Abstract: Introduce a soft start device that realizes stepped frequency conversion and stepless adjustment by controlling the transistor and its application in the main fan of large coal mine.
Keywords: three-stage frequency conversion, soft start device
Due to the particularity of production in the coal mine, the mine ventilation system is related to the safe production of the mine, so the ventilation system has a decisive position in coal production. Due to the long power supply line and large starting pressure drop, it is the most important thing to enhance the reliability of the system to ensure that the equipment can safely and reliably start the fan and switch the main and standby switches. In November 2006, Xinyuan Mine of Yangmei Coal Group, the main fan fan newly put into operation is GAF type axial fan (this fan is the largest fan in the Asian coal mine after query). The main fan fan motor 10KV 5000KW asynchronous motor. In order to better solve the impact on the power grid during the start-up and the impact on the load encountered in the project, this system adopts a three-stage variable frequency high-voltage soft start device independently developed and produced by Liaoning Rongxin Power Electronics Co., Ltd.
1. Several starting methods of soft starter
According to the principle of motor starting: 1, step-down starting mode. The traditional decompression starting methods of the motor include Y-Δ start, autotransformer decompression start, reactor start, etc. These starting methods all belong to step-by-step decompression starting, which has obvious shortcomings, that is, secondary inrush current appears during the starting process. At present, the common starting method of high voltage is liquid water resistance starting, and the SCRs are connected in series to reduce pressure. 2. Frequency conversion starting mode. With the development of IGBT technology, the voltage level and capacity of high-voltage frequency conversion are getting larger and larger, but because of the price factor has always restricted its development.
Rongxin Power Electronics Co., Ltd. successfully developed a three-level frequency conversion high-voltage soft starter based on SVC, which has the characteristics of three-level frequency conversion stepless voltage regulation.
2. Technical principles and characteristics of three-stage frequency conversion high-voltage soft start
Connect the high-voltage soft start in series between the power supply and the motor. The principle of the main circuit is shown in Figure 1.
3. Practical application in the main fan motor of Xinyuan Mine.
Xinyuan Mine of Yangmei Coal Group is a newly built mine. Its power grid capacity is 35KV, 10000KVA. Since this power grid is responsible for the entire underground and power supply of electrical equipment on the well, the power grid has a small margin. The operation of the equipment has strict requirements on the starting current of the main fan. And because it is located in a high-gas area, it uses an axial fan with large air volume and high negative pressure (two-stage fan blades are currently the largest axial fan in Asian mines), and the power of the main fan motor is 10KV, 5000KW. In the whole starting process, it has the advantages of large starting torque, small starting current, smooth starting and short starting time. The measured data is shown in Table 1.
4 Conclusion
The system was formally put into operation in November 2006, and has been running well so far, without any malfunction. It has found a high-performance, cost-effective starting device for large-scale motor equipment for mining in the future.
references:
[1] Wang Chengyuan, Xia Jiakuan, Yang Junyou, etc. Modern Motor Control Technology. Beijing: Machinery Industry Press, 2007.
[2] Li Dehua. AC speed regulation system. Beijing: Electronic Industry Press. 2003.
[3] Wu Fengjiang, Gao Hanying, Sun Li, etc. Research on the fast algorithm of SUPWM based on DSP. Electric Drive 2006 (9): 44 ～ 49.
[4] Huang Jun, Wang Zhaoan. Power Electronics Converter Technology. Beijing: Machinery Industry Press. 1999.
[5] Xie Baochang, Ren Yongde. DSP control technology of motor and its application. Beijing: Beijing University of Aeronautics and Astronautics Press. 2005.
[6] Chen Boshi. Electric Drive Automatic Control System-Motion Control System (Third Edition). Beijing: Machinery Industry Press, 2004.
[7] Bimal K. Bose. Modern Power Electronics and AC Drive. Wang Cong, Zhao Jin, Yu Qingguang, Cheng Hong, etc. Beijing: Machinery Industry Press, 2005.
[8] Hu Changsheng, Han Yu, Su Xing, etc. Research on high cost-effective soft starter [J]. Power Electronics Technology, 2004, 38 (5). 51 ~ 85.
[9] Su Xing. Research on Electronic Soft Starter [D]. Hangzhou: Zhejiang University, 2004.
Keywords: three-stage frequency conversion, soft start device
Due to the particularity of production in the coal mine, the mine ventilation system is related to the safe production of the mine, so the ventilation system has a decisive position in coal production. Due to the long power supply line and large starting pressure drop, it is the most important thing to enhance the reliability of the system to ensure that the equipment can safely and reliably start the fan and switch the main and standby switches. In November 2006, Xinyuan Mine of Yangmei Coal Group, the main fan fan newly put into operation is GAF type axial fan (this fan is the largest fan in the Asian coal mine after query). The main fan fan motor 10KV 5000KW asynchronous motor. In order to better solve the impact on the power grid during the start-up and the impact on the load encountered in the project, this system adopts a three-stage variable frequency high-voltage soft start device independently developed and produced by Liaoning Rongxin Power Electronics Co., Ltd.
1. Several starting methods of soft starter
According to the principle of motor starting: 1, step-down starting mode. The traditional decompression starting methods of the motor include Y-Δ start, autotransformer decompression start, reactor start, etc. These starting methods all belong to step-by-step decompression starting, which has obvious shortcomings, that is, secondary inrush current appears during the starting process. At present, the common starting method of high voltage is liquid water resistance starting, and the SCRs are connected in series to reduce pressure. 2. Frequency conversion starting mode. With the development of IGBT technology, the voltage level and capacity of high-voltage frequency conversion are getting larger and larger, but because of the price factor has always restricted its development.
Rongxin Power Electronics Co., Ltd. successfully developed a three-level frequency conversion high-voltage soft starter based on SVC, which has the characteristics of three-level frequency conversion stepless voltage regulation.
2. Technical principles and characteristics of three-stage frequency conversion high-voltage soft start
Connect the high-voltage soft start in series between the power supply and the motor. The principle of the main circuit is shown in Figure 1.
Figure 1 Schematic diagram of the main circuit
3. Practical application in the main fan motor of Xinyuan Mine.
Xinyuan Mine of Yangmei Coal Group is a newly built mine. Its power grid capacity is 35KV, 10000KVA. Since this power grid is responsible for the entire underground and power supply of electrical equipment on the well, the power grid has a small margin. The operation of the equipment has strict requirements on the starting current of the main fan. And because it is located in a high-gas area, it uses an axial fan with large air volume and high negative pressure (two-stage fan blades are currently the largest axial fan in Asian mines), and the power of the main fan motor is 10KV, 5000KW. In the whole starting process, it has the advantages of large starting torque, small starting current, smooth starting and short starting time. The measured data is shown in Table 1.
date | Wind leaf series | Fan blade angle | Starting current | Starting time | Normal current after starting |
10.20 | First class wind blade | -15 | 1.8Ie | 25S | 80A |
-10 | 1.8Ie | 28S | 100A | ||
-5 | 2Ie | 30S | 150A | ||
0 | 2Ie | 33S | 180A | ||
Secondary wind blade | -15 | 2Ie | 25S | 200A | |
-10 | 2Ie | 30S | 240A | ||
-5 | 2.3Ie | 35S | 300A | ||
0 | 2.4Ie | 38S | 340A |
4 Conclusion
The system was formally put into operation in November 2006, and has been running well so far, without any malfunction. It has found a high-performance, cost-effective starting device for large-scale motor equipment for mining in the future.
references:
[1] Wang Chengyuan, Xia Jiakuan, Yang Junyou, etc. Modern Motor Control Technology. Beijing: Machinery Industry Press, 2007.
[2] Li Dehua. AC speed regulation system. Beijing: Electronic Industry Press. 2003.
[3] Wu Fengjiang, Gao Hanying, Sun Li, etc. Research on the fast algorithm of SUPWM based on DSP. Electric Drive 2006 (9): 44 ～ 49.
[4] Huang Jun, Wang Zhaoan. Power Electronics Converter Technology. Beijing: Machinery Industry Press. 1999.
[5] Xie Baochang, Ren Yongde. DSP control technology of motor and its application. Beijing: Beijing University of Aeronautics and Astronautics Press. 2005.
[6] Chen Boshi. Electric Drive Automatic Control System-Motion Control System (Third Edition). Beijing: Machinery Industry Press, 2004.
[7] Bimal K. Bose. Modern Power Electronics and AC Drive. Wang Cong, Zhao Jin, Yu Qingguang, Cheng Hong, etc. Beijing: Machinery Industry Press, 2005.
[8] Hu Changsheng, Han Yu, Su Xing, etc. Research on high cost-effective soft starter [J]. Power Electronics Technology, 2004, 38 (5). 51 ~ 85.
[9] Su Xing. Research on Electronic Soft Starter [D]. Hangzhou: Zhejiang University, 2004.
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