Choppers
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This document discusses a separately excited DC motor that is controlled using a DC chopper. It describes the components and operating modes of the system. The DC chopper converts a fixed DC input voltage to a variable output voltage, which is used to power the separately excited DC motor. The chopper and motor combination has three operating modes - motoring, regenerative braking, and dynamic braking. The chopper allows for efficient speed control of the separately excited DC motor.
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2) A chopper-fed DC drive works by connecting a DC chopper between a fixed-voltage DC source and DC motor to vary the armature voltage.
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This document provides an overview of generators, including their principle of operation, history, and types. It discusses how generators work by converting mechanical energy to electrical energy using electromagnetic induction. The history outlines early electrostatic generators and the invention of dynamos and alternators. There are two main types of generators - AC and DC generators - with AC generators being most commonly used in power systems today. Synchronous and induction generators are types of AC generators that are further described.
generators
This document provides an overview of generators, including their principle of operation, history, and types. It discusses how generators work by converting mechanical energy to electrical energy using electromagnetic induction. The history outlines early electrostatic generators and the invention of dynamos and alternators. There are two main types of generators - AC and DC generators - with AC generators being most commonly used in power systems today. Synchronous and induction generators are types of AC generators that are further described.
CONTROL OF ELECTRICAL MACHINES
This document provides an overview of control circuits and components for electrical machines, including DC motors and AC motors. It discusses various switch types, relays, timers, and interlocking circuits used in motor controls. For DC motors, it describes series relay starters, time acceleration starters, field failure protection, and plugging control. For AC motors, it covers DOL starters, star-delta starters, automatic transformer starters, reversing motor direction, and dynamic braking. The document is a technical report submitted by K. Venkatachalam on the topic of controlling electrical machines.
motor_1684283145.pdf
The document discusses various control devices and starting methods for industrial motors. It describes disconnecting switches, manual circuit breakers, cam switches, pushbuttons, control relays, thermal relays, magnetic contactors, and proximity detectors that can be used for motor control. Starting methods covered include direct online, stator resistance, autotransformer, star-delta, and rotor resistance starting. Soft starting and reversing motor direction are also summarized. Diagrams are used to illustrate control systems and motor connections.
Special Purpose machines.ppt
This document discusses several types of special-purpose electric machines and their applications. It covers brushless DC motors, stepping motors, single-phase induction motors, split-phase motors, and capacitor-start motors. The key applications of these motors include robotics, vehicle propulsion, aerospace, automotive control, computer disk drives, fans, and household appliances. The document provides details on the operating principles, advantages, and disadvantages of different motor types.
Lecture 4-ELECTRIC MOTORS-ACTUATION SYSTEMS2.ppt
This document discusses robot actuation and feedback components, including electric motors and servo motors. It provides details on different types of DC motors like series wound, shunt wound, compound wound, and separately excited motors. It also covers stepper motors, explaining their specifications and full step and half step commutation sequences. Servo motors are defined as motors that can rotate with precision using a closed-loop feedback system to control the shaft position. Applications of different motor types are also listed.
Vipul.maiet
The document discusses the construction and working of DC motors. It describes the key components of a DC motor including the stator, rotor, yoke, poles, field windings, armature windings, commutator, and brushes. It also explains the different types of DC motors such as permanent magnet, separately excited, self-excited, shunt wound, series wound, and compound wound motors. Applications of different DC motor types are also summarized.
Project_1
Permanent magnet synchronous motors (PMSMs) are electronically commutated using a closed-loop controller and switching power supply. The controller provides current pulses to the motor windings that control the speed and torque. PMSMs use electronic commutation of the stator windings rather than a mechanical commutator, allowing for easier control and a wider speed range compared to motors with mechanical commutators. The operating principle involves current in the armature windings interacting with the permanent magnets' magnetic field to generate torque for rotation based on Fleming's left hand rule.
Drives.pptx
This document provides information about different types of drives (actuation systems) including DC motors, AC motors, and stepper motors. It discusses the construction, working principles, advantages, disadvantages, and applications of each motor type. DC motors include brushed and brushless types. AC motors include synchronous and induction types. Stepper motors can be permanent magnet, variable reluctance, or hybrid synchronous types and operate by dividing a full rotation into discrete steps through electromagnetic pulses.
Electronic control of dc motors
1) The document discusses controlling DC motors using silicon-controlled rectifiers (SCRs). SCRs can be used in a circuit connected to a DC motor to control its speed.
2) Applying different voltages to the motor armature by controlling the gate current of SCRs allows variable speed control of the DC motor. Longer conduction times of the SCRs apply more voltage and increase motor speed.
3) Electronic control methods for DC motors include flux control, armature voltage control, open-loop speed control using rheostats, and closed-loop speed control using techniques like PI, PD, or PID control.
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An improved modulation technique suitable for a three level flying capacitor ...
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integration into modern power electronic systems. Through the amalgamation of
sinusoidal pulse width modulation (SPWM) with a high-frequency square wave
pulse, this controlling technique attains energy equilibrium across the coupling
capacitor. The modulation scheme incorporates a simplified switching pattern
and a decreased count of voltage references, thereby simplifying the control
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一比一原版(CalArts毕业证)加利福尼亚艺术学院毕业证如何办理
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Choppers
- 1. DC CHOPPER FED SEPARATELY EXCITED MOTOR: SUBMITTED BY S.RAJA RAJESHWARI (14F40) M.S.SATISH (14F49) V.DEEPAKKUMAR (14F61)
- 2. CHOPPERS: • Chopper is basically a static power electronics device which converts fixed dc voltage / power to variable dc voltage or power. • It is nothing but a high speed switch which connects and disconnects the load from source at a high rate to get variable or chopped voltage at the output • Chopper can increase or decrease the dc voltage level at its opposite side.
- 3. DC CHOPPER: • A DC chopper is a static device that converts fixed dc input voltage to a variable dc output voltage directly. • A chopper can be said as dc equivalent of an ac transformer as they behave in an identical manner. • This kind of choppers are more efficient as they involve one stage conversion. • Just like a transformer, a chopper can be used to step up or step down the fixed dc output voltage. • Choppers are used in many applications all over the world inside various electronic equipments. • A chopper system has a high efficiency, fast response and a smooth control
- 4. SEPARATELY EXCITED DC MOTOR: • Separately excited dc motor has field coils similar to that of shunt wound dc motor, here the field is supplied from a constant voltage so that the field current is constant. • Usually, in other DC motors, the field coil and the armature coil both are energized from a single source. The field of them does not need any separate excitation. • But, in separately excited DC motor, separate supply Provided for excitation of both field coil and armature coil.
- 5. 3 MODES OF OPERATION: There are three modes of operation of the DC chopper used in a separately excited motor: • Motoring • Regenerative braking • Dynamic braking
- 9. MODE 2: REGENERATIVE BRAKING
- 13. MODE 3: DYNAMIC BRAKING
- 14. DYNAMIC BRAKING: • In this method of braking, the motor which is at a running condition is disconnected from the source and connected across a resistor. • When the motor is disconnected from the source ,the rotor keeps rotating due to inertia and works as a self-excited generator. • When the motor works as a self-excited generator ,the flow of current and torque reverses. • During braking, to maintain the steady torque, sectional resistances are cut one by one.
- 15. APPLICATIONS : • Used in speed control of the separately excited dc motor • Offers smooth control ,high efficiency and fast response. • Used to step down or step up the fixed dc input voltage.