Hardware-in-the-loop (HIL) is considered as a realistic approach for the development of system and control due to the inclusion of an actual hardware system. In this paper, a HIL approach is adopted for the comprehensive analysis and development of a grid connected VSI system using a field programmable gate array (FPGA). The control techniques must deal with trade-off, based on the features and limitations. Therefore, a grid-connected VSI system is developed considering employment of two different conventional control techniques: hysteresis current control (HCC) and PI-based space vector modulation (PI-SVM), as well as finite state model predictive control (FS-MPC) as a modern control technique for investigation considering different parameters. All three control systems are developed through a digital simulator of Xilinx that is integrated with MATLAB-Simulink, while considering an FPGA based system development and testing through FPGA HIL co-simulation methodology.

Selection of PWM Methods for Common-Mode Voltage and DC-Link Capacitor Current Reduction of Three-Phase VSI

This paper evaluates several important pulse-width modulation (PWM) methods developed to reduce the common-mode voltage (CMV) or DC-link capacitor current (DCC) of two-level three-phase voltage source inverter (VSI) in motor drive applications. In addition, a PWM selection criterion is introduced to properly utilize these advanced PWM methods in the VSI system. In the motor drive systems, the high CMV generates the large common-mode current, which may cause electromagnetic emissions and motor damages. Also, the large DCC may have an adverse effect on the life expectancy and increase the volume of DC-link capacitor. Therefore, reducing the CMV and DCC is required in modern VSI systems. So far, various PWM methods have been studied to reduce these CMV and DCC. However, they need to be fairly compared and evaluated together under the same condition to provide information so that power electronics engineers can select the appropriate PWM method when designing their motor drive systems. In this paper, the principle of these PWM methods is reviewed and their performance is analytically evaluated. Then, the PWM selection criterion is described based on the comprehensive evaluation studies. Lastly, the simulation and experimental results with an interior permanent magnet synchronous motor (IPMSM) drive system are presented to validate the presented PWM selection criterion.

Neural Network-Based Optimisation of Sinusoidal PWM Controller for VSI-Driven BLDC Motor

Abstract Although increasing the number of switches increases the switch losses, most designed controllers focus on controlling an inverter circuit with more than six switches. The paper aims to address this issue that arises in implementation of the voltage source inverter (VSI) for brushless DC (BLDC) motors. It optimises the sinusoidal pulse width modulation (PWM) controller, minimising total harmonic distortion (THD) while keeping the VSI’s circuit at six switches to avoid increased switching losses. This was achieved by applying an artificial neural network (ANN) to generate a signal, which combines with the already existing reference and carrier signals. The addition of the new signal to the existing signals contributed to generating more pulses compared with the conventional sinusoidal PWM. Simulink was used to design the system and analyse its performance with the conventional and neutral point clamped (NPC) VSI systems. Results indicated that the proposed system performs better when controlled with an LCC filter. Compared with the control experiments, its output waveform has the lowest THD value, which is 6.04%. The switching losses of all the systems were also computed. Results from the computation indicated that the proposed system is capable of reducing the switching losses by 0.6 kW compared with the NPC VSI brushless DC motor (BLDCM) system. BLDCM speed was tested across various conditions; the results are reported in Section 5.

A resonant damping control and analysis for LCL-type grid-connected inverter

The inverter becomes an essential part in the distributed energy units, where an inductor–capacitor–inductor (LCL) filter is an up-to-date adoption for grid interfacing. However, the challenging issue of resonance related to the LCL-filter worsens the dynamic control characteristics and produces stability threat for the voltage source inverter system. The proper design of inverter control plays a substantial part in ensuring a steady state operation and a high quality of grid injected current according to grid connection codes. This paper offers a different design method of inverter control which alters the inner damping loop structure to enhance the damping and stability features of the inverter system. In the proposed solution, a modified compensator is employed through the LCL filter network and filter capacitor current feedback loop, the resultant augmented plant’s output is then sent back at the reference point of a grid-connected inverter system to damp the unwanted resonance spike. This particular arrangement to form a damping loop is termed as parallel feedforward compensation. The damping loop is implemented by calculating the filter capacitor current, and a first order high-pass filter is employed as a damper in the suggested arrangement. Moreover, for comparative studies and analysis, the conventional filter capacitor current feedback active damping method is selected. In addition, the stability margins and control performance of the open current loop are examined under different filter parameters values. The substantial results of the suggested structure are quicker dynamic response, comparatively improved resonance damping, better tracking performance and higher delay compensation capability. A laboratory prototype is established to confirm the effectiveness of the suggested scheme on the bases of control performance and stability margins.

Dual‐sliding mode control of nine‐switch inverter

This work introduces a novel dual-sliding mode control approach for nine-switch inverter topology. The nine-switch inverter helps regulate multiple ac-loads by using fewer semiconductor devices than the conventional two parallel voltage source inverter system. However, achieving independent control of two sets of ac loads is not a straightforward task when a nine-switch inverter feeds separate load stages. Regarding this consideration, a dual-sliding mode controller that includes a specific decision-making algorithm can be an efficient solution for a multi-load control problem. The proposed strategy offers a good compensation performance for the unconnected load stage under different load utilization profiles. The designed closed-loop system has a rapid response to sudden load change, and no unwanted interaction between individual load stages is observed. The detailed design steps and performance analyses are reported. Experimental results demonstrate the capability and usefulness of the proposed control strategy.

Model‐based control of four‐leg inverter for UPS applications considering the effect of neutral line inductor

A control approach for three-phase four-leg LC-filtered voltage source inverters (VSIs) is proposed for an uninterruptible power supply (UPS) application. A filter inductor in the fourth (neutral) leg of the VSI is considered to enhance the output voltage quality when feeding different types of loads in such a system. The proposed approach is based on the modelling of UPS VSI system in the dq0 synchronous frame. First, the switching functions of the inverter under study are extracted from the achieved system model. Afterward, the control approach is developed by introducing a virtual time constant, which simultaneously affects the system's damping ratio, and a virtual undamped natural frequency in the switching functions. It offers flexibility for improving the system dynamic and steady-state responses as desired. While the final time constant decreases the transient response time and overshoot, the resulting undamped natural frequency leads to alleviation of steady-state error in the output voltage. The performance of the proposed control approach is evaluated via SIMULINK-based and real-time simulation results.

Implementation of four dimensional space vector modulation for five phase voltage source inverter

In this paper, a Four Dimensional Space Vector Modulation (4D-SVM) is implemented for five phase Voltage Source Inverter (VSI) to improve the performance of the inverter. The 4D-SVM control technique generates switching pulses for five phase VSI system. The reference vector for 4D-SVM is identified by tracking subcubes and prisms located in the complex 4D-cubic region. The 4D-SVM for five phase inverter includes 32 switching state vectors; all the switching states are non-redundant switching states, which are located in 32 vertices of the 4D-cube. The proposed five phase inverter with 4D-SVM reduces CMV and Total Harmonic Distortion (THD) and minimized neutral current value. The minimization of CMV leads to avoid the damage of the winding and increases the life time of the motor. So for in two level inverter, the CMV is reduced up to V dc /3 times of input voltage; In this proposed system, made an attempt to reduce the CMV level below this reported value. The simulation and hardware results are verified using matlab simulink and Field Programmable Gate Array (FPGA) processor.

Observer-based adaptive threshold diagnosis method for open-switch faults of voltage source inverters

In this paper, the problem of open-switch faults of a voltage source inverter system is investigated. A new fault diagnosis method based on an observer and an adaptive threshold is proposed. This method only needs to utilize the signals existing in a system without the need for extra hardware circuits. First, an observer is designed on a model of a three-phase voltage source inverter system to estimate currents. Then, an adaptive threshold is designed on fault residuals, dynamics of the currents and variations of the system operating state. Moreover, the dead time and switching delay time are also included in the threshold to consider practical applications. Furthermore, to achieve on-line real-time diagnosis and to improve the reliability of the proposed method, the averages of the current residuals in a current fundamental period are defined as diagnostic variables. Finally, the reliability and effectiveness of the proposed method are verified by simulation and experiment results.

Implementation Strategy for Resource Optimization of FPGA-Based Adaptive Finite Control Set-MPC Using XSG for a VSI System

Finite control set-model predictive control (FCS-MPC) for the power electronic systems has been implemented using the field-programmable gate array (FPGA), considering an alternative solution to handle the computational burden of the control algorithm. However, FPGA resource utilization is a concern for optimum design and development of the FCS-MPC. This article presents analytical approach-based implementation strategies using the Xilinx system generator (XSG), considering the real-time operation of the FCS-MPC for a three-phase voltage source inverter (VSI). Moreover, an adaptive prediction model is proposed to adapt to the change in the load current. The percentage total harmonic distortion (THD), dynamic response, and steady-state error are evaluated for system-performance analysis. The implementation strategies are compared based on FPGA resource utilization for the FCS-MPC in the stationary αβ- and rotating dq-frames considering the fixed, approximated, and adaptive values of a coefficient used for current prediction. The lookup tables (LUTs), flip-flops, and digital signal processor (DSP) slices have been opted as the utilization indices of the FPGA resources for comparative analysis. The optimum design-based controller model is used for FPGA-based experimental system implementation. The simulation and experimental results are used for the performance evaluation of the FCS-MPC in both αβ- and dq -frames. Moreover, change in the switching-state constraint is included in the cost function and controller performance is evaluated corresponding to the weighting factor for the approximated and adaptive coefficient values.

Impedance-Based Analysis of Digital Control Delay in Grid-Tied Voltage Source Inverters

Digital control delay is studied as one of the leading factors causing instability in grid-tied voltage source inverter (VSI) systems. However, how this delay affects the small-signal output impedance of the VSI and how the change in impedance shape further influences the system stability are still not clear. This article, for the first time, thoroughly analyzes the impact of delay on the dq-frame output impedance of the VSI operating in both the single current loop control mode and the dual-loop control mode. It is found that when delay is considered, a distinct magnitude drop and a phase rise always exist at the high-frequency area of the impedance, which is named the “impedance trough.” By studying the dq-frame output impedance of the VSI, the origin of the impedance trough, and its analytical relationships with the current loop dynamics, voltage loop dynamics, and delay values are unveiled. Meanwhile, the influence of the impedance trough on the stability of the grid-tied VSI system under these two control modes is evaluated through d-d channel impedance matching and generalized Nyquist criterion (GNC). It is demonstrated that the joint effects of delay and control parameters result in the impedance mismatch between the grid and the VSI, which is the root cause of high-frequency oscillations in the grid-tied system. Finally, experimental results verify the analysis.

PI-PD Denetleyicisi ile Fotovoltaik ve Rüzgar Türbini Entegre Bina Sisteminde Gerilim Kontrolü

With the gradual decline in fossil fuels, the area of interest for electric power generation has shifted to wind turbines and other sources of DC electricity such as PV (photovoltaic). Since the voltage output values of these sources vary over a wide range, DC/AC inverters should be used which give an increased constant output voltage and well controlled output voltage. In residential buildings that meet the energy need from non-continuous renewable energy sources such as solar panels and wind turbines, it is very important to ensure constant quality power flow to the building, especially when energy demand varies sharply. In this study, it is aimed to control the voltage consumed in the houses by controlling the three phase PWM (pulses width modulation) voltage source inverter system (VSI) with PI-PD controller in the integrated smart building system of renewable energy sources (solar panel and wind turbine). First the building integrated solar and wind systems (BIPv/Wt-Building Integrated PV Panel and Wind Turbine) design, then the controller design and the simulation of the system have been made at this research. After obtaining the transfer function of the BIPv/Wt system, the parameters of the PI-PD controller were calculated using the frequency response analysis method. In the BIPv/Wt system, we used PI-PD, integer order PI and fractional order PI control structures to control the closed voltage control loop in the DC/AC inverter system used to control the voltage used in the building. In order to compare the voltages of the control structures on the voltage used in the building, we installed our system on the Matlab / Simulink platform and performed simulations for two test scenarios. Depending on the phase voltages plotting the simulation results and the harmonic values measured, it is seen that using PI-PD control has more positive results for the systems showing the energy demand for the day such as building systems.

Dual Motor Control using Double Zero Sequence Injection Method in Five Leg Voltage Source Inverter

This paper presents in to Dual Motor Control using double zero sequence injection method in 5- leg voltage source inverter. As industry looking for reducing the semiconductor switching devices, like IGBT/MOSFET’s in dual induction motor control. The main reason behind reducing the switching elements to reduce the weight, cost and size of the components. As conventional inverter require six inverter legs to control two induction motors. In this proposed work five inverter legs used instead of six legs in dual motor control. With this reduced one leg, two switching devices will be reduced and one phase of the inverter leg is common between the two motors, so called five leg inverter (FLI). The main switching methodology used for inverter control is Carrier based Double Zero Sequence Injection Method (DZSM). This Double Zero Sequence Injection Method applied to FLI system is having the one common leg. One of the C Phase modulation signal added to other modulating signals of all phases of other motor respectively. A subsequent each phase degree of freedom is represented by the zero-sequence signal. This paper investigates the independent speed control of dual induction motors at different speeds connected to five leg voltage source inverter system, using MATLAB/SIMULINK Software.

FPGA-Based Implementation of Finite Set-MPC for a VSI System Using XSG-Based Modeling

Finite set-model predictive control (FS-MPC) is used for power converters and drives having unique advantages as compared to the conventional control strategies. However, the computational burden of the FS-MPC is a primary concern for real-time implementation. Field programmable gate array (FPGA) is an alternative and exciting solution for real-time implementation because of the parallel processing capability, as well as, discrete nature of the hardware platform. Nevertheless, FPGA is capable of handling the computational requirements for the FS-MPC implementation, however, the system development involves multiple steps that lead to the time-consuming debugging process. Moreover, specific hardware coding skill makes it more complex corresponding to an increase in system complexity that leads to a tedious task for system development. This paper presents an FPGA-based experimental implementation of FS-MPC using the system modeling approach. Furthermore, a comparative analysis of FS-MPC in stationary αβ and rotating dq frame is considered for simulation as well as experimental result. The FS-MPC for a three-phase voltage source inverter (VSI) system is developed in a realistic digital simulator integrated with MATLAB-Simulink. The simulated controller model is further used for experimental system implementation and validation using Xilinx FPGA: Zedboard Zynq Evaluation and Development Kit. The digital simulator termed as Xilinx system generator (XSG) provided by Xilinx is used for modeling-based FPGA design.

High-Accuracy Capacitance Monitoring of DC-Link Capacitor in VSI Systems by LC Resonance

Monitoring the condition of a dc-link capacitor is important for the reliability-critical voltage source inverter (VSI) systems. With the ever increasing application of a metalized poly propylene film (MPPF) capacitor, a new challenge for dc-link capacitor condition monitoring (CM) is presented due to the very small equivalent series resistance and capacitance end-of-life criterion (typically 2%–5%) of an MPPF capacitor. To improve the accuracy of capacitance estimation, a novel quasi-online CM method is proposed in this paper, which introduces an LC resonance intentionally when system is not in operation. Experimental work is carried out to validate the method and the results show that 1% capacitance estimation accuracy can be achieved in a 3-kW induction machine variable frequency drive system. Because of the signal measurement at large amplitude (e.g., nominal current) and the time-based multi-parameters identification algorithm, the method is accurate and inherently insensitive to the system parameters variation, measurement noise, and effect of temperature drift. In practice, the method can be implemented using the system available sensors with no need of hardware modification. Moreover, since the resonance current is limited and decays shortly, the condition of a dc-link capacitor can be monitored safely and frequently on-site in a VSI system.

Development and Modelling of Three Phase Inverter for Harmonic Improvement using Sinusoidal Pulse Width Modulation (SPWM) Control Technique

This paper describes the design of a 400 V, three-phase voltage source inverter system using Sinusoidal Pulse Width Modulation (SPWM) control technique. Pulse Width Modulation (PWM) is an internal control technique for inverters. The Sinusoidal Pulse Width Modulation (SPWM) technique is the type of PWM used in this work. The aim is to reduce the harmonic produced by the inverter. Current standards require that total harmonic distortion (THD) be minimal. A three-phase SPWM signal is implemented in order to create an output voltage which is closer to a true sine wave and reduce harmonics. The development and model were implemented using MATLAB Simulink soft-ware and hardware parameters. The addition of a low pass filter circuit aids the achievement of smoother sine waveforms and a reduced THD value of 0.17%. The proposed concept has been validated through experimentally on a laboratory prototype by using DSP TMS320F28335 real-time digital control. The experimental outcomes emphasize the authenticity of the suggested technique in reducing harmonics, which can be promising to power quality improvement.

Design and Development of Three-Phase Voltage Source Inverter for Variable Frequency Drive

Three phase induction motors are the workhorse of industry. Variable speed operation of the motor enables substantial energy savings through implementation of variable frequency drives. This project concerns on the design and implementation of three-phase voltage source inverter (VSI) for variable frequency drive. The focus was to generate variable frequency output suitable to be fed to the induction motor for the purpose of variable speed control. SPWM signal was generated through SIMULINK algorithm. The VSI circuit was designed, fed with SPWM trigger signal and simulated for variable frequency output in terms of line-to-neutral and line-to-line voltage across R-L load. In the experimental setup, the real VSI system was developed, the SPWM trigger signal generated through SIMULINK and interfaced to hardware using Arduino microcontroller. The output is dropped across resistive load and parameters line-to-neutral and line-to-line voltage was measured. Three set of output voltage with frequency of generated at 20Hz, 50Hz and 70Hz. Thus, experimental result validated that variation of frequency of voltage output of the VSI has been successfully achieved.