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兰州交通大学毕业设计英文翻译（原文）A direct deadbeat control of a PWM single-phase voltage source inverterKeywords Converter control, Pulse Width Modulation (PWM), Voltage Source Inverters (VSI), deadbeat control.Abstract A new deadbeat controller configuration for a pulse width modulated single-phase voltage source inverter is offered. A control system contains a deadbeat controller that enables one to obtain a finite duration transient in the neighborhood of an equilibrium state. A deadbeat controller is constructed without resort to transform system variables for obtaining the Frobenius form of a system matrix. A procedure of synthesis of deadbeat controller parameters is illustrated by the example of a voltage inverter with an active-inductive load.Introduction One of the main rates of power supply systems are their dynamic properties. Traditional approach to improve those properties by using classic regulators with constant parameters 1 has exhausted the potentialities. Therefore, recently, interest to control systems based on regulators with changing parameters has increased. The socalled aperiodic regulators (deadbeat controllers) belong to them, allowing finite duration transients to be gained 2-4.The algorithm of deadbeat control is known for a long time, but for control of semiconductor converters it was not attracted because of implementation complexity in practice. This fact can be explained by following. In order to obtaina finite transient a matrix of a difference equation of a closed-loop system should be made nilpotent. It is attained by conversion of initial variables which reduces a matrix to the Frobenius form. Summation of signals allows to divide into parts ,its nilpotent term from a Frobenius matrix. Also it is required to fulfill an inverse transformation because initial variable must enter into a system input instead of converted variables. Considering that system input equations are made concerning physical variables for which measuring there are appropriate sensors, for conversion of variables it is necessary to provide two additional devices or additional instructions for a direct program control. Thus, practical implementation of the known method of deadbeat control requires additional hardware or software expenditures.Converter structure A well-known structure of an H-bridge VSI and output voltage waveforms are shown in Fig. 1. The VSI if fed by dc voltage source and it supplies a resistive-inductive load ( load). The two pairs of ideal switches S1, S4 and S2, S3 are alternately closed and open by pulse width modulator. Control system of VSI forms the pulse width modulated voltage according to the sinusoidal reference signal . Due to inductive element the load voltage grows and falls exponentially during time intervals and () respectively. Thus, VSI produces the output voltage whose average value varies sinusoidally. (a) (b)Fig. 1:(a) Simplified schematic of a single phase VSI, (b) output PWM voltage and load voltage waveformsStructure of the control system with a direct deadbeat controllerTo implement a deadbeat control the feedbacks on physical variables of systemare used. The number of feedbacks is equal to the dimension of converter ma-thematical model.The observed converter is characterized by a model of the second order. Therefore a feedback is fulfilled on the two variables: load voltage and control pulse duration.Converter model without a deadbeat controllerConverter difference equations consist of an equation relating load voltage and an equation relating control pulse duration. A voltage equation is derived from the solution of differential equations made for load voltage on the recurren-ce interval of processes:where Vi is an input dc voltage .T is a switching (clock) period. An equation for control pulse duration follows from a requirement of control system operation. In the capacity of the latter a device that integrates an output coordinate (load voltage vo) within a clock period T. Assuming Vref = const during clock period, the expression for control law is given by:where k and Tc are constants.From this expression the difference equation of the closed-loop system followsThe gained difference equations represent a nonlinear discrete mathematical model of the VSI. This model is applied for simulation of transients. For synthesis of an aperiodic regulator, a linear model gained by linearization of nonlinearmodel is used.ConclusionA new deadbeat controller configuration for a pulse width modulated single-phase voltage source inverter has been proposed. A procedure of synthesis of deadbeat controller parameters has been illustrated by the example of a single-phase inverter with the active-inductive load and with the output vo