Research On Z-source T-type Inverter

With the progress of the times,all countries in the world are constantly innovating and developing.However,energy is an indispensable factor in development.Solar energy has become the first choice for new energy sources.The inverter is used as an energy conversion interface to connect photovoltaics.The power generation system and the load are the core of the entire photovoltaic system.Three levels rely on higher efficiency than two levels,and are used in various high power applications.However,due to the pressure reduction characteristics of their own structures,in order to obtain high voltage output,it is necessary to achieve boost on the DC side.Additional circuitry is needed.Obviously,this will cause the system structure to be complex and increase cost.Therefore,in order to solve the above mentioned problems,the Z source T?type inverter topology is analyzed in this paper.The Z source has the advantage of unique boost in the straight?through state and the T?type inverter does not require the simple structure advantages of the front?stage clamping diode.Combining them and proposing a new modulation algorithm,the simulation was finally carried out and the experimental platform was built to verify the scientific rationality of the proposed algorithm.Because of the inherent DC?side capacitor voltage division of the three?level inverter,the voltage on the capacitor side is not equal,that is,the midpoint potential is unbalanced,and the consequent consequence is that the output waveform is poor and there is more harmonic content.For these existing problems,a three?level space?loss modulation method similar to two?level modulation is proposed.The potential balance control is achieved by changing the action time of the upper and lower pass?through states,and while controlling the balance,In the straight?through state to achieve the purpose of boosting.Then simulate the circuit in the simulink environment in MATLAB,and compare whether to add the output of this algorithm to obtain the scientific rationality of the new modulation algorithm.Finally,a hardware circuit with the model STMS32 as a core processor is designed,which roughly includes the design of the power supply circuit and the drive circuit,determines various parameters in the Z?source network,including the Z?source network capacitance and the parameter values of the inductor,and the selection of the switch tube.Type,build experimental platform,the experimental result proves the accuracy and plausibility of the simulation again,that is to prove the scientificity of this modulation algorithm.