Inverter Power Supply Research Articles

Influence of Power Supply Energy Characteristics upon the Stability of MMA Process

The paper provides the results of experimental study of how the technological characteristics (amount of spatter, stability of the welding process) of manual metal arc welding (MMA) depend upon power supplies providing various kinds of energetic impact upon the electrode metal (inverter power supply, diode rectifier). It was established that inverter power supplies (as they reduce peak loading) provide better quality of welds (more stable process, lower amount of spatter) and this reduces the fabrication cost due to the reduction of deseaming operations, lower welding material consumption as well as improving the service reliability of the welding constructions.

Development of Voltage Regulation Plan by Composing Subsystem with the SFES for DC On-line Electric Vehicle

The study of the application process of the relatively small size ‘Superconducting Flywheel Energy Storage (SFES)’ system is conducted to regulate voltage fluctuation of the DC On-Line Electric Vehicle (OLEV) system, which is designed by using DC power system network. It is recommended to construct the power conversion system nearby the substation because the charging system is under the low voltage. But as the system is usually built around urban area and it makes hard to construct the subsystems at every station, voltage drop can occur in power supply inverter that is some distance from the substation. As the alternative of this issue, DC distribution system is recently introduced and has possibility to solve the above issue. In this paper, SFES is introduced to solve the voltage drop under the low voltage distribution system by using the concept of the proposed DC OLEV which results in building the longer distance power supply system. The simulation to design the SFES by using DC power flow analysis is carried out and it is verified in this paper.

High-power, low-pressure, inductively coupled RF plasma source using a FET-based inverter power supply

A high-density plasma of density greater than 1019 m−3 is successfully produced in 1.5 Pa argon by an inductively coupled RF discharge with a 70-mm-diameter source cavity, where a 10-turn water-cooled RF loop antenna is wound onto the source tube and an axial magnetic field of ∼70 G is applied by two solenoids to reduce plasma loss onto the source cavity. The RF antenna is powered from a frequency-tunable field-effect-transistor-based inverter power supply, which does not require variable capacitors to match the impedance, at a frequency of ∼350 kHz and the RF power can be increased up to ∼8 kW. It is also demonstrated that the source is operational with an axial magnetic field provided by permanent magnet (PM) arrays; then the density in the case of the PM arrays is higher than that in the case of the solenoids. The role of the magnetic filter downstream of the source tube is demonstrated; a radially uniform plasma density exceeding 1018 m−3 and an electron temperature of ∼1–2 eV are obtained at ∼100 mm downstream of the open exit of the source tube.

150kV/30kW inverter for electron beam welding power supply design

150kV/30kW inverter for electron beam welding power supply design

Short-Circuit Current Calculation of a Power System with a Grid-Connected Inverter

This paper analyzes the difference between conventional power supply and inverter power supply short circuit characteristics, pointing out that the short circuit current does not contain transient DC component. The inverter power supply can be regarded as AC current source with sudden change of current at moment of short-circuit to calculate the current periodic component. The method to calculate the short circuit current of power grid with both conventional rotating generator and inverter power supply is proposed and evaluated.

Maximization of the working domain of an Atmospheric Pressure Townsend Discharge (APTD) using a current-source static converter

The objective of this paper is to present the implementation of a square- wave current inverter power supply, and to describe its effect on the working domain of an Atmospheric Pressure Townsend Discharge (ATPD) in nitrogen. The results show that it allows a substantial increase of the percentage of time during which the discharge is ON (on-time) and therefore of the power delivered to the discharge, reaching almost 10 W/cm2 in pure nitrogen. Moreover, the increase of the on-time of the discharge implies a decrease of the extinction off-time between two discharges, and thus an increase of the memory effect from one discharge to the following one, as it is monitored by using electrical and optical measurements. This leads to a larger working domain of the ATPD, even when adding impurities in nitrogen.

A Control Strategy for Inverter Type High Voltage Power Supply for NBI

An inverter type high voltage power supply has been designed for the acceleration of ITER NBI system. This type of power supply can regulate the output voltage rapidly by the duty cycle modulation of the inverter switches. However, when the duty cycle is too small, the output ripple will be lager. This paper studies a new control strategy of the power supply, the output voltage is regulated by inverter duty cycle, also by adjusting the DC-link voltage. The front rectifier of this power supply is constructed by thyristor bridges, while the inverter is a three phase three level inverter. Control system for this power supply is designed in this paper. Simulation results is given, and the results demonstrate that the topology and control strategy can limit the voltage ripple while maintain the rapid voltage response.

Alternative Technique of Inverter Power Source Synchronization

In devices synchronized with electric mains and sensitive to interference (particularly to an inverter power source) it is expedient to also synchronize the power source. The paper describes a method of synchronizing the inverter power supply with the mains. The general aspects of the method are discussed in detail, and possible hardware implementations are considered. External factors and internal parameters affecting the quality of synchronization are analyzed. The results of practical implementation of this method for synchronization of klystron filament power supply are presented

Stable V/F Control of Open Winding Surface Mounted Permanent Magnet Synchronous Motor Drives with SPWM Strategy

This paper presents dual inverter power supply open-end winding of surface mounted permanent magnet synchronous motor (OW-SPMSM) drive system for fans and pumps energy saving by V/f control. On the principle of OW-SPMSM drive system, this paper puts forward a unified Sine wave pulse width modulation strategy (SPWM) of dual inverter, which is easy to real time implementation for the calculation of this method is less than SVPWM, its performance is as good as the SVPWM in terms of harmonic power balance. Accordingly, a power factor closed loop control was introduced into the drive system to achieve stable volts/hertz (V/F) control. The system simulation model was investigated in detail; its results show that the proposed drive system has greatly improved the system dynamic performance.

Design of Sine Wave Inverter Power Supply Based on STM32

The paper design a high performance 20KW grid inverter based on STM processor, and describes the overall structure of the inverter, and design the hardware circuit and the software design scheme; finally produce the prototype and test. The experimental results show that: in the condition of rated power inverter can stabilize output valid values of 220V 3%, frequency is sine wave AC 50HZ, output voltage has small harmonic content and high reliability, and has a good application prospect in the field of photovoltaic power generation.

Investigating the Influence of the Power Supply Type upon the Properties of the Weld Joints under Manual Arc Welding

The given work considers the influence of the power supply type (diode rectifier DR-306 and inverter Nebula-315) upon the chemical composition, microstructure, mechanical properties of weld joints and upon health characteristics of the manual arc welding process.It has been ascertained that the power supply type has a significant influence upon the weld joints properties and health characteristics of the manual arc welding process. Using a new generation inverter power supply allows less heat input into the weld bead, thus, decreasing silicium and manganese burning, improving impact resistance of weld joints under low (negative) temperature and reduces the risk of respiratory diseases for the workers.

Integrated Models of a Gas Metal ARC Welding Process and Inverter based Power Supply for Process Control Simulation Studies

The objective in this paper was to combine the simulation of a Gas Metal Arc Welding (GMAW) process model with the simulation model of an inverter-based power machine. The GMAW process was considered as an electrical circuit and the mathematical model was based on physical descriptions of several parts of the GMAW process, as were the electric circuit of the power supply, the arc dynamics, and the electrode melting process. A simple welding application was simulated and the welding parameters were derived from several experimental conditions. Next, the dynamic behaviour of a full-bridge DC-DC converter was simulated and a suitable discrete PI controller proposed for welding current feedback control. Both models, the GMAW model and the inverter power supply model, were combined into a new simulation model of the GMAW process application together with an inverter based welding machine. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8016

Design and implementation of a discrete‐time H ‐infinity controller for uninterruptible power supply systems

This study provides a digital ℋ ∞ controller design suitable for uninterruptible power supply inverters, yielding results that comply with the IEC 62040-3 Standard. An augmented state space model for the system is given, taking into account the delay from the digital implementation of the control signal, and resonant controllers that ensure asymptotic tracking of the reference and good rejection of load disturbances. It is shown a case where an ℋ ∞ optimal state feedback controller cannot provide good results because of the high control gains. To solve this problem, an ℋ ∞ suboptimal controller is proposed, taking into account a prescribed bound for the ℋ ∞ norm of the closed-loop system and a parameter for limitation of the norm of the control gain vector. This suboptimal controller provides gains that lead to suitable results, complying with the constraints from the IEC 62040-3 Standard. These results are compared with those from a widely used state feedback controller, providing superior performance, even with a much simpler design procedure. Simulation and experimental results have a good correspondence. Finally, the study illustrates that the ℋ ∞ norm of the closed-loop system can be seen as the output impedance over the frequency. From this information, using the small gain theorem, one can get the admittance value of the linear loads that preserve stability when connected to the uninterruptible power supply.

Simulation of voltage doubling rectifying circuit in 150 kV high-voltage inverter power supply

Simulation of voltage doubling rectifying circuit in 150 kV high-voltage inverter power supply

Study of Induction Heating Power Supply Based on 74HC4046

According to the change of resistivity and magnetic permeability of iron load which will influence the resonance frequency in the process of induction heating, this paper presents a frequency tracking system based on the 74HC4046. It can control the output frequency of the power supply in real time, and make the power output frequency to trace the resonance frequency of load. This paper also analyses the phase compensation of the control system, and proposes a new way of phase compensation. The corresponding simulation experiment is done finally. It provides the theory basis to analyze and design an inverter power supply.

Transient Analysis of Induction Machines Using Time-Stepping Finite Element Method Coupled with the Circuit Equations

A field-circuit coupled finite element method has been applied on one induction machines for the transient analysis in case of inverter power supply and sinusoidal voltage supply in this paper. The focus is to build the time-stepping finite element method with external circuit coupled to the electromagnetic field equations and achieve voltage supply. The problem of the motion of rotor is solved through moving boundary by interpolation in the moving coordinate system. The induction machine starting transient simulation has been completed using Finite element equations indirect coupled with mechanical equation. The influence of the electromagnetic field and performance has been analyzed compared with sinusoidal condition. This method can be used for dynamic analysis of any power supply taking into account the magnetic nonlinearity of the core material. The established machine overall structure model is closer to the actual. Compared to the traditional analysis method, we can reduce the dependency of experience design. It can also be used for analysis and optimization of the new machine

A simplified control strategy for single-phase UPS inverters

Abstract Though there are many strategies to control single-phase uninterruptible power supply (UPS) inverters, they suffer from some drawbacks, the main being complexity. This paper proposes a simple dual-loop controller for the single-phase UPS inverter with the LC filter. The suggested control scheme uses the capacitor current as the feedback signal in the inner current loop. No fictitious phase generation or reference frame transformations are required, and simple proportional gains are employed as both voltage and current regulators. A feedforward of the derivative of the output voltage is also proposed, which significantly improves the performance of the closed loop control system. Then, based on the model of the inverter with the proposed control strategy, a simple and systematic design procedure is presented. Finally, the theoretical achievements are supported by extensive simulations.

Paralleling Inverters Study of EAST Vertical Stability Coil Power Supply

Experimental advanced superconducting tokamak vertical stability (VS) coil power supply is a large capacity single phase inverter power supply. To meet the requirement of large current and fast response, multi-inverters in parallel is presented, which based on carrier phase-shifted modulation technology. In parallel inverter system, the disperse circuit parameters and phase-shift carriers between parallel inverter units will cause circulating current, which contains fundamental component and a large number of harmonic components. In this paper, the model of circulating current is analyzed when VS coil power supply is working in voltage given mode, and an instantaneous current sharing control strategy is proposed based on the combination of current sharing inductor and instantaneous circulating current feedback control. Parallel inverter units are connected together through current sharing inductors which can change the impedance characteristic of the circulating impedance and well restrain the high-frequency circulating current. Then, the real part of the circulating impedance will be increased and the ability to restrain the low-frequency circulating current will be advanced by introducing virtual resistance, which is realized in the instantaneous circulating current feedback routine. The designations of the current sharing inductor and the virtual resistance are provided. The results of simulation and experiment verify that this current-sharing strategy is available and efficient.

The Application of Phase-Locked Loop Frequency Tracking in the Intelligence-Type Induction Heating Power Supply

As the induction heating power was working, its load resonant frequency constantly changes. In order to improve the efficiency of power supply, it requires that the inverter output frequency can follow changes in natural frequency of the load, namely the frequency tracking control. Aiming at the deficiency of the frequency tracking control system, this paper presents a method that the phase locked loop (PLL) tracking system works on real-time control of the output frequency of the power supply,and introduces a phase locked mathematical model which fits the inverter power supply, and offers a simulated analysis by using PSPICE. Through experiments, the system proves to be good at frequency tracking.

Electromagnetic Vibration Test of Reactor with Inverter Power Supply

With the development of power electronics technology, PWM devices have been widely used. Non-sinusoidal power brings us serious vibration problem. In this paper, vibration acceleration measuring system is applied for detecting the vibration of reactor under SPWM modulated wave.