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45-527: (Redirected from Afe ) AFE or Afe may refer to: Active front end, in variable-frequency drives Advanced FLOW engineering (aFe), a manufacturer of high performance automotive parts Afe Annang , a political unit of the Annang people of Nigeria AfE-Turm /Uni-Turm (English: AfE Tower), a demolished skyscraper in Frankfurt, Germany Afrique Football Élite ,

90-537: A phase converter having single-phase converter input and three-phase inverter output. Controller advances have exploited dramatic increases in the voltage and current ratings and switching frequency of solid-state power devices over the past six decades. Introduced in 1983, the insulated-gate bipolar transistor (IGBT) has in the past two decades come to dominate VFDs as an inverter switching device. In variable- torque applications suited for Volts-per-Hertz (V/Hz) drive control, AC motor characteristics require that

135-459: A pulse-width modulation (PWM) rectifier and a PWM inverter to the DC-link. The DC-link quantity is then impressed by an energy storage element that is common to both stages, which is a capacitor C for the voltage DC-link or an inductor L for the current DC-link. The PWM rectifier is controlled in a way that a sinusoidal AC line current is drawn, which is in phase or anti-phase (for energy feedback) with

180-557: A VFD system is usually a three-phase induction motor . Some types of single-phase motors or synchronous motors can be advantageous in some situations, but generally three-phase induction motors are preferred as the most economical. Motors that are designed for fixed-speed operation are often used. Elevated-voltage stresses imposed on induction motors that are supplied by VFDs require that such motors be designed for definite-purpose inverter-fed duty in accordance with such requirements as Part 31 of NEMA Standard MG-1. The VFD controller

225-440: A VFD, the stopping sequence is just the opposite as the starting sequence. The frequency and voltage applied to the motor are ramped down at a controlled rate. When the frequency approaches zero, the motor is shut off. A small amount of braking torque is available to help decelerate the load a little faster than it would stop if the motor were simply switched off and allowed to coast. Additional braking torque can be obtained by adding

270-615: A braking circuit (resistor controlled by a transistor) to dissipate the braking energy. With a four-quadrant rectifier (active front-end), the VFD is able to brake the load by applying a reverse torque and injecting the energy back to the AC line. Many fixed-speed motor load applications that are supplied direct from AC line power can save energy when they are operated at variable speed by means of VFD. Such energy cost savings are especially pronounced in variable-torque centrifugal fan and pump applications, where

315-409: A conveyor application for smoother deceleration and acceleration control, which reduces the backlash that can occur when a conveyor is accelerating or decelerating. Performance factors tending to favor the use of DC drives over AC drives include such requirements as continuous operation at low speed, four-quadrant operation with regeneration, frequent acceleration and deceleration routines, and need for

360-790: A football club in Bamako, Mali Amniotic fluid embolism , a potentially fatal complication of pregnancy Analog front-end , in electronics Armed Forces Entertainment , a United States Department of Defense agency Assembly of French Citizens Abroad , a French government body Association of Spanish Footballers (Spanish: Asociación de Futbolistas Españoles) Authorization for expenditure , also known as cost in accounting Kake Airport , Alaska, United States, by FAA location identifier Putukwam language , by ISO 639-3 language code State Railways Administration of Uruguay (Spanish: Administración de Ferrocarriles del Estado ), Uruguay's government-owned railroad company Topics referred to by

405-497: A means for an operator to start and stop the motor and adjust the operating speed. The VFD may also be controlled by a programmable logic controller through Modbus or another similar interface. Additional operator control functions might include reversing, and switching between manual speed adjustment and automatic control from an external process control signal. The operator interface often includes an alphanumeric display or indication lights and meters to provide information about

450-406: A pure electrical means of communication. Typical means of hardwired communication are: 4-20mA , 0-10VDC, or using the internal 24VDC power supply with a potentiometer . Speed can also be controlled remotely and locally. Remote control instructs the VFD to ignore speed commands from the keypad while local control instructs the VFD to ignore external control and only abide by the keypad. Depending on

495-427: A relatively large physical volume, and when electrolytic capacitors are used, in the case of a voltage DC-link, there is potentially a reduced system lifetime. A cycloconverter constructs an output, variable-frequency, approximately sinusoid waveform by switching segments of the input waveform to the output; there is no intermediate DC link. With switching elements such as SCRs , the output frequency must be lower than

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540-534: A step-up transformer is placed between a LV drive and a MV motor load. MV drives are typically rated for motor applications greater than between about 375 and 750 kW (503 and 1,006 hp). MV drives have historically required considerably more application design effort than required for LV drive applications. The power rating of MV drives can reach 100 MW (130,000 hp), a range of different drive topologies being involved for different rating, performance, power quality, and reliability requirements. It

585-436: A wide range of single-phase and multi-phase AC motors. Low-voltage (LV) drives are designed to operate at output voltages equal to or less than 690 V. While motor-application LV drives are available in ratings of up to the order of 5 or 6 MW, economic considerations typically favor medium-voltage (MV) drives with much lower power ratings. Different MV drive topologies (see Table 2) are configured in accordance with

630-546: Is a solid-state power electronics conversion system consisting of three distinct sub-systems: a rectifier bridge converter, a direct current (DC) link, and an inverter. Voltage-source inverter (VSI) drives (see 'Generic topologies' sub-section below) are by far the most common type of drives. Most drives are AC–AC drives in that they convert AC line input to AC inverter output. However, in some applications such as common DC bus or solar applications, drives are configured as DC–AC drives. The most basic rectifier converter for

675-400: Is also often available to allow the VFD to be configured, adjusted, monitored, and controlled using a computer. There are two main ways to control the speed of a VFD; networked or hardwired. Networked involves transmitting the intended speed over a communication protocol such as Modbus , Modbus / TCP , EtherNet/IP , or via a keypad using Display Serial Interface while hardwired involves

720-596: Is constructed from intersections of a saw-toothed carrier signal with a modulating sinusoidal signal which is variable in operating frequency as well as in voltage (or current). Operation of the motors above rated nameplate speed (base speed) is possible, but is limited to conditions that do not require more power than the nameplate rating of the motor. This is sometimes called "field weakening" and, for AC motors, means operating at less than rated V/Hz and above rated nameplate speed. Permanent magnet synchronous motors have quite limited field-weakening speed range due to

765-421: Is different from Wikidata All article disambiguation pages All disambiguation pages Variable-frequency drive A variable-frequency drive ( VFD , or adjustable-frequency drive , adjustable-speed drive , variable-speed drive , AC drive , micro drive , inverter drive , or drive ) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying

810-414: Is drawing less than 50% of its rated current from the mains in the low-speed range. A VFD can be adjusted to produce a steady 150% starting torque from standstill right up to full speed. However, motor cooling deteriorates and can result in overheating as speed decreases such that prolonged low-speed operation with significant torque is not usually possible without separately motorized fan ventilation. With

855-443: Is estimated that drive technology is adopted in as many as 30–40% of all newly installed motors. An energy consumption breakdown of the global population of AC motor installations is as shown in the following table: AC drives are used to bring about process and quality improvements in industrial and commercial applications' acceleration, flow, monitoring, pressure, speed, temperature, tension, and torque. Fixed-speed loads subject

900-485: Is lastly useful to relate VFDs in terms of the following two classifications: CSI or VSI (six-step or PWM ), cycloconverter, matrix Electro-mechanical Slip energy recovery (Kramer/Scherbius) CSI (LCI), cycloconverter, VSI Axial or disk Interior VSI VSI VSI Topologies AC-to-AC converter Referring to Fig 1, AC-AC converters can be categorized as follows: There are two types of converters with DC link: Any dynamic braking operation required for

945-606: Is the alternative option of indirect energy conversion by employing the Indirect Matrix Converter (Fig. 5) or the Sparse matrix converter which was invented by Prof. Johann W. Kolar from the ETH Zurich. As with the DC-link based VSI and CSI controllers (Fig. 2 and Fig. 3), separate stages are provided for voltage and current conversion, but the DC-link has no intermediate storage element. Generally, by employing matrix converters,

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990-745: The frequency of the input electricity. Depending on its topology , it controls the associated voltage or current variation. VFDs are used in applications ranging from small appliances to large compressors. Systems using VFDs can be more efficient than hydraulic systems , such as in systems with pumps and damper control for fans. Since the 1980s, power electronics technology has reduced VFD cost and size and has improved performance through advances in semiconductor switching devices, drive topologies, simulation and control techniques, and control hardware and software. VFDs include low- and medium-voltage AC–AC and DC–AC topologies. Pulse-Width Modulating (PWM) variable-frequency drive projects started in

1035-540: The 1960s at Strömberg in Finland. Martti Harmoinen  [ fi ] is regarded as the inventor of this technology. Strömberg managed to sell the idea of PWM drive to Helsinki Metro in 1973 and in 1982 the first PWM drive SAMI10 were operational. A variable-frequency drive is a device used in a drive system consisting of the following three main sub-systems: AC motor, main drive controller assembly, and drive/operator interface. The AC electric motor used in

1080-456: The United States, an estimated 60–65% of electrical energy is used to supply motors, 75% of which are variable-torque fan, pump, and compressor loads. Eighteen percent of the energy used in the 40 million motors in the U.S. could be saved by efficient energy improvement technologies such as VFDs. Only about 3% of the total installed base of AC motors are provided with AC drives. However, it

1125-426: The VFD controller. Basic programming of the microprocessor is provided as user-inaccessible firmware . User programming of display , variable, and function block parameters is provided to control, protect, and monitor the VFD, motor, and driven equipment. The basic drive controller can be configured to selectively include such optional power components and accessories as follows: The operator interface provides

1170-716: The VSI drive is configured as a three-phase, six-pulse, full-wave diode bridge . In a VSI drive, the DC link consists of a capacitor which smooths out the converter's DC output ripple and provides a stiff input to the inverter. This filtered DC voltage is converted to quasi- sinusoidal AC voltage output using the inverter's active switching elements. VSI drives provide higher power factor and lower harmonic distortion than phase-controlled current-source inverter (CSI) and load-commutated inverter (LCI) drives (see 'Generic topologies' sub-section below). The drive controller can also be configured as

1215-544: The chart's four quadrants are defined as follows: Most applications involve single-quadrant loads operating in quadrant I, such as in variable-torque (e.g. centrifugal pumps or fans) and certain constant-torque (e.g. extruders) loads. Certain applications involve two-quadrant loads operating in quadrant I and II where the speed is positive but the torque changes polarity as in case of a fan decelerating faster than natural mechanical losses. Some sources define two-quadrant drives as loads operating in quadrants I and III where

1260-430: The constant magnet flux linkage . Wound-rotor synchronous motors and induction motors have much wider speed range. For example, a 100 HP, 460 V, 60 Hz, 1775  RPM (4-pole) induction motor supplied with 460 V, 75 Hz (6.134 V/Hz), would be limited to 60/75 = 80% torque at 125% speed (2218.75 RPM) = 100% power. At higher speeds, the induction motor torque has to be limited further due to

1305-427: The contactor thus turns on the drive and has it output to a designated speed. Depending on the sophistication of the drive multiple auto-starting behavior can be developed e.g. the drive auto-starts on power up but does not auto-start from clearing an emergency stop until a reset has been cycled. Referring to the accompanying chart, drive applications can be categorized as single-quadrant, two-quadrant, or four-quadrant;

1350-452: The corresponding AC line phase voltage. Due to the DC-link storage element, there is the advantage that both converter stages are to a large extent decoupled for control purposes. Furthermore, a constant, AC line independent input quantity exists for the PWM inverter stage, which results in high utilization of the converter’s power capability. On the other hand, the DC-link energy storage element has

1395-489: The input. Very large cycloconverters (on the order of 10 MW) are manufactured for compressor and wind-tunnel drives, or for variable-speed applications such as cement kilns. In order to achieve higher power density and reliability, it makes sense to consider Matrix Converters that achieve three-phase AC-AC conversion without any intermediate energy storage element. Conventional Direct Matrix Converters (Fig. 4) perform voltage and current conversion in one single stage. There

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1440-420: The load's torque and power vary with the square and cube , respectively, of the speed. This change gives a large power reduction compared to fixed-speed operation for a relatively small reduction in speed. For example, at 63% speed a motor load consumes only 25% of its full-speed power. This reduction is in accordance with affinity laws that define the relationship between various centrifugal load variables. In

1485-418: The lowering of the breakaway torque of the motor. Thus, rated power can be typically produced only up to 130–150% of the rated nameplate speed. Wound-rotor synchronous motors can be run at even higher speeds. In rolling mill drives, often 200–300% of the base speed is used. The mechanical strength of the rotor limits the maximum speed of the motor. An embedded microprocessor governs the overall operation of

1530-433: The model a VFD's operating parameters can be programmed via: dedicated programming software, internal keypad, external keypad, or SD card. VFDs will often block out most programming changes while running. Typical parameters that need to be set include: motor nameplate information, speed reference source, on/off control source and braking control. It is also common for VFDs to provide debugging information such as fault codes and

1575-513: The motor can be realized by means of braking DC chopper and resistor shunt connected across the rectifier. Alternatively, an anti-parallel thyristor bridge must be provided in the rectifier section to feed energy back into the AC line. Such phase-controlled thyristor-based rectifiers however have higher AC line distortion and lower power factor at low load than diode-based rectifiers. An AC-AC converter with approximately sinusoidal input currents and bidirectional power flow can be realized by coupling

1620-492: The motor to a high starting torque and to current surges that are up to eight times the full-load current. AC drives instead gradually ramp the motor up to operating speed to lessen mechanical and electrical stress, reducing maintenance and repair costs, and extending the life of the motor and the driven equipment. Variable-speed drives can also run a motor in specialized patterns to further minimize mechanical and electrical stress. For example, an S-curve pattern can be applied to

1665-481: The motor to be protected for a hazardous area. The following table compares AC and DC drives according to certain key parameters: ^ High-frequency injection AC drives can be classified according to the following generic topologies: Most drives use one or more of the following control platforms: Variable-frequency drives are also categorized by the following load torque and power characteristics: VFDs are available with voltage and current ratings covering

1710-433: The motor voltage magnitude, angle from reference, and frequency so as to precisely control the motor's magnetic flux and mechanical torque. Although space vector pulse-width modulation (SVPWM) is becoming increasingly popular, sinusoidal PWM (SPWM) is the most straightforward method used to vary drives' motor voltage (or current) and frequency. With SPWM control (see Fig. 1), quasi-sinusoidal, variable-pulse-width output

1755-453: The operation of the drive. An operator interface keypad and display unit is often provided on the front of the VFD controller as shown in the photograph above. The keypad display can often be cable-connected and mounted a short distance from the VFD controller. Most are also provided with input and output (I/O) terminals for connecting push buttons, switches, and other operator interface devices or control signals. A serial communications port

1800-402: The same polarity. In starting a motor, a VFD initially applies a low frequency and voltage, thus avoiding high inrush-current associated with direct-on-line starting . After the start of the VFD, the applied frequency and voltage are increased at a controlled rate or ramped up to accelerate the load. This starting method typically allows a motor to develop 150% of its rated torque while the VFD

1845-450: The same term [REDACTED] This disambiguation page lists articles associated with the title AFE . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=AFE&oldid=1249927800 " Category : Disambiguation pages Hidden categories: Articles containing Spanish-language text Short description

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1890-435: The speed and torque is same (positive or negative) polarity in both directions. Certain high-performance applications involve four-quadrant loads (Quadrants I to IV) where the speed and torque can be in any direction such as in hoists, elevators, and hilly conveyors. Regeneration can occur only in the drive's DC link bus when inverter voltage is smaller in magnitude than the motor back- EMF and inverter voltage and back-EMF are

1935-404: The states of the input signals. Most VFDs allow auto-starting to be enabled. Which will drive the output to a designated frequency after a power cycle, or after a fault has been cleared, or after the emergency stop signal has been restored (generally emergency stops are active low logic). One popular way to control a VFD is to enable auto-start and place L1, L2, and L3 into a contactor. Powering on

1980-691: The voltage magnitude of the inverter's output to the motor be adjusted to match the required load torque in a linear V/Hz relationship. For example, for 460 V, 60 Hz motors, this linear V/Hz relationship is 460/60 = 7.67 V/Hz. While suitable in wide-ranging applications, V/Hz control is sub-optimal in high-performance applications involving low speed or demanding, dynamic speed regulation, positioning, and reversing load requirements. Some V/Hz control drives can also operate in quadratic V/Hz mode or can even be programmed to suit special multi-point V/Hz paths. The two other drive control platforms, vector control and direct torque control (DTC), adjust

2025-421: The voltage/current-combination ratings used in different drive controllers' switching devices such that any given voltage rating is greater than or equal to one to the following standard nominal motor voltage ratings: generally either 2 + 3 ⁄ 4 .16 kV (60 Hz) or 3 + 3 ⁄ 6 .6 kV (50 Hz), with one thyristor manufacturer rated for up to 12 kV switching. In some applications

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