The industrial electric motor market is growing at a fast pace and is expected to reach a value of $150 billion by 2020.
In order to stay competitive in this industry, it is important to optimize high-efficiency motor design and manufacturing.
In this blog post, we will discuss the latest industrial electric motor production trends and how to optimize high-efficiency motors for your business.
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Dongchun motor tiene una amplia gama de motores eléctricos que se utilizan en diversas industrias, como el transporte, la infraestructura y la construcción.
In recent years, with the development of power electronics, computer technology and control theory, the global market of industrial electric motors has grown greatly.
With the emergence of rare earth permanent magnet materials and magnetic composites, various new, high-efficiency and special motors have appeared one after another.
As the international community attaches increasing importance to energy conservation, environmental protection and sustainable development, the production of high-efficiency motors has become the development direction of global industrial motors.
In the context of global energy consumption reduction, high-efficiency and energy-saving policies have been introduced to further promote the accelerated development of the global industrial motor manufacturing industry。
Transformation of the motor industry towards intelligence and energy saving
At present, the technology of ordinary low-voltage electric motors is relatively mature, but there are still more technical thresholds in the fields of high-power high-voltage electric motors, electric motors for special environmental applications and super high-efficiency electric motors.
The comprehensive development trend of the global motor market is mainly manifested in the following points:
the industry is developing towards intelligence and integration.
Traditional motor manufacturing has realized the cross-fertilization of advanced electronic technology and intelligent control technology.
The future for the industrial use of small and medium-sized motor systems, continuous development, optimization of intelligent control technology, to achieve the motor system control, sensing, drive and other functions of integrated design and manufacturing, is the development trend of the electric motor industry.
Electric motor manufacturing to differentiation, specialization, high efficiency, energy saving direction
Electric Motor products are widely used in various fields such as energy, transportation, petroleum, chemical industry, metallurgy, mining and construction.
With the deepening of the global economy and the continuous improvement of the level of science and technology, the situation that the same type of motor is used for different nature and different occasions at the same time in the past is being broken, and the electric motor products are gradually developing in the direction of professionalism, differentiation and specialization.
In recent years, the global environmental protection policy has pointed out a clear policy direction for improving the efficiency of electric motors and their control systems. Therefore, the electric motor industry needs to accelerate the energy-saving transformation of existing production equipment, promote high-efficiency green production process, develop new generation of energy-saving electric motors, electric motor systems and control products, testing equipment, improve the technical standard system of electric motors and systems, and make efforts to enhance the core competitiveness of electric motors and systems products.
Optimized design and material selection of energy-efficient electric motors
Energy-efficient electric motors use high-quality materials and optimized design to achieve higher efficiency.
For example, the higher the aluminum content in the rotor, the higher the slot filling factor in the stator, and the lower the resistance losses.
Optimized rotor structure and rotor-stator air gap reduce stray load losses.
Improved cooling fan design minimizes wind resistance losses for electric motor cooling, and higher quality and thinner steel stacks are used for rotor and stator cores to greatly reduce magnetization losses.
Optimize the size of the stator and rotor laminations and the quality of the steel used in them
Hysteresis losses and eddy current losses together are called core losses, and about 20% of the total losses are caused by eddy current and core saturation.
The eddy currents generated in the laminations move relative to the changing magnetic field, resulting in significant power losses.
Stacked stator cores reduce eddy current losses and based on iron mass, resistivity, density, thickness, frequency and flux density, eddy current losses can be minimized with more stacks.
Hysteresis losses are generated in the magnetic circuit when the flux is constantly changing.
Most of the load materials used in electric motors are steels used in the stator and rotor cores, and flux density and core losses are minimized by reducing the laminations thickness.
Hysteresis losses can be reduced by annealing a better grade of steel for the laminations to change the grain structure for easier magnetization.
Eddy current losses are reduced by increasing the resistivity of the silicon containing steel, but the silicon content increases die wear during stamping because it increases the hardness of the steel.
Steel crystals damaged during stamping severely reduce the magnetic quality of the affected volume.
Annealing flattens the stack and recrystallizes the crystals damaged during the stamping process, thus extending a thin sheet thickness into the stack.
Stator lamination using dipping bath process
Impregnating the stator strengthens the electrical insulation of the stator winding against chemicals or harsh environmental influences and enhances heat dissipation.
Thermoset plastics including epoxy resins, phenolic resins and polyesters are used to impregnate the stator.
Immersion is the immersion of the stator into the resin for a longer period of time to ensure optimal penetration and protection.
Another method of impregnation is known as vacuum pressure, which uses a tank that is first evacuated and then pressurized to achieve penetration of the stator.
Achieving the extraction of air pockets from the electrical windings improves the thermal conductivity of the windings.
Optimize the design of the stator tank to maximize the volume of insertable copper
The slot fill rate affects the stator winding mass to some extent.
A low slot fill rate leads to 60% of the total losses, so in order to reduce the total losses, the stator winding mass must be larger, thus reducing the resistance.
Compared to standard efficiency motors, high efficiency electric motors contain more than 20% extra copper and the insulated windings of the stator are placed in slots in the steel sheet.
The cross-sectional area must be large enough to meet the rated power of the electric motor. Generally, induction motors use open or semi-enclosed stator slots.
In a semi-enclosed slot, the slot opening is much smaller than the slot width, making winding more difficult and time-consuming to manufacture than in an open slot.
The number of stator slots must be selected during the design phase, as that number affects weight, cost and operating characteristics.
The advantages of electric more slots are reduced leakage resistance, reduced tooth pulsation losses and improved overload capacity. The disadvantages of electric more stator slots are increased cost, increased weight, increased magnetization current, increased iron losses, poor cooling, increased temperature rise and reduced efficiency.
Rotor die casting using high quality pure aluminum
A custom designed rotor maximizes starting torque, reduces conductor resistance and increases efficiency.
Most induction motor rotors are of squirrel cage design. They are robust, simple and less expensive, but they have a lower starting torque.
Copper rotors improve efficiency, but are both difficult and expensive to manufacture.
Optimal air gap between rotor and stator
The air gap is the radial distance between the rotor and stator of a motor in a standard radial electric motor.
In order to improve the efficiency of the design, the optimum air gap needs to be maintained.
Air gap dimensions relate to the design of the stator, rotor, electric motor housing and bearings.
All of these affect the precise alignment of the stator and rotor shafts.
Use of high performance electromagnetic enameled wire
Magnet or enameled wire is an electrolytically refined copper or aluminum wire that has been fully annealed and coated with one or more layers of insulation.
For example, wires with a total of 12 layers of insulation are used. Typical insulation films, which increase with temperature range, are polyethylene, polyurethane, polyester and polyimide up to 250°C.
Thicker rectangular or square magnet wire is wrapped with high temperature polyimide or fiberglass tape, using more copper, and larger conductor bars and conductors increase the cross-sectional area of the stator and rotor windings, which reduces winding resistance and decreases losses due to current, and the high-efficiency electric motor stator windings typically have 20% more copper in them.
The electric motor consists of many parts, each part provides different structural and functional properties, resulting in different functions in the motor system, and each part provides functional advantages and disadvantages that ultimately affect the motor input performance.
By optimizing the performance of each component of the electric motor, the performance of the electric motor is ultimately optimized.
Conclusión
At present, the electric motor manufacturing industry is gradually changing from "big and complete" to "specialization and intensification" to cope with the globalized market competition.
In the future, driven by the low-carbon environmental protection policy, industrial motors will be fully developed towards green energy saving.
Dongchun motor is electric motor manufacturer in China, who is focus on high effiency motor.
