斩波串级调速系统暂态过程分析及控制与保护研究

发布时间：2018-01-08 15:31

本文关键词：斩波串级调速系统暂态过程分析及控制与保护研究　出处：《华北电力大学(北京)》2017年博士论文　论文类型：学位论文

【摘要】：定子侧变频调速和转子侧串级调速均属于现代交流调速技术,变频调速从电机定子侧接入,电机输出的功率需要全部流过变频器,称为全功率控制;由于高压大功率电机的电流或电压很高,所以需要很好的解决电力电子元件并联技术或串联技术。串级调速设备从电机转子侧接入,其控制的功率为电机转差功率,最大仅为电机额定功率的14.815%,电机在50%额定转速时,转子电压仅为转子开路电压的50%,并且随着转速的升高,转子电压降低,通常转子电压低于1k V,相比于变频器的6kV或10k V电压等级,则属于低压范畴,设备费用低廉,自身损耗小于电机额定功率的1%,对运行环境要求较低,只需放置在普通厂房即可。斩波串级调速系统结构简单、安全稳定、可靠性高,即使串级调速设备调速过程中出现故障,异步电机可以完全脱离斩波串级调速装置转换到转子短接全速运行,因而,斩波串级调速系统在高压大功率电机调速方面具有独特的优势。目前对斩波串级调速系统的研究主要侧重于原理性理论研究和仿真建模研究并与工程应用结合很少。由于缺乏系统性的静态、动态和暂态特性研究,系统的设计、控制保护系统设计缺乏基础,造成长期以来斩波串级调速系统的运行稳定性、可靠性得不到保证。论文首次针对斩波串级调速系统动态和暂态特性进行了系统的深入研究和分析并给出结果,研究和设计了可靠地控制保护系统,结合工程实践确认了上述研究和设计结果的正确性,主要开展了以下研究工作:1、系统全面的分析了斩波串级调速系统正常启动和正常调速时的动态过程。由于绕线式异步电机启动特性与转子回路串接电阻阻值有直接关系,根据简化的电机机械特性公式,绘制出不同阻值对应的电机转矩-转速曲线;针对风机、泵类平方转矩负载,提出了较精确的绕线式异步电机启动电阻阻值和电机启动时间的计算方法。基于暂态分析,计算出了斩波串级调速主回路各主要电参数之间的输入输出关系,对电感电流和电容电压的纹波特性进行了分析和计算。2、根据异步电机等效电路、参数折算以及斩波串级调速系统分析,建立了等效的直流电路;根据建立的等效直流电路建立了斩波串级调速系统动态关系的双输入双输出三阶变参数非线性微分方程组;根据状态方程,建立系统的暂态特性结构框图。分析了负载扰动时斩波串级调速系统转速和电流的动态变化过程及幅度和恢复时间等抗扰动性能,并进行仿真验证,对比了不同稳定工况下负载扰动前后的动态变化峰值、恢复时间以及稳定后的数据;分析了轻载和过载工况时斩波串级调速系统的运行特点,以及对设备内器件的影响。进行了网压跌落瞬间斩波串级调速系统的暂态分析,并提出了网压跌落的应对措施。3、全面系统分析了调速设备内部多种电力电子器件不同故障时斩波串级调速的暂态特性。首先分析了整流桥故障,根据二极管烧断的情况,分别分析了单管烧断、同侧两只二极管烧断以及不同侧不同桥臂的两只二极管烧断的多种情况;分别分析了IGBT和逆阻二极管断路和短路的故障情况和故障后的暂态波形,以及故障后对其他器件的影响;分析了斩波串级调速系统逆变桥内晶闸管故障,单只晶闸管断路和短路两种故障下的暂态波形分析。针对高压停电现象,分析了斩波串级调速系统的暂态过程,并进行了理论计算。4、对斩波串级调速系统内关键器件快恢复二极管特性进行深入分析,提出了一种新的快恢复二极管建模方法,建立了精确的数学模型。对IGBT器件基本结构和工作原理进行了全面分析,建立精确的IGBT开通关断过程数学模型;建立的IGBT器件模型可以完全表征实际器件开关暂态时电压、电流的动态变化过程以及器件的工作特性,并且能在一定程度上反映器件的开关特性对系统的影响。5、分析了斩波串级调速系统与水阻启动单元串联和并联连接方式的优缺点;针对并联方式和串联方式分别设计了斩波串级调速系统的启动控制逻辑。在串联方式的基础上设计了启动直接进调速的控制及故障控制逻辑,解决了斩波串级调速系统不能启动直接进调速的问题。基于暂态特性分析,首次提出了基于毫秒级分辨率合理的斩波串级调速系统的状态投切控制逻辑,主要包括:全速转调速控制逻辑、调速转全速控制逻辑、调速停车控制逻辑,该逻辑经试验样机波形测试,并得以工程应用验证了其正确性。基于斩波串级调速系统调速故障下的暂态特性分析,提出毫秒级分辨的接触器动作保护逻辑和快切保护逻辑。基于有源逆变器颠覆故障、高压失电、瞬时停电和供电线路快切的暂态特性分析,提出了接触器动作保护与电子保护相结合的保护方法,并给出了电子保护电路器件的选型依据。最后根据斩波串级调速系统稳态情况下的主回路动态特性与系统调速特性、机械特性建立其状态平均方法下的微分方程,并推出了斩波串级调速系统的转速特性,在此基础上应用二阶、三阶工程最佳法,给出了斩波串级调速系统转速双闭环控制以及控制器参数的工程计算方法。
[Abstract]:The stator side and rotor side VVVF cascade control belong to modern AC speed regulation technology, frequency control from the motor stator side access, output power of the motor to all through the inverter, control for full power; the current or voltage of high voltage high power motor is very high, so need a good solution to power electronic components or parallel technology tandem cascade speed control technology. Equipment from the rotor side access, the control power of motor slip power, only to a maximum of 14.815% of the rated power of motor, motor in 50% rated speed, rotor voltage rotor voltage is only 50%, and with the increase of rotational speed, the rotor voltage decreases, the rotor voltage is lower than usual 1K V, compared to 6kV or 10K V inverter voltage level, it belongs to the low voltage equipment category, low cost, its loss is less than 1% of the rated power of motor, the operating environment requirements are relatively low, only put You can set in the ordinary plant. Chopper cascade speed control system has the advantages of simple structure, high reliability, safety and stability, even if a fault occurs the cascade speed regulating process equipment, the asynchronous motor can be completely separated from the chopper cascade speed control device converts to short circuited rotor running at full speed, therefore, chopper cascade speed control system has unique advantages in high power motor speed. The present research on chopper cascade speed control system is mainly focused on the principle of theory research and simulation modeling and engineering application with little. Due to the lack of systematic research on static, dynamic and transient characteristics, system design, control and protection system design and the lack of foundation, the operation stability of long chopper cascade speed control the reliability can not be guaranteed. For the first time for chopper cascade speed control system dynamic and transient characteristics of in-depth research and analysis system And the results are given, and the design of reliable control and protection system, the correctness of the results confirmed the above research and design combined with the engineering practice, mainly carried out the following research work: 1 system, a comprehensive analysis of the dynamic process of chopper cascade speed regulation system of normal starting and normal speed. The winding type asynchronous motor starting the characteristics and the rotor circuit resistance has a direct relationship, according to the mechanical characteristics of the motor and simplified formula, draw the different resistance corresponding to the motor torque speed curve; the fan, pump square torque load, puts forward the calculation method of precise winding type asynchronous motor starting resistor and motor start time based on transient. Analysis of the relationship between input and output chopper cascade speed control between the main circuit main electric parameters calculation, ripple characteristics of the inductor current and capacitor voltage are analyzed and calculated. .2, according to the equivalent circuit of asynchronous motor, analysis level control system parameter conversion and chopper cascade, a DC equivalent circuit; according to the equivalent circuit of a double input and double output chopper cascade speed control system of the dynamic relationship between the three order nonlinear differential equations with variable parameters; according to the state equation, the transient characteristics of the structure diagram is established system. Analysis of dynamic change and load disturbance amplitude of chopper cascade speed and current level control system and the recovery time of anti disturbance performance, and simulation, compared the different working condition of dynamic load peak before and after the disturbance, recovery time and stable data; analysis of operating characteristics of light load and overload condition for chopper cascade speed control system, and the influence of device in the equipment is analyzed. The transient voltage sags chopper cascade speed control system, and Put forward measures to deal with the pressure drop of the.3 network, a comprehensive analysis of the transient characteristics of the speed control equipment of power electronic devices within a variety of different fault chopper cascade speed control. First analyzes the fault according to the diode rectifier bridge, burnt, burned tube are analyzed, a variety of ipsilateral two diodes burned and different side different arm burned two diodes; analyzes transient waveforms of fault and fault IGBT and inverse open circuit and short circuit resistance diode after fault, and on other devices; analysis of chopper cascade speed control system fault level inverter in thyristor open circuit and short circuit transient waveform analysis two the single fault thyristor. For high voltage power failure, analysis of the transient process of chopper cascade speed control system, and the theoretical calculation of.4, the key device of chopper cascade speed regulation system in fast recovery The in-depth analysis of complex diode characteristics, proposed fast recovery diode is a new modeling method, establish a precise mathematical model. The basic structure and working principle of IGBT device is analyzed, the establishment of precise IGBT on-off process mathematical model; IGBT model established can fully express the actual switching transient voltage the dynamic process of current, and the device characteristics, and can to some extent reflect the switching characteristic influence on the system of.5, analyzes the advantages and disadvantages of chopper cascade speed control system and the water resistance starting unit series and parallel connection; the parallel mode and the series are designed for chopper cascade speed control system start control logic control. Based on the design of the series start directly into control and fault control logic to solve the chopper cascade speed control system The problem can not be started directly into the control. Based on the analysis of transient characteristics, first proposed the reasonable millisecond resolution chopper cascade speed control system state switching control based on logic, including: full rotary speed control logic, the turn at full speed control logic, control logic control parking, the logic test prototype waveform test, and can be the engineering application verifies its correctness. Analysis of transient characteristics of variable speed control system under the fault level on chopper based on proposed contactor protection logic of millisecond resolution and fast switching protection logic. Active inverter subversion fault based on high voltage power failure, analysis of transient characteristics of instantaneous power supply line and fast cutting, puts forward protection method of contactor protection and electronic protection combination, and gives a basis for electronic circuit protection devices selection. According to the steady state level chopper cascade speed control system The main loop dynamic characteristics and speed characteristics of the system, establish the differential equations of the state average method of the mechanical characteristics, and introduced the speed characteristics of chopper cascade speed control system, based on the application of two order, three order engineering optimal method, gives the chopper cascade speed control system speed double closed-loop control and controller parameters the engineering calculation method.

【学位授予单位】：华北电力大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM301.2

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