Motor Systems Energy Management Best Practices A Webinar Sponsored by: Natural Resources Canada Canadian Industry Program for Energy Conservation (CIPEC) January 15th, 2014 Instructor: Gilbert McCoy, PE WSU Energy Program Big Picture Perspectives: Industrial Motor Systems Industrial motor systems: Are the single largest electrical end use category in the North American economy Account for 28% of Canada/s total electrical energy use. (17% in U.S.). 2 Motor Systems Management Training Motor Systems Energy Use 3 Motor Systems Management Training Industrial Motor System Savings Potential Industrial motor system energy use can be decreased by 11% to 18% if industries deploy all mature/proven and costeffective energy efficiency technologies Source: 1999 Xenergy Study 4 Motor Systems Management Training A motor SYSTEM is the entire energy delivery process, from electric feed to finished product Utility feed Ultimate goal Transformer ? Breaker/ starter ASD (maybe) Motor Driven Load Mechanical Work 5 Motor Systems Management Training What is efficiency? Efficiency = Output / Input Efficiency = (Input - Losses) / Input Efficiency = Output / (Output + Losses) They’re all mathematically equivalent. 6 Motor Systems Management Training Overall Efficiency ηsystem = ηeqpt x ηGear/Belt x ηMotor x ηVFD x ηIn-plant distribution system x ηTransformer 7 Motor Systems Management Training Typical Motor System Losses Useful Work Controller losses <1 to ~5% for ASD Electrical distribution system losses <1 to 5% Coupling device losses <1 to >10% for large speed reduction Motor losses 3.5 to >10% Load modulation devices 0 to 50% Driven load losses 30 to 50% for pumps and fans Basic Motor Improvements (Component Substitution) Motor Management Training Typical Motor System Losses Useful Work Controller losses <1 to ~5% for ASD Electrical distribution system losses <1 to 5% Coupling device losses <1 to >10% for large speed reduction Motor losses 3.5 to >10% Load modulation devices 0 to 50% Driven load losses 30 to 50% for pumps and fans Advanced Motor Improvements (Systems Optimization) Motor Management Training Motor Efficiency Definitions “Energy Efficient” This covers 3-phase induction motors with efficiencies equal to or exceeding that in table 12-11 of NEMA’s MG 1 standard. It pertains to low voltage (<600V) motors from 2-poles to 8-poles and 1-500 HP. “NEMA Premium™ Efficient” This covers 3-phase induction motors from 2-poles to 6-poles. It pertains to low voltage motors from 1-500 HP and medium voltage motors (>600 & <5000V) from 250 HP to 500 HP. See http://www.nema.org/premiummotors To Compare all the motor efficiency standards, see http://www.energy.wsu.edu/ftpep/pubs/engineering/motors/EfficiencyStandards.pdf 10 Motor Systems Management Training Standard, EE, PE Motors – Amount of Copper, Size of Rotor Courtesy: Toshiba 11 Motor Systems Management Training 12 Motor Systems Management Training Canada’s Motor Efficiency Regulations 13 Motor Systems Management Training Premium Efficiency Motors Required Require that all General Purpose 1-200 hp motors attain NEMA Premium levels (MG1 12-12) as of January 1, 2011 Seven categories of motors must be designed to meet Energy Efficient levels (MG1 12-11) U-Frame Motors Design C motors Closed couple pump motors Footless motors Vertical solid shaft normal thrust (tested horizontally) 8 Pole motors (900 rpm) All poly-phase motors with voltages up to 600 volts These standards Apply to New Motor Sales Including Imports 14 Motor Systems Management Training Additional Minimum Motor Performance Levels 201 to 500 Horsepower low voltage General Purpose Design B motors must be rated at Energy Efficient (MG1 12-11) levels. The U.S. DOE has proposed increasing the U.S. standards for 201 to 500 hp motors to Premium Efficiency levels plus requiring Premium Efficiency performance from Brake Motors (to 30 hp) and NEMA Design C Motors (to 200 hp). 900 RPM motors would also be covered by these proposed standards. 15 Motor Systems Management Training Basic Motor Management Planning Motor Survey and Savings Opportunities 16 Motor Systems Management Training Motor Management Planning Goals and Benefits: Provide dollar savings through reduced energy costs Efficiency = More Profit Minimize energy consumption (energy cost per unit of product) Maximize efficiency while reducing downtime Improve system reliability and productivity 17 Motor Systems Management Training Motor Management Planning Actions Develop a motor inventory and tracking system Replace critical motors with histories of frequent failures immediately Develop a new motor purchase policy Identify which motors should be replaced with Premium Efficiency units when they fail Establish a PEM-Ready spares inventory Adopt model motor repair standards Consider Life Cycle Cost Analysis Motor Systems Management Training Information Requirements for Motor Management Planning Understand Utility Rates and Incentives Gather Motor Nameplate Data Establish Motor Operating Profiles Tune Your Electrical Distribution System Obtain Measurements at Connected Loads Know Your Load Requirements 19 Motor Systems Management Training Understand your Utility Rate Schedule Decatur Utilities General Power Rate (Schedule GSA) Code 54, 55, 59 Demand Charge = $10.45/kW-mo Energy Charge = $0.06028/kWh Single Shift DC EC DC% $12,540 $14,105 47.1% Two Shifts Three Shifts $12,540 $12,540 $26,644 $52,805 32.0% 19.2% Assumes: Annual energy costs for a 100 kW load 20 Motor Systems Management Training Gather Nameplate Information Frame Type/Size Voltage Rated Horsepower Amps, Rated Load Time Rating, i.e. Duty Maximum ambient Temperature RPM at Rated Load Insulation Class Design Letter Service Factor Frequency Number of Phases Locked Rotor Code, MG1 Part 10.37 (kVA/hp) Efficiency, Rated Load Other Optional Information Motor Systems Management Training Develop Inventory of Significant Motor-Driven Systems Include Nameplate Data on: Motor Coupling Driven Equipment Load Requirements 22 Motor Systems Management Training Focus on High Priority Motors Larger motors (60 hp or 45 kW and above) Motors driving centrifugal loads Production critical process (reliability issue) “Bad Actor” systems Over 2000 hours per year utilization Implement predictive and preventive maintenance. Non special purpose motors Include spares 23 Motor Systems Management Training Estimating Operating Hours 24 Motor Systems Management Training Repair versus Replace: You Need to Consider... First cost of repair and new motor purchase. Efficiency of existing and proposed new motor at their operating points. Urgency and availability of each alternative. Possible modifications to the mounting. Annual hours of operation. Cost of down time. Utility incentives Available Warranties CanMOST can help 25 Motor Systems Management Training Replace Motors Less than 25 hp (18.5 kW) 26 Motor Systems Management Training Replace versus Repair Existing Standard Efficiency Motors 27 Motor Systems Management Training ----------------------------------------------------------------------------------------------------------------------------- Over a 20-year life, the energy savings from a PEM are enough to buy OVER THREE more motors -------------------------------- -------------------------------- 28 Motor Systems Management Training Coverage Charts tell a Story (for 200 hp or 150 kW 1200 RPM Motors) 10 Count of Frame 9 1 8 7 status efficiency_level HP RPM_Sync Voltage Spare - Std - 200 - 1200 - 575 Spare - PE - 200 - 1200 - 575 InPlant - Std - 200 - 1200 - 575 InPlant - PE - 200 - 1200 - 575 InPlant - EE - 200 - 1200 - 575 6 5 4 8 3 2 1 1 1 1 0 447T 449T Frame 449TC 29 Motor Systems Management Training A Strategic Spares Inventory ( for 75 hp or 55 kW 1800 RPM Motors) 20 18 16 Count of Frame 2 1 14 12 10 8 15 status efficiency_level HP RPM_Sync voltage_rating Spare - Std - 75 - 1800 - 8 Spare - PE - 75 - 1800 - 8 InPlant - Std - 75 - 1800 - 8 InPlant - PE - 75 - 1800 - 8 6 4 2 0 1 365T 30 Frame Motor Systems Management Training Motor Action Plan Old Motor New Motor Motor # 1 Replace W / EE When Failed Motor # 2 Downsize / Replace W / EE When Failed Motor # 3 Immediate Replacement W / EE Motor # 4 Replace W/Standard or Repair When Failed Motor # 5 Investigate ASD Potential 31 Motor Systems Management Training Sample Motor Tags (Courtesy Advanced Energy) 32 Motor Systems Management Training Advanced Motor Management Planning System Optimization Techniques 33 Motor Systems Management Training Tune Your In-Plant Distribution System Over/Under voltage improvement Reduce or eliminate voltage unbalance Use voltage drop or infrared survey to identify and eliminate hot spots due to loose, pitted, or worn contacts, fuse clips or terminations Correct for poor power factor 34 Motor Systems Management Training Operation Under Abnormal Conditions Voltage unbalance shortens the life of a three-phase motor. Unbalance is defined as 100 times the maximum deviation of the line voltage from the average voltage, divided by the average voltage. For example, if the measured line voltages are 462, 463, and 455 volts, the average is 460 volts. Unbalance is 100% x (460 - 455)/460 = 1.1% 35 Motor Systems Management Training Undervoltage with Unbalance Source: Advanced Energy, 2013 36 Motor Systems Management Training Power Transmission Systems V-belts have a peak efficiency of 95 to 98% at the time of installation. Efficiency deteriorates by as much as 5% over time if slippage occurs and the belt is not properly tensioned. 37 Motor Systems Management Training Consider Notched Belts Notched belts have slots that run perpendicular to the belt’s length and can be used in the same smooth pulleys as equivalent rated V-belts. Their efficiency is about 2% higher than for a standard V-belt. 38 Motor Systems Management Training ….or Synchronous Belts Synchronous belts (also called cogged, timing or high-torque belts) are toothed and require the installation of toothed drive sprockets. Their efficiency is 98% over a wide load range. Synchronous belts require less maintenance and re-tensioning, operate in wet and oily environments, and run slip-free. However, they are noisy, transfer vibrations and are unsuitable for shock loads. 39 Motor Systems Management Training Efficiency Range versus Gear Type 40 Motor Systems Management Training Match Equipment to Load Requirements 41 Motor Systems Management Training Overall Efficiency (Baseline) ηsystem = ηPump x ηGear/Belt x ηMotor x ηLine x ηTransformer = (0.48) x (0.95) x (0.919) x (0.98) x (0.99) = 0.406 x 100% or 40.6% 42 Motor Systems Management Training Pump Replacement Results ---250 hp MV motor and pump replaced by 125 hp LV motor-driven pump ---Motor efficiency improves from 91.9% to 96.2% ---Pump efficiency improves from 48.2% to 73.9% ---Annual energy savings of 712,150 kWh, equivalent to 50.8% of baseline energy use. Original Pump Operating Power = 167.7 kW Final Pump Operating Power = 82.4 kW 43 Motor Systems Management Training Electronic Adjustable Speed Drives 44 Motor Systems Management Training Good Candidates for ASDs Any fluid mover that is currently controlled by throttling valves, dampers or bypass flows much of the time Any fixed flow fluid mover that provides greater than needed flow much of the time Existing applications with less efficient speed control devices, especially where there is considerable operating time below 90% load or where high to moderate torque is required at reduced speed Where older less efficient and high maintenance DC drive systems are currently being used 45 Motor Systems Management Training Pump Operating Point 46 Motor Systems Management Training ASD Flow Control 47 Motor Systems Management Training Water Power at Operating Point 60.0 Head Pressure, Feet 50.0 40.0 30.0 20.0 10.0 0.0 0 100 200 300 400 500 600 700 Flow, Gallons Per Minute 800 900 1000 48 Motor Systems Management Training Water Power with Flow Reduced by Throttling 60.0 Head Pressure, Feet 50.0 40.0 30.0 20.0 10.0 0.0 0 100 200 300 400 500 600 700 Flow, Gallons Per Minute 800 900 1000 49 Motor Systems Management Training Water Power with Flow Reduced by VSD 60.0 Head Pressure, Feet 50.0 40.0 30.0 20.0 10.0 0.0 0 100 200 300 400 500 600 700 Flow, Gallons Per Minute 800 900 1000 50 Motor Systems Management Training Water Power Reduction with Variable Speed Operation 60.0 Head Pressure, Feet 50.0 40.0 30.0 20.0 10.0 0.0 0 100 200 300 400 500 600 700 Flow, Gallons Per Minute 800 900 1000 51 Motor Systems Management Training Constant Pump Efficiency is Maintained for Systems Dominated by Friction Losses 200 Head, ft 30 150 40 50 60 100 70 75 80.5 (BEP) 75 50 0 0 1000 2000 3000 4000 Flow rate, gpm 5000 Motor Systems Management Training Pump Efficiency does not Remain Constant in a System with Static Head 200 Head, ft 30 150 40 50 60 100 70 75 80.5 (BEP) 75 50 0 0 1000 2000 3000 4000 Flow rate, gpm 5000 Motor Systems Management Training Motor and Drive Efficiency Constant and Variable Torque Loads 54 Motor Systems Management Training Ideal Load Profile for ASDs High Operating Hours at Low Flows 55 Motor Systems Management Training Conducting a “Bin” Energy Savings Analysis 56 Motor Systems Management Training Inherent ASD Benefits • Controls speed variations • Provides process control • Eliminates startup impacts causing system vibration • Provides fault tolerance • Supports low current soft starts • Restarts spinning load • Controls speed swings • Enhances product quality • Power Factor Improvement • Conserves more energy than any other option at speed turn-downs below about 90%. 57 Motor Systems Management Training Advanced Super Premium Efficiency Motor Designs Permanent Magnet and Switched Reluctance Motors: ---Require an electronic power converter or controller to control both torque and speed (inherent variable speed capability) ---Compact/high power density (not available in NEMA T-Frame sizes so difficult to use as retrofits) ---Above Premium Efficiency performance but with high cost. Suitable for niche applications. 58 Motor Systems Management Training For Additional Information CanMOST Technical Fact Sheet: http://oee.nrcan.gc.ca/industrial/equipment/software/FactSheet.pdf CanMOST download site: http://oee.nrcan.gc.ca/industrial/equipment/software/intro.cfm BC Hydro Industrial Success Stories: http://www.bchydro.com/powersmart/business/industrial/success_stori es/quesnel_river_pulp.html Copper Development Association (CDA) Case Studies on Energy Efficiency: http://www.copper.org/publications/pub_list/energy_efficiency.html U.S. DOE Motor Energy Tip Sheets: http://www1.eere.energy.gov/manufacturing/tech_assistance/technical_ 59 publications.html Motor Systems Management Training 60 Motor Systems Management Training
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