How to select electric motor05.09.2020
10 things to consider when choosing an electric motor
Mar 20, · First, you must choose between three main groups of electric motors: The AC asynchronous motor (single-phase or three-phase) The synchronous motor: DC motor (direct current), brushless, etc. The stepper motor; In order to choose between these three groups, it is necessary to determine the type of application required as this will influence your choice/5(2). Choosing an Electric Motor. When choosing an electric motor there are different requirements to consider to make sure you get the perfect drive solution for your product. With the guide below covering aspects of motor design such as torque, duty cycle, thermal limits and efficiency, we hope to provide a reference point when selecting your motor.
There are so many variables to consider that it can be difficult to know where to start. Given the price of batteries and electric motors, in order to find the most economical solution, you should look for a powertrain that will fit required vehicle performances as close as possible. In this article, we will overview 10 basic questions that cocoa butter is good for what need to answer before attempting to find the right motor for your project.
Basically, you need to determine the most demanding requirements of your vehicle as well as evaluate how various road conditions will impact performance of the powertrain:. The properties of the vehicle such as size, weight, overload and aerodynamics are crucial vehicle characteristics that will ultimately determine speed, torque and power requirements of the electric motor. These aspects will help understand the effects of the operating conditions of the vehicle and are essential to the selection of the right powertrain.
Have them within reach for the next steps. How is the vehicle being used is also very important. What will be the usual driving how to select electric motor of the vehicle?
Will it be driven in an urban area with many stops? Will it be driven on long distances with only a few stops? All of this will help to determine the vehicle configuration series hybrid, parallel hybrid, all electric and battery pack how to select electric motor and ultimately impact the choice of the powertrain. Is the vehicle hybrid or full electric?
If hybrid, is it parallel hybrid or series hybrid? As a rule of thumb, if the vehicle routes are not predictable or if it will be driven on long distances, usually the hybrid architecture is preferred.
The full electric configuration is well suited for in city driving where the distance is not too long between charging points, the speed is low and the amount of stops is high. What is the targeted maximum speed of the vehicle? How long how to select electric motor it have to be sustained, maybe it is used only for passing?
What are the gearbox ratios available if using a gearbox and the differential ratio? What is the rolling radius of the wheel? All of these questions must be answered and used in the calculations to determine the maximum speed the electric motor has to reach in your application. The maximum torque enables the vehicle to start in a given slope.
You need to find the highest grade the vehicle will need to ascend. Using that grade, it is possible to calculate the highest torque required by the electric motor considering the differential and gearbox if using a gearbox! Maximal weight is also to be taken into consideration.
Sometimes the maximum power is found simply at maximum speed this is the case where the vehicle as a large frontal area or goes at very high speed. This translates to having a motor powerful enough to go through all the different conditions the vehicle can be submitted to!
The maximum power enables the vehicle to reach and maintain a constant speed under stringent slope and speed conditions. To calculate the maximum power, you need to have a simulator that takes in account the drag and friction coefficients of the vehicle in addition to the forces needed for the climb. Again, the duration of the condition also matters: contrary to combustion engines, the peak power of the electric motor cannot be sustained continuously and it would be over engineered to select the electric motor to be able to do the worst hill climb conditions with no time constraints.
The battery capacity is typically calculated using a simulator to go through a reference cycle typical of the usage of the vehicle. From that value, the capacity of the battery can be calculated by multiplying it with the desired range.
The battery voltage is dependent on the size of the vehicle. As the battery voltage increases, the current output is lowered. So in the cases where the vehicle continuous what is a compliance officer responsible for is high like in bigger vehicles, you want to keep the size of the conductors at a manageable level by increasing the battery voltage. There are normally two ranges of voltages: Vdc and Vdc.
This is because of the voltage limitation of IGBTs used in the motor controller and the two main standard voltages available for them: Vdc and Vdc. Will the powertrain architecture require a gearbox? Last but not least, what is your budget? In a previous blog post, we reviewed the different electric motor technologies available on the market, their pros and cons and their relative usage in electric vehicles.
Once you gather all the information mentioned above, you need the right tools to allow you to calculate the components requirements from the vehicle performance. TM4 can help you make an enlightened choice in your motor selection.
Contact-us with the above information at hand. You must be logged in to post a comment. Kindly suggest me battery specifications. Hi Chris, Greetings from India! I am aware of the limitation that poses on the torque current it can handle at a low voltage of 48V. I would like to explore the ISG tolpology above with the two clutchesto be possibly integrated with engine assembly and mainly to tap the energy during coasting, braking and engine dragging for recuperation.
The machine rating I am looking for are somewhat as below. Thanks in advance. I want to make my beetle go miles fully on electric. What do i need to do on my conversion? Its a stock gas motor with a 5 speed. Hi Karen, You question is rather general, the first thing I would do how to transfer photos from ipod to computer windows 7 to find a suitable motor and inverter that would provide good performance and build on that.
If you know the performance you are looking for, you can look at different online simulators that can identify the right motor for you. TM4 is working mainly with vehicle integrators and is not geared towards passenger vehicle conversions. I think there are companies providing products and services that can help you achieve your goal. By Christian Pronovost. Basically, you need to determine the most demanding requirements of your vehicle as well as evaluate how various road conditions will impact performance of the powertrain: 1.
Vehicle characteristics The properties of the vehicle such as size, weight, overload and aerodynamics are crucial vehicle characteristics that will ultimately determine speed, torque and power requirements of the electric motor.
Driving cycles How is the vehicle being used is also very important. Vehicle configuration what is a practice manager, hybrid Is the vehicle hybrid or full electric? TM4 can offer most of these configurations. Maximal speed What is the targeted maximum speed of the vehicle? Maximal torque The maximum torque enables the vehicle to start in a given slope.
Battery Capacity The battery capacity is typically calculated using a simulator to go through a reference cycle typical of the usage of the vehicle.
Battery Voltage The battery voltage is dependent on the size of the vehicle. Gearbox or direct-drive? Cost Last but not least, what is your budget? To sum up Once you gather all the information mentioned above, you need how to get sound on my computer windows xp right tools to allow you to calculate the components requirements from the vehicle performance.
Author Recent Posts. Christian Pronovost. Product Manager at TM4 Inc. Christian Pronovost received a B. He has been involved in the design of the core technology of current motors and inverters for automotive electric powertrain technologies. Latest posts by Christian Pronovost see all. Leave a Reply Cancel reply You must be logged in to post a comment.
Log in to Reply. Good luck with your project!
Step 1: Know the load characteristics
10 things to consider when choosing an electric motor 1. Vehicle characteristics The properties of the vehicle such as size, weight, overload and aerodynamics are crucial 2. Driving cycles How is the vehicle being used is also very important. What will be the usual driving cycles of the 3. How to Choose an Electric Motor When you are attempting to choose the perfect motor, the following should always be considered: Cross reference the manufacturer's part or model number from the motor itself. This information is usually on the nameplate of the motor. These are the basics to consider while selecting a motor. Consider an application’s purpose and which current it uses to select the appropriate type of motor. An application’s specifications such as voltage, current, torque, and velocity will determine which motor is most appropriate so be sure to pay attention to its requirements.
Premium Membership. Study specialized electrical engineering articles and papers in Low- and High-Voltage areas. For line-operated motors , loads fall into three general categories: constant torque , torque that changes abruptly, and torque that change gradually over time. Bulk material conveyors, extruders, positive displacement pumps, and compressors without air unloaders run at relatively steady levels of torque.
Sizing a motor for these applications is simple once the torque or horsepower for the application is known. Load demands by elevators, compactors, punch presses, saws, and batch conveyors change abruptly from low to high in a short time, often in a fraction of a second. Loads from centrifugal pumps , fans, blowers, compressors with unloaders, and similar equipment tend to be variable over time.
In choosing a motor for these conditions, consider the highest continuous load point, which typically occurs at the highest speed. The rule of thumb for motor horsepower is: Select only what you need, and avoid the temptation to oversize or undersize. Calculate the required horsepower from this formula:. Another consideration is inertia, particularly during startup. Every load represents some value of inertia, but punch presses, ball mills, crushers, gearboxes that drive large rolls, and certain types of pumps require high starting torques due to the huge mass of the rotating elements.
Type B is the industry standard and is a good choice for most commercial and industrial applications. Duty cycle is the load that a motor must handle over the period when it starts, runs, and stops. Continuous duty is by far the simplest and most efficient application. The duty cycle begins with startup, then long periods of steady operation where the heat in the motor can stabilize as it runs.
A motor in continuous duty can be operated safely at or near its rated capacity because the temperature has a chance to stabilize. Intermittent duty is more complicated. The life of commercial airplanes is measured by their number of landings; in the same way, the life of a motor is proportional to the number of starts it makes. Frequent starts shorten life because inrush current at startup heats the conductor rapidly. Because of this heat, motors have a limited number of starts and stops that they can make in an hour.
If your motor is going to operate at altitudes that are substantially above sea level, then it will be unable to operate at its full service factor because, at altitude, air is less dense and does not cool as well. Thus, for the motor to stay within safe limits of temperature rise, it must be derated on a sliding scale. A common cause of motor failure is problems with the motor windings, and the solution often is to rewind the old motor.
Because it is economical in terms of initial cost, rewinding of motors is very common particularly for motors of more than 10 horsepower. A HP motor may use several hundred dollars more in electricity each year due to this drop in efficiency, compared to its original efficiency.
The operating cost may be even more compared to a new high efficiency motor. I am into Halloween big time. I have several animated figures that I put out in my yard. I use 12v auto wiper motors mostly. This year I got the idea that i would like to make a merry go round the playground type. I would make it out of PVC and make it as light as possible. I would sit 4 small skeletons on it and would have it turning constantly. Like I said it would be made as light as possible.
It would not hold a real child. I am not sure what rpm to use, I thought maybe 4or 5, also I figure I would need a motor with a considerable amount of torque. I plan on having a pully on the merry go round and pully on the motor and a drive belt or chain. I am not a rich person so of course I am trying to do this at a low cost as usual.
Could you suggest a motor that might fit my needs? I thought maybe a v clothes dryer motor might work but not sure how much torque they have. It could also be a DC motor as long as I can get a converter for it.
I would be appreciated if you let me know which BLDC motor is suitable for 1 tonne air conditioner compressor. Thank you for urs sharing of knowledge.
I would be appreciated if you let me know what is the optimal working power for Weg 6. Search for:. More Information ». Electric Motor. Step 1: Know the load characteristics For line-operated motors , loads fall into three general categories: constant torque , torque that changes abruptly, and torque that change gradually over time.
The most critical consideration for selecting a motor in these cases is to choose one whose speed-torque curve exceeds the load torque curve. Motors for these applications need to have special ratings so that the temperature rise at startup does not exceed the allowable temperature limit.
A properly sized motor must be able to turn the load from a dead stop locked-rotor torque , pull it up to operating speed pull-up torque , and then maintain the operating speed. This is an important consideration for mining elevators, conveyors, blowers, and other equipment that operates at high altitudes. It is generally cost-effective to replace motors under 10 horsepower with new high-efficiency motors rather than rewind them.
When deciding whether to buy a new motor or rewind the old one, consider the cost difference between the rewind and a new high-efficiency motor, and the potential increase in energy costs of a rewound motor that is less efficient than the original. Related EEP's content with sponsored links. It helps you to shape up your technical skills in your everyday life as an electrical engineer.
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