Low Complexity Model Predictive Direct Power Control Of Dual Three-Phase Permanent Magnet Synchronous Generator

Compared with three-phase motor,multiphase motor has many advantages with high output power,small torque ripple,good fault-tolerant performance and soon.It has attracted much attention in electric vehicles,wind power generation,aerospace,ship propulsion and other fields.In this paper,the low complexity model predictive direct power control of dual three-phase permanent magnet synchronous generator(Dual Three-Phase Permanent Magnet Synchronous Generator,DTP-PMSG)is studied.The main research contents of this paper are as follows:1.Firstly,the mathematical model of DTP-PMSG is established,and the vector space decoupling mathematical model of generator is derived.The voltage equation,flux linkage equation and torque equation after decoupling are given.The analysis shows that the method realizes the complete decoupling of voltage vector and eliminates the coupling relationship between each winding.Secondly,through the vector space decoupling technology,the six dimensional subspace of DTP-PMSG system is decomposed into three mutually perpendicular subspaces:the fundamental subspace,the harmonic subspace and the zero order subspace.In order to improve the utilization rate of dc bus voltage,twelve outermost large vectors of the fundamental subspace are selected to construct the switch table,and direct power control(DPC)is studied.However,due to the lack of harmonic subspace control,the harmonic current of DPC is large.2.In order to solve the problems of large stator current harmonics and power pulsation in DTPPMSG system,a synthetic vector MPDPC algorithm is proposed by combining MPDPC with DPC and fully considering the multi vector and multi degree of freedom characteristics of DTP-PMSG.Firstly,the synthetic vector is substituted into the power model,then the cost function is used to find the optimal synthetic vector in the unit period,and the operation time of the vector is calculated by using the principle of power deadbeat,and the synthetic vector and zero vector are acted simultaneously in the unit period.The simulation results show that this method effectively reduces the power ripple of the system and reduces the current harmonics.3.MPDPC needs to optimize the cost of twelve synthesized vectors in a unit cycle,which requires a large amount of calculation.In order to reduce the computational complexity,a low complexity MPDPC algorithm is proposed.This method first calculates the position of the target voltage vector by directly calculating the zero vector negative conjugate complex power difference,and then selects the optimal voltage vector according to the principle of minimum power error,without traversal optimization,which effectively reduces the complexity of calculation.4.The experimental platform of the DTP-PMSG is built.The principle and development process of the hardware and software design in it are introduced.Based on it,experiments are carried out.The experimental results are shown,and the effectiveness and practicability of the proposed synthetic vector duty cycle MPDPC and the low-complexity MPDPC are verified.