Inverter Switching Research Articles

Modular high frequency resonant inverters in constant power mode

ABSTRACT In this paper, a modular resonant inverter is proposed for high frequency industrial heating applications. To maintain a uniform heating profile, the inverter is operated in constant power mode. A hybrid voltage and frequency control is proposed. Voltage control is used for active power tracking while frequency control is used to minimise circulating current due to reactive power and to achieve soft switching for the inverter switches. Analytical and test results are shown to verify the proposed approach.

Research on Underwater Constant High-Voltage DC Switching Technology for MCSEM.

The marine controlled source electromagnetic (MCSEM) transmitter can transmit high currents near the seabed to detect the electrical structure of the seafloor. The use of three-phase alternating current (AC) transmission can lead to three-phase imbalance, which results in an excessive current in one phase's power line and affects the safety of the tow cable. This paper proposes an MCSEM underwater constant high-voltage direct-current (DC) switching scheme that replaces AC transmission with DC transmission. This scheme can fundamentally avoid three-phase imbalance and the AC loss caused by inductance. After establishing a simulation model to analyze the effect of the scheme, the relevant hardware units were designed. The hardware unit mainly consists of three parts: a DC switching inverter unit, a filter unit, and a step-down rectification unit. The DC inverter unit controls six insulated gate bipolar transistor (IGBT) modules with sinusoidal pulse width modulation (SPWM) signals to convert DC to three-phase AC power; the filter unit filters out extra harmonic components; and the step-down rectification unit converts high-voltage three-phase AC to low-voltage DC. The scheme ultimately achieved an adjustable DC output of 48.3-73.4 V under a constant DC input voltage of 3000 V and effectively reduced the current on the cable. This scheme has the potential to replace the previous AC transmission, reducing the risk of tow cable burnout and enhancing the safety of MCSEM operations.

A Noninvasive Sliding Mode Observer Based Approach for Detecting Open-Circuit Faults in HERIC Inverters

This article presents a new technique for detecting and localizing the open-circuit (OC) faults in the semiconductor switches of the Highly Efficient and Reliable Inverter Concept (HERIC) converter. It is a transformerless Photovoltaic (PV) inverter based on the full-bridge topology, with two extra switches on the AC side called ac bypass switches. The proposed method uses a sliding mode observer (SMO) to detect faults in the AC bypass switch and main switches of the full bridge inverter. To diagnose OC faults in the AC bypass leg, two parallel SMOs are created based on the converter’s state space model. Similarly, two SMOs are designed for the main switches. A residual is generated by combining the observed and measured grid currents to accurately locate the OC fault within the inverter system. To localize the faulty main switch, once the fault is detected the inverter is reconfigured and based on the grid current the faulty switch is identified. A major benefit of this method is that it does not rely on additional sensors for fault diagnosis, making the system more robust. The effectiveness and reliability of this approach are demonstrated through simulation studies. In addition, a laboratory prototype is developed to validate the practical applicability of the method.

High-Frequency Modified Bridgeless AC-DC PFC Rectifier for Ceiling-Fan

High current percentage total harmonics distortion (%THD), low supply power factor (SPF), and high input-power are main concern in an existing brushless direct current motor ceiling-fan (BLDCMCF). This paper presents AC-DC coupled-inductor-based bridgeless switched-inductor Cuk-converter (CIB-BLSICC) for BLDCMCF to address these concerns. CIB-BLSICC improves supply power quality (SPQ) and reduces input-power. Switched-inductor branch using coupled-inductor provides high-step-down-gain (HSDG), which offers an appropriate operating duty for BLSICC. Front-end CIB-BLSICC is developed in discontinuous mode (DCM) with changeable output voltage and a low component count, which reduces converter's overall size. DCM design offers auto power-factor correction (PFC) at a supply-mains. Variable output-voltage makes voltage source inverter (VSI) control easy (offers inverter switching at fundamental-frequency) with low switching-losses and helps speed-control. In addition to improving CF's (ceiling-fan's) overall efficiency, bridgeless design of PFC-converter lowers losses caused by conduction. Using reference speed of fan, CIB-BLSICC calculates its operational duty in order to create fixed-frequency PWM-pulses (200 kHz) while supply-voltage remains constant. This simple-control brings CF's price down by removing need for a sophisticated sensing-circuit, a DC-link sensor, and a voltage-controller. Test results confirm concept and design, which demonstrate a %THD of 1.483%, a crest-factor of 1.48, SPF of 0.9991, and a power-input of 27.93 W.

Acoustic Noise Mitigation in Slip Angle Controlled DTC of Open-End Winding Induction Motor Drive Using Dual Randomized AISPWM for EV Application

Low vibration and acoustical noise as well as effective DC link usage are the demands of industries and Electric Vehicles (EV). Direct Torque Control (DTC) of Induction Motors (IMs) meet the EV and other modern industry requirements. Still, flux as well as torque swings lead to higher acoustical noise. Consequently, EVs as well as working place noise have become major concerns, affecting the health of individuals. Efficiency of dc link use is improved by Space Vector Pulse Width Modulation (SVPWM). Yet, SVPWM is not efficient in lowering acoustical noise. Different RPWM techniques can lower acoustic noise. Still, the lower degree of randomisation makes the noise reduction difficult. This work presents a Hybrid Dual Random PWMs (HDRPWMs) based Alternate Inverter Switching (AIS) strategy for Slip-Angle Controlled Direct Torque Control of an Open End Winding IM Drive (OEWIMD). This technique is aimed to lower the acoustical noise for EVs. The intended PWMs seek to show how well HDRRPWMs distribute the acoustical noise spectra in contrast to conventional techniques.

Predictive direct power control of a grid connected photovoltaic system, associated with an active power filter

This paper deals with power quality improvement using a three-phase active power filter (APF) connected to a PV power system. This paper deals with power quality improvement using a three-phase active power filter (APF) connected to a PV power system. The DC-DC boost converter acting as an interface within the PV system and the three-phase voltage source inverter. A fuzzy logic maximum power point tracking (MPPT) controller is used to obtain the maximum power from the PV system. Furthermore, the optimal selection of the inverter switching states is realized by combination of direct power control (DPC) and a predictive method. Modelling and simulation of the system were performed by using Matlab/Simulink software.

ХАРАКТЕРИСТИКИ РЕЗОНАНСНИХ СИСТЕМ ДЛЯ ОТРИМАННЯ ВИСОКОЇ НАПРУГИ НА НАВАНТАЖЕННІ ЄМНІСНОГО ТИПУ

The work is devoted to the comparative analysis of currents in inverter circuits of transformerless resonant and transformer resonant and non-resonant systems of the same power for obtaining high voltage on a capacitive load. The purpose of the work is to determine the type of system characterized by the smallest average operating current of the inverter switches. The dependence of the currents in the circuits of the inverters on the parameters of the resonant circuits was obtained, the results of calculations according to which allow us to state that the use of a transformerless circuit to ensure the same power of systems for obtaining high voltage on a capacitive type load will allow to almost halve the average operating current in the inverter circuit. Simulation modeling of the processes in the studied schemes was carried out, which confirms the obtained theoretical results. The use of high-voltage transformerless resonant systems to obtain high voltage on a capacitive load will allow to halve the nominal and maximum permissible current characteristics of the power elements of the converters. Ref. 10, fig. 3.

Single‐stage single‐phase multiport DC–AC inverter suitable for standalone applications due to its notable performance in different operation modes

AbstractA new multiport DC–AC converter is proposed for standalone and off‐grid tied applications. The configuration converts power from DC to AC form in a single stage with suitable voltage gain. To increase the certainty of supporting power, the converter is designed to operate in four modes, including battery‐alone mode. The other advantage of the presented work is supplying the output power during unbalanced voltage conditions of the input ports. The advanced features of the converter for being used in standalone applications are related to the suitable placement and structure of the bidirectional port. In addition, the configuration is designed in a way to contain appropriate structural properties such as the existence of a common ground between the DC section and inverter, continuity of input currents, configured by an acceptable number of components, and low‐voltage stress on the DC–DC section's switches. Furthermore, it has an impedance network to protect the inverter's switches in a shoot‐through state. To confirm the converter advantages from the mentioned points of view, it has been compared with similar configurations. A prototype rated at 110 V is prepared to demonstrate the advantages of the converter performance per different conditions. The results of the steady‐state and transient experiments validate the suitability of the presented converter.

Investigation of Dead Time Losses in Inverter Switching Leg Operation: GaN FET vs. MOSFET Comparison

This paper investigates the commutation transients of MOSFET and GaN FET devices in motor drive applications during hard-switching and soft-switching commutations at dead time operation. This study compares the switching behaviors of MOSFETs and GaN FETs, focusing on their performance during dead time in inverter legs for voltage source inverters. Experimental tests at various phase current levels reveal distinct switching characteristics and energy dissipation patterns. A validated simulation model estimates the experimental energy exchanged and dissipated during switching transients. The results demonstrate that GaN FETs exhibit lower overall losses at shorter dead times compared to MOSFETs, despite higher reverse conduction voltage drops. The study provides a quantitative framework for selecting optimal dead times to minimize energy losses, enhancing the efficiency of GaN FET-based inverters in low-voltage motor drive applications. Finally, a dead time optimization strategy is proposed and described.

Reduce energy consumption - causes of CMOS inverter switching delay and its influencing factors

This paper offers a comprehensive examination of the Complementary Metal-Oxide-Semiconductor (CMOS) inverter, a quintessential component in contemporary digital integrated circuits, renowned for its minimal power consumption, robust noise resistance, and adaptability. The focus of this investigation is the switching delay of the CMOS inverter, a pivotal attribute that exerts substantial influence on the overall functionality of the circuitry. This discourse undertakes a detailed exploration of the factors contributing to the CMOS inverter switching delay, dissecting the influence of both intrinsic and extrinsic elements. Initially, the analysis delineates the origins of the switching delay in CMOS inverters, categorizing them into internal and external determinants. Subsequently, the study meticulously examines methodologies to modulate these factors, thereby achieving effective control over the delay. By implementing strategic optimizations, this research aims to diminish latency and enhance operational efficiency. Through a theoretical lens, this paper elucidates the complex interplay between these inherent and external factors, culminating in the optimization of the CMOS inverter switching delay. The insights garnered from this analysis are poised to offer a substantive theoretical foundation for the design of more efficient and reliable digital circuits in the current technological milieu.

An LCC-CS bilateral matching network for high efficiency energy conversion in high-frequency piezoelectric rotary ultrasonic machining system

The processing efficiency and machining quality of piezoelectric rotary ultrasonic machining (PRUM) system are closely related to its electromagnetic energy conversion units and electroacoustic energy conversion units. Generally, the high efficiency and high-power capacity of PRUM systems are limited by several energy conversion devices including the capacitive piezoelectric transducer (PT) load, loosely coupled rotating transformer (RT), and non-soft switching inverter. This article improves the overall performance of high-frequency PRUM system by bilateral matching network. On the rotating side, the compared results of five different static matching schemes show that the CS matching scheme ensures stable and efficient vibration of capacitive PTs even under incomplete matching. On the stationary side, a dynamic LCC matching scheme is adopted to keep the output impedance angle of H-bridge inverter in the weak inductive state. Finally, the proposed high-order matching network in this article makes the efficiency of high-frequency PRUM system over 90 % steadily.

A hybrid methodology based battery power management and torque control of open-end winding induction motor drive for electric vehicles

This paper proposes a hybrid strategy for an isolated battery-powered induction motor drive with two stages fed by an inverter and open-end winding, designed for electric vehicle applications. The hybrid approach, termed EOO-RERNN, combines the Eurasian Oystercatcher Optimizer (EOO) and Recalling Enhanced Neural Network methods. RERNN predicts the control pulses generated by EOO, which are utilized to control the voltage source inverter (VSI) switches. The system comprises dual motors, two battery packs (BPs), and VSIs supplying power to both the rear motor (RM) and front motor (FM). The primary objective of the EOO-RERNN technique is to regulate each DC-link's power share to maintain equilibrium in the electric vehicle's charge. Direct Torque Control (DTC) is employed due to its quick and precise torque response and tolerance for parameter variations. Proper tuning is required to control the state of charge battery level. The EOO-RERNN method is implemented in the Matrix Laboratory (MATLAB) platform, with performance contrasted to other methods such as Wild Horse Optimizer (WHO), Grasshopper Optimization Algorithm (GOA), and Heap-Based Optimizer (HBO). Simulation results indicate a motor speed of 4850 rpm for the EOO-RERNN method.

APPLICATION OF SOFT SWITCHING IN THREE-PHASE VOLTAGE INVERTERS OF TRACTIONAL ROLLING STOCK

Autonomous voltage inverters with PWM, which are used in electric drive systems with brushless motors, occupy an important place in the complex of electrical equipment of modern traction rolling stock of railways. The article presents the results of the research of the traction three-phase bridge voltage inverter with soft switching of power switches. Using the soft switching mode allows you to reduce the switching losses in the power transistors of the keys, increase the PWM frequency and improve other performance indicators of the converter. It is advisable to implement soft switching in the key transistors of the three-phase voltage inverter using soft switching nodes with fast-acting four-quadrant switches based on IGBT. It is proposed to consider the possibility of using transistor switches of a voltage inverter with capacitive non-dissipative snubbers at high PWM frequencies. For this purpose, a synthesis of the scheme and algorithm for the implementation of soft switching in a three-phase bridge voltage inverter with bipolar sinusoidal PWM with soft switching nodes with high-speed four-quadrant switches based on IGBT was performed. An analysis of the characteristics of the three-phase voltage inverter was carried out when using high-speed switches in the soft switching nodes to implement soft switching in the power transistors of the inverter switches.On the basis of the study, it is proposed to modernize the scheme of the soft switching unit in order to provide better preparation for the switching of the power transistors of the keys at large load currents. The improved soft switching unit includes low-voltage sources of constant voltage, which will compensate for energy losses in the recharging circuit of the snubber capacitors and contribute to the soft switching on of the power transistors of the voltage inverter keys. The performance test was carried out and the characteristics of the converter were analyzed when using a modernized soft switching node using simulation modeling in the MATLAB package.

A false trigger pulse elimination circuit for low-frequency energy harvesting active rectifiers

Abstract In this article, a false trigger pulse elimination circuit is proposed to be used for a low-frequency energy harvesting active rectifier. It is divided into two-stage circuits, each stage almost including a switching signal generation circuit, a switching inverter, and an inverter to eliminate false triggering pulses on the rising edge and falling edge respectively. There is an edge detection circuit in each switching signal generation circuit, generating a switching signal that controls the switching inverter’s on-off behavior. This allows the inverter to achieve inverter output voltage clamping by turning off its inverter function and turning it into a switch that is only turned on at the high or low level. At the same time, a thyristor delay element is used to determine and adjust the effective level time of the switching signal, which can reach over 150 μs, completely covering the rising or falling edge false trigger pulse so that no GΩ-level resistors are needed in the low-frequency field. The results show that the low-frequency false trigger pulse elimination circuit proposed in this article can better eliminate false trigger pulses on both rising and falling edges. It can also achieve on-chip integration, reduce the power consumption of the self-adaptive delay compensation loop, and enhance the stability of the circuit.

An energy efficient control method of a photovoltaic system using a new three-phase inverter with a reduced common mode voltage

This paper presents a new energy-efficient space vector pulse width modulation (SVPWM) for controlling the switches of a New three-phase inverter (NTPI) for photovoltaic (PV) applications to reduce switching losses, the peak value, and the dv/dt of the common mode voltage (CMV) with fewer number of switches. The proposed system offers a reliable operation in PV energy system with less leakage current and increased efficiency because of the reduction of the CMV, the source of leakage current in PV inverter-based application. Moreover, this also optimizes the operation of electric vehicle application with lower bearing failure. The performance of the proposed system with the new SVPWM is evaluated to the existing PWM in the literature, as well as the active zero state pulse width modulation (AZSPWM) of the two-level inverter introduced under identical conditions. Experiments and MATLAB simulations have both been used in this study.

P‐5: 27‐inch Ultra‐Narrow‐Border LCD with a Two‐Stage Output Gate Driver Circuit

A two‐stage output gate driver circuit with a clock‐controlled inverter is proposed and investigated. High and low voltage switching of inverter diminishes the positive bias stress of amorphous silicon TFTs in the circuit. The design of one cell with two‐stage output reduces the number of blocks in the gate driver circuit by half. This circuit was successfully developed for a 27‐inch LCD product with a 1.88 mm border.

Review of Three-Phase Soft Switching Inverters and Challenges for Motor Drives

Review of Three-Phase Soft Switching Inverters and Challenges for Motor Drives

Solar Photo Voltaic Connected Quasi Z Source Inverter for Grid and utility Application

This paper discusses the use of quasi-Z-source inverters, in utility grid systems. These inverters enhanced dependability and one-stage buck and boost abilities make them appropriate for photovoltaic power conditioning applications. The small signal sate space method utilized for the proposed system using Quasi ZSI for utility and grid integration application. Shoot through state also implemented on dc side to enhanced the voltage gain. The Controlling of dc side and ac side also implemented in MATLAB using state space transfer function. A two-stage controlling technique implemented on two level 6 switch inverters with SPWM with P & O MPPT and PI controller. The proposed system has solar PV array rating of 5.5kW and utilized in distribution purpose. A simple boost controlling technique has been implemented to obtained the desired gain and less ripples are present in the current due to the presence of inductor in the QZSI impedance network. During light loading the surplus power injected to the grid with the help of PLL system and when load demand increases the power take from the grid smoothly without loss of synchronism. The system has better stability and fast dynamic response during transient. The THD has been observed at the inverter and load side with LC filter, THD within the permissible limit as per IEEE std 1547.

A Switched Z-Source and Switched Capacitor Multi-Level Inverter Integrated Low Voltage Renewable Source for Grid Connected Application

Most of the renewable sources generate power at lower voltage levels in the range of 20-50V which cannot be utilized by the loads. Therefore, stacking multiple modules in series increases the voltage level or using conventional boost converter or QZSis helpful. However, due to series stacking and boost converter or QZS there is a great power loss and also have reliability issues.The QZS inverter has very less boosting gain in the range of 2times. Theconventional boost converter or QZSis replaced with SZSC for voltage boosting and inverter operation. The SZSC boosts the voltage 4-5 times to the input voltage level. For further mitigation of harmonics, the conventional 6-switch inverter is replaced with switched capacitor MLI. Multiple renewable sources are at the input which include PV array, battery unit and PMSG wind module. The battery unit is a support to the renewable sources PV array and wind module. The DC link voltage stability is achieved by the battery unit placed in parallel to the renewable sources. The renewable sources share power to the grid through the SZSC and switched capacitor MLI. For DC voltage stability a CV control is integrated to SZSC. And for synchronized power sharing to the grid, a grid voltage feedback synchronization control is included for the control of MLI. A low rating renewable system is modelled and integrated to grid using Simulink MATLAB software. A comparative analysis is carried out operating the system with QZS and SZSC. The performances of the SZSC and MLI are evaluated by the graphs generated by the simulation of the modelled system.

Analysis and control of split-source current-type inverter for grid-connected applications

Current source inverters (CSIs) have been widely used for renewable energy sources integration with the utility grid. However, traditional CSIs provide only voltage-boost power conversion, which can be considered a limitation for grid-interfacing applications when consistent tracking of a widely varying input voltage is necessary. Hence, an additional front-end converter is usually utilized in an attempt to step down the input source voltage. Nevertheless, adding the dc-dc bucking stage would reduce the system reliability and its overall efficiency, increase the converter cost, and complicate the control scheme. In order to address the aforementioned shortcomings, this paper proposes a novel three-phase single-stage inverter, suitable for low-power applications, called split-source current-type inverter (SSCTI). The proposed converter can achieve high current boosting capability with lower component count and high-quality output current in comparison with other single-stage topologies. In addition, it utilizes the conventional modulation scheme of the CSI, while maintaining low current stresses on the inverter switches. Comprehensive analysis, modelling, and closed-loop control scheme of the proposed converter are developed. Also, a comparison between the proposed topology and several single-stage topologies is carried out. Moreover, an experimental prototype is built to validate the proposed converter analysis under steady-state operation and different transient scenarios.