Simulation On Three-phase Voltage Source Rectifier

This thesis, from the point of generality and based on the background of rectifying device in the electromagnetic exploration field, centers on analysis and design of the three-phase voltage source rectifier system, which is based on space voltage vector pulse width modulation(SVPWM).The initial phase of coordinate transformation from three phase static coordinate to two phase static coordinate which is called Park transformation and from two phase rotating reference frame to two phase static coordinate is uncertain in the double closed-loop control system.There exists noise in acquiring grid voltage and current.Switching frequency of three-phase voltage source rectifier based on direct power control is uncertain,it uses switching table and hysteresis control which are difficult to achieve in digital realm.Firstly, system parameter design. System parameter contains the main circuit parameters and control system parameters. The main circuit parameters mainly contain AC-side input inductor,DC-side output capacitor,given output voltage of the DC-side.Control system parameters mainly contain SVPWM modulation parameters, proportional-integral(PI) controller parameters,data accuracy of fixed constant(data digits, decimal digits),data bits of the continuous domain and discrete domain interface module, etc. According to the active and transient current track index,design inductors.In order to meet the the following performance and immunity of the voltage-loop control indicator and limit the DC voltage dynamic when load disturbance,design the capacitor reasonably. In order to meet the the following performance and immunity,design PI controller of voltage loop and current loop. To meet the simulation accuracy and minimize the hardware occupancy rate,design the data bits of the control system.Secondly, system control strategy.Control system of three-phase voltage-source SVPWM rectifier is designed,simulated and experimented by using the double closed-loop feed-forward decoupling control and direct power control based on SVPWM. Digital PLL and digital filter are built based on conventional double closed-loop control which contains voltage loop and current loop.To reduce the number of voltage sensor,introducing SVPWM in the control system based on the conventional voltage-oriented control and virtual flux control,which forms direct power control based on SVPWM. Thirdly, build continuous-domain model based on Simulink.The double closed-loop feed-forward decoupling control model and direct power control model based on space vector pulse width modulation are built based on Simulink,main circuit and control system parameters are designed, the correctness of the algorithm is verified by off-line simulation.Fourthly, build discrete-domain model based on VHS-ADC platform. High-speed digital signal processing platform(VHS-ADC) model library lacks of power electronics models, construct a large number of power electronic model to build the two discrete-domain three-phase voltage type SVPWM rectifier real-time control simulation model eventually.Digital phase-locked loop is added to follow the frequency and phase of grid voltage, which can solve insecure system operation that caused by the uncertain initial phase.Finite impulse response(FIR) filter is added to process signal and reduce the interference. The direct power control method is combined with SVPWM,it makes dynamic response faster, simplifies the system and improves system performance.The two models in both continuous and discrete domain are constructed on the basis of simulink and the high-speed signal processing system which is called VHS-ADC,it is based on field programmable gate array(FPGA) and belonged to Lyrtech company in Canada.The validity of the proposed discrete domain control model is proved by the experiment research.It has directive significance in the verification of high power experiment,it is convenient to develop and produce the prototype machine.