What is the prospect of insulation paper for switched reluctance motors?
Switched reluctance motor insulation paper is a new type of speed control drive system that emerged in the early 1980s with the rapid development of power electronics, microcomputers, and control skills. It has the characteristics of simple structure, reliable operation, and advanced power, becoming a strong competitor for communication motor insulation paper speed control systems, DC motor insulation paper speed control systems, and brushless DC motor insulation paper speed control systems, Causing widespread attention from experts and business communities from various countries. Emerson Electric, a multinational motor insulation paper company, also sees switch reluctance motor insulation paper as a new skill and economic growth point for its next century speed control drive system. Nowadays, insulation paper for switched reluctance motors has been widely or begins to be used in various fields such as industry, aviation, and household appliances.
In 1970, the stepper motor insulation paper research group at Leeds University in the UK pioneered the prototype of Switched Reluctance Motor (SRM) insulation paper, which was the earliest research on SRM insulation paper. In 1972, further research was conducted on low-power motors with semiconductor switches (10w~1kw). By 1975, there had been substantial development, and it had always been expanded to provide equipment for 50kw battery cars. In 1980, SRD Ltd. was established in the UK, specializing in the research, development, and design of the SRD system. In 1983, the UK (SRD Ltd.) first launched the SRD series of products, named OULTON. In 1984, TASC Drive Systems also launched their products. Other SRD Ltd. have developed a drive system suitable for trams, which has been operating for 500 kilometers by 1986. The presentation of this product has caused significant reactions in the electrical transmission industry. Many utility policies have reached unexpectedly high levels, and the overall system's inductive utility pricing policies have reached or exceeded some of the widely used variable speed transmission systems in industry for a long time. From the articles on the SRD system at the international conferences in the 1990s, it can be seen that the research on the SRD system has now moved from confirming its benefits, developing and applying it, to discussing design theory and optimizing design. We have conducted more in-depth discussions on the working theory, optimized design, and construction methods of SR motor insulation paper, controllers, power converters, etc.
2、 Introduction to Principle and Advantages: The Switched Reluctance Motor Drive System (SRD) is a relatively chaotic electromechanical integrated device. The working requirements of SRD are usually based on real-time online inspection of rotor orientation, speed, and current, and then summarized according to the control policy to provide control instructions, complete work control and maintenance functions. The rotor orientation inspection process is one of the primary components of SRD, and the detected rotor orientation signal is the basis for accurate logical switching of each phase of the main switch equipment, and also provides speed response signals for the speed control process. Switched reluctance motor insulation paper has the talent of regeneration and high system power. The theoretical research and practical application of insulation paper for switched reluctance motors have confirmed that this system has many significant benefits: (1) the structure of motor insulation paper is simple and stable, the production skills are simple, the cost is low, and it can work at extremely high speeds; The stator coil is simple to embed, with short and robust ends, and works reliably, making it suitable for various harsh, high temperature, and even strong oscillation environments. (2) The loss mainly occurs in the stator, and the motor insulation paper is easy to cool; The rotor does not have permanent magnets, allowing for a higher temperature rise. (3) The torque direction is independent of the current direction, which can greatly simplify the power converter and reduce the system cost. (4) The power converter will not exhibit direct defects and has high reliability. (5) The starting torque is high, and the low-speed function is good. There is no appearance of impulse current when starting an induction motor. (6) Wide speed regulation scheme, flexible control, and easy to achieve various specially requested torque speed characteristics. (7) It has high power within a wide range of speed and power schemes. (8) Capable of working in four quadrants and possessing strong regenerative braking talent. (9) Fault tolerance is the key to success. The fault-tolerant body of the switch reluctance motor insulation paper is now damaged in one phase of the motor insulation paper, and the motor insulation paper can still work. Compared with the widely used variable frequency variable speed induction motors at the time, the insulation paper for switched reluctance motors has significant advantages or competitiveness in terms of cost, power, speed regulation function, unit volume power, reliability, heat dissipation, etc. If the power of the first generation of switched reluctance motor insulation paper (developed in 1983) is lower than that of high-efficiency variable frequency variable speed induction motors in low-power schemes, the power of the second generation of switched reluctance motor insulation paper (developed in 1988) has all surpassed that of high-efficiency variable frequency variable speed induction motors. Even more valuable is that the insulation paper of the switched reluctance motor can adhere to higher power within a wide range of speed and power schemes, which is difficult to compare with variable frequency variable speed induction motors. In order to achieve the speed regulation characteristics near the insulation paper of an induction motor and a DC motor, a chaotic vector control system needs to be selected. However, the insulation paper of a switched reluctance motor can obtain different mechanical characteristics required by different loads by adjusting the registration angle, turn off angle, voltage, and current. The control is simple and flexible, and can easily end soft start and four quadrant operation. Moreover, as this is a purely logical control method, it is very simple and intelligent, After modifying the software, the working characteristics of the motor insulation paper were adjusted to meet different requirements. Due to the inherent torque instability of the insulation paper for switched reluctance motors, it may cause significant noise and oscillation. In fact, this condition is usually related to the unreasonable design and operation of the motor insulation paper. After optimizing the design and operation strategy of the motor insulation paper, torque instability and noise can be effectively suppressed. Accurately recognizing this is crucial for the development and application of the insulation paper for switched reluctance motors. The servo motor insulation paper developed by SRD Ltd. for switched reluctance motors has a torque of only 0.05%. The strategies of optimizing excitation control, twice commutation control, the source of motor insulation paper noise, stator oscillation mode, and calculation of stator natural frequency discussed in recent years have active promoting effects on reducing motor insulation paper noise. As the level of design and production progresses, noise will inevitably further decrease.
3、 The application of insulation paper for switched reluctance motors has made significant progress in recent years. It has been successfully applied in various fields such as electric vehicle drive, general industry, household appliances, and textile machinery, with power solutions ranging from 10W to 5MW and speeds up to 100000 r/min.
3.1 The application field of switch reluctance motor insulation paper in electric vehicles is electric vehicles. Nowadays, the drive motor insulation paper of electric motorcycle and electric bicycle mainly includes permanent magnet brushless and permanent magnet brush, but the use of switched reluctance motor insulation paper drive has its own advantages. When high energy density and system power are crucial policies, insulation paper for switched reluctance motors becomes a good policy.
The motor insulation paper structure of the SRD switch reluctance motor insulation paper drive system is compact and robust, suitable for high-speed work, and the driving circuit is simple, low in cost, reliable in function, relatively high in power within a wide range of speed schemes, and can easily end four quadrant control. These characteristics make the SRD switched reluctance motor insulation paper drive system very suitable for various working conditions of electric vehicles, and it is a highly potential model in electric vehicles. The characteristics of SRD are high torque ripple and high noise; In addition, compared to permanent magnet motor insulation paper, the power density and power are relatively low; Another drawback is the use of directional sensors, which increases structural clutter and reduces reliability. Therefore, sensorless SRD is also one of the future trends. The main benefits of switched reluctance motor insulation paper are as follows: (1) It not only has high power, but also can adhere to high power within a wide range of power and speed schemes, which is difficult for other types of drive systems to achieve. This characteristic is particularly suitable for the working conditions of electric vehicles, which is conducive to the continued driving journey of electric vehicles. (2) The insulation paper of the switched reluctance motor is very simple, and after selecting the appropriate control strategy and system design, it meets the requirements of four-quadrant operation of electric vehicles, and can also adhere to strong braking talent in high-speed working areas. (3) Switched reluctance motor insulation paper has excellent heat dissipation characteristics, and can obtain larger output power in a small volume, reducing the volume and weight of motor insulation paper. (4) After adjusting the registration angle and turn off angle, the insulation paper of the switched reluctance motor can fully achieve the excellent control characteristics of the excitation DC motor insulation paper drive system. This is a purely logical control method, which is very simple and intelligent. Then, it can be programmed from scratch or replaced with circuit components, conveniently satisfying the requirements of different working characteristics. (5) Switched reluctance motor insulation paper, whether used for motor insulation or power converters, is very stable and reliable, requiring little or no maintenance. It is suitable for various harsh and high-temperature environments and has excellent adaptability.
3.2 The textile industry has made significant progress in the electromechanical integration level of China's textile machinery industry over the past decade, and electromechanical integration skills have been widely used in new textile machinery. The content of this skill includes preemptive information processing and control skills, that is, a control system based on an accounting machine, consisting of PLC, industrial control computer, microcontroller, human-machine interface, fieldbus, etc; Advanced driving skills, including variable frequency speed regulation, communication servo, stepper motor insulation paper, etc; Check sensing skills and actuator; Precision mechanical skills, etc. Cotton textile equipment is a representative electromechanical integration product, such as new roving machines, slitting warping machines, sizing machines, etc. In the meantime, the main transmission skills of shuttleless looms have also made new breakthroughs: the selection of switched reluctance motor insulation paper as the main transmission of shuttleless looms has brought many benefits, reducing transmission gears, eliminating the need for belt and belt pulley, eliminating the need for electromagnetic clutch and brake disc, eliminating the need for weft finding motor insulation paper, saving energy by 10% and other benefits. There are already products of switched reluctance motor insulation paper and drivers in China (Beijing Zhongfang Electromechanical Research Institute), We are still collaborating with the main machine factory of shuttleless looms to develop and apply skills, hoping to quickly achieve success and fill the gap in China.
3.3 The use of switched reluctance motor insulation paper (SRD) in the coke industry is particularly suitable for mine conveyors, electric traction shearers, and small and medium-sized winches due to its high starting torque and low starting current, allowing for repeated heavy load starting without the need for other power transformers, energy conservation, and simple maintenance.
In the 1990s, the UK successfully developed a 300kW switched reluctance motor insulation paper for scraper conveyors, which has excellent performance. China has successfully developed a 110kW switched reluctance motor insulation paper for the gangue winch, and a 132kW switched reluctance motor insulation paper for the dragging of belt conveyors. Our excellent starting and speed regulation functions have been eagerly awaited. China also uses switch reluctance motor insulation paper for electric traction
