發(fā)布時間：2018-03-01 14:37

  本文關鍵詞： 車載感應電機 直接轉矩控制 空間矢量脈寬調制 滑模變結構 模型參考自適應　出處：《吉林大學》2016年碩士論文　論文類型：學位論文

【摘要】：隨著環(huán)境污染與能源危機問題的日益顯現(xiàn),汽車工業(yè)領域逐漸將混合動力汽車視為行業(yè)發(fā)展的重要趨勢。驅動系統(tǒng)作為混合動力汽車的核心組成部分,對汽車控制性能有重要影響。由于交流感應電機本身具有易于生產、結構簡單、成本低、效率高和可靠性好等優(yōu)點,國內外大部分混合動力汽車選擇以交流感應電機為驅動電機。直接轉矩控制作為一種新興交流電機控制技術,具備控制思路新穎、目標明確以及系統(tǒng)結構簡單等優(yōu)點,與其它控制策略相比有明顯優(yōu)勢。本文選擇以混合動力車載感應電機為研究對象,結合車載感應電機運行條件對直接轉矩控制系統(tǒng)進行分析研究,并針對傳統(tǒng)直接轉矩控制系統(tǒng)中存在的一些缺陷設計優(yōu)化改進方案。主要研究內容如下:1.在傳統(tǒng)直接轉矩控制系統(tǒng)中,轉矩和定子磁鏈偏差由滯環(huán)比較器獲得,再通過開關矢量選擇表選擇合適的電壓矢量。這種控制結構使系統(tǒng)受到滯環(huán)寬度的影響,電壓矢量只能在有限個數(shù)中切換,并且造成逆變器開關頻率不固定。本文基于空間矢量脈寬調制技術對控制系統(tǒng)進行改進,SVPWM技術可以根據(jù)上一周期磁鏈和轉矩的偏差預測出下一周期的期望空間電壓矢量,并且期望電壓矢量能夠由所在扇區(qū)內的兩個相鄰非零電壓矢量和零矢量作用合成。不僅克服電壓矢量數(shù)量上的限制,也固定了逆變器的開關頻率。實現(xiàn)對定子磁鏈平滑調節(jié),優(yōu)化電機轉矩脈動。2.在直接轉矩控制系統(tǒng)中,需要獲得準確的電機轉速才能實現(xiàn)系統(tǒng)的閉環(huán)控制。但是,測速儀器不僅增加經濟成本還需要定期維護,在一些工業(yè)條件下較難實現(xiàn)。本文根據(jù)交流電機數(shù)學模型和直接轉矩控制原理,結合模型參考自適應原理設計轉速估計環(huán)節(jié),實現(xiàn)對電機轉速的精確估計。3.本文利用滑模變結構控制理論對控制系統(tǒng)進行優(yōu)化。根據(jù)滑模變結構控制理論,設計磁鏈滑模控制器和轉矩滑�？刂破�,替代原始SVPWM模塊中PI調節(jié)器生成參考電壓。同時設計定子磁鏈滑模觀測器,提高定子磁鏈觀測精度。利用李雅普諾夫穩(wěn)定性原理驗證變結構控制器和觀測器的穩(wěn)定性。通過應用滑模變結構控制,克服了系統(tǒng)在實際運行過程中電機參數(shù)變化和外界擾動的影響,有效的增強了系統(tǒng)的魯棒性。在MATLAB/Simulink環(huán)境中建立控制系統(tǒng)仿真模型。通過對比分析仿真實驗結果,證明改進后直接轉矩控制系統(tǒng)的定子磁鏈軌跡和電機轉矩脈動獲得明顯改善,同時實現(xiàn)對電機轉速精確估計。實驗結果驗證了優(yōu)化方案的有效性。
[Abstract]:With the emergence of environmental pollution and energy crisis, hybrid electric vehicles (HEV) are regarded as an important trend in automobile industry. The driving system is the core component of HEV. The AC induction motor has the advantages of easy production, simple structure, low cost, high efficiency and good reliability. Most hybrid electric vehicles at home and abroad choose AC induction motor as the driving motor. As a new AC motor control technology, direct torque control has the advantages of novel control ideas, clear objectives and simple system structure. Compared with other control strategies, this paper chooses the hybrid vehicle loaded induction motor as the research object and analyzes the direct torque control system in combination with the on-board induction motor operating conditions. The main research contents are as follows: 1. In the traditional direct torque control system, the torque and stator flux deviation are obtained by hysteresis comparator. Then the switching vector selection table is used to select the appropriate voltage vector. This control structure makes the system be affected by the hysteresis width, and the voltage vector can only be switched in a limited number. Based on space vector pulse width modulation (SVPWM), an improved SVPWM technique can be used to predict the expected space voltage vector for the next period according to the deviation of flux and torque in the previous period. Moreover, the expected voltage vector can be combined by two adjacent nonzero voltage vectors and zero vectors in the sector. It not only overcomes the limitation of the number of voltage vectors, but also fixes the switching frequency of the inverter. In the direct torque control system, the accurate speed of the motor is needed to realize the closed-loop control of the system. However, the speed measuring instrument not only increases the economic cost, but also needs to be maintained on a regular basis. It is difficult to realize in some industrial conditions. According to the mathematical model of AC motor and the principle of direct torque control, combined with the adaptive principle of model reference, the speed estimation link is designed in this paper. In this paper, the sliding mode variable structure control theory is used to optimize the control system. According to the sliding mode variable structure control theory, the flux chain sliding mode controller and the torque sliding mode controller are designed. Instead of the Pi regulator in the original SVPWM module, the reference voltage is generated. At the same time, the stator flux linkage sliding mode observer is designed. The stability of variable structure controller and observer is verified by using Lyapunov stability principle. It overcomes the influence of motor parameter change and external disturbance during the actual operation of the system, and effectively enhances the robustness of the system. The simulation model of the control system is established in the MATLAB/Simulink environment. The simulation results are compared and analyzed. It is proved that the stator flux locus and the torque ripple of the motor are obviously improved after the improvement of the direct torque control system, and the accurate estimation of the motor speed is also realized. The experimental results verify the effectiveness of the optimized scheme.
【學位授予單位】：吉林大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：U469.7

【參考文獻】

相關期刊論文 前10條

1 鈕怡飆;;混合動力汽車現(xiàn)狀及發(fā)展趨勢淺析[J];汽車與配件;2015年50期

2 趙湘衡;楊武;王敏懷;;基于MRAS無速度傳感器的PMSM直接轉矩控制[J];中南大學學報(自然科學版);2015年10期

3 苑偉華;潘峰;路瑤;;基于滑模策略的直接轉矩控制研究[J];電氣傳動;2015年08期

4 趙輝;胡仁杰;;SVPWM的基本原理與應用仿真[J];電工技術學報;2015年14期

5 佘致廷;盧文斗;譚瓊瓊;丁時云;張紅梅;;PMSM神經網(wǎng)絡模型參考自適應的速度控制[J];控制工程;2015年S1期

6 周偉;程如煙;，

本文編號：1552397