motors and motor drives€¦ · teledyne lecroy company confidential 14-6-2016 3phases drive output...

June 2016

Power analysis Tools for modern Power applications

Francesco Raimondi, Distributor Manager, on behalf of AR Benelux

LeCroy founded in 1964 by Walter LeCroy

Origins are high speed digitizers for particle physics

research

Teledyne LeCroy corporate headquarters is located in

Chestnut Ridge, NY

Teledyne LeCroy has the most advanced technology

and widest line of Real-Time digital oscilloscopes

(from 40 MHz to 100 GHz)

Long History of Innovation in Digital Oscilloscopes

Teledyne LeCroy became the world leader in

protocol analysis with the purchase of CATC and

Catalyst, and creating a protocol analyzer division

based in Santa Clara, CA.

In August 2012, LeCroy was acquired by Teledyne

Technologies and was renamed Teledyne LeCroy

Teledyne LeCroy Overview

14-6-2016 Teledyne LeCroy Company Confidential

Key competence:

- Signal acquisition

- WaveShape Analysis and Processing

Agenda

Defining “Power”

“Power” Overview

Power Testing – Instrument / Solution Overview

Motor Drive Analyzer – Overview of Capabilities

Accuracy Comparisons

Test Examples

480V Drive Efficiency Analysis

Brushless DC Power Tool Analysis

Serial Busses Decoding

Conclusions

Questions & Answers


Introduction “Power” Definition

“power” has many meanings and many different applications…..

“Power” Definitions These are just a few of them…Let’s be clear what we mean when we say “Power”

Utility, Grid, Household, Line, Power Line, Mains - “Power” This is the 50/60 Hz sinusoidal voltage/current power flowing to your home or business, measured by a

kWh meter

Power Semiconductor Device - “Power” This is the power consumed by the power semiconductor MOSFET or IGBT device during switching,

conduction, or OFF states

Digital Power Management - “Power” This is the ON/OFF voltage management of the DC power supply rails on a motherboard or embedded

computing system

Power Supply Startup Sequencing - “Power” This is the management of the ramp times and sequences of different DC power supply rails on a

motherboard or embedded computing system

Power Electronics Inverter/Converter - “Power” Testing This is the measurement of a complex mix of line (50/60 Hz) frequency input, variable frequency output,

DC and control/sensor signals for debug, troubleshooting and validation purposes

Power Analysis, classic This is the measurement of the Watts or Volt-Amperes that a product (“system”) consumes and/or the

efficiency of power consumption for the product


Intro to the main topic

Oscilloscopes measure time variant voltages and currents.

AC line voltage, current and power ratings are familiar to many of you.

In a power conversion system/motor drive are voltages and currents.

AC input/output of power electronics converters/inverters use or generate

AC line voltages, currents and powers.

All these are known topics and applications. What is new?

The need to better understand how the power electronic is operating

dynamically and correlate electrical to mechanical measurements and

to serial busses commands


Line Power

“AC” Power – The Basics

Electric Power “The rate at which energy is transferred to a

circuit”

Units = Watts (one Joule/second)

For purely resistive loads P = I2R = V2/R = instantaneous V*I

The current vector and voltage vector are in perfect phase

For capacitive and inductive loads P ≠ I2R since voltage and current are not in

phase Capacitive Loads

The current vector “leads” the voltage vector by angle φ

Purely capacitive load has angle φ = 90°

For inductive loads The current vector “lags” the voltage vector

angle φ

Purely inductive load has angle φ = 90°

VA-N

IA

N

VA-N

IA

N

IA

N VA-N

Purely resistive load

Capacitive load

Inductive load

P = I2R

P ≠ I2R

P ≠ I2R

φ

φ


“AC” Power – The Basics Introducing Power Factor

Phase Angle (φ)

Indicates the angular difference between the current and voltage vectors

Degrees: 0 to 90°

or radians

Power Factor (PF, or θ)

= cosφ for purely sinusoidal waveforms

But inverter drive output voltage waveforms are PWM and are therefore not sinusoidal

Unitless, 0 to 1,

1 = V and I in phase, purely resistive load

0 = 90° out of phase, purely capacitive or purely inductive load

Not typically “signed” – current either leads (capacitive load) or lags (inductive load) the voltage

VA-N

IA

N

VA-N

IA

N

IA

N VA-N

Purely resistive load

Capacitive load

Inductive load

φ

φ


“AC” Power – The Basics Introducing Real, Apparent and Reactive Power

Real Power

P, in Watts

= instantaneous V*I (in 1 period)

Apparent Power

│S│, in Volt-Amperes, or VA

= VRMS*IRMS RMS on given power cycle

S = √(P2+Q2)

Reactive Power

Q, in Volt-Amperes reactive, or VAr

Does not “transfer” to load during a power cycle, just “moves around” in the circuit

Some Q is necessary in AC transmission

Too much causes various problems

Utilities control Q in transmission and distribution

Power Factor = P / │S│

Real Power

Ima

gin

ary

Po

we

r

φ

S

Q

P


Power Measurements: Power Conversion and Motor Drive

Power electronics circuits are used to “convert” line power to different voltages and frequencies, depending on user and application requirements.

Understanding Power Conversion Evolution The technologies have gotten better, and this has created new markets for power conversion

Desig

n C

om

ple

xity

and P

ow

er

Leve

ls

Low (<300V,

<1000W)

High (>1000W,

3-phase)


Powerful Trends Are Driving Exponential Growth Especially in two specific power conversion applications areas

Electric power generation from Distributed Energy Resources (DERs)

Grid-tied inverters for putting distributed generation (e.g. solar, wind) onto the grid

“Smart” power electronics for maintaining grid stability with high amounts of distributed generation

Electric/hybrid vehicle propulsion DC-AC Converters

Power storage to batteries

Regenerative braking

Power distribution to motors


Example: Motor Drive “Control System”

Create PWM gate drive signals to power semiconductors

Inputs to the control and user-created algorithms determine what PWM gate driver signals to output to the motor drive power electronics section

Industrial users of Motor Drives buy “off-the-shelf” drives/controls

Consumer/Industrial product developers design their own control system


Typical Motor Drive Block Diagram: AC-AC Conversion A Higher Power and/or Three Phase Power Conversion Application

Six power

transistors

High control complexity (MCU)

Serial Interfaces

Sensors

3-Phase Output AC-AC

Conversion


Typical Automotive DC-DC Converter Diagram An Electric and Hybrid Electric Vehicle (EV / HEV) Propulsion Application

10 power transistors

(not incl. VFD)

High control complexity (MCU)

Serial

Interfaces Sensors

>1 kW DC-DC

Conversion


Typical Mechatronics Application Washing Machine

High control complexity

Serial

Interfaces

Sensors and

Actuators Six power

transistors


Instruments to measure and characterize

Back to Beginning

“Static” Power Analysis Calculation and display of mean power values in a table

Power Analyzer (PA) with Motor

Integration Option

Teledyne LeCroy Motor Drive Analyzer

8ch, 12-bits, up to 1 GHz

14-6-2016

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Teledyne LeCroy Company Confidential

“Dynamic” Power Analysis A Motor Drive Analyzer can perform complex dynamic drive analysis on long acquisitions


Integration Option



14-6-2016

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X Teledyne LeCroy Company Confidential

“Complete” Drive Test Capability Oscilloscope capabilities permit complete drive system debug and validation


Integration Option

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Motor Drive Analyzer vs. Power Analyzer (PA) - Summary

14-6-2016

Capability Teledyne LeCroy MDA800

Motor Drive Analyzer

Power Analyzer

Instrument

Static

Power

Analysis

Yes Short records.

Constant load/speed.

Numerics value table.

Correlation to controls.

Yes Short records.

Constant load/speed.

Numerics value table.

Dynamic

Power

Analysis

Yes Long time durations

Variable loads/speeds. Statistics Table.

Per-cycle Waveforms.

No

X Complete

Test

Capability

Yes View 3-phase waveforms.

Mixed Signal (MSO).

Serial Trigger & Decode.

Probes & Accessories.

No Single use instrument.


Accuracy Comparison, cont’d Results Direct Comparison and Comments

ΣVRMS

(L-L)

ΣVRMS

(L-N)

ΣIRMS P S Q PF Phase

Power

Analyzer (PA)

8.549 V 4.924 V 1.271 A 6.438 W 18.777 VA 17.638 VAR .3429 69.95°

Teledyne

LeCroy

8.6063 V 4.9566 V 1.2619 A 6.406 W 18.764 VA 17.636 VAR .341 70.036°

% Difference +0.67% +0.66% -0.72% -0.49% -0.07% -0.01% -0.55% +0.12%

This is worst case comparison for Teledyne LeCroy

We are using voltage and current probes, whereas Power Analyzer (PA) is using direct voltage and current inputs

Comparison is very favorable to Teledyne LeCroy

These results would not have been possible with an 8-bit acquisition system

The high quality Teledyne LeCroy probes used in this case are also a benefit

Larger motors would require Power Analyzer to use probes or other step-down measurement devices

There would likely be no accuracy advantage to the power analyzer in that case


Application Examples

Back to Beginning

Application 1: 480V Drive Efficiency Analysis


3Phases Drive output

Using 2 Watt meters

4 Channels used

2V2A

for each power bus

In the lower rails we

can see all needed

power measurements:

P, Q, S, PF as well

Vrms and Irms

Typical steady state, i.e.

Static measurements

What happens when

motor is accelerating

or load is changing?


3Phases Drive output – Dynamic behavior

Dynamic behavior

First problem

discovered: C6 goes

out of scale.

2 watt meters

measurements on

input and output

8 analog channels

are required to

carry on all power

measurements

We can see the

evolution of P, ƞ,

PF,… and correlate

them because we

measure them in

each cycle

Innovative display

allows to see all

these


3Phases Drive output: Load change dynamic analysis

Let’s givea detailed

look at the period

sequence. Drive out

has variable frequency

so that a Per-cycle

Dynamic analysis

measurements are

made and reported in

a separate curves,

accessible by

cursorsor

Sync channels for

ACin and DRVout can

be different, so the

results for each power

analysis behavior over

time are correct

Application 2: Brushless DC Power Tool Analysis


• Zoom + gate

capability

• Analog + Digital

channels to see

sensors

• Correlation of

Speed, Torque,

Power

• Q-Scape Display

• XYZ display

(Torque VS

Speed)


Display: DRV out

and Torque vs

Speed

Zoom + Gate

Correlate Speed,

Torque and P

The XY plots

show Torque vs.

Speed

Application 3: Serial busses decoding

CAN Bus Symbolic decoding


Flex ray 10Mbit/s Decoding example


Conclusions

Today is possible to better understand how the power electronic is

operating dynamically and correlate electrical to mechanical

measurements and to serial busses commands

possibility to correlate measurements carried on all 4 power busses:

DC, ACin, DRVout and Mechanical

Strong acquisition system:

8 analog channels + 16 digital, up to 1GHz bandwidth, 12 bits vertical

resolution, 2.5GS/s and lot of memory…

Innovative and powerful display

Mosaic, Q-scale, Zoom+Gate

Capability to develop customized applications


Questions?

More information?

www.arbenelux.com

motors and motor drives€¦ · teledyne lecroy company confidential 14-6-2016 3phases drive output...

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