Z源四开关逆变器-无位置传感器无刷直流电机系统运行控制

Based on Z-source four-switch inverter, this project focuses on the detection of rotor initial position, the detection of motor commutation signal and the torque ripple reduction, and designed to improve the reliability and safety of brushless DC motor (BLDCM) systems. By revealing the nonlinear time-varying relationship between the saturation degree of the stator core and detecting voltage vector, a time-sharing detection method will be proposed, which realizes the detection of rotor initial position with the asymmetric voltage vector of Z-source four-switch inverter. Under the diverse conduction modes of Z-source four-switch inverter fed BLDCM, In this project, a auxiliary function based on line-to-line back EMF integral is designed in the three-phase conduction mode and a direct back EMF method based on shoot-through vector will be developed in the two-phase conduction mode, which gets away from the dependence on floating phase in the traditional methods, solves the detecting difficulties due to the diversity of conduction mode and achieves the accurate detection of motor commutation signal. In order to obtain a smooth output torque, a predictive control method will be proposed to reduce the torque ripple in the normal conduction period, and the booster mechanism in Z-source four-switch inverter will be utilized to suppress commutation torque ripple. The achievements of this project will realize the position sensorless operation of BLDCM system, reduce the ripple of the BLDCM output torque, the improve running quality of motor systems, and further enhance the reliability and service life of the mechanical equipment.

为了提高无刷直流电机系统的可靠性和安全性，本项目基于Z源四开关逆变器，围绕转子初始位置检测、电机换相信号检测、转矩波动抑制展开研究。项目通过揭示定子铁心饱和程度与检测电压矢量之间的非线性时变关系，提出分时检测方法，在不对称电压矢量下实现转子初始位置检测。针对四开关逆变器驱动下无刷直流电机的多元化导通模式，项目在三相导通换相周期设计基于线反电动势积分的辅助函数法，并在两相导通换相周期设计基于直通矢量的直接反电动势法，摆脱了传统方法对断开相的依赖，克服了多元化导通模式带来的反电动势过零点检测困难，实现了电机换相信号准确检测。为了获得更平稳的电磁转矩，项目提出预测控制方法抑制正常导通区转矩波动，并提出基于Z源四开关逆变器升压环节的换相转矩波动抑制新方法。项目研究成果将实现无刷直流电机无位置传感器运行，降低无刷直流电机转矩波动，提高电机系统运行品质，进一步改善机械装备的可靠性和服役寿命。

为了提高无刷直流电机系统的可靠性和安全性，本项目基于Z源四开关逆变器，围绕转子初始位置检测、电机换相信号检测、转矩波动抑制展开研究。项目揭示了定子铁心饱和程度与检测电压矢量之间的非线性时变关系，提出了基于不对称电压矢量注入法的转子初始位置检测方法；设计了独特的超高频信号耦合注入拓扑，提出了适用于逆变器矢量缺失的转子初始位置检测新方法。针对四开关逆变器驱动下无刷直流电机的多元化导通模式，项目提出了基于反电动势函数的无位置传感器控制方法，摆脱了传统方法对断开相的依赖，克服了多元化导通模式带来的反电动势过零点检测困难。在无刷直流电机的高速运行区，提出了换相信号误差补偿方法，实现了电机换相信号准确检测。针对故障重构后的四开关逆变器，通过注入等效零矢量产生响应电流，本项目提出了无位置传感器永磁电机带速重投控制方法。为了获得更平稳的电磁转矩，本项目提出了单级预测控制方法调节Z源逆变器电压和电机转速，抑制正常导通区转矩波动。同时，针对无刷直流电机的换相过程，提出了两种升压控制方法，有效降低了无刷直流电机的换相转矩波动。项目研究成果将实现无刷直流电机无位置传感器运行，降低无刷直流电机转矩波动，提高电机系统运行品质，进一步改善机械装备的可靠性和服役寿命。