1. Introduction A new generation of high-performance switched reluctance speed-regulating energy-saving motor systems has been developed and applied in many fields. This switched reluctance speed-regulating energy-saving motor system is a high-tech mechatronics product integrating microprocessor technology, modern control theory, power electronics technology, intelligent control, and motor integration. It possesses excellent speed regulation performance, high reliability, and high energy efficiency. Its performance surpasses that of imported frequency converters and can completely replace them. This is due to the following characteristics. 1.1 Main features of high-performance switched reluctance speed regulation energy-saving motor system (1) High efficiency and energy saving: The system efficiency is above 90% and the efficiency factor is above 0.9 within a wide speed regulation range and load range. The no-load current is less than 1A. (2) Low starting current and high starting torque: When the starting current is 30% of the rated operating current, the starting torque can reach 150% of the rated torque. (3) Superior speed regulation performance: The speed regulation ratio exceeds 1:20. The speed stability is <0.1%. The measured data shows that it can reach 0.06%. (4) Material saving: Saves about 1/3 of the copper material. (5) Simple production process, high reliability and fully digital design, can be remotely controlled by the network. So what are its advantages compared to the Y (star) series motor + frequency converter? 1.2 Comparison of structure and reliability with Y series motor + frequency converter (1) Comparison of switched reluctance motor SRM and Y series motor 1) The Y series motor is made of silicon steel sheets stacked in the rotor, with squirrel cage bars and aluminum loss, the process is relatively complicated, the mechanical strength is relatively low, and the reliability is relatively low; while in the stator: its distributed winding consumes more copper; the peak voltage of the winding is more than 1,000 volts, there is insulation aging, and the life is relatively short. 2) The switched reluctance motor SRM is made of silicon steel sheets stacked in the rotor (see Figure 1), without windings, without squirrel cage bars, the process is simple, the mechanical strength is high, and the reliability is high; in the stator (see Figure 1), the concentrated winding consumes less copper; the peak voltage of the winding is tens of volts, there is no insulation aging, and the life is long. (2) Comparison of Switched Reluctance Motor Controller (SRD) and Frequency Converter 1) Frequency Converter The main circuit topology of the frequency converter or brushless DC motor is shown in Figure 2a. Its main circuit has a through-short circuit hazard: when a phase circuit fails, it cannot generate a rotating magnetic field and the motor cannot run. 2) Controller (SRD) The main circuit topology of the switched reluctance motor system controller is shown in Figure 2b. Its main circuit does not have a through-short circuit hazard; when a phase circuit fails, each phase winding works independently and the motor can continue to work. 1.3 Comparison of performance with Y-series motor + frequency converter 1) Y-series motor + frequency converter In terms of power factor. The rated point is generally around 0.8, and it drops very quickly after deviating from the rated point. In terms of starting current: it is generally 4 to 7 times the rated current; its speed regulation performance: the frequency is best between 36 and 45 Hz, and the efficiency drops sharply below 36 Hz; no-load current: taking 30 kW as an example, the motor current is about 10 to 15 A. 2) Switched Reluctance Motors (SRMs) have a power factor that is generally around 0.95 over a wide range, reaching a maximum of 0.99, and are capacitive loads. The starting current is 30% of the rated current, and 150% of the rated torque can be obtained. Speed ​​regulation performance: speed ratio exceeds 1:20; speed stability: speed fluctuation <0.1%, actual measured data shows it can reach 0.06%; no-load current: taking a 30 kW system as an example, the system current is approximately 0.5A. From the above comparison, it can be seen that the high-performance switched reluctance speed-regulating energy-saving motor system has unique advantages. These "unique advantages" depend on its novel structure. [align=center] [/align] 2. Structural Characteristics of High-Performance Switched Reluctance Speed-Regulating Energy-Saving Motor Systems The switched reluctance speed-regulating energy-saving motor system is a brand-new system, and it is already intelligent and modular (as shown in Figure 3). It not only has excellent speed regulation performance, but also comprehensive protection functions, and has been widely used in many fields. Since its inception, this technology has attracted attention from the electrical and other industries due to its wide speed range, good mechanical characteristics, excellent starting and braking performance, energy saving, and easy maintenance. As shown in Figure 3, the switched reluctance speed-regulating energy-saving motor system is composed of an SRM (switched reluctance motor) and an SRD (controller, including signal processing and power conversion components), forming an electromechanical integrated device capable of exchanging electrical power and mechanical energy input and output; that is, converting electrical energy into mechanical energy, and possibly converting mechanical energy into electrical energy. The actual system can be composed of five main parts: a switched reluctance motor (SRM), a power converter, a microcontroller, and current and position detectors. 2.1 Structural Characteristics of the Switched Reluctance Motor (SRM) It is the component in the system that realizes energy conversion, and it has fundamental differences compared to traditional reluctance motors. Structurally, the SRM adopts a doubly salient pole form, meaning both the stator and rotor are salient pole structures; the stator coils use concentrated windings instead of distributed windings; and the voltage applied to the stator windings is a discontinuous rectangular wave instead of a continuous sine wave. The rotor is made of silicon steel sheets stacked together, without windings or permanent magnets, and the stator has concentrated windings on each pole. Figure 4 shows a cross-sectional view of a 12/8 pole (12 poles stator, 6 poles rotor) four-phase SRM. The SRM has two unique operating modes: current chopping at low speed and single-pulse angle control at high speed. In the current chopping mode, the system controls the torque by adjusting the magnitude of the phase winding current, so it is necessary to accurately know the magnitude of the actual current in the winding and to provide feedback on the current. In the angle position control mode, the system controls the torque by adjusting the trigger angle and the turn-off angle. At this time, the current is no longer used as a control quantity, but in order to prevent the system from overload or malfunction, overcurrent protection is required, so current detection is required in the system. (1) Mechanical characteristics of SRM motor and performance comparison with other speed control systems follow the "principle of minimum magnetic reluctance". After energization, the magnetic circuit tends to change or transform towards the path of minimum magnetic reluctance. When the rotor salient pole and the electronic salient pole are misaligned, the air gap is large and the magnetic reluctance is large. Once the stator magnetic pole winding is energized, a magnetic pull force will be formed on the rotor salient pole, making the air gap smaller and the magnetic reluctance of the magnetic circuit smaller. At the same time, the energizing phase sequence of the stator magnetic pole winding can be switched by an electronic switch according to a certain logic relationship to form a continuous rotating torque. The speed regulation function of the switched reluctance motor is achieved by the switch reluctance motor rotating position detector, power converter and controller (microcontroller) working together. Figure 5 shows the mechanical characteristics of the SAM switched reluctance motor. The reason why it is said to have good mechanical characteristics is that the starting torque is 2 to 3 times greater than the rated torque, as shown by curve A in Figure 5. Table 1 shows the performance comparison of SRM with other speed regulation systems. It can be seen from Table 1 that SRM has high efficiency, low power consumption and energy saving. (2) Power converter The power converter is a switching component that connects the power supply and the motor winding. It feeds power into the motor and can also feed the energy stored in the motor's magnetic field back to the power source. The switching device used in its power conversion circuit is an insulated-gate bipolar transistor (IGBT). It is worth noting that, unlike other systems, the switched reluctance speed-regulating energy-saving motor system can easily achieve different performance characteristics and meet specific performance indicators by changing the motor's operating mode and control parameters. Especially when using a microcontroller as the control core, it often only requires software modification to meet many different performance requirements of the user. 3. Typical Application Examples of High-Performance Switched Reluctance Speed-Regulating Energy-Saving Motor Systems in Oil Pumping and Central Air Conditioning Energy-Saving Systems The application range of high-performance switched reluctance speed-regulating energy-saving motor systems is very wide. With the continuous advancement of technological capabilities and the improvement of semiconductor integrated control technology, its systems have been serialized and applied in industrial sectors, household appliances, and national defense. The following uses applications in oil pumping and central air conditioning energy-saving systems as typical examples. 3.1 Composition and Characteristics of an Oilfield Pumping Unit Drive System Based on SR The system composition is shown in Figure 6. Its features are: 1) Low starting current and high starting torque: When the starting current is 30% of the rated operating current, the starting torque can reach 150% of the rated torque. 2) No demagnetization problem. 3) Increased production benefits: The switched reluctance speed control system can achieve fast upstroke and slow downstroke, thereby increasing the oil filling degree and increasing oil production. 4) Line and maintenance benefits: Based on the above data analysis, using this system can greatly reduce line and power supply capacity, save investment costs, and reduce maintenance costs. 5) Convenient speed adjustment: It can frequently start and stop and switch between forward and reverse operation. 6) Simple operation: There is no need to change the pulley when adjusting the speed; the speed can be adjusted directly by adjusting the button, which can save the crane fees, labor costs, and downtime costs previously incurred when changing the pulley. 7) Long service life: The switched reluctance speed control system can achieve soft start and fast upstroke and slow downstroke characteristics, reducing the wear of the sucker rod and the impact of well conditions, extending the service life, and reducing the number of maintenance times. 8) Anti-electricity theft: If a busbar is built for DC power supply, it can prevent electricity theft. The optimal range is between 36 Hz and 36 Hz; below this range, efficiency drops sharply. 3.2 Composition and Characteristics of an Intelligent Remote Drive System for Oilfield Pumping Units Based on SR The system composition is shown in Figure 7. In addition to possessing all the advantages of the basic type, the remote system also has the following characteristics: It can perform remote monitoring and control; it can achieve peak-shifting and valley-filling control of the pumping unit through a mobile network system, thus optimizing power consumption patterns, reducing oil production costs, and resolving the power grid supply and demand contradiction; it achieves remote monitoring and control without the need for external equipment and sensors, thus making operation simpler and more reliable: for example, the pumping unit's stroke rate can be indirectly measured based on the motor speed (traditionally measured by installing sensors, which has poor reliability and short lifespan); the rod tension can be indirectly calculated and measured based on the motor current; the flow rate can also be calculated and measured based on the motor speed and current; since the SRM's no-load current is very small, less than one ampere, when the belt breaks, it can be determined based on the motor current, thus promptly notifying relevant personnel for handling. Reduce losses and improve production efficiency; because the remote system integrates remote communication, network, and drive control, it can greatly save equipment costs and operation and maintenance costs; it significantly improves the informatization and automation level of the oil pumping unit, which is more in line with the trend of development; this system can save energy and reduce consumption, improve production efficiency, and improve process control level, thereby improving the core competitiveness of enterprises. 3.3 Central Air Conditioning Energy Saving System Based on SR 1) Working Principle The system uses computer technology + fuzzy control technology. The control unit and signal acquisition unit form a closed-loop control system. Through the optimized control of the process parameters (temperature, pressure, etc.) and equipment parameters (motor power) of the cooling fan and water pump, the fan and water pump always operate in the most energy-saving mode under the required conditions. Under the premise of ensuring user comfort, the motor speed is automatically adjusted to completely solve the problem of energy waste. 2) System Features: Utilizing a state-of-the-art switched reluctance motor (SR) system, the system comprises a temperature and pressure sensing system, a PLC control system, the SR motor itself, and a cooling pump, forming a closed-loop control system. It compares and calculates the feedback values ​​of temperature and pressure differences with the set target values, and automatically adjusts the motor speed through the PLC system, maximizing energy savings while meeting process requirements. This overcomes the limitations of conventional asynchronous motors with their fixed-speed operation, such as the narrow speed range and inherent power consumption of commonly used frequency converters, achieving energy savings of 30% to 80%. The fan system of the SR-based central air conditioning energy-saving system is shown in Figure 8a. The cooling and chilled pump system of the SR-based central air conditioning energy-saving system is shown in Figure 8b. 3.4 SR-Based CAM Field Network System The new generation of high-performance switched reluctance speed-regulating energy-saving motors and control systems also features a CAN bus interface, enabling fieldbus network control of the equipment. This improves the system's automation and informatization levels, facilitates user control, achieves better control effects, and enhances energy efficiency. A comparative analysis of several commonly used energy-saving technologies for central air conditioning motors (three-phase asynchronous motors, three-phase asynchronous motors + frequency converter control, and SR energy-saving speed regulation systems). 1) Three-phase asynchronous motors operate at a fixed speed, resulting in a low power factor and low efficiency; they are not speed-adjustable, simple and reliable, but have a large impact on equipment during startup, a large starting inrush current, and affect the normal operation of the power grid; they also suffer from insulation aging in the distributed windings, with inter-turn peak voltages reaching over 1000 volts, resulting in a moderate lifespan compared to other motors. 2) Three-phase asynchronous motors + frequency converter control utilize frequency conversion speed regulation, single-parameter linear control, and variable speed control, resulting in a lower power factor and energy savings of 20%–50%; they have a good degree of automation, a narrow speed range, and are optimally positioned between 36–45 Hz, with efficiency dropping sharply below 36 Hz; they employ soft starting, causing no impact on the equipment. However, the control circuit is relatively complex and prone to breakdown and short circuits, causing fires; it contains high-order harmonics, has a low power factor, pollutes the power grid, and is harmful to the human body with long-term exposure; high-order harmonics cause aging of the motor insulation (distributed windings withstand peak inter-turn voltages of over 1000 volts, plus high-order harmonic voltages), resulting in a shorter motor lifespan. 3) The SRM energy-saving speed regulation system uses computer control + fuzzy control technology, multi-parameter nonlinear control, variable speed control, high power factor (up to 0.99), high efficiency, saving 30% to 80% of energy; it has the best degree of automation, a wide speed range, and a speed ratio of over 1:20, with efficiency around 90% over a wide speed range; it features soft start, causing no impact on equipment. The control circuit does not experience breakdown and short circuits, the motor structure is simple, and operation is safe and reliable: low starting current, high starting torque, high power factor, and no impact or pollution on the power grid; the motor structure is simple and robust, with no insulation aging (concentrated windings withstand peak inter-turn voltages of only tens of volts), resulting in the longest motor lifespan. 3.5 Building Water Supply System (1) System Scheme (see Figure 9) (2) System Features Users can set the required process (pressure, flow) parameters, and can choose to control the motor, valve, and speed control device, or choose the fully automated optimized operation mode. It can monitor process parameters such as flow, pressure, liquid level, and temperature in real time.