The AC Induction Motor (ACIM) is the workhorse of industrial and domestic applications, due to its simple construction and durability. The control of ACIM can be accomplished by simple open loop control technique using conventional Volt-Hertz method. But, when dynamic responses are required, it is essential to use a closed loop control technique to reduce high current transients. The aim of this paper is to design a closed loop control of ACIM using SVPWM technique and compare the performance with conventional method. This is implemented by using dsPIC for controlling the drive, as it provides higher efficiency and lower operating costs, (i.e.,) it reduces the cost of drive components. Key words: AC Induction Motor, SVPWM, dsPIC I.INTROUCTION The AC induction motor (ACIM) is the workhorse of industrial and residential motor applications due to its simple construction and durability. These motors have no brushes to wear out or magnets to add to the cost. The rotor assembly is a simple steel cage. ACIM’s are designed to operate at a constant input voltage and frequency, but you can effectively control an ACIM in an open loop variable speed application if the frequency of the motor input voltage is varied. If the motor is not mechanically overloaded, the motor will operate at a speed that is roughly proportional to the input frequency. As you decrease the frequency of the drive voltage, you also need to decrease the amplitude by a proportional amount. Otherwise, the motor will consume excessive current at low input frequencies. This control method is called Volts-Hertz control. In practice, a custom Volts-Hertz profile is developed that ensures the motor operates correctly at any speed setting. This profile can take... ... middle of paper ... ...rated in Figure 1. Coordinate Transforms Through a series of coordinate transforms the time invariant values of torque and flux can be indirectly determined and controlled with classic PI control loops. The process starts out by measuring the three phase motor currents. In practice you can take advantage of the constraint that in a three-phase system the instantaneous sum of the three current values will be zero. Thus by measuring only two of the three currents you can know the third. The cost of the hardware is reduced because only two current sensors are required. IV. CLARK TRANSFORM Fig.2 Clark Transform The first transform is to move from a 3-axis, 2-dimensional coordinate system referenced to the stator of the motor to a 2-axis system also referenced to the stator. The process is called the Clarke Transform, as illustrated in Figure 2. V. PARK TRANSFORM
The Wankel rotary engine named after the designer, Felix Wankel, was engineered in the early 1930’s. The rotary engine was unlike the conventional four stroke internal combustion engines and lacked the need for pistons, valves and camshafts. With only three moving parts involved in the design, this engine showed great promise in reliability and efficiency. The first Wankel rotary model was shown in 1960, not as an engine, but as a pump drive. Instead of the very complicated system involved in a conventional reciprocating piston engine, the wankel engine incorporated triangular “rotors” (see figure 1) that rotate within an epitrochoidal chamber around an eccentric shaft. Not only is this engine much more simple (only 3 moving parts rather
The experiment test-bed is composed of a DC motor, an engine, a chain drive, a shaft and other accessorial components. The DC motor is used to drive the engine shaft and its speed can be up to 1450 r/min.
The first type of forced induction system is the turbocharger. A turbocharger is essentially the same as a supercharger, except where they get their power from. A turbocharger is powered by exhaust gasses that have been produced by the engine and are forcing their way through the turbofold, or the exhaust manifold that the turbo is housed in. The exhaust gas pushes its way through the turbocharger and hit the turbine wheel. Vehicles that usually find the need for a turbocharger from the factory are four or six cylinder engines. Standard in most European vehicles such as Mercedes, Audi, Volkswagen and Volvo. These cars are known for their small displacement motors, and great gas efficiency, due to this setup...
A maglev system is nonlinear and its open-loop response is unstable because of the nature of the magnetic forces used. PI controllers are based on a linearized model, so they do not compensate for certain variations. These variations can occur when a magnetic bearing experiences a working load change on the rotor during operation, ...
A direct current in a set of windings creates a polar magnetic field. A torque acts on the rotor due to its relation to the external magnetic field. Just as the magnetic field of the rotor becomes fully aligned with the external magnetic field, the direction of the current in the windings on the armature reverses, thereby reversing the polarity of the rotor's electromagnetic field. A torque is once again exerted on the rotor, and it continues spinning.
Rockis, Gary, and Glen Mazur. Electrical Motor Controls for Integrated Systems. 4th ed. Homewood, IL: American Technical, 2009. Print
Tesla had an ingenious mind. He saw ideas and problems that others couldn’t see or understand. One day while he took a stroll in a park he came up with a revolutionary idea. His whole life, and the world around him, was about to changed. The young Tesla built and successfully ran a prototype of his induction motor. At first, no one was interested in this invention so he later moved to the New York in 1884, looking for a better chance to show to the world of his groundbreaking invention, and later accepted a job offer from Thomas Edison.
At the point when permanent magnet is utilized to create magnetic field in a DC motor, the motor is known as permanent magnet DC motor or PMDC motor. The motor can be easily to build. These motors are usually
Our orthocyclically-wound motor coil makes it possible to manufacture the stator windings with the highest possible copper fill factor, allowing for a shortened motor length while increasing power output by up to 80
In the field, most of the motors are induction motors. Now-a-days, industry has become more concerned about the performance of the motor. By improving the efficiency of motors we can save energy, reduce operating costs, and improve the End-User Profitability. In case of any failure, motors usually can be rewind, it is often worthy to replace a damaged motor with a new one to save energy and improve reliability.
To simplify the calculation in control system design, it is common to use first order approach and assume the system to be linear. To realize this project, the matematical model of 3-phase BLDC motor system being used is needed.
To understand how this motor works, we must understand the relationship between electricity, and magnetism or simply put electromagnetism. Direct electric current in a simple description: There are two requirements for current flow. The first is a source of electrical potential energy or EMF (electro motive force,). The second is a conductor that provides a complete loop to carry the current. The reason a conductor will conduct is found on the atomic level. A conductive atom’s valance shell is not completely full electrons will flow from atom to atom because of this. When these electrons move from one atom to another that is electrical current (a brief description that is).
Ac motors are mainly use for larger aircrafts. There are two main types of ac motors , depending on the type of rotor used. The first type is synchronous motor , which does not reply on induction and as a result , can rotate exactly at the supply frequency or a sub multiple of the supply . the magnetic field on the rotor is either generated by current delivered through slip motors and also rings or by a permanent magnet. Other types od the motor include eddy current motors. AC /DC mechanically commuted machines in which speed is dependent on the voltage and the connection. Second type is a induction motor which runs slightly slower than the supply frequency. The magnetic field on the rotor of the motor is created by an induced current . when the rotor rotates, the stator conductors are cut by the magnetic flux hence the reason an induced E.M.F is produced by them, because the magnetic poles are alternative N and S , they induced an E.M.F and hence current is armature conductors which first flow in one direction and then in the order. The single phase motor operates in a single phase supply and for use on numerous application like ceiling fans and also refrigerators ,food mixers ect. A single phase induction motor physically looks similar to that of the three phase induction motor except that its stator is
The necessity of motion to produce a current is due to the fact that electromagnetic induction involves a time-varying magnetic field. The same effects can be produced by moving the coil toward and away from a motionless magnetic source. In either case, the key to producing the current is certainly the motion of the magnet or the wire. The magnetic lines of the magnetic field must pass through a loop of the coiled wire.
Electrical motors play an important role in today’s society, from powering domestic appliances like blenders to industrial equipment such as trains. It almost seems impossible to not use an electric motor in our daily lives. In the comfort of our home, electric motors will operate fans, refrigerators, and air conditioners to just name a few. Researchers are constantly looking for new ways to incorporate electrical motors in our lives.