基于變頻調(diào)速系統(tǒng)的低壓穿越性能研究
發(fā)布時間：2018-08-09 07:37
【摘要】：近年來,隨著電力電子技術(shù)的迅猛發(fā)展,變頻器以其節(jié)能降耗的顯著優(yōu)勢,在發(fā)電廠輔助設(shè)備中普遍使用。然而,由于變頻器對電網(wǎng)電壓波動十分敏感,當電網(wǎng)發(fā)生故障引起電壓暫降或短時中斷,如果該變頻器不具備一定的低壓穿越能力,將會引發(fā)變頻器低電壓而跳閘,進而威脅發(fā)電廠機組的安全,嚴重影響電網(wǎng)安全穩(wěn)定運行。因此,對變頻調(diào)速系統(tǒng)低壓穿越性能的研究具有非常重要的實際應(yīng)用意義。本文首先闡述了低壓穿越和雙PWM變頻器的相關(guān)概念,分析現(xiàn)階段國內(nèi)外學(xué)者專家針對火電廠變頻調(diào)速系統(tǒng)低壓穿越技術(shù)問題的研究現(xiàn)狀,詳細地給出雙PWM變頻器調(diào)制方法的實現(xiàn)和控制系統(tǒng)的設(shè)計,進而完成了雙PWM變頻器的仿真,然后以火電廠變頻調(diào)速系統(tǒng)為基礎(chǔ),通過現(xiàn)場測試的方式對兩種不同型號變頻器的低壓穿越性能進行評估。本文的主要工作如下:(1)從變頻器的基本結(jié)構(gòu)出發(fā),分析了網(wǎng)側(cè)變換器的拓撲結(jié)構(gòu)和工作原理,分別建立了在三相靜止坐標系下以及兩相旋轉(zhuǎn)坐標系下網(wǎng)側(cè)變換器的數(shù)學(xué)模型,并根據(jù)其拓撲結(jié)構(gòu)和數(shù)學(xué)模型的推導(dǎo)公式來說明網(wǎng)側(cè)變換器的工作原理。(2)以三電平逆變器主電路結(jié)構(gòu)為基礎(chǔ),著重研究三電平SVPWM(空間矢量脈寬調(diào)制)算法,對其穩(wěn)態(tài)工作情況下每相輸出時開關(guān)狀態(tài)的變化進行分析,并給出了一種依據(jù)最近三矢量原則合成參考電壓矢量的算法。通過判斷參考電壓矢量的位置來適當選取基本矢量,進而得到每個基本矢量的作用時間和相應(yīng)的作用順序,再將矢量的作用時間分配給對應(yīng)的矢量狀態(tài),從而有效地控制開關(guān)管的導(dǎo)通與關(guān)斷。(3)完成了對雙SVPWM變頻器網(wǎng)側(cè)、負載側(cè)變換器控制系統(tǒng)的設(shè)計,均采用雙閉環(huán)控制策略。網(wǎng)側(cè)變換器采用電壓外環(huán)、電流內(nèi)環(huán)控制,負載側(cè)變換器則采用功率外環(huán)、電流內(nèi)環(huán)控制,并由相應(yīng)的傳遞函數(shù)確定了 PI調(diào)節(jié)器的參數(shù)。通過MATLAB/SIMULINK平臺搭建雙SVPWM變頻器的仿真模型,仿真結(jié)果表明了SVPWM算法的有效性和控制系統(tǒng)設(shè)計的可行性,輸出電壓、電流波形的質(zhì)量較好,提高了整流器和逆變器的轉(zhuǎn)換效率。(4)以安徽某火電廠輔機變頻調(diào)速系統(tǒng)(給粉機)為例,對不同型號的給粉機變頻器隨機各選取一臺進行低壓穿越性能測試,得到輔機變頻調(diào)速系統(tǒng)低壓穿越性能測試結(jié)果,分析并得出測試結(jié)論。針對不具備低壓穿越能力的被試輔機變頻器,本文探討了幾種方案以此解決發(fā)電廠輔機變頻調(diào)速系統(tǒng)低壓穿越的問題,提高了電網(wǎng)安全穩(wěn)定運行的可靠性。
[Abstract]:In recent years, with the rapid development of power electronics technology, frequency converter is widely used in auxiliary equipment of power plant because of its remarkable advantage of saving energy and reducing consumption. However, because the inverter is very sensitive to the voltage fluctuation of the power network, if the inverter does not have a certain low voltage traversing capacity, it will cause the converter to trip down at low voltage if the voltage drop or short time interruption is caused by the fault of the power network. Then it threatens the safety of power plant units and seriously affects the safe and stable operation of power grid. Therefore, it is very important to study the low-voltage traversing performance of variable-frequency speed regulation system. In this paper, the concepts of low voltage traversing and double PWM converter are introduced, and the current research status of domestic and foreign scholars and experts on low voltage traversing technology of frequency conversion speed regulating system in thermal power plant is analyzed. The realization of double PWM frequency converter modulation method and the design of control system are given in detail, and then the simulation of double PWM converter is completed, and then based on the frequency conversion speed regulation system of thermal power plant, The low-voltage traversing performance of two different types of inverters is evaluated by field test. The main work of this paper is as follows: (1) starting from the basic structure of the converter, the topology and working principle of the grid-side converter are analyzed, and the mathematical models of the grid-side converter in the three-phase stationary coordinate system and the two-phase rotating coordinate system are established, respectively. The working principle of the grid-side converter is explained according to its topological structure and mathematical model. (2) based on the main circuit structure of three-level inverter, the three-level SVPWM (Space Vector Pulse width Modulation) algorithm is studied emphatically. The change of switching state in each phase output is analyzed, and an algorithm for synthesizing reference voltage vectors based on the principle of the nearest three vectors is presented. By judging the position of the reference voltage vector, the basic vector is properly selected, and then the action time and the corresponding sequence of action of each basic vector are obtained, and then the working time of the vector is allocated to the corresponding vector state. Thus the switch on and off are effectively controlled. (3) the double closed loop control strategy is used to design the control system of double SVPWM converters on the grid side and load side. The voltage outer loop and current inner loop are used in the grid-side converter, while the power outer loop and current inner loop are used in the load-side converter. The parameters of the Pi regulator are determined by the corresponding transfer function. The simulation model of double SVPWM inverter is built on MATLAB/SIMULINK platform. The simulation results show that the SVPWM algorithm is effective and the design of control system is feasible. The quality of output voltage and current waveform is good. The conversion efficiency of rectifier and inverter is improved. (4) taking the frequency conversion speed regulating system of auxiliary machine of a thermal power plant in Anhui province as an example, the low voltage traversing performance test is carried out by selecting one frequency converter of different type power feeder at random. The test results of low voltage traversing performance of frequency conversion speed regulating system of auxiliary machine are obtained, and the test results are obtained. In view of the frequency converter of the auxiliary machine without low voltage traversing ability, this paper discusses several schemes to solve the problem of low voltage crossing of frequency conversion speed regulating system of auxiliary machine in power plant, and improves the reliability of safe and stable operation of power network.
【學(xué)位授予單位】：安徽大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM921.51;TM621
本文編號：2173374
[Abstract]:In recent years, with the rapid development of power electronics technology, frequency converter is widely used in auxiliary equipment of power plant because of its remarkable advantage of saving energy and reducing consumption. However, because the inverter is very sensitive to the voltage fluctuation of the power network, if the inverter does not have a certain low voltage traversing capacity, it will cause the converter to trip down at low voltage if the voltage drop or short time interruption is caused by the fault of the power network. Then it threatens the safety of power plant units and seriously affects the safe and stable operation of power grid. Therefore, it is very important to study the low-voltage traversing performance of variable-frequency speed regulation system. In this paper, the concepts of low voltage traversing and double PWM converter are introduced, and the current research status of domestic and foreign scholars and experts on low voltage traversing technology of frequency conversion speed regulating system in thermal power plant is analyzed. The realization of double PWM frequency converter modulation method and the design of control system are given in detail, and then the simulation of double PWM converter is completed, and then based on the frequency conversion speed regulation system of thermal power plant, The low-voltage traversing performance of two different types of inverters is evaluated by field test. The main work of this paper is as follows: (1) starting from the basic structure of the converter, the topology and working principle of the grid-side converter are analyzed, and the mathematical models of the grid-side converter in the three-phase stationary coordinate system and the two-phase rotating coordinate system are established, respectively. The working principle of the grid-side converter is explained according to its topological structure and mathematical model. (2) based on the main circuit structure of three-level inverter, the three-level SVPWM (Space Vector Pulse width Modulation) algorithm is studied emphatically. The change of switching state in each phase output is analyzed, and an algorithm for synthesizing reference voltage vectors based on the principle of the nearest three vectors is presented. By judging the position of the reference voltage vector, the basic vector is properly selected, and then the action time and the corresponding sequence of action of each basic vector are obtained, and then the working time of the vector is allocated to the corresponding vector state. Thus the switch on and off are effectively controlled. (3) the double closed loop control strategy is used to design the control system of double SVPWM converters on the grid side and load side. The voltage outer loop and current inner loop are used in the grid-side converter, while the power outer loop and current inner loop are used in the load-side converter. The parameters of the Pi regulator are determined by the corresponding transfer function. The simulation model of double SVPWM inverter is built on MATLAB/SIMULINK platform. The simulation results show that the SVPWM algorithm is effective and the design of control system is feasible. The quality of output voltage and current waveform is good. The conversion efficiency of rectifier and inverter is improved. (4) taking the frequency conversion speed regulating system of auxiliary machine of a thermal power plant in Anhui province as an example, the low voltage traversing performance test is carried out by selecting one frequency converter of different type power feeder at random. The test results of low voltage traversing performance of frequency conversion speed regulating system of auxiliary machine are obtained, and the test results are obtained. In view of the frequency converter of the auxiliary machine without low voltage traversing ability, this paper discusses several schemes to solve the problem of low voltage crossing of frequency conversion speed regulating system of auxiliary machine in power plant, and improves the reliability of safe and stable operation of power network.
【學(xué)位授予單位】：安徽大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM921.51;TM621
【參考文獻】
相關(guān)期刊論文 前10條
1 綦慧;盧昭禹;;I型NPC式三電平變流器中點電位平衡控制的研究與實現(xiàn)[J];電氣技術(shù);2016年12期
2 鄭重;李衛(wèi)華;耿華;楊耕;;火電廠輔機變頻器低電壓穿越技術(shù)綜述[J];電力自動化設(shè)備;2016年12期
3 余發(fā)山;劉根鋒;張宏偉;耿沖;;單相PWM整流器前饋解耦控制策略研究[J];電源技術(shù);2016年10期
4 孔凡超;胡世杰;劉孟茹;牟振天;陳汝巍;;NPC三電平逆變器SVPWM的研究[J];電子世界;2016年10期
5 湯偉;劉路登;殷駿;李剛;;火電機組輔機變頻調(diào)速系統(tǒng)低電壓穿越測試[J];中國電力;2016年02期
6 丁慧慧;陳劍;史經(jīng)叢;張曉;;三相電壓型PWM整流器改進的不平衡控制策略[J];電力電子技術(shù);2016年01期
7 王曉宇;張濤;劉樹;操豐梅;劉志超;楊奇遜;;火電廠輔機變頻器低電壓穿越電源[J];電力自動化設(shè)備;2015年05期
8 高娜;柴貴蘭;;一種基于αβ變換前饋控制策略的三相PWM整流系統(tǒng)設(shè)計[J];自動化與儀器儀表;2015年04期
9 史麗萍;于婷;羅朋;馮學(xué)俊;;基于改進擾動功率法的電壓暫降源定位[J];電測與儀表;2015年07期
10 周道軍;;變頻器防低電壓穿越分析[J];江蘇電機工程;2015年02期
，本文編號：2173374
本文鏈接：http://sikaile.net/kejilunwen/dianlidianqilunwen/2173374.html
最近更新
教材專著
