Friday, April 13, 2007
Motor Technologies Compete for Space in Small Variable Speed Drives
Alternately called speed controls, small variable speed drives (VSDs) typically range from 10 to 2000 watts in output power. The core of this lower power class is best represented by VSDs ranging from 75 to 750 watts, often described as the fractional horsepower segment of this important family. Applications can be found in many markets; some of the most popular uses include variable speed conveyors, multi-axis conveyors, bar feeders, fans, compressors, pumps, mixers, food processing equipment, automated ticket handling equipment, body scanning actuators, and centrifuges.
Regardless of the type of application, a VSD must control the speed of the motor over a wide speed range. It holds the motor's velocity signal within a specified range as a function of voltage, temperature, and load changes. Actual performance parameters include speed range and speed regulation. Other important performance parameters include motor torque, power levels, input current levels, and motor efficiency.
Two control strategies are used in industry: open-loop control and closedloop control. Open-loop control depends on the electric motor's internal regulation. Closed-loop control techniques measure the motor's speed and compare it to the desired speed values.
Advertisement
Most smaller VSDs in use today continue to employ brush DC motors for a majority of applications due to their lower unit cost and ease-of-use, but technology change is on the immediate horizon. Two different VSDs - brushless PM and AC induction driven VSDs - are competing technology replacements. Both provide performance enhancements and better long-term cost savings than equivalent brush DC VSDs.
At the beginning of the design process, users may select a brushless PM VSD (employing a brushless DC motor) because they need high performance capability and are willing to pay more to obtain it. AC induction VSDs, on the other hand, are selected for longer life requirements and acquisition pricing similar to brush DC VSDs.
Emerging Pressure Points
Factory automation machines used in lower intermittent duty cycle applications will continue to use brush DC VSDs as their first choice; however, an increasing number of factory machine builders are looking at lower life cycle costs. Key elements for better life cycle costs include longer life expectancy, lower maintenance costs, better power efficiency, lower electromagnetic interference (EMI), and lower thermal stress. These elements provide the user with cost savings over a longer time period.
The rapid increase in the use of nonlinear power electronics found in today's DC and AC VSDs has significantly increased the level of EMI in industry. The impact of government regulations and industry standards (FCC, IEEE, and IEC) concerning EMI levels places a premium on lower EMI performance. As a result emphasis is now placed on implementing new circuitry dedicated to minimizing EMI and using electric motors with lower EMI signatures.
AC induction USDs
The popularity of smaller AC induction motors in lower cost and higher volume markets (appliances, vending machines, etc.) has fostered its use in VSDs in industrial and factory automation markets.
The AC induction motor is a brushless AC motor with demonstrated longer life and lower maintenance performance. Power electronics packages continue to drop in price as quantities begin to climb and the semiconductor industry's manufacturing processes shrink electronic device size and package more components on a smaller volume of silicon. Of the many types of VSDs used, the inverter driven three-phase VSD and the single-phase control VSD are currently the most popular.
Benefits and disadvantages of the brushless AC VSD versus the brush DC VSD can be seen in the following comparison. The 90-watt, single-phase ES01+VS1590A VSD and the 200-watt, three-phase BHF62AT VSD from Oriental Motor represent two different AC closed-loop control schemes. The ES01 AC VSD uses a pulse generator to control speed regulation over a 17.8 to 1 speed range. The larger three-phase BHF62AT AC VSD uses a sensorless vector closed-loop control with inverter drive. The. two AC VSDs show similar regulation capabilities to the 90-watt brush DC VSD using a closed-loop back EMF control scheme. The DC motor has a wider speed range and better power efficiency, but its major limitations are in life cycle costs and EMI performance. (The brush DC motor generates large amounts of EMI.) While the DC VSD has lower acquisition, installation, and operating costs, the unit life expectancy is much shorter (due primarily to motor brush life). The lower performance AC induction motors achieve the same acquisition costs as the brush DC VSD at a longer life expectancy and much lower EMI levels.
Regardless of the type of application, a VSD must control the speed of the motor over a wide speed range. It holds the motor's velocity signal within a specified range as a function of voltage, temperature, and load changes. Actual performance parameters include speed range and speed regulation. Other important performance parameters include motor torque, power levels, input current levels, and motor efficiency.
Two control strategies are used in industry: open-loop control and closedloop control. Open-loop control depends on the electric motor's internal regulation. Closed-loop control techniques measure the motor's speed and compare it to the desired speed values.
Advertisement
Most smaller VSDs in use today continue to employ brush DC motors for a majority of applications due to their lower unit cost and ease-of-use, but technology change is on the immediate horizon. Two different VSDs - brushless PM and AC induction driven VSDs - are competing technology replacements. Both provide performance enhancements and better long-term cost savings than equivalent brush DC VSDs.
At the beginning of the design process, users may select a brushless PM VSD (employing a brushless DC motor) because they need high performance capability and are willing to pay more to obtain it. AC induction VSDs, on the other hand, are selected for longer life requirements and acquisition pricing similar to brush DC VSDs.
Emerging Pressure Points
Factory automation machines used in lower intermittent duty cycle applications will continue to use brush DC VSDs as their first choice; however, an increasing number of factory machine builders are looking at lower life cycle costs. Key elements for better life cycle costs include longer life expectancy, lower maintenance costs, better power efficiency, lower electromagnetic interference (EMI), and lower thermal stress. These elements provide the user with cost savings over a longer time period.
The rapid increase in the use of nonlinear power electronics found in today's DC and AC VSDs has significantly increased the level of EMI in industry. The impact of government regulations and industry standards (FCC, IEEE, and IEC) concerning EMI levels places a premium on lower EMI performance. As a result emphasis is now placed on implementing new circuitry dedicated to minimizing EMI and using electric motors with lower EMI signatures.
AC induction USDs
The popularity of smaller AC induction motors in lower cost and higher volume markets (appliances, vending machines, etc.) has fostered its use in VSDs in industrial and factory automation markets.
The AC induction motor is a brushless AC motor with demonstrated longer life and lower maintenance performance. Power electronics packages continue to drop in price as quantities begin to climb and the semiconductor industry's manufacturing processes shrink electronic device size and package more components on a smaller volume of silicon. Of the many types of VSDs used, the inverter driven three-phase VSD and the single-phase control VSD are currently the most popular.
Benefits and disadvantages of the brushless AC VSD versus the brush DC VSD can be seen in the following comparison. The 90-watt, single-phase ES01+VS1590A VSD and the 200-watt, three-phase BHF62AT VSD from Oriental Motor represent two different AC closed-loop control schemes. The ES01 AC VSD uses a pulse generator to control speed regulation over a 17.8 to 1 speed range. The larger three-phase BHF62AT AC VSD uses a sensorless vector closed-loop control with inverter drive. The. two AC VSDs show similar regulation capabilities to the 90-watt brush DC VSD using a closed-loop back EMF control scheme. The DC motor has a wider speed range and better power efficiency, but its major limitations are in life cycle costs and EMI performance. (The brush DC motor generates large amounts of EMI.) While the DC VSD has lower acquisition, installation, and operating costs, the unit life expectancy is much shorter (due primarily to motor brush life). The lower performance AC induction motors achieve the same acquisition costs as the brush DC VSD at a longer life expectancy and much lower EMI levels.
Smart Power Modules suit low-power appliance motor drives
Rated from 50 W to 3 kW, Motion-SPM(TM) 500 V multi-chip Models FSB50250 and FSB50450 each combine 6 fast recovery MOSFET's and 3 half-bridge high-voltage ICs in one thermally efficient, Tiny-DIP package designed for BLDC motors with built-in control. Gate-driver ICs offer high-isolation, 5 V CMOS/TTL interface and under-voltage lockout protection. High-speed level-shifting function permits operation from single power supply voltage, eliminating need for opto-isolation.
********************
Fairchild's SPM portfolio is the industry's most comprehensive line-up of power modules--50 W to 3 kW--for inverter motors
South Portland, Maine-June 8, 2005-Fairchild Semiconductor's (NYSE: FCS) Motion-Smart Power Modules (SPM(TM)) offer a highly integrated solution for low-power (below 100 W), brushless dc (BLDC) motor applications. The Motion-SPM devices integrate multiple functions in a single compact package, offering a simplified motor drive solution to speed engineering design, reduce PC board space and enable energy-efficient and reliable designs in home appliances. Motion-SPM multi-chip modules combine six fast recovery MOSFETs (FRFET(TM)) and three half-bridge high-voltage ICs (HVIC) in one thermally efficient, ultra-compact (29 mm x 12 mm) Tiny-DIP package designed for BLDC motors with built-in control.
"The low-power appliance market is selecting high-voltage brushless dc (BLDC) motors over single-phase AC induction motors, due to their increased efficiency (from 50 to 90%), decreased acoustic noise and vibration, and higher power density per volume and weight. Fairchild's Motion-SPMs make it possible to build the motor control into the BLDC assembly," said Taehoon Kim, vice president of Fairchild's High-Power product line. "By integrating power analog and power discrete IC functionality into a single package, the SPM represents how Fairchild understands--and meets--the thermal efficiency, reliability and board space demands of the home appliance market. In addition to offering advantages over non-integrated solutions, the new Motion-SPM series makes Fairchild's SPM portfolio the industry's most comprehensive line-up of power modules covering inverter motors used in a full range of 50 W to 3 kW appliances."
Advertisement
Each Motion-SPM uses advanced FRFET and HVIC devices to ensure the performance and long-term reliability of the end product, while simplifying motor inverter designs. The Motion-SPMs' FRFETs optimize system efficiency by lowering switching and conduction losses during low-current conditions. For ruggedness, they provide a wider reverse bias safe operating area (RBSOA) than IGBTs of similar ratings. By using the MOSFETs' body diodes as freewheeling diodes, Motion-SPMs eliminate the need for additional components, improving the efficiency and noise immunity. The gate-driver ICs increase reliability through high-isolation, 5 V CMOS/TTL interface and under-voltage lockout (UVLO) protection features.
Additional features of the Motion-SPM series streamline the design process. The HVICs' high-speed level-shifting function permits operation from a single power supply voltage, a technique that makes space-consuming opto-isolation unnecessary. By providing optimal control of switching speeds, Motion-SPMs lower electromagnetic interference (EMI), enabling designers to decrease the design costs related to reducing noise. In addition, these modules save space while increasing reliability by offering three divided negative DC-link terminals for inverter current sensing.
The 500 V FSB50250 and FSB50450 (2 A- and 3 A-rated, respectively) are each housed in a 23-lead DIP. These products are lead-free (Pb-free).
With this introduction of low-power SPM products, Fairchild now offers the most comprehensive portfolio of power modules covering the full range of 50 W to 3 kW appliances. The Motion-SPM series represent the way Fairchild uses its design and manufacturing expertise, as well as a deep understanding of the markets it serves, to offer both integrated and non-integrated solutions that meet specific application requirements.
********************
Fairchild's SPM portfolio is the industry's most comprehensive line-up of power modules--50 W to 3 kW--for inverter motors
South Portland, Maine-June 8, 2005-Fairchild Semiconductor's (NYSE: FCS) Motion-Smart Power Modules (SPM(TM)) offer a highly integrated solution for low-power (below 100 W), brushless dc (BLDC) motor applications. The Motion-SPM devices integrate multiple functions in a single compact package, offering a simplified motor drive solution to speed engineering design, reduce PC board space and enable energy-efficient and reliable designs in home appliances. Motion-SPM multi-chip modules combine six fast recovery MOSFETs (FRFET(TM)) and three half-bridge high-voltage ICs (HVIC) in one thermally efficient, ultra-compact (29 mm x 12 mm) Tiny-DIP package designed for BLDC motors with built-in control.
"The low-power appliance market is selecting high-voltage brushless dc (BLDC) motors over single-phase AC induction motors, due to their increased efficiency (from 50 to 90%), decreased acoustic noise and vibration, and higher power density per volume and weight. Fairchild's Motion-SPMs make it possible to build the motor control into the BLDC assembly," said Taehoon Kim, vice president of Fairchild's High-Power product line. "By integrating power analog and power discrete IC functionality into a single package, the SPM represents how Fairchild understands--and meets--the thermal efficiency, reliability and board space demands of the home appliance market. In addition to offering advantages over non-integrated solutions, the new Motion-SPM series makes Fairchild's SPM portfolio the industry's most comprehensive line-up of power modules covering inverter motors used in a full range of 50 W to 3 kW appliances."
Advertisement
Each Motion-SPM uses advanced FRFET and HVIC devices to ensure the performance and long-term reliability of the end product, while simplifying motor inverter designs. The Motion-SPMs' FRFETs optimize system efficiency by lowering switching and conduction losses during low-current conditions. For ruggedness, they provide a wider reverse bias safe operating area (RBSOA) than IGBTs of similar ratings. By using the MOSFETs' body diodes as freewheeling diodes, Motion-SPMs eliminate the need for additional components, improving the efficiency and noise immunity. The gate-driver ICs increase reliability through high-isolation, 5 V CMOS/TTL interface and under-voltage lockout (UVLO) protection features.
Additional features of the Motion-SPM series streamline the design process. The HVICs' high-speed level-shifting function permits operation from a single power supply voltage, a technique that makes space-consuming opto-isolation unnecessary. By providing optimal control of switching speeds, Motion-SPMs lower electromagnetic interference (EMI), enabling designers to decrease the design costs related to reducing noise. In addition, these modules save space while increasing reliability by offering three divided negative DC-link terminals for inverter current sensing.
The 500 V FSB50250 and FSB50450 (2 A- and 3 A-rated, respectively) are each housed in a 23-lead DIP. These products are lead-free (Pb-free).
With this introduction of low-power SPM products, Fairchild now offers the most comprehensive portfolio of power modules covering the full range of 50 W to 3 kW appliances. The Motion-SPM series represent the way Fairchild uses its design and manufacturing expertise, as well as a deep understanding of the markets it serves, to offer both integrated and non-integrated solutions that meet specific application requirements.
Integrated Stepper Module controls up to 5 stepper motors. As Part Of Their Total Motion Control Solution
Aegis(TM) Shaft Grounding Coupling prevents electrical damage to bearings of AC motors with variable frequency drives by safely passing harmful shaft current to ground. With Electron Transport Technology(TM), coupling provides virtual short between shaft and motor frame that keeps shaft current and voltage from building up. It provides cleanroom-quality bearing isolation with dust-proof seal that also protects against water spray.
********************
MECHANIC FALLS, ME - The revolutionary new Aegis(TM) Shaft Grounding Coupling (SGC) from Electro Static Technology prevents electrical damage to bearings of AC motors by safely passing harmful shaft current to ground. Extremely effective yet low-cost, the Aegis coupling provides an ultra-low impedance path from shaft to frame, allowing current induced by variable frequency drives (VFDs) to pass to ground without damaging motor bearings or the bearing race.
When variable frequency drives are used with AC motors, current is induced along the motor shaft. When it overcomes the resistance of the grease, this current discharges through the motor bearings causing frosting, pitting, fluting, and fusion craters which can lead to premature motor failure. With its patent-pending Electron Transport Technology(TM), the Aegis coupling solves this problem by providing a "virtual short" between the shaft and motor frame that keeps shaft current and voltage from building up in the first place. Easily installed and maintenance free, the Aegis coupling is a reliable, low-cost alternative to less effective mitigation schemes such as brushes.
Advertisement
In addition to eliminating damaging shaft current, the Aegis SGC provides cleanroom-quality bearing isolation with a dustproof seal that also protects against water spray. Developed initially for 5 to 15 HP NEMA motors (the largest installed base of motor/drive applications), the Aegis SGC is ideal for HVAC, cleanroom, petrochemical, manufacturing, transportation, and other applications where VFDs are used. Additional sizes will be available in the immediate future.
Electro Static Technology is a global leader in the elimination and/or mitigation of induced electrical charges. Other products include FLX-P(TM) flexible peel-and-stick passive static eliminators for printers, copiers, and other imaging devices. Electro Static Technology is a division of Illinois Tool Works (ITW), a $10 billion multinational conglomerate operating in 44 countries.
********************
MECHANIC FALLS, ME - The revolutionary new Aegis(TM) Shaft Grounding Coupling (SGC) from Electro Static Technology prevents electrical damage to bearings of AC motors by safely passing harmful shaft current to ground. Extremely effective yet low-cost, the Aegis coupling provides an ultra-low impedance path from shaft to frame, allowing current induced by variable frequency drives (VFDs) to pass to ground without damaging motor bearings or the bearing race.
When variable frequency drives are used with AC motors, current is induced along the motor shaft. When it overcomes the resistance of the grease, this current discharges through the motor bearings causing frosting, pitting, fluting, and fusion craters which can lead to premature motor failure. With its patent-pending Electron Transport Technology(TM), the Aegis coupling solves this problem by providing a "virtual short" between the shaft and motor frame that keeps shaft current and voltage from building up in the first place. Easily installed and maintenance free, the Aegis coupling is a reliable, low-cost alternative to less effective mitigation schemes such as brushes.
Advertisement
In addition to eliminating damaging shaft current, the Aegis SGC provides cleanroom-quality bearing isolation with a dustproof seal that also protects against water spray. Developed initially for 5 to 15 HP NEMA motors (the largest installed base of motor/drive applications), the Aegis SGC is ideal for HVAC, cleanroom, petrochemical, manufacturing, transportation, and other applications where VFDs are used. Additional sizes will be available in the immediate future.
Electro Static Technology is a global leader in the elimination and/or mitigation of induced electrical charges. Other products include FLX-P(TM) flexible peel-and-stick passive static eliminators for printers, copiers, and other imaging devices. Electro Static Technology is a division of Illinois Tool Works (ITW), a $10 billion multinational conglomerate operating in 44 countries.
Grounding Coupling works with 5-15 hp NEMA motors
Aegis(TM) Shaft Grounding Coupling prevents electrical damage to bearings of AC motors with variable frequency drives by safely passing harmful shaft current to ground. With Electron Transport Technology(TM), coupling provides virtual short between shaft and motor frame that keeps shaft current and voltage from building up. It provides cleanroom-quality bearing isolation with dust-proof seal that also protects against water spray.
********************
MECHANIC FALLS, ME - The revolutionary new Aegis(TM) Shaft Grounding Coupling (SGC) from Electro Static Technology prevents electrical damage to bearings of AC motors by safely passing harmful shaft current to ground. Extremely effective yet low-cost, the Aegis coupling provides an ultra-low impedance path from shaft to frame, allowing current induced by variable frequency drives (VFDs) to pass to ground without damaging motor bearings or the bearing race.
When variable frequency drives are used with AC motors, current is induced along the motor shaft. When it overcomes the resistance of the grease, this current discharges through the motor bearings causing frosting, pitting, fluting, and fusion craters which can lead to premature motor failure. With its patent-pending Electron Transport Technology(TM), the Aegis coupling solves this problem by providing a "virtual short" between the shaft and motor frame that keeps shaft current and voltage from building up in the first place. Easily installed and maintenance free, the Aegis coupling is a reliable, low-cost alternative to less effective mitigation schemes such as brushes.
Advertisement
In addition to eliminating damaging shaft current, the Aegis SGC provides cleanroom-quality bearing isolation with a dustproof seal that also protects against water spray. Developed initially for 5 to 15 HP NEMA motors (the largest installed base of motor/drive applications), the Aegis SGC is ideal for HVAC, cleanroom, petrochemical, manufacturing, transportation, and other applications where VFDs are used. Additional sizes will be available in the immediate future.
Electro Static Technology is a global leader in the elimination and/or mitigation of induced electrical charges. Other products include FLX-P(TM) flexible peel-and-stick passive static eliminators for printers, copiers, and other imaging devices. Electro Static Technology is a division of Illinois Tool Works (ITW), a $10 billion multinational conglomerate operating in 44 countries.
********************
MECHANIC FALLS, ME - The revolutionary new Aegis(TM) Shaft Grounding Coupling (SGC) from Electro Static Technology prevents electrical damage to bearings of AC motors by safely passing harmful shaft current to ground. Extremely effective yet low-cost, the Aegis coupling provides an ultra-low impedance path from shaft to frame, allowing current induced by variable frequency drives (VFDs) to pass to ground without damaging motor bearings or the bearing race.
When variable frequency drives are used with AC motors, current is induced along the motor shaft. When it overcomes the resistance of the grease, this current discharges through the motor bearings causing frosting, pitting, fluting, and fusion craters which can lead to premature motor failure. With its patent-pending Electron Transport Technology(TM), the Aegis coupling solves this problem by providing a "virtual short" between the shaft and motor frame that keeps shaft current and voltage from building up in the first place. Easily installed and maintenance free, the Aegis coupling is a reliable, low-cost alternative to less effective mitigation schemes such as brushes.
Advertisement
In addition to eliminating damaging shaft current, the Aegis SGC provides cleanroom-quality bearing isolation with a dustproof seal that also protects against water spray. Developed initially for 5 to 15 HP NEMA motors (the largest installed base of motor/drive applications), the Aegis SGC is ideal for HVAC, cleanroom, petrochemical, manufacturing, transportation, and other applications where VFDs are used. Additional sizes will be available in the immediate future.
Electro Static Technology is a global leader in the elimination and/or mitigation of induced electrical charges. Other products include FLX-P(TM) flexible peel-and-stick passive static eliminators for printers, copiers, and other imaging devices. Electro Static Technology is a division of Illinois Tool Works (ITW), a $10 billion multinational conglomerate operating in 44 countries.
Subscribe to Posts [Atom]
