2323 采煤機搖臂設(shè)計

2323 采煤機搖臂設(shè)計,采煤,搖臂,設(shè)計 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計（論文）中期檢查表指導(dǎo)教師： 韓曉明 職稱： 教授 所在院（系）： 機械與動力工程系 教研室（研究室）： 機械與動力工程部 題 目 采煤機搖臂設(shè)計學(xué)生姓名 李繼釗 專業(yè)班級 08 機設(shè) 4 班 學(xué)號 0828070064一、選題質(zhì)量：（主要從以下四個方面填寫：1、選題是否符合專業(yè)培養(yǎng)目標，能否體現(xiàn)綜合訓(xùn)練要求；2、題目難易程度；3、題目工作量；4、題目與生產(chǎn)、科研、經(jīng)濟、社會、文化及實驗室建設(shè)等實際的結(jié)合程度）所選題目完全符合專業(yè)培養(yǎng)目標，涉及到許多已學(xué)過的專業(yè)知識。畢業(yè)設(shè)計是對大學(xué)四年的所選專業(yè)知識的能力，提高綜合素質(zhì)，以便更好地與實際相接軌。此題目難易程度適中，適合本科生畢業(yè)設(shè)計的要求。在做畢業(yè)設(shè)計的過程中翻閱了大量相關(guān)知識，對采煤機搖臂方面的知識有了比較系統(tǒng)的了解。2、開題報告完成情況：畢業(yè)論文設(shè)計書已基本完成，大部分資料已找到三、階段性成果：搖臂整體設(shè)計方案以確定各零件的數(shù)據(jù)已基本完成已開始 cad 作圖四、存在主要問題：一些傳動系統(tǒng)的參數(shù)還不能確定Cad 作圖不是很熟悉五、指導(dǎo)教師對學(xué)生在畢業(yè)實習(xí)中，勞動、學(xué)習(xí)紀律及畢業(yè)設(shè)計（論文）進展等方面的評語指導(dǎo)教師： （簽名）年 月 日河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計（論文）開題報告題目名稱 采煤機搖臂設(shè)計學(xué)生姓名 李繼釗專業(yè)班級08 機設(shè) 4 班 學(xué)號0828070064一、 選題的目的和意義：采煤機是實現(xiàn)煤礦生產(chǎn)機械化和現(xiàn)代化的重要設(shè)備之一。機械化采煤可以減輕體力勞動、提高安全性，達到高產(chǎn)量、高效率、低消耗的目的。采煤機分鋸削式、刨削式、鉆削式和銑削式四種：采煤機是一個集機械、電氣和液壓為一體的大型復(fù)雜系統(tǒng),工作環(huán)境惡劣,如果出現(xiàn)故障將會導(dǎo)致整個采煤工作的中斷,造成巨大的經(jīng)濟損失.隨著煤炭工業(yè)的發(fā)展,采煤機的功能越來越多,其自身的結(jié)構(gòu)、組成愈加復(fù)雜,因而發(fā)生故障的原因也隨之復(fù)雜。雙滾筒采煤機綜合了國內(nèi)外薄煤層采煤機的成功經(jīng)驗，是針對我國具體國情而設(shè)計的新型大功率薄煤層采煤機。采煤機是煤炭工業(yè)的重要機械，近幾年隨著煤炭工業(yè)的發(fā)展，采煤機向著重型化方向發(fā)展。本設(shè)計主要是對采煤機搖臂進行設(shè)計，從而在實際的設(shè)計過程中，不斷地發(fā)現(xiàn)問題解決問題，使產(chǎn)品性能進一步提高，從而更好的適應(yīng)煤炭工業(yè)的發(fā)展。2二、 國內(nèi)外研究綜述：20 世紀 40 年代初，英國和前蘇聯(lián)相繼研制出了鏈式采煤機，這種采煤機是通過截鏈截落煤，在截鏈上安裝有被稱為截齒的專用截煤工具，其工作效率低。同時德國研制出了用刨削方式落煤的刨煤機。50 年代初，英國和德國相繼研制出了滾筒式采煤機，在這種采煤機上安裝有截煤滾筒，這是一種圓筒形部件，其上安裝有截齒，用截煤滾筒實現(xiàn)落煤和裝煤。這種采煤機與可彎曲輸送機配套，奠定了煤炭開采機械化的基礎(chǔ)。這種采煤機的主要缺點有二點：其一是截煤滾筒的高度不能在使用中調(diào)整，對煤層厚度及其變化適應(yīng)性差；其二是截煤滾筒的裝煤效果不佳，限制了采煤機生產(chǎn)率的提高。進入 60 年代，英國、德國、法國和前蘇聯(lián)先后對采煤機的截割滾筒做出革命性改進。其一是截煤滾筒可以在使用中調(diào)整其高度，完全解決對煤層賦存條件的適應(yīng)性；其二是把圓筒形截割滾筒改進成螺旋葉片式截煤滾筒，即螺旋滾筒，極大地提高了裝煤效果。這兩項關(guān)鍵的改進是滾筒式采煤機稱為現(xiàn)代化采煤機械的基礎(chǔ)。三、 畢業(yè)設(shè)計（論文）所用的主要技術(shù)與方法：翻閱資料，調(diào)查文獻，模擬仿真，調(diào)查研究3四、 主要參考文獻與資料獲得情況：李昌熙 沈立山 高榮 《采煤機》.煤炭工業(yè)出版社，1988王啟廣 李炳文. 《采掘機械與支護設(shè)備》.中國礦業(yè)大學(xué)出版社，2006.4王三民. 《機械設(shè)計計算手冊》.化學(xué)工業(yè)出版社，2009.1濮良貴.《機械設(shè)計》.高等教育出版社，2005.12主要在圖書館和網(wǎng)上查詢五、 畢業(yè)設(shè)計（論文）進度安排（按周說明）第 1-2 周，實習(xí)第 3-4 周，提交實習(xí)報告第 5-6 周，提交開題報告第 7-9 周，初步擬定總體設(shè)計方案第 10-14 周，主要設(shè)計階段第 15 周，完成并修改論文第 16 周，提交畢業(yè)論文六、 指導(dǎo)教師審批意見：指導(dǎo)教師： （簽名）年 月 日 4外文翻譯英文翻譯Switched Reluctance Motors Drive for the Electrical Traction in ShearerAbstract—The paper presented the double Switched Reluctance motors parallel drive system for the electrical traction in shearer. The system components, such as the Switched Reluctance motor, the main circuit of the power converter and the controller, were described. The control strategies of the closed-loop rotor speed control with PI algorithm and balancing the distribution of the loads with fuzzy logic algorithm were given. The tests results were also presented. It is shown that the relative deviation of the average DC supplied current of the power converter in the Switched Reluctance motor 1 and in the Switched Reluctance motor 2 is within ?10%.Keywords- switched reluctance; motor control; shearer; coalmine; electrical driveI. INTRODUCTIONThe underground surroundings of the coal mines are very execrable. One side, it is the moist, high dust and inflammable surroundings. On the other side, the space of roadway is limited since it is necessary to save the investment of exploiting coal mines so that it is difficult to maintain the equipments. In the modern coal mines, the automatization equipments could be used widely. The faults of the automatization equipments could affect the production and the benefit of the coal mines. The shearer is the mining equipment that coal could be cut from the coal wall. The traditional shearer was driven by the hydrostatic transmission system. The fault ratio of the hydrostatic transmission system is high since the fluid in hydrostatic transmission system could be polluted easily. The faults of the hydrostatic transmission system could affect the production and the benefit of the coal mines directly. The fault ratio of the motor drive system is lower than that of the hydrostatic transmission system, but it is difficult to cool the motor drive system in coal mines since the motor drive system should be installed within the flameproof enclosure for safety protection. The motor drive system is also one of the pivotal parts in the automatization equipments. The development of the novel types of the motor drive system had been attached importance to by the coal mines. The Switched Reluctance motor drive could become the main equipments for adjustable speed electrical drive system in coal mines [1], because it has the high operational reliability and the fault tolerant ability [2]. The Switched Reluctance motor drive made up of the double-salient pole Switched Reluctance motor, the unipolar power converter and the controller is firm in the motor and in the power converter. There is no brush structure in the motor and no fault of ambipolar power converter in the power converter [3][4]. The Switched Reluctance motor drive could be operated at the condition of lacked phases fault depended on the independence of each phase in the motor and the power converter [5]. There is no winding in the rotor so that there is no copper loss in the loss and there is only little iron loss in the rotor. It is easy to cool the motor since it is not necessary to cool the rotor. The shearer driven by theSwitched Reluctance motor drive had been developed. The paper presented the developed prototype.II. SYSTEM COMPONENTSThe developed Switched Reluctance motors drive for the electrical traction in shearer is a type of the double Switched Reluctance motors parallel drive system. The system is made up of two Switched Reluctance motors, a control box installed the power converter and the controller. The adopted two Switched Reluctance motors are all three- phase 12/8 structure Switched Reluctance motor, which were shown in Figure 1. Figure 1. Photograph of the two three-phase 12/8 structure Switched Reluctance motorThe two Switched Reluctance motors were packing by the explosion-proof enclosure, respectively. The rated output power of one motor is 40 KW at the rotor speed 1155 r/min, and the adjustable speed range is from 100 r/min to 1500r/min. The power converter consists of two three-phase asymmetric bridge power converter in parallel. The IGBTs were used as the main switches. Three-phase 380V AC power source was rectificated and supplied to the power converter. The main circuit of the power converter was shown in Figure 2.In the controller, there were the rotor position detection circuit, the commutation circuit, the current and voltage protection circuit, the main switches’ gate driver circuit and the digital controller for rotor speed closed-loop and balancing the distribution of the loads.III. CONTROL STRATEGYThe two Switched Reluctance motor could all drive the shearer by the transmission outfit in the same traction guide way so that the rotor speed of the two Switched Reluctance motors could be synchronized. The closed-loop rotor speed control of the double Switched Reluctance motors parallel drive system could be implemented by PI algorithm. In the Switched Reluctance motor 1, the triggered signals of the main switches in the power converter are modulated by PWM signal, the comparison of the given rotor speed and the practical rotor speed are made and the duty ratio of PWM signal are regulated as follows,1() 1(1)()e=gfkikpknDKe?????Awhere, ng is the given rotor speed, nf is the practical rotorspeed, e is the difference of the rotor speed, is the increment 1()kD?of the duty ratio of PWM signal of the Switched Reluctance motor 1 at k time, Ki is the integral coefficient, Kp is the proportion coefficient, ek is the difference of the rotor speed at k time, ek-1 is the difference of the rotor speed at k-1 time, D1(k) is the duty ratio of PWM signal of the Switched Reluctance motor 1 at k time, and D1(k-1) is the duty ratio of PWM signal of the Switched Reluctance motor 1 at k-1 time.The output power of the Switched Reluctance motordrive system is approximately in proportion to theaverage DC supplied current of the power converter asfollows, where, P2 is the output power of the Switched 2inpI?Reluctance motor drive system, Iin is the average DC supplied current of the power converter. In the Switched Reluctance motor 2, the triggered signals of the main switches in the power converter are also modulated by PWM signal. The balancing the distribution of the loads between the two Switched Reluctance motors could be implemented by fuzzy logic algorithm. In the fuzzy logic regulator, there are two input control parameters, one is the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors, and the other is the variation of the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors. The output control parameter is the increment of the duty ratio of the PWM signal of the Switched Reluctance motor 2. The block diagram of the double Switched Reluctance motors parallel drive system for the electrical traction in shearer was shown in Figure 3.The deviation of the average DC supplied current ofthe power converter between the two Switched Reluctance motors at the moment of ti is:12inieI??.1iie?where, ei-1 is the deviation of the average DC suppliedcurrent of the power converter between the two SwitchedReluctance motors at the moment of ti-1. The duty ratio of the PWM signal of the Switched Reluctance motor 2 at the moment of ti is2()(1)2()iiiD????where, is the increment of the duty ratio of the PWM signal of ()i?the Switched Reluctance motor 2 at the moment of ti and D2(i-1) is the duty ratio of the PWM signal of the Switched Reluctance motor 2 at the moment of ti-1.The fuzzy logic algorithm could be expressed asfollows,if and then U~ ? ~ifEi?~CjE?~U?i = 1,2,…, m, j = 1,2, …,nwhere, E~ is the fuzzy set of the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors, E~C is the fuzzy set of the variation of the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors, and U~ is the fuzzy set of the increment of the duty ratio of the PWM signal of the Switched Reluctance motor 2.The continuous deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors could be changed into the discrete amount at the interval [-5, +5], based on the equations as follows,??? []102eieINTK?AThe discrete increment of the duty ratio of PWM signal of the Switched Reluctance motor 2 at the interval [-5, +5] could be changed into the continuous amount at the interval [-1.0%, +1.0%], based on the equations as follows,12()[]0.i DDINTK??AAThere is a decision forms of the fuzzy logic algorithm based on the above principles, which was stored in the programme storage cell of the controller.While the difference of the distribution of the loads between the two Switched Reluctance motors could be got, the duty ratio of PWM signal of the Switched Reluctance motor 2 will be regulated based on the decision forms of the fuzzy logic algorithm and the distribution of the loads between the two Switched Reluctance motors could be balanced.IV. TESTED RESULTSThe developed double Switched Reluctance motors parallel drive system prototype had been tested experimentally. Table I gives the tests results, where is the relative deviation of the average DC 1?supplied current of the power converter in the Switched Reluctance motor 1, is the relative deviation of the average DC supplied 2current of the power converter in the Switched Reluctance motor 2, and, 1210%iniiiiI??????122iniiiiI?It is shown that the relative deviation of the average DC supplied current of the power converter in the SwitchedReluctance motor 1 and in the Switched Reluctance motor2 is within 0%?V. CONCLUSIONThe paper presented the double Switched Reluctance motors parallel drive system for the electrical traction in shearer. The novel type of the shearer in coal mines driven by the Switched Reluctance motors drive system contributes to reduce the fault ratio of the shearer, enhance the operational reliability of the shearer and increase the benefit of the coal mines directly. The drive type of the double Switched Reluctance motors parallel drive system could also contribute to enhance the operational reliability compared with the drive type of the single Switched Reluctance motor drive system.中文譯文開關(guān)磁阻電動機驅(qū)動電牽引采煤機摘要-本文介紹了雙開關(guān)磁阻電動機并聯(lián)傳動系統(tǒng)控制驅(qū)動電牽引采煤機。 本文介紹了系統(tǒng)的各個組件，如開關(guān)磁阻電機，主電路中的功率變換器和控制器等。 這里給出了它的控制原理，它主要是用 PI算法和載荷均勻分布的模糊算法獲得信號來控制電機轉(zhuǎn)速這樣一個閉環(huán)系統(tǒng)。 這里也列出了它的測試結(jié)果。測試結(jié)果表明，在磁阻電動機 1上供應(yīng)的平均直流電流于在磁阻電動機 2上的相對誤差在 10％以內(nèi)。 關(guān)鍵詞：開關(guān)磁阻； 電機控制； 采煤機； 煤礦；電牽引。 1、導(dǎo)言地下礦井周圍的環(huán)境是相當惡劣的。 一方面，它非常潮濕和高粉塵并且屬于易燃易爆環(huán)境。 而在另一方面，井下的空間是非常有限的，因為它要節(jié)約開采礦井的投資，所以這些給井下設(shè)備的維護帶來了很大的困難。 在現(xiàn)代煤礦開采過程中，自動化設(shè)備得到了廣泛的使用，但是自動化設(shè)備的故障，可以影響到煤礦的正常生產(chǎn)和生產(chǎn)效益。 采煤機是可以將煤從煤壁中開采下來的采礦設(shè)備。傳統(tǒng)的采煤機是用液壓傳動系統(tǒng)驅(qū)動的，但是由于液壓系統(tǒng)中的油液很容易被污染所以導(dǎo)致液壓系統(tǒng)的故障率很高。液壓傳動系統(tǒng)的故障可能直接影響礦井的生產(chǎn)和效益。電機驅(qū)動系統(tǒng)的故障率相對液壓傳動系統(tǒng)是比較低的，但是由于電機安裝在防暴外殼中所以給電機的冷卻帶來了困難。 電機驅(qū)動系統(tǒng)也自動化設(shè)備是其中的關(guān)鍵部件，所以發(fā)展新型電動機調(diào)速系統(tǒng)一直是煤礦開采重視的問題。 開關(guān)磁阻電機驅(qū)動之所以能成為煤礦主要設(shè)備的調(diào)速電氣傳動系統(tǒng)，[1] 因為它具有較高的運行可靠性和容錯能力[2] 。 開關(guān)磁阻電機驅(qū)動由雙凸極開關(guān)磁阻電機，單極功率變換器和控制器組成，它們被固定在電機和電力變換器中。 在電機中沒有電刷結(jié)構(gòu)，并且雙極功率變換器的功率變換器的故障率比較低。 開關(guān)磁阻電動機可以用在電機和功率變換器相故障少，而且每種相故障取決于其本身的情況下。開關(guān)磁阻電機中沒有繞組轉(zhuǎn)子等，所以沒有銅損的損失，只有在轉(zhuǎn)動過程中很少的鐵損。這樣開關(guān)磁阻電機就很容易冷卻了，因為它沒有必要冷卻轉(zhuǎn)子。 采煤機用的開關(guān)磁阻電機驅(qū)動已經(jīng)研制成功。 文章中給出了樣機。 二、系統(tǒng)組件研制成功的驅(qū)動電牽引采煤機的開關(guān)磁阻電機驅(qū)動是一種雙重開關(guān)磁阻電動機并聯(lián)驅(qū)動的系統(tǒng)。 該系統(tǒng)是由兩個開關(guān)磁阻電動機和一個安裝功率變換器和控制器的控制箱。 通過兩個開關(guān)磁阻電動機都是三相 12 / 8結(jié)構(gòu)。開關(guān)磁阻電機如圖 1所示。 兩個開關(guān)磁阻電動機都分別包在防爆外殼中。其中電機額定功率 40千瓦，額定轉(zhuǎn)速 1155轉(zhuǎn)/分鐘，調(diào)速范圍從 100轉(zhuǎn)/ 分鐘到1500r/min 。功率轉(zhuǎn)換包括兩個三相對稱橋功率轉(zhuǎn)換器并聯(lián)。 該 IGBT的則作為主開關(guān)。三相 380V交流電源被整流并供應(yīng)給電源轉(zhuǎn)換器。主電路中的功率變換器如圖2所示。IGBTS 是主要使用的開關(guān)磁阻電機。在控制器中，有轉(zhuǎn)子位置檢測電路，整流電路，電壓和電流的保護電路，主開關(guān)的柵極驅(qū)動電路和閉環(huán)轉(zhuǎn)速，負荷平衡分布的數(shù)字控制器。 三 控制策略這兩個開關(guān)磁阻電機都可以在相同的牽引導(dǎo)軌上驅(qū)動所有采煤機的輸電裝備，因此這兩個開關(guān)磁阻電動機轉(zhuǎn)子的轉(zhuǎn)速就可以達到同步。這個以閉環(huán)系統(tǒng)控制轉(zhuǎn)速的雙重開關(guān)磁阻電動機驅(qū)動系統(tǒng)時可以采用 PI算法。 在開關(guān)磁阻電動機 1中，功率變換器中主開關(guān)的觸發(fā)信號是通過調(diào)制PWM信號來給定的，當比較給定轉(zhuǎn)速和實際轉(zhuǎn)速時，所用占空比的 PWM 信號，其規(guī)定如下： e=gfn?1() 1()kikpkDKe????A(1))在上式中，ng 表示給定的轉(zhuǎn)速， nf表示實際的速度， e表示給定和實際轉(zhuǎn)速之間的偏差， 表示開關(guān)磁阻電動機 1在 K時刻時 PWM信號占空比的變化()k量，Ki 表示積分系數(shù)，Kp 是比例系數(shù)，ek 表示在 k時刻時轉(zhuǎn)子轉(zhuǎn)速的差值，ek－1 表示在 k－1 時刻時轉(zhuǎn)子轉(zhuǎn)速的差別，D1(k) 表示 k時刻時開關(guān)磁阻電機 1上 PWM的占空比，D1(K-1)表示 k－1 時刻時開關(guān)磁阻電機 1上 PWM的占空比。開關(guān)磁阻電動機調(diào)速系統(tǒng)的輸出功率是與所供應(yīng)的直流電流成比例的，其轉(zhuǎn)換關(guān)系如下： 在此式中，P2 是開關(guān)磁阻電動機調(diào)速系統(tǒng)的輸出功2inpI?率， 表示電源轉(zhuǎn)換器所供應(yīng)的直流電流的平均值。inI圖 2 主電路中的功率轉(zhuǎn)換器在開關(guān)磁阻電動機 2 中，電源轉(zhuǎn)換中主開關(guān)的觸發(fā)信號也是通過 PWM信號所給定的。 這兩開關(guān)磁阻電動機可以通過模糊邏輯算法來平衡其所承受的載荷。在模糊邏輯算法的調(diào)節(jié)中，有兩個輸入控制參數(shù)，一個是電力轉(zhuǎn)換器供應(yīng)這兩個開關(guān)磁阻電動機的直流電流平均值之間的偏差，另一個是電力轉(zhuǎn)換器供應(yīng)這兩個開關(guān)磁阻電動機的直流電流平均值之間偏差的變化。 輸出參數(shù)是開關(guān)磁阻電動機 2的 PWM信號占空比的增量。在圖 3的方框圖中給出了電牽引采煤機中雙重開關(guān)磁阻電動機的并聯(lián)驅(qū)動系統(tǒng)。在 Ti時刻電力轉(zhuǎn)換器供應(yīng)給這兩個開關(guān)磁阻電動機的直流電流的平均值的偏差為： ： 12inieI??.1iie??上式中，ei-1 表示在 ti－1 時刻電力轉(zhuǎn)換器供應(yīng)給這兩個磁阻電動機開關(guān)的平均直流電流的偏差。在 ti時刻開關(guān)磁阻電機 2的 PWM信號的占空比為：2()(1)2()iiiD????上式中， 表示在 ti時刻時開關(guān)磁阻電機 2的 PWM信號占空比的增量， 表示在 ti－1 時刻時開關(guān)磁阻電機 2的 PWM信號的占空比。()i圖 3 電采煤機中的雙磁阻開關(guān)并聯(lián)系統(tǒng)方塊圖這種模糊邏輯算法可以表示成如下形式：if and then U~ ? ~ifEi?~CjE?~U?i = 1,2,…, m, j = 1,2, …,n上式中， 表示電源轉(zhuǎn)換器供應(yīng)給這一對開關(guān)磁阻電動機的平均直流電流的偏差的模糊值， 表示電源轉(zhuǎn)換器供應(yīng)給這兩個開關(guān)磁阻電動機的平均直流~電流偏差的變化的模糊值， 表示開關(guān)磁阻電動機 2的 PWM信號占空比增量的~U模糊值。電力轉(zhuǎn)換器供應(yīng)給這兩個開關(guān)磁阻電動機的平均直流電流之間的連續(xù)偏差可以在區(qū)間[ -5 ，+5 ]的范圍內(nèi)變化，其理論根據(jù)如下：[eiINTK?A102e在區(qū)間[-5 ，+5] 范圍內(nèi)，開關(guān)磁阻電動機 2的 PWM信號占空比的離散增量可以表示成在區(qū)間[-1.0%, +1.0%]內(nèi)的連續(xù)變化，其理論根據(jù)如下： 12()[]i DINTK??AA0.D基于上述原則模糊邏輯算法就形成了既定形式，這將被儲存在控制器的存儲空間中。當這兩個開關(guān)磁阻電動機之間負載有差異時，基于模糊邏輯算法的既定形式開關(guān)磁阻電機 2的 PWM信號的占空比能夠得到調(diào)整，從而這兩個開關(guān)磁阻電動機上的負載便可以達到平衡。 四、測試結(jié)果研制成功的雙開關(guān)磁阻電機并聯(lián)驅(qū)動系統(tǒng)樣機已經(jīng)進行了測試實驗。 表一給出了測試結(jié)果，其中 是開關(guān)磁阻電動機 1中，供應(yīng)給電源轉(zhuǎn)換開關(guān)的平均1?直流電流相對誤差， 是開關(guān)磁阻電動機 2中，供應(yīng)給電源轉(zhuǎn)換開關(guān)的平均直2流電流相對誤差。測試結(jié)果表明，磁阻開關(guān)電動機中供給電源轉(zhuǎn)換開關(guān)的電流偏差在 之10%?內(nèi)。五、結(jié)論文中描述了電牽引采煤用的雙開關(guān)磁阻電動機并聯(lián)傳動系統(tǒng)。 在礦區(qū)使用的開關(guān)磁阻電動機調(diào)速系統(tǒng)驅(qū)動的新型采煤機大大降低了采煤機的故障率，提高采煤機的運行可靠性能直接提高煤礦的經(jīng)濟效益。 驅(qū)動型的雙重開關(guān)磁阻電動機并聯(lián)驅(qū)動系統(tǒng)相比驅(qū)動型的單一開關(guān)磁阻電動機調(diào)速系統(tǒng)也有助于提高運行可靠性。