【作者】 王虎；

【导师】 王晋；

【作者基本信息】 华中科技大学 ， 电气工程， 2023， 硕士

【摘要】 深层油气资源开发是提高我国能源自给率、保障能源安全的重要途径。目前深层油气开发主要面临开发难度大、成本高的问题,急需研发先进的井下电动钻具和潜油电泵等钻采装备。永磁同步电机长电缆驱动系统是电动钻具和潜油电泵的核心设备。在传统的永磁同步电机长电缆驱动系统中,长电缆一方面会引起行波反射导致的机端过电压问题,另一方面由于长电缆阻抗压降较大,逆变器侧需要输出更高的电压。现有的基于电压源型逆变器和电流源型逆变器的驱动系统存在需加装正弦波滤波器,或需要特殊开关器件等问题。本文提出一种基于差分式升压逆变器(Differential Boost Inverter,简称DBI)的永磁同步电机长电缆驱动系统,从系统的数学建模、逆变器主电路设计和控制系统设计等方面开展研究。首先,建立了DBI的数学模型,提出了DBI的双闭环控制方法;结合永磁同步电机的数学模型和矢量控制方法,提出了基于DBI的永磁同步电机长电缆驱动系统的四闭环级联控制策略,分析了系统的谐振频率以及长电缆的影响。其次,推导了逆变器主电路电参数的表达形式,考虑电压电流纹波和系统谐振频率等约束,提出了逆变器主电路元器件的选型方法。为了实现电感电流环和电容电压环对交流指令的跟踪控制,提出了谐振频率可变的比例积分准谐振控制器(PIR)及其离散方法。以各个控制环路带宽为设计指标,给出了各个环路控制器参数的整定方法。搭建了系统仿真模型,对逆变器主电路设计方法和系统控制方法进行了验证。最后,介绍了实验平台的组成,开展了阻感负载实验、电机空载起动实验和电机负载实验。实验表明逆变器主电路设计符合指标要求,控制系统能够稳定运行,各个控制环路延迟较低、误差较小。针对较大q轴电流指令下电感电流环出现衰减的问题,通过调整输入电压和电容电压直流偏置,减小占空比变化范围,优化了电感电流环的控制效果,显著提升了系统的带载能力。更多还原

【Abstract】 Deep oil and gas resources exploration is an important requirement to improve energy self-sufficiency and ensure energy security for our country.At present,deep oil and gas exploration is mainly faced with the problems of difficulty and high cost,and it is urgent to develop advanced downhole electric drilling tools,electric submersible oil pumps and other drilling equipment.Long feed cable permanent magnet synchronous motor drive system is the core equipment of electric drilling tools and submersible electric pumps.In the long feed cable drive system,on the one hand,the long cable will cause the problem of machine end overvoltage caused by traveling wave reflection,on the other hand,due to the large resistance voltage drop of the long feed cable,the inverter side needs to output a higher voltage.The existing driving systems based on voltage source inverter and current source inverter need to install sine wave filter,or need special switching devices.In this paper,a DBI based drive system for permanent magnet synchronous motor with long feed cable is proposed,which is studied from the aspects of mathematical modeling,inverter main circuit design and control system design.Firstly,the mathematical model of DBI is established,and the double-closed-loop control method of DBI is proposed.Combined with the mathematical model and vector control method of permanent magnet synchronous motor,the four-closed-loop cascade control method of DBI based drive system for permanent magnet synchronous motor is proposed.The resonance frequency of the system and the influence of long cable are analyzed.Secondly,the expression form of the electrical parameters of the main circuit of the inverter is derived.The selection method of the main circuit components of the inverter is proposed considering the constraints of voltage and current ripple and system resonant frequency.A proportional integral quasi-resonant controller(PIR)with variable resonant frequency and its discrete method are proposed to realize the tracking control of AC instructions of inductor current loop and capacitor voltage loop.The tuning method of each loop controller parameter is given taking the bandwidth of each control loop as the design index.The simulation model is built,and the main circuit design method and system control method of inverter are verified.Finally,the composition of the experimental platform is introduced,and the resistance load experiment,motor no-load starting experiment and load experiment are carried out.The experiment shows that the main circuit design of the inverter meets the requirement of the index,the control system can run stably,and each control loop has low delay and small error.In order to solve the problem of attenuation of inductance current loop under large qaxis current instruction,the input voltage and capacitor voltage DC offset were adjusted to reduce the range of duty ratio variation,optimize the control effect of inductance current loop,and significantly improve the load capacity of the system.更多还原