Abstract
A novel traction AC motor is proposed by grouping magnets and coils in the stator design with aluminium as substantial for the housing of stator and end ring. The stator back iron is designed with silicon steel. As a result, the magnet can provide more repulsion when revolving the rotor, lowering the input side current. The configuration of the motor was changed to increase its effectiveness in terms of efficiency, and its performance appearances were investigated to compare it to the traditional design of motor. Magnet software was used to simulate the novel constructed induction motor. Most of the factories depend on this induction motor for its significant impact on industrial production and being an essential component of the plant for developing countries’ economic development. Using motor solver software, this paper examines the performance characteristics of a novel constructed induction motor, including efficiency, power factor, and losses. The output of the developed induction motor is compared to that of a traditional three-phase 2.2 kW induction motor for traction application using a motor solver.
1. Introduction
The self-starting properties, simple construction, robustness, economy, efficiency, and low maintenance are all advantages of induction motors in industrial applications. Induction motors are used in lifts, cranes, hoists, traction, and other applications [1]. This paper’s modified motor is optimized for applications that involve high torque at high speeds. Electrical machines have two applications: one transforms electrical into mechanical energy, and the other transforms mechanical into electrical energy [2]. An electrical machine relies on the electric and magnetic fields interaction through an air gap to function. Thermal limit is the most important factor that determines how well an electrical machine works. As a result, insulating materials with strong thermal properties are used to distinguish the two circuits. The circuit must be durable enough to bear the mechanical loads subjected by transferring energy through the air gap [3].
In the electric circuit, ohmic losses occur, whereas in the case of the magnetic circuit, hysteresis and eddy current losses occur. The efficiency of insulating materials, as well as electric and magnetic circuits, is affected by continuous heat dissipation, while the machine is working [4]. The efficiency of insulating materials degrades as the temperature rises. Hence, the temperature in the circuit elements turns out to be the primary limiting factor in deciding the machine’s run time. When a thermal limit of the machine is exceeded, it leads to adverse effects [5].
In electric traction applications, traditional sensors have been changed to a sensorless method to monitor the speed of induction motor [6]. As a result, the machine’s temperatures must be constantly controlled and managed to confirm that a machine’s mechanical, electrical, and environmental conditions are optimal. The temperatures in machines are predicted using thermal models of various complexities, depending on the application. While comparing the machine’s temperature measurements, the model’s accuracy is also significant. A thermal model using Fourier’s law and Ohm’s law of electrical conduction can be used to calculate the short-term overloading of a system. As a result, a thermal model is critical for motor safety and periodic monitoring. The statistically analyzed induction motor was operated by an Arduino intelligent controller [7, 8].
In the literature, approximations of values are utilized to determine that the induction motor’s design parameters were thought to be sufficient. However, in today’s world, machine efficiency and cost of manufacture are more important than ever, and there is a greater demand for such machines [9]. The ability to compute magnetic fields in the electrical system made the finite element method (FEM) popular. The precise values of rotor variables will improve motor design and performance; however, rotor currents as well as other factors are found in an analytical way since direct measurement of rotor quantities is hard [10]. The rotor quantities are calculated using FEM by calculating the current and flux density distribution. Stator and rotor currents were calculated using winding function along coupled circuit models. The proposed methodology of calculation is simple and straightforward to use, and the results must be found without the use of a postprocessor. The use of copper rotors in the induction motor increases performance and reduces losses due to copper’s higher conductivity. This allows for more design versatility, which results in a smaller motor [11, 12].
Copper has a 60 percent higher electrical conductivity than aluminium, which reduces rotor side I2R losses and improves overall performance. After calculations, motor modelling with copper rotors revealed a minimum 15 percent to 20 percent of reduction in losses. Since the basic concern is the cost associated, using a heavier and more costly material is not a feasible choice. Single inverter-fed multiple induction motors have replaced the traditional induction motor fed with a single inverter [13, 14]. The temperature study of a three and five-phase AC motor is the focus of this paper. The efficiency of a motor is largely determined by heat-induced losses, which can cause problems by raising the temperature in the motor above the optimum temperature [15].
Improving electric motor performance is critical, and the efficiency of various forms of drives used in transportation and industries is a primary goal for all countries [16]. This can be accomplished by either the scale of the motors or adding low-loss laminations. Motor geometry may also be mathematically optimized to increase performance. Due to the limited space available on vehicles, mounting a traction motor becomes difficult. The torque-speed characteristics of Integrated Pest Management (IPM) make it ideal for traction applications because it allows for a wider speed array and continuous power approach procedure. This can be either controlled or tuned by proper designing of the electrical motor [17].
The thermal limit of an electrical system is the most important factor that determines how well it works. The efficiency of insulating materials, as well as electric and magnetic circuits, is affected by heat dissipation continuously, while the machine is working. The efficiency of insulating materials degrades as the temperature rises. Temperature of the machine’s circuit elements is the primary limiting factor that decides the machine’s run time as a result. When a machine’s thermal limit is exceeded, it has adverse implications [18].
Temperatures in machines must be regularly controlled and managed to warrant that they operate in the best mechanical, electrical, and environmental conditions possible. The temperature rise in machines is forecasted using thermal models of various complexities, depending on the application. When matched to the physical heat capacities of the system, the level of accuracy of the models was significant. A thermal model can predict machine overloading for a short period of time. As a result, a thermal model is critical for motor safety and condition monitoring [19, 20].
The field-circuit coupled finite element approach is used to forecast the behaviour of an induction motor (IM) with variable voltage excitation. The mathematical analysis is carried out by estimating nonlinear finite element time-stepping equations that are connected with the equations of an electrical circuit as well as the mechanical displacements. The revised nodal approach is used to explain the circuit equations. The Laplace equation’s localized analytical expression is used to enhance the accuracy of electromagnetic torque. The created field-circuit coupled algorithm mimics the performance, including both single-phase and three-phase induction motors. The comparison of the code’s findings, FLUX 2-D, the commercial finite element package, and the results of this experiment also revealed that the field-circuit paired technique and associated generated program are valid [21].
This paper varies load circumstances in a single-phase induction motor and discusses the impact on electromagnetic properties in both balanced and unbalanced operations. The magnetic field, electromagnetic losses, and magnetic torque are measured using the time-stepping finite element technique for six distinct loads based on a balanced-load situation. To describe the presence of load fluctuation and unbalanced operation, the spatial distribution of the air gap magnetic field is analyzed. The components of electromagnetic losses are examined in terms of the primary characteristics that degrade operational efficiency as the load varies. The results demonstrate the significance of developing magnetic balance for high performance, and the design guidelines for SPIMs operating at numerous operating points are reviewed [22].
This paper introduces Motor Analysis-PM, a one-of-a-kind and powerful freeware application, and explores its use in the electromagnetic structural analysis and design of permanent-magnet synchronous (PM) motor drives for the electric vehicle (EV) sector. This strategic developmental motor software application considerably accelerates the modelling and designing of PM motors by combining finite element (FE) and analysis techniques. Using Motor Analysis-PM, the modelling and analysis process for a 50 kW PM motor utilized in a commercialized EV is shown and discussed. The numerical findings acquired from either the PM motor drive design or implementation application are verified with obtained experimental observations to confirm that the software’s programme is valid. The numerical and experimental findings support this software’s versatility in delivering correct motor design analysis in short design periods, and that is very appealing to EV and PM motor manufacturers [23].
Bearingless induction motors (BIMs) are a novel kind of motor that has noncontact rotor stabilization and low frictional losses. One significant flaw with this type of motor is that all the functionality is significantly dependent on the width of the rotor slot. This work aims to address the problem by combining the analysis method with the finite element analysis method (FEM). First, an analytical technique is used to disclose the effect on motor starting characteristics, which is then confirmed using finite element modelling. Second, the influence of the air gap on the distribution of the radial harmonic magnetic field is investigated and utilized by the fast Fourier transform (FFT). In the meantime, the performance impact of the engine load is calculated. Third, we investigate the relationship between the width of the rotor slot, the suspension force, and the unbalanced force of magnetic attraction. Finally, simulation and actual results show that BIM generated using the combined analysis method and finite element analysis not only provides excellent torque and suspension characteristics but also reduces load loss and improves the accuracy of mathematical models. This study provides a theoretical framework and method for optimizing future engine designs [24].
Analysis methods, finite element methods, and field-circuit coupling methods are frequently used in the current motor design procedure. The analytic method requires less time to calculate and immediately reveals the influence of rotor parameters. However, this often overlooks the phenomena of magnetic saturation and flux scattering. In this regard, in practice, it is necessary to introduce certain correction factors into the mathematical model of the engine. The finite element approach provides high accuracy when calculating motor torques, radial forces, and losses because it takes into account real-world parameters such as flux saturation and eddy current effects. Field-circuit coupling technology couples magnetic fields to external circuits and mechanical movements. It has been effectively used in the study of transient characteristics of motors, and the calculation accuracy is high. Currently, these technologies are used to evaluate and improve the parameters of the rotor. Deep and shallow rods were combined in, and FEM simulations show that this design can significantly improve engine starting performance while maintaining operational economics. A finite element model of the motor was used to investigate the effect of the number of alternate rotors on the load current, output torque ripple, and power factor to determine the appropriate stator rotor groove ratio to improve the motor and performance activity. In the analysis, equations for stator and rotor current harmonics were derived and showed that a closed slot rotor induction motor does not necessarily have a lower stator current harmonic than an open slot rotor motor. It uses an open slot structure to effectively minimize low-order current harmonics. An analytical method was used to optimize the design of a rectangular rotor slot, and mathematical models of the dynamic properties such as size and frequency of the rotor design were built. Simulation and experimentation confirm this method [25].
The temperature is the key factor for the better procedure and life of the engine that can run endlessly under loaded conditions. The performance of these motors has improved with a few percentage points to have a significant effect on their energy consumption and operation. To maximize the performance, a modern stator casing is constructed using aluminium rather than traditional cast iron. Since it has a lower conductivity than copper, only 61 percent of the same is used. While an increase in silicon in the core causes a decrease in saturation flux density, which reduces performance, this paper discovered that switching the stator back to iron content improves efficiency.
Section 2 describes the design and dynamic modelling of a novel induction motor using a magnet and analysis using a motor solver. Section 3 deals with the results and analysis of the proposed designed induction motor and compares it with the conventional motor. Section 4 describes hardware results and analysis of the modified induction motor. Section 5 concludes all the simulation and hardware results of the proposed method.
2. Design and Analysis of Novel Induction Motor Design Using Magnet and Motor Solver
It is predominant to have a well-defined model of an induction motor for transient purposes so that a detailed investigation of the induction motor is possible. Since there is a high risk of motor damage, the creation of such conditions for induction motor in real life is dangerous. The investigation was carried out with the help of mathematical modelling, and these processes help in making correct choice of protection and automation devices which in turn are extremely important for induction motor reliable operation. Induction motor equivalent circuit includes various parameters such as stator, rotor, and magnetizing current, resistance for modelling using magnet software.
Due to the technological errors or due to errors in observations, motor parameters may differ from manufacturer to manufacturer, showing a deviation of 10% to 20% from the exact value. Hence, accurate values of the motor are needed to design high-quality drives by designers [21, 22]. The induction motor drive structure is designed for traction application with the conventional stator coil design, as depicted in Figure 1.
The lumped parameter and FEM models are two of the most commonly used thermal models. Calculating temperature rises was done using a thermal network model or a lumped parameter model. FEM is a modern technique for studying the thermal behaviour of electrical machines in comparison to the lumped parameter method. The cooling capacity of an asynchronous motor based on the heat transferring pattern can be used to define its nominal power. Since FE analysis requires complex 3D geometrics, analytical methods for determining heat transfer in a machine are simpler than modelling heat transfer using finite element (FE) analysis. The dynamic thermal analysis is time-consuming, despite the use of faster microprocessors in FE analysis. Conventionally, thermal models were designed assuming that the machines were in a steady state under constant temperatures. This model can be utilized in a variety of industrial settings, including power plants and propulsion machines. The main disadvantage of using similar thermal models was assessing the steady-state temperature and the heat transfer process during transient loading variations [26].
The precise values of rotor variables will improve motor design and performance, but rotor currents and other variables are obtained using analytical methods since direct measurement of rotor quantities is difficult. The following equations explain the dynamic modelling of induction motor architecture.
The stator voltage equation is given bywhere , , , , and .
Substituting (2) and (3) in (1), the modified stator voltage equation is given by the following equations:
At stationary reference, .
At stationary, .
Substituting equations (6) and (7) in equation (5), the rotor voltage equation is represented by the following equations:
At stationary, .
Now,
At stationary, ,
The parameters from the mathematical model are depicted in Table 1.
Here,
The above equations are represented by the matrix as given as follows:
, , and .
Here, inductance matrix and resistance matrix are L and R, respectively. R matrix is the addition of R1 and R2 matrices. The following factor influences the design of the modified motor:where C0 is the output coefficient, is the speed in rps, Li is the net iron length, Sf is the stacking factor, L is the stator core length, D is the diameter of the stator core, is the stator winding factor, is the depth of the stator core, is the flux density through stator, is the flux in stator, ac is the specific electric loading, is the specific magnetic loading, Bav = 0.6 Wb/m2, and ac = 10,000 ac/m.
The KVA rating of the machine is given by
For overall good design,
. Outer diameter of stator = D = 245 mm.
The stator slots are designed by the following equation:
Ys = slot pitch lies b\w 15 to 25 mm, Ys = 21 mm, , and rotor slots = Sr = 19.
Length of air gap is represented by
The total number of conductors is given by
and net iron length are given by the following equations:
Bcs = 1.2 Wb\m2.
The outer diameter is given by
The length of mean turn is
Pole pitch is
Min width of stator tooth is
Order of slot harmonics is as follows:
It is defined as eliminating the 13th harmonic
Electrical angle of skew is
Distribution factor for the Nth harmonic is
Rotor bar current was designed by the following:
For m/c, ms = 3.
Rms value of end ring current is as follows:
Min width of rotor teeth Wir (min) is
The above equation is modelled in magnet software, and the results are analyzed using a motor solver.
A novel traction motor is implemented by the alignment of magnets and coils in the stator design compared with the conventional motor design with aluminium as being considerable for the housing of stator and end ring. As a result, the novel designed stator setup can provide more repulsion when revolving the rotor, lowering the input side current. The formation of the motor was altered to increase its efficiency, and its performance compared it to the conventional traction motor design as illustrated in Figure 2. From the above design and analysis, the parameter and their value for the proposed design are listed in Table 2.
The dynamic modelling of the induction motor is simulated in MATLAB/Simulink platform from the above design; the speed response of induction motor analysis is depicted in Figure 3. The induction motor parameters such as torque and speed are established from the simulation of dynamic model. The performance characteristics of induction motor have been analyzed by the dynamic modelling of induction motor using the estimated parameters.
(a)
(b)
The dynamic modelling of the induction motor is simulated in MATLAB/Simulink platform from the above design; the torque response of induction motor analysis is depicted in Figure 4. From the above results, the proposed induction machine has improved speed performance and reduced amplitude with increased frequency of torque pulsation compared with the conventional induction motor. The novel dynamically modelled induction motor is now considered for performance analysis using a motor solver.
(a)
(b)
3. Results and Discussion of Proposed Induction Motor Design
The estimated parameters of a 3HP induction motor are built in motor solver. A novel three-phase squirrel-cage induction motor is equipped with a stator made of a combination of magnets, and a coil with a copper rotor bar is designed in this work. As a result, the magnet can provide more repulsion when rotating the rotor, which in turn reduces the input current. The stator has three-phase coils and laminated silicon steel, while the rotor has conductive copper and steel. Figure 5 depicts the proposed induction motor, and its performance has been examined.
A motor is made up of two parts: (i) stator and (ii) rotor. The stator is made of laminated steel with 3-phase coils, while the rotor is made of steel and aluminium. The windings of the stator have a 120-degree angle between them. The cross-sectional view of the above-mentioned conventional and proposed induction motors is illustrated in Figures 6 and 7, respectively.
Induction motors are modelled in magnet software using estimated parameters from the same data as before. Torque is proportional to slip under steady-state load conditions due to the presence of rotor resistance. The torque curve is cut in as the leakage resistance of the rotor and stator increases. The power factor varies depending on the load. As shown in Figures 8 and 9, the flux distribution and current density output of the proposed motor design outperform that of the conventional motor.
In the conventional motor configuration shown in Figure 10, the motor efficiency ranges from 63 percent to 78 percent. The motor achieves its optimum efficiency for the high speed at 1400 rpm, as shown in Figure 11. As a result, the newly developed novel motor possesses better performance than the conventional three-phase motors in locomotive traction applications.
The power factor value of an induction motor varies depending on the load. The range of 0.7 to 0.8 of cosΦ is the best estimate. Thermal reaction plays an important role in the illustration of a traction motor created on a specific variable. Without thermal parameters consideration, the electrical machines may get damaged by insulation breakdown, which leads to lesser torque. To observe the implementation of thermal behaviours, thermal factors need to be considered. Figure 12 shows the thermal environment of an induction motor. It is possible to view quality results for induction motors in motion investigation for input power, end ring current densities, efficiency, coenergy bar current, bar current densities, torque, rotor angle, loss energy, voltage, current, flux linkage, output power, and source phase angle.
The performance of the designed proposed machine is compared with the conventional motor using the estimated values. The torque capability, energy, and coenergy of novel induction motor have been enhanced compared with the traditional motor as depicted in Figures 13 and 14. When the torque ripple and loss analysis of the proposed motor is compared to that of the conventional motor, the proposed motor has a lower amplitude of torque ripple and loss of induction motor.
The novel induction motor outperforms conventional motors by having lower torque ripple, higher efficiency, less current ripples, higher torque density, and lower losses. It also has other benefits, such as reduced copper stator losses and reduced noise.
4. Prototype of Novel Induction Motor Implementation and Its Discussion
The stationary stator reference frame approach is used for the dynamic modelling of conventional machines. Physical parameters of the conventional motor are determined after effective dynamic modelling. The motor solver based on the motor’s physical parameters is developed, and its output characteristics are noted and analyzed.
After that, the aforementioned structural improvements to the motor are implemented and simulated. The adjusted motor’s output characteristics were demonstrated, and comparisons of various behavioural characteristics were analyzed and compared to traditional methods. The parameter of the proposed method is needed to estimate. Figure 15 depicts the hardware configuration of the parameter estimation of the proposed machine. To increase torque, the increase in electrical and mechanical loading is needed for the same frame size, resulting in higher copper losses and lower performance. Since the improved motor’s rotor is made of aluminium, the losses are lower, and the performance is higher. For high-efficiency remanufacturing, an innovative method of using permanent magnets in the rotor was investigated; since the cost of permanent magnets was high, only a less efficient approach can be investigated. By increasing the stack length of prototype motors, efficiency improvements were investigated. But, since the machines were already designed for optimal efficiency levels, no major gains in efficiency could be made. The designed stator winding factor is depicted in Figure 16.
A novel traction AC motor is proposed by grouping magnets and coils in the stator design with aluminium as substantial for the stator housing and rotor bar and end ring. The stator back iron is designed with silicon steel. As a result, the magnet can provide more repulsion when revolving the rotor, lowering the input side current. The designed machine is validated with a hardware setup to verify the magnet software simulation performance. The stator in this study is designed such that a combination of magnets and coils provides additional repulsion for rotating the rotor, lowering the input current, and increasing efficiency as depicted in Figure 17.
The speed and torque performance of the proposed method are illustrated in Figure 18. The efficiency and power factor of two induction motors with the same rating are analyzed from hardware setup, which is depicted in Table 3. However, the designed induction machine has higher efficiency and power factor compared with the conventional machines.
Illustration of an AC motor is created on specific variables, one among which is the thermal reaction of the electric motor caper. Breakdown of insulation affects electrical devices, resulting in lower torque efficiency without consideration of thermal parameters. Thermal considerations must be addressed when examining the regulation of thermal behaviours. Without taking into account the induction motor thermal parameters, insulation failure affects electrical machines, which in turn affect torque output. Table 4 shows the reduced losses of the proposed induction motor.
Hence, the temperature analysis needs to be measured to observe the fulfillment of thermal deportment. Therefore, the temperature effect of the designed motor is analyzed. The proposed motor has a higher withstanding temperature capability associated with the traditional three-phase motor as depicted in Table 5.
5. Conclusions
A novel induction motor has been effectively designed by using magnet software and analyzed by motor solver. The performance of the novel designed motor is associated with that of a conventional induction motor using a motor solver. The efficiency of a modified motor was enhanced in this research by altering the structure of the stator with magnets and coil, also using aluminium for the casing, rotor bar, end ring, and silicon steel for the stator back iron. As a result, the magnet can provide more repulsion when revolving the rotor, lowering the input side current. The output of the developed induction motor is compared to that of a traditional three-phase 2.2 kW induction motor for traction application using a motor solver. The proposed design has enhanced performance characteristics for traction application, including the efficiency, power factor, losses, energy, coenergy, temperature effect, and torque ripple than the conventional motor.
Data Availability
For the data-related queries, kindly contact Baseem Khan ([email protected]).
Conflicts of Interest
All authors declare no conflicts of interest.