英文原文Switched Reluctance Motors Drive for theElectrical Traction in ShearerH. ChenCollege of Information and Electrical EngineeringChina University of Mining motor control; shearer; coal mine; electrical drive I. 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 the Switched 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. The 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. Figure 1.Photograph of the two three-phase 12/8 structure Switched Reluctance motorThe 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 2Figure 2. Main circuit of the power converter. 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, where, is the given rotor speed, is the practical rotor speed, is the difference of the rotor speed, is the increment of the duty ratio of PWM signal of the Switched Reluctance motor 1 at k time, is the integral coefficient, 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 motor drive system is approximately in proportion to the average DC supplied current of the power converter as follows, where, P2 is the output power of the Switched 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. Figure 3. Block diagram of the double Switched Reluctance motors parallel drive system for the electrical traction in shearerThe deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors at the moment of ti is where, Iin1 is the practical average DC supplied current of the power converter in the Switched Reluctance motor 1 at the moment of ti, Iin2 is the practical average DC supplied current of the power converter in the Switched Reluctance motor 2 at the moment of ti. The variation of the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors at the moment of ti is where, ei-1 is the deviation of the average DC supplied current of the power converter between the two Switched Reluctance 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 is where, ΔD2(i) is the increment of the duty ratio of the PWM signal of 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 as follows, where, E is the fuzzy set of the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors, EC 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, The continuous variation of the deviation of the average DC supplied current of the power converter between the two Switched Reluctance motors could also be changed into the discrete amount at the interval [-5, +5], based on the equations as follows, The 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, There 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 σ is the relative deviation of the average DC supplied current of the power converter in the Switched Reluctance motor 1, σ is the relative deviation of the average DC2 supplied current of the power converter in the Switched Reluctance motor 2, and, TABLE I.TESTS RESULTS OF PROTOTYPEIt 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% . 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. REFERENCES [1] H. Chen, G. Xie, “A Switched Reluctance Motor Drive System for Storage Battery Electric Vehicle in Coal Mine,” Proceedings of the 5th IFAC Symposium on Low Cost Automation, pp.95-99, Sept. 1998. [2] H. Chen, X. Meng, F. Xiao, T. Su, G. Xie, “Fault tolerant control for switched reluctance motor drive,” Proceedings of the 28 Annual Conference of the IEEE Industrial Electronics Society, pp.1050-1054, Nov. 2002. [3] R. M. Davis, W. F. Ray, R. J. Blake, “Inverter drive for switched reluctance motor：circuit and component ratings,” IEE Proc. B, vol.128, no.3, pp. 126-136, Sept. 1981. [4] D. Liu, et al., Switched Reluctance Motor Drive. Beijing: Mechanical Industry Press, 1994. [5] H. Chen, J. Jiang, C. Zhang, G. Xie, “Analysis of the four-phase switched reluctance motor drive under the lacking one phase fault condition,” Proceedings of IEEE 5th Asia-Pacific Conference on Circuit and Systems, pp.304-308, Dec. 2000. 中文譯文電牽引采煤機的開關磁阻電動機摘要：本章介紹了電牽引采煤機雙重開關磁阻電動機的并聯(lián)驅動系統(tǒng)。該系統(tǒng)由開關磁阻電動機，功率變換器電路和控制器組成。給出了由通過采用比例積分算法的調(diào)節(jié)轉子速度的閉環(huán)回路和模糊邏輯算法實現(xiàn)的負荷的均衡分布組成的控制策略。介紹了實驗結果。開關磁阻電動機 1 和開關磁阻電動機 2 的功率變換器的平均直流的相對誤差為 。0%?關鍵詞：開關磁阻；電動控制；采煤機；煤礦；電傳動Ⅰ.介紹煤礦的地下環(huán)境是非常惡劣的。一方面由于它是潮濕的,高粉塵的,和易燃的環(huán)境。另一方面，為了節(jié)約開采成本，巷道空間是有限，以至于設備很難維護。自動化設備在現(xiàn)代化煤礦已經(jīng)得到廣泛應用。自動化設備的故障會直接影響到煤礦的產(chǎn)量和效益。采煤機是采煤的主要礦山設備。傳統(tǒng)的滾筒采煤機是通過液壓傳動系統(tǒng)傳動的。液壓傳動系統(tǒng)的故障率很高，因為液壓傳動系統(tǒng)的液體很容易受環(huán)境污染。液壓傳動系統(tǒng)的故障直接影響到煤礦的產(chǎn)量和效率。電傳動系統(tǒng)比液壓傳動系統(tǒng)的故障率低。但是，礦井中電機傳動系統(tǒng)的散熱性差，是因為為了煤礦安全，電機傳動系統(tǒng)被封裝在防爆的外殼內(nèi)。電機傳動系統(tǒng)是自動化設備的重要組成部分。電機傳動系統(tǒng)的小說類型的發(fā)展對煤礦很重要。開關磁阻電動機傳動是煤礦調(diào)速傳動系統(tǒng)的主要設備，由于它的高工作可靠性和高容錯能力。由雙極點開關磁阻電動機，單級功率變換器和控制器組成的開關磁阻電動機傳動是電動機和功率變換器的核心。電動機沒有毛刷，功率變換器沒有雙極功率變換器的故障。開關磁阻電動機傳動可以在缺相的情況下運行，它是依靠電動機和功率變換器相位獨立性來實現(xiàn)的。轉子上沒有繞組，以至于轉子上沒有銅損和很小的鐵損。因為不需要冷卻轉子，所以很容易冷卻電動機。由開關磁阻電動機傳動的采煤機正在不斷發(fā)展。本章介紹了發(fā)展的樣機。Ⅱ系統(tǒng)組成電牽引采煤機的開關磁阻電動機傳動是一個雙重開關磁阻電動機并聯(lián)傳動系統(tǒng)。這個系統(tǒng)是由兩個開關磁阻電動機，一個控制箱，這個控制箱是安裝在功率變換器和控制器上。采用的開關磁阻電動機是三相 12/8 結構的開關磁阻電動機，如圖一所示。雙重開關磁阻電動機分別包裝在防爆外殼內(nèi)。電動機的額定功率是 40KW，轉速是 1155r/min，調(diào)速范圍是100r/min~1500r/min。圖一：三相 12/8 結構的開關磁阻電動機功率變換器是由兩個三相不對稱橋式變換器并列組成。IGBTs 是電路的主要開關元件。經(jīng)整流后三相交流 380V 電源提供給功率變換器。功率變換器的主要電路如圖二所示。圖二：功率變換器的主要電路控制器由轉子位置檢測電路，整流電路，電流和電壓保護電路，主要開關的門極驅動電路和閉環(huán)調(diào)速數(shù)字控制器和負荷均衡分配組成。Ⅲ.控制方法采用同一個牽引方法，雙重開關磁阻電動機通過傳送設備用來驅動采煤機，來確保雙重開關磁阻電動機的轉子速度同步運行。并聯(lián)驅動的雙重開關磁阻電動機的閉環(huán)轉子調(diào)速回路可以通過比例積分算法來實現(xiàn)。在開關磁阻電動機 1 中，功率變換器主要開關的觸發(fā)信號是通過 PWM 信號調(diào)制的。比較給定的轉子速度和實際的轉子速度， PWM的占空比調(diào)節(jié)如下：其中， 是給定的轉子速度， 是實際的轉子速度， 是轉子速度的差。 在 k 時刻內(nèi)，開關磁阻電動機 1PWM 信號占空比的增量。 是積分系數(shù)， 比例系數(shù)， 轉子速度在 K 時間內(nèi)的差。 轉子速度在K-1 時間內(nèi)的差， 在 k 時刻內(nèi)，開關磁阻電動機 1PWM 信號占空比，在 k-1 時刻內(nèi)，開關磁阻電動機 1PWM 信號占空比。開關磁阻電動機傳動系統(tǒng)的輸出功率和功率變換器的電流成正比，如下所示：其中， 是開關磁阻電動機傳動系統(tǒng)的輸出功率， 功率變換器的平均直流電流。在開關磁阻電動機 2 中，功率變換器主要開關的觸發(fā)信號是通過 PWM信號調(diào)制的。雙重開關磁阻電動機之間的負荷均衡分布是通過模糊邏輯算法來實現(xiàn)的。在模糊邏輯調(diào)節(jié)器中有兩個輸入控制參數(shù)，一個是雙重開關磁阻電動機之間的功率變換器的平均電流的偏差，另一個是雙重開關磁阻電動機之間的功率變換器的平均直流電流的偏差的變化。輸出控制參數(shù)是開關磁阻電動機 2 PWM 信號占空比的增量。電牽引采煤機雙重開關磁阻電動機并列傳動系統(tǒng)的方框圖見圖三所示。圖三： 電牽引采煤機并列傳動系統(tǒng)的方框圖功率變換器平均直流電流在雙重開關磁阻電動機之間的偏差在 時刻為：其中， 在 時刻，功率變換器在開關磁阻電動機 1 中實際平均直流電流，在 時刻，功率變換器在開關磁阻電動機 2 中實際平均直流.雙重開關磁阻電動機在 時刻的功率變換器平均直流電流的偏差的變量為：其中， 是雙重開關磁阻電動機在 時刻的功率變換器平均電流的偏差。開關磁阻電動機 2 在 時的 PWM 信號的占空比為：其中， 在 時刻的 PWM 信號占空比的增量， 是開關磁阻電動機 2 在 時刻的 PWM 信號的占空比。模糊邏輯算法用以下來表示：其中， 為模糊集合開關磁阻電動機間的功率變換器的平均直流電流的相對誤差， 為模糊集合開關磁阻電動機間的功率變換器的平均直流電流的相對誤差的變量， 為模糊集合中開關磁阻電動機 2 PWM 信號占空比的增量。開關磁阻電動機間的功率變換器的平均直流電流的相對誤差在［-５，+ ５］區(qū)間內(nèi)的連續(xù)偏差可以轉變?yōu)榉稚⑵睢９饺缦拢洪_關磁阻電動機間的功率變換器的平均直流電流的相對誤差在區(qū)間內(nèi)的連續(xù)變量可以轉變?yōu)榉稚⒆兞?。公式如下：在區(qū)間［-５，+５］內(nèi)，開關磁阻電動機２的功率變換器ＰＷＭ信號的占空比的分散增量可以轉變?yōu)樵趨^(qū)間［-１.０％，+１.０％］內(nèi)的連續(xù)增量，公式如下：根據(jù)上面的原理，這里是模糊邏輯算法的一個判定形式。模糊邏輯算法是存儲在控制器的程序存儲單元內(nèi)。當檢測到雙重開關磁阻電動機負荷分配差異的時候，開關磁阻電動機２中的ＰＷＭ占空比將被調(diào)節(jié)，這是根據(jù)模糊邏輯算法的判定形式，從而，雙重開關磁阻電動機負荷分配將會達到平衡狀態(tài)。Ⅳ.實驗結果發(fā)展的雙重開關磁阻電動機并聯(lián)傳動系統(tǒng)樣機已經(jīng)通過實驗測量得到了。表一給出了測試結果，其中 為開關磁阻電動機１的功率變換器的平均直流電流的相對誤差， 為開關磁阻電動機２的功率變換器的平均直流電流的相對誤差，即：表一：樣機的實驗結果該表顯示了開關磁阻電動機 1 和開關磁阻電動機 2 的功率變換器的平均直流的相對誤差為 0%?Ⅴ．結論本章介紹了電牽引采煤機雙重開關磁阻電動機的并聯(lián)驅動系統(tǒng)。開關磁阻電動機驅動系統(tǒng)驅動了礦井中的小型采煤機有助于減少采煤機的故障率，提高了采煤機的工作可靠性，直接增加了煤礦的效益。相對于單級開關磁阻電動機的驅動，雙重開關磁阻電動機并聯(lián)傳動系統(tǒng)的驅動也有助于提高工作可靠性。REFERENCES [1] H. Chen, G. Xie, “A Switched Reluctance Motor Drive System for Storage Battery Electric Vehicle in Coal Mine,” Proceedings of the 5th IFAC Symposium on Low Cost Automation, pp.95-99, Sept. 1998. [2] H. Chen, X. Meng, F. Xiao, T. Su, G. Xie, “Fault tolerant control for switched reluctance motor drive,” Proceedings of the 28 Annual Conference of the IEEE Industrial Electronics Society, pp.1050-1054, Nov. 2002. [3] R. M. Davis, W. F. Ray, R. J. Blake, “Inverter drive for switched reluctance motor：circuit and component ratings,” IEE Proc. B, vol.128, no.3, pp. 126-136, Sept. 1981. [4] D. Liu, et al., Switched Reluctance Motor Drive. Beijing: Mechanical Industry Press, 1994. [5] H. Chen, J. Jiang, C. Zhang, G. Xie, “Analysis of the four-phase switched reluctance motor drive under the lacking one phase fault condition,” Proceedings of IEEE 5th Asia-Pacific Conference on Circuit and Systems, pp.304-308, Dec. 2000.