Drives and Pump Optimization Discussion on Pump Optimization Principles and “Need to Know” Drive Technology Smart Water for Smart Cities Workshop 11:00am Tuesday May 20, 2014 Presented by Paul Krasko

Water Wastewater (WWW) Challenges: Energy Usage Demand for WWW Age of infrastructure Legislative compliance Reduced financial resources Energy efficiency awareness Energy use Process = 70% Pumping = 16%

Finnish Technical Research Center Report: “Expert systems for diagnosis of the condition and performance of centrifugal pumps” Evaluation of 1690 pumps at 20 process plants: Average pumping efficiency is below 40% Over 10% of pumps run below 10% efficiency Major factors affecting pump efficiency Throttled control valves Pump over-sizing Seal leakage causes highest downtime and cost What do you think is a good pumping efficiency? Any ideas? Maybe 80%?

System Curve Uncertainty Results in Uncertain Pump Operation - and higher costs Has everyone seen this? Good, help me with this! First, how often to we operate at the specified operating point. Not often! So when we do not have as much flow, we can cycle the pump on an off, inject a discharge valve or use a VFD. Which one do you think I like? If we use a discharge valve, the valve changes system curve upward and energy still is consumed similar to full flow. If we use a VFD, it changes the pump curve and Al Gore is happy!

Pumping System Characteristics Pump operating point Duty point: rate of flow at certain head Pump operating point: intersection of pump curve and system curve Flow Head Static head Pump performance curve System curve Pump operating point SUGGEST ADDING (BEP) TO THE SLIDE, The rate of flow at a certain head is called the duty point. The pump performance curve is made up of many duty points. The pump operating point is determined by the intersection of the system curve and the pump curve as shown in the Figure The Best Efficiency Point (BEP) is the pumping capacity at maximum impeller diameter, in other words, at which the efficiency of the pump is highest. All points to the right or left of the BEP have a lower efficiency. What the VFD does is change the pump curve only and decreases energy. A discharge valve changes the system curve only Example - 400 GPM pump at 45 psi, Do not need that flow very often Lower flow to 200 GPM. Thottle valve follows the pump curve to lower to 200 gpm. VFD follows the system curve, huge energy savings.

Pumps System Overview and Fundamentals

Overview The pumping system: Pumps Motors, engines Piping Components End-use Pumps Motors, engines Piping Valves and fittings Controls and instruments Heat exchangers Tanks Others Water treatment Wastewater treatment Water distribution Power generation Irrigation Speaker Notes Guys, I am just worrying about my little VFD turning the motor, etc. You are worrying about all this other stuff. Describe the main components, including: Pumps; Prime movers: Electric motors, diesel engines, and air systems; Piping (used to carry fluid); Valves (used to control flow); and, Other fittings, controls, and instruments. Describe the end-use equipment, including heat exchangers, tanks, and hydraulic machines. Highlight that other common systems components include filters, strainers, and heat exchangers. Any evaluation of a pumping system should consider the interaction between these components, and not just the pump itself. This is referred to as the systems approach to pumping system evaluation. The pump(s) and the system must be designed and treated as one entity, not only to ensure correct operation, but also to reap the benefits of energy-efficient pumping. 7

Overview, continued System Approach Component optimization involves segregating components and analyzing in isolation System optimization involves studying how the group functions as one as well as how changing one component can help the efficiency of another Electric utility feeder Transformer Motor breaker/starter Adjustable speed drive (electrical) Speaker Notes Highlight that the overall efficiency of the operation is the product of the efficiency of each incorporated energy component. For example, optimizing a single component may improve or reduce the overall efficiency depending of its effects on other components. Any effort made towards reducing energy consumption and cost must take into consideration the entire energy flow train. <click to show arrows>Explain that there are other factors to consider in addition to efficiency. Reliability, for example, is a more important consideration in many industrial applications. These two factors are often complimentary for pumps themselves. Operating at or near a pump’s best efficiency point (BEP) will reduce damaging loads experienced and lead to increased reliability as a result. Explain that systems are generally classified as closed or open: Closed systems recirculate fluid around set paths and the frictional losses of system piping and equipment are the dominant loads. Open systems have specified inputs and outputs, transferring fluids from one point to another and often have significant static head requirements due to elevation and tank pressurization needs. Motor Coupling Pump Fluid System Served Process(es) 8

Pump Fundamentals There are two basic types of pumps: Centrifugal Use a rotating impeller to increase velocity of a liquid and its stationary components direct discharge flow to convert velocity to increased pressure Types include axial, mixed flow, and radial Positive Displacement (PD) Move a set volume of liquid and pressure is obtained as the liquid is forced through the pump discharge into the system Types include piston, screw, sliding vane, and rotary lobe Speaker Notes Describe the two most basic types of pumps, including: Centrifugal pumps, which are the most common type of industrial pump and also offer the best opportunity for performance improvements. Most literature and training on pumping systems focuses on centrifugal pumps. In addition, 80-90% of industrial pumps are centrifugal pumps. Rely on a rotating, vaned disk attached to a driven shaft. The disk increases fluid velocity, which translates to increased pressure. Positive Displacement (PD) pumps, which offers precise flow at higher pressure. The PD pump, unlike the Rotodynamic pump, moves a set volume of liquid and pressure is obtained as liquid is forced through the pump discharge into the system converting energy to pressure. The markets need for a broad range of pumping solutions has been the driver for the universe of technologies shown here for PD pumps. 9

Pump Fundamentals, continued Centrifugal Pumps Impart energy to the liquid by increasing its speed in the impeller and then converting the speed to pressure through diffusion in the volute. Speaker Notes Need to add moving graphic files to these slides They are from Module 1 Topic 2 page 4 of 31 and 15 of 31. Describe rotodynamic pumps, which are constant head devices that impart the same amount of head to any liquid with the following two exceptions: Increases in fluid viscosity; and, Multi-phase fluids. Further explain rotodynamic pumps by describing how: An increase in viscosity will reduce the performance of rotodynamic pumps, causing reductions in efficiency, flow, and developed head. Multiphase flows can also have adverse effects on rotodynamic pump performance. Liquid/gas mixtures lower the specific gravity of a solution but may also drastically reduce the flow rate through the pump due to the volume change of the vapor bubbles as they pass from the low pressure areas in the pump to the areas of higher pressure. Solid/liquid mixtures may have an opposite effect on the required pump power, depending on the specific gravity of the solids suspended in the flow. Input power is used to increase velocity of fluid through rotation of impeller. When fluid exits the impeller, therefore velocity is reduced, increasing pressure. 10

AC Motors - Variable Torque Applications Variable Torque (VT) 100 % Torque, Flow, & HP (Amps) Torque SUGGEST LABELING SLIDE WITH AFINITY LAWS STATED Back to our infinity laws! 50 Flow HP % Speed 50 100 (Base)

Pump Fundamentals, continued PD Pumps Impart energy by applying mechanical force directly to the liquid through a collapsing volume Speaker Notes Need to add moving graphic files to these slides They are from Module 1 Topic 2 page 4 of 31 and 15 of 31. Describe the types of positive-displacement pumps, which are reciprocating, metering, and rotary pumps. Explain how PD pumps will transport fluid from inlet to outlet, where input power is used to create the force to transport this volume against internal and system resistance. In addition, PD pumps create flow. Explain how PD pumps may be found almost anywhere and everywhere but a generally accepted view is that over 90% go into applications within these top six industrial market segments. Specifically, in the following markets: Oil and Gas; Water and Wastewater Treatment; Chemical; Food, Beverage and Pharmaceutical. Power; and, General Industrial (Marine / Medical / OEM). 12

Energy Efficiency in Pumps Load Characteristics Water Wastewater Load Characteristics Variable Torque Constant Torque Constant Power Typical Applications Centrifugal Pumps and Blowers Positive Displacement Pumps, Blowers, Mixers, and Chemical Feed Pumps No applications Energy Savings Potential Substantial Potential – Largest of all VFD applications Lowest Potential No Potential CONSTANT TORQUE IS MENTIONED HERE, HOWEVER NOT THEREAFTER…….SHOULD CT BE DISCUSSED IN PRESENTATION? The Main Target ( first priority) The Next Step ( second priority)

Pump Head Pressure Static head is the energy needed to overcome an elevation or pressure difference between the suction and discharge vessels. Frictional head loss increases by the square of the velocity change of the liquid in the pipe. In most cases: Speaker Notes Describe how friction effects the hydraulic design, where the the more fluid you pump, and the faster you pump it, will increase the friction losses. 14

Pump Head Pressure System Head Curve produced by US DOE PSAT Software Static Head Friction Head Speaker Notes System Head Curve produced by US DOE PSAT Software 15

Pump Head Pressure Friction Head May occur in pump systems due to hydraulic losses in: Piping Valves Fittings (e.g., elbows, tees) Equipment (e.g., heat exchangers) Which are used to control flow or pressure by: Automated flow and pressure control valves Orifices Manual throttling valves Speaker Notes Describe friction and how it can an increase in friction can causes more energy to be used. 16

Variable frequency drive (vfd) benefits with Pumps

Energy Efficiency in Pumping Systems Motor costs

Energy Efficiency in Pumps Energy wastes How your money is wasted! Car example : …try to regulate the speed of your car keeping one foot on the accelerator the other on the brake. Pump example : … try to adjust the pump output running the motor at full speed control the flow with a throttle valve Do any of you still use valves? Be honest! Still one of the most common control methods in industry ….. with a considerable waste of energy

VFD Benefits with Pumps Physical laws for centrifugal loads It’s pure physics: Due to the laws that govern centrifugal pumps, the flow of water decreases directly with pump speed Affinity laws of centrifugal loads: Flow = f (motor speed) Pressure = f (motor speed)2 Power = f (motor speed)3

VFD Benefits with Pumps Physical laws for centrifugal loads A motor running at 80% of full speed requires 51% of the electricity of a motor running at full speed.

VFD Benefits with Pumps Physical laws for centrifugal loads A motor running at 50% of full speed requires 12.5% of the electricity of a motor running at full speed.

VFD Benefits with Pumps Physical laws for centrifugal loads A small reduction in speed produces a significant reduction in power Relevant applications : Pumps The resisting torque of centrifugal pumps varies with the square of the speed : T = kN² Power is a cubed function P = kN³ EX 50HP 10Hrs/day, 250 days @$.08 With 15% average speed reduction ATL = $7,460 VFD = $4,188 Savings = $3,272 Today, less than 10% of these motors are controlled with variable speed drives

Efficiency of pumping systems

VFD Benefits with Pumps Other Benefits In addition to energy savings, using a VFD has many other advantages: Less mechanical stress on motor and system Less mechanical devices - Less maintenance Process regulation with PID regulators, load management functions Reduce noise, resonance avoidance Performance and flexibility, range settings, above base operations Easier installation and settings, drive mechanics Can be controlled with automation, communication networks

Steps to obtain pump optimization

Pump Optimization Complete a detailed Pump Assessment Pumps are usually consuming more energy than necessary: The pump is oversized and has to be throttled to deliver the right amount of flow. Energy is lost in the valve. Pumps that are not running close to their best efficiency points (BEP) operate at lower efficiency. Throttled pumps usually fall into this category. Pumps are running with by-pass, or recirculation, lines open. Pumps are running although they could be turned off. The pump is worn and the efficiency has deteriorated. The pump/system was installed or designed incorrectly (piping, base plate etc.) Ladies and Gentlemen this is the tough one!

Pump Optimization Complete a detailed Pump Assessment To determine whether these reasons apply, some basic information is needed: Actual system demand (flow and pressure) Operational flow rate as a function of time (the duration curve) Flow controls The pump curve Where the pump operates on the curve

Process Energy Optimization Automation is the key Develop consistent and appropriate milestone and deliverable expectations Standardize program schedule tracking requirements Establish key energy management performance metrics Produce meaningful reports that allow for clear and concise decision-making Install additional monitoring equipment as needed

Considerations for Variable frequency drives for water and wastewater

VFD Topics Type(s) Enclosure/Environment/Packaging Harmonics/Harmonic Mitigation IEEE 519 Accessibility Sustainability Data Bulletin 8800DB1302

VFD Considerations The industry has standardized on PWM 6 pulse drives. Where 6 pulse refers to the front end of the drive and a bridge of 6 diodes converting incoming AC to DC power. A DC bus (capacitor) Insulated Gate Bipolar Transistors (IGBT) as the output components The output of which generates a simulated RMS waveform with a constant V/Hz ratio

One of These…

Packaging… NEMA UL Type 1/12 MCC Enclosed Altivar Plus

Harmonics Mitigation This continues to be a big topic in Water and Wastewater The motor loads on VFDs are a large percentage of the total load. Many consultants have standardized on designs by HP requiring line reactors or multipulse drives (typically 18 pulse). There are multiple solutions One size does not fit all. Schneider Electric offers as standard…18 pulse VFD, Passive Harmonic Filter and Active Harmonic Mitigation

Harmonics Reduction Typical AC drive 100HP Typical 6 pulse AC drive without line reactor Input voltage: orange Input current: cyan Large current spikes due to capacitors charging Peak currents = 300 amps Harmonic current distortion Large double humped current waveform significantly contributes to harmonic content. Total Harmonic Distortion Current THDI = 80% Typical 6 pulse input current waveform. Note the large 300 amp peak currents. The large double humped current waveform significantly contributes to harmonic content.

Harmonics Reduction AC drive with 3% line reactor 100HP Typical 6 pulse AC drive With 3% line reactor Input voltage: orange Input current: cyan Lower current spikes due to capacitors charging Peak currents = 190 amps Harmonic current distortion Significant double humped current waveform reduced Total Harmonic Distortion Current THDI = 38%

18 Pulse Drive Using the Same 6 Pulse Inverter… STD 6 Pulse Inverter 18 pulse Diode Bridge Line Reactor Phase Shifting XFMR

18-Pulse Power Converter Configuration DC Bus connections to Altivar 61/71 Drive

18-Pulse Drives: What You Get 6-Pulse power converter (no line reactor) 18-Pulse power converter The voltage and current waveforms comparison between a 6 pulse and 18 pulse units, Clean power performance

Passive Harmonic Filter Drive Using the Same 6 Pulse Inverter… STD 6 Pulse Drive Passive Harmonic Filter

Passive Harmonic Filter Drive Passive Harmonic Filter Mitigation provides as good or better than 18 pulse. Better mitigation given voltage imbalance Footprint of drive is typically smaller than 18 pulse. Efficiency of drive is better than 18 pulse Losses of 18 pulse bridge + Transformer + Line Reactor > Passive Harmonic Filter Cost is typically lower than 18 pulse Output to the motor is identical. What’s not to like?

Data on side by side comparisons of 18 Pulse and Passive Harmonic Filter.

Results

Results

Accusine Used with One or Many 6 Pulse Drives…

The Variable Frequency Drive for WWW The Altivar ® 61 is our standard 6 pulse inverter for variable speed applications used in centrifugal pump and fan / blower applications offering the highest level of features, functions, and flexibility. This same inverter is the heart of our configured enclosed applications, 18 Pulse Drives, Motor Control Centers and our new Passive Filter Packages. All the Inverter parts, programming, troubleshooting, wiring, interfacing, etc. is common. 47

Drives System Center Product Offering Altivar 61/71 Plus Designed for rugged municipal process environments. Custom options to serve a wide range of applications. Growing sectors requiring high horsepower drives NEMA Type 12 enclosure Altivar 71 125-700hp, 460VAC 125-700hp, 600VAC Altivar 61 125-900hp, 460VAC 125-800hp, 600VAC

Drives System Center Product Offering Altivar 61/71 Plus Altivar 71 700-1800hp, 460VAC 700-2100hp, 600VAC Altivar 61 900-2000hp, 460VAC 800-2500hp, 600VAC Altivar 71 125-700hp, 460VAC 125-700hp, 600VAC Altivar 61 125-900hp, 460VAC 125-800hp, 600VAC

Drives System Center Product Offering Variable Torque 125-900hp, 460VAC 125-800hp, 600VAC Constant Torque 125-700hp, 460VAC 125-700hp, 600VAC Drives System Center Product Offering Top mount ventilation Schneider Electric Enclosure Control transformer Flexibility for control requirements with swiveling control panel Altivar power converter Easy maintenance – power converter mounted on rail system Fused disconnect Motor connection Line contactor (optional) DV/DT motor filter (optional) Bottom entry Standard 4” plinth (8” optional) for bottom entry

Drives System Center Product Offering Variable Torque 900-2000hp, 460VAC 800-2500hp, 600VAC Constant Torque 700-1800hp, 460VAC 700-2100hp, 600VAC Incoming Cubicle Inverter Cubicle Outgoing Cubicle Cooling Cubicle Cubicle fans Line reactor Operator interface Heat exchanger Flexibility for control requirements with swiveling control panel Mandatory start up by Schneider Electric Engineering Cooling (deionized water) will ship seperately Circuit breaker Cooling pump Line connection Line reactor Motor connection Plinth

Other Drive/System Application Considerations Enclosed drive or packaged drive short circuit current rating SE = 100k amps as standard Power loss ride through – especially for pump stations SE meets Semi F47 standards Communication capabilities SE offers Modbus Serial and 11 additional Protocols as options. Built in web server and diagnostic web displays with Ethernet. Built in Bluetooth interface capability

Considerations for total cost of ownership (TCO) of your next pumping system

3 Steps to the Most Efficient… Design and Operation Energy efficiency management Asset management Energy cost management

Step 1 Energy Efficiency Management Scenario 1 Static head = 50% system head Pump rated for the system Scenario 2 Static head = 85% system head Pump oversized for the system Energy saved with variable vs. fixed speed drives at 100% and 60% flow, according to the static head and pump sizing. The operating point is represented as the intersection of the pump curve with the system curve.

Step 2 Asset Management Newer Drive technology can significantly improve efficiency and life of your next pump system by operating close to Best Efficiency Point (BEP ).

Step 3 Energy Cost Management Knowing the breakdown of your electric utility costs may uncover opportunities for savings. Drives can assist to reduce all aspects of this cost.

Questions? Jeff Szwec <Insert Title> US Drives, Softstarts and Drive Systems 8001 Knightdale Blvd. Knightdale, NC 27545-9023 Office: 919.266.8360 | Mobile: 919.824.9114 Jeff.Szwec@Schneider-Electric.com www.schnedier-electric.com

appendix

VFD Application Considerations Keep motor lead lengths as short as possible VFD environment (0-40ºC), clean and non-condensing Enclosure rating (NEMA 1, NEMA 12, NEMA 3R) Ensure 3 metallic conduits are used (motor, power, and controls) Be careful with underground runs! Dedicated ground wires from motor to VFD and from power source to VFD Use line reactors for harmonic distortion control and enhanced protection from AC line transients Size VFD based on amp rating (6-pole motors and up) Disconnect Issues Harmonic calculations

Broad array of drive solutions Passive Harmonic Filter Drive in MCC 18 Pulse Drive 61