Research And Application On The New High-Power Inverter

With the development of science and technology in the power electronic switching devices and related fields, the power converter and a series of technology has been developing rapidly, thus devices based on pulse-width modulation (PWM) converters have emergenced, such as the inverters and inverter typed power supplies. In recent years, due to the demand of increased market power, high-power inverter modulation technique has become a hot research issue.The inverter main circuit topology is generally composed of a plurality of switching elements, and usually using the PWM modulation step modulation process technology. By taking the combination of PWM modulation and H-bridge circuit, an output voltage which has the stepped waveform can be obtained. The output voltage waveform is composed of numerous small ladder ladder approximate sine wave, so often utilize the stepped modulation to name this modulation voltage technique. A stepwise voltage modulation can improve the capacity of the inverter and its response speed, thus it is widely used in high power inverter occasions. But there is a certain conflict between the turn-off switching frequency of the switching element capacity, and when utilizing the PWM modulation technique to improve the inverter performance will be limitated by the inverter switching frequency, therefore the inverter main circuit topology structure and modulation current of the inverter has become a key problem exists. Aimed to solve the key problems, and focused on the multi-level H-bridge inverter control strategy and regulation, the paper has done the analysis focus on the following aspects:(1) The establishment of an ideal cascade H-bridge inverter model, elaborated based on multi-level cascaded H-bridge inverter control principle, to build the system model in Matlab/Simulink simulation study conducted for controller design and its parameters selected for the research and analysis;(2) Presents a control scheme based on improved inverter switch modulation: Based on the control part of the inverter UPS inverter improvements will flip its modulation section, which developed a inverter switch The new modulation strategy. That is based on the principle of the inverter modulation of step voltage control switch design analysis and improvement. And build a system model in Matlab/ Simulink for simulation analysis.(3) Through a combination of theory and simulation methods, presents a direct introduction of the dual H-bridge PWM inverter cascaded modulation strategy. On the basis of analysis of the main circuit topology and working principle of the ladder with independent DC voltage source PWM modulation direct introduction of dual PWM modulator and the corresponding simulation. And build a model in Matlab/ Simulink simulation study conducted.(4) Based on the theory of cascaded H-bridge, we propose to introduce a dual PWM control voltage at one end of the ladder, based on the new inverter PWM modulation strategy, which proposes a H-bridge inverter voltage ladder Based on the introduction of dual-end PWM PWM modulation. Built in Matlab/Simulink model of the primary circuit simulation study, and with the direct introduction of dual PWM inverter modulation were analyzed.(5) On the basis of these two dual PWM modulation, we propose a new inverter modulation strategy and a detailed simulation analysis of the influencing factors. To verify the feasibility of the new modulation strategy, using the two programs. H-bridge modules that supply voltage proportional to the DC side with the H-bridge DC supply voltage proportional unit separately modulated test too. In Group 3 H-bridge inverter premise of the H-bridge using ladder wave modulation PWM triangular carrier wave compared with the ladder come modulation waveform, thus forming a new type of inverter modulation strategies.