Torque: The torque output of a motor is the amount of rotational force that the motor develops. The torque of a small electric motor is commonly measured in either inch pounds (in-lbs), Newton meters (N-m) or other directly converted units of measure.
Do AC motors have high torque?
AC motors are often used for their high-speed and variable torque, but typically torque will exhibit a drop as the motor speed increases. … DC motors can provide a more constant torque over the speed range, and generally provide faster response to load changes that AC motors.
How do you calculate AC motor torque?
- Torque (lb.in) = 63,025 x Power (HP) / Speed (RPM)
- Power (HP) = Torque (lb.in) x Speed (RPM) / 63,025.
- Torque (N.m) = 9.5488 x Power (kW) / Speed (RPM)
- Power (kW) = Torque (N.m) x Speed (RPM) / 9.5488.
What is a motor torque speed curve?
The torque-speed curve begins at the crossing of the Y axis, where torque is maximum and speed is zero. This is the stall torque—the maximum torque when the motor is running at nominal voltage. The curve slopes downward until it intersects the X axis—that is, zero torque and maximum speed.
Should torque be high or low?
Because there is generally a limit on how fast you can spin an engine, having higher torque allows for greater horsepower at lower rpms. This is also why people talk about “low-end torque” being important for better power at slower speeds.
How does torque work in motor?
Torque is a rotating force produced by an engine’s crankshaft. The more torque an engine produces, the greater its ability to perform work. The measurement is the same as work, but slightly different. Since torque is a vector (acting in a certain direction), it’s quantified by the units pound-feet and newton-meters.
Do AC or DC motors have more torque?
AC motors are generally considered to be more powerful than DC motors because they can generate higher torque by using a more powerful current. However, DC motors are typically more efficient and make better use of their input energy.
Which motor is used for high torque?
Series wound DC motors are best for applications that require high startup torque, without the need for speed regulation. Like a shunt motor, as a load is applied to a DC series motor, the motor speed decreases, which reduces the back EMF and increases the net voltage.
Why is the DC motor preferred over AC motor?
Because DC motors have higher starting torque compared to AC motors, they are preferred for applications like electrical traction. They are considered ideal for dealing with heavy loads for starting conditions in machines such as locomotives and cranes.
How do you increase the torque of an AC motor?
There are three ways to improve the starting torque of Single phase induction Motor
- Internal Rotor Resistance. The across the line starting torque at low speed can be increased by increasing the rotor resistance. …
- External Rotor Resistance. …
- Variable Voltage/Frequency.
Which is better torque at low rpm or torque at high rpm?
“Higher torque at lower r.p.m. means you have a lot more horsepower at lower r.p.m., which makes it easier to tow things from a standstill. That’s usually how trucks are geared,” Murray said. “High torque at higher r.p.m. means more power while you’re already underway, which usually results in higher top speed.
How much torque does a 1 hp motor have?
The 1800 RPM, 1HP motor produces 3 ft.lbs of torque at 1800 RPM. The 3600 RPM, 1HP motor produces 1.5 ft. lbs.
What are torque curves?
plots the torque of a motor against the speed the motor is going at. The relationship between speed and torque varies dramatically across different types of motor and also between manufacturers.
Does voltage affect AC motor speed?
The speed of an AC motor is dependent on the number of poles it has and the line frequency of the power supply, not on it’s voltage. Common AC motor units are constructed with either two or four poles.
How do you read a torque curve?
Look at the shape of the torque curve – Generally the graph should be relatively smooth with no big bumps or dips. The graphs should not be wavy throughout. A wavy or bumpy graph usually means bad boost control or a just a bad tune. Be aware some dynos smooth the graph more than others.
Why does torque drop at high RPM?
At high RPM, torque drops off primarily from intake and exhaust flow restriction. Volumetric Efficiency declines because the engine can’t breathe any faster. Mechanical efficiency also declines at higher RPM, due to increased frictional resistance. This further reduces torque at the output.
Is 400 Nm of torque a lot?
Large engines, both petrol and diesel, are inherently high torque. … It’s worth noting that engines producing much more than 400 Nm (295 lb/ft) of torque, whether petrol or diesel, are usually at their best teamed with an automatic gearbox.
What is peak RPM?
An engine doesn’t necessarily produce its maximum power at its highest rpm. Engine specifications typically present the peak horsepower figure followed by the rpm at which it occurs, such as 252 hp at 5,600 rpm. … Many cars have a tachometer to indicate engine rpm, usually measured in thousands.
How is torque calculated in an AC induction motor?
Torque of a three phase induction motor is proportional to flux per stator pole, rotor current and the power factor of the rotor. T ∝ ɸ I2 cosɸ2 OR T = k ɸ I2 cosɸ2 .
Why do we torque a motor?
Torque motors excel in their ability to directly drive applications. There’s no need for a transmission/gearbox. The moving rotor of the torque motor is glued or clamped directly on the driven part. Throughout the rev-range a high continuous torque is available.
What makes a motor high torque?
A high torque motor is toroid shaped, like a donut, and thus has a large diameter and short axis. These motors can directly drive the application without additional mechanics, like worm wheels, belts or pulleys.
Does Tesla use AC or DC motors?
Tesla, for example, uses alternating current (AC) induction motors in the Model S but uses permanent-magnet direct current (DC) motors in its Model 3. There are upsides to both types of motor, but generally, induction motors are somewhat less efficient than permanent-magnet motors at full load.
Are AC motors brushless?
The two main types of AC motors are induction motors and synchronous motors. … The brushless wound-rotor doubly fed motor is a synchronous motor that can function exactly at the supply frequency or sub to super multiple of the supply frequency.
Why is AC more efficient than DC?
Hence, the voltage through transmission lines is very high, which reduces the current, which in turn minimizes the energy lost through transmission. This is why alternating current is preferred over direct current for transmitting electricity, as it is much cheaper to change the voltage of an alternating current.
Which AC motor has the highest starting torque?
DC Series motors have high starting torque but induction motors have wide range of speed control.
Which motor is high speed AC or DC?
DC motors offer better speed variation and control and produce more torque than AC motors. The two types of DC motors include: Brushed: One of the oldest types of motor, brushed motors are internally commutated electric motors powered by direct current.
Which DC motor gives high starting torque?
The torque of the DC series motor is proportional to the square of the armature current. That is why DC series motor has high starting torque. The DC series motor produces the highest torque among all kinds of motors.
Which DC motor is preferred for high speed?
25,000rpm motor dc 12v has acquired the highest response among electronics hobbyists for high speed operations. Best option for use in electronics projects.
What is the disadvantage of DC motor?
DC Motor Advantages & Disadvantages
| Advantages | Disadvantages |
|---|---|
| Inexpensive controls for speed regulation | Cogging at speeds of less than 300 rpm |
| Generally a low-cost motor option | Significant power loss on full wave rectified voltage |
| Easily pairs with gear reducers | High starting torque can damage reducers |
•
Are AC motors cheaper than DC?
Alternating-current (AC) and direct-current (DC) motors have traditionally served distinctly different applications due to their construction and inherent operating characteristics. In general, AC motors were smaller, less expensive, lighter and more rugged than DC motors.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.