Q&A with EV measurement engineering consultants Coty Harrison and Cristian Loris of Yokogawa Take a look at&Measurement.
When tasked with measuring {the electrical} energy of complicated techniques like EVs, an inexperienced engineer might first attain for common instrumentation like oscilloscopes, knowledge acquisition (DAQ) techniques and digital multimeters (DMMs). Whereas these devices serve helpful roles in electrical testing—oscilloscopes analyze time-dependent alerts, DAQs deal with large-scale knowledge and DMMs give attention to basic electrical measurements—they don’t seem to be fitted to making traceable and correct electrical energy measurements.
All three common instruments endure the identical shortfalls—they don’t seem to be designed to measure energy precisely however as a substitute precisely measure DC or, in some instances, clear AC RMS. Utilizing oscilloscopes, DAQs and DMMs to measure energy may compromise product design by creating important (typically invisible) measurement errors.
The proper instrument to measure energy in complicated EV techniques is a purpose-built energy analyzer that captures three core parameters—voltage, present and energy—in addition to a number of essential further parameters (relying on what system you might be testing) that contribute to understanding the effectivity and general system efficiency.
To be taught extra about purpose-built energy analyzers, Charged just lately chatted with measurement engineering consultants Coty Harrison and Cristian Loris of Yokogawa Take a look at&Measurement. Based in 1911, Yokogawa is a world firm that gives a variety of merchandise that measure electrical and optical alerts and different important engineering parameters. The corporate’s techniques are used throughout industries like power, manufacturing, and more and more in EVs and renewable power.
Charged: Are you able to give us a high-level clarification of why purpose-built energy analyzers are important in EV system growth?
Coty Harrison: In EV purposes, measurement accuracy have to be reliably maintained throughout a variety of frequencies and circumstances, so it’s important that you’ve got a system that captures many various components and channels.
We designed our latest energy analyzers to supply precision with an error margin as little as 0.03%. This implies producers can confidently confirm effectivity features within the 1-2% vary, which is important for aggressive developments.
For instance, in creating and testing a brand new EV traction motor design, you want a system that permits engineers to comprehensively measure electrical parameters in addition to mechanical parameters like velocity and torque.
Accuracy turns into particularly necessary throughout validation, as producers should guarantee their merchandise meet stringent effectivity and efficiency benchmarks earlier than manufacturing or supply to clients. As EVs gained traction and competitors elevated available in the market, engineers started creating extra modern and sophisticated designs, which meant extra sophisticated measurements. For instance, we designed our latest energy analyzers to supply precision with an error margin as little as 0.03%. This implies producers can confidently confirm effectivity features within the 1-2% vary, which is important for aggressive developments.
New supplies like silicon carbide (SiC) and gallium nitride (GaN) permit greater switching charges, so devices additionally advanced to satisfy more and more demanding switching necessities. For EV purposes, it’s not a need however a necessity for an influence analyzer to help sampling charges as much as 10 mega samples per second (MSps) per channel. And once you mix that with 18-bit analog-to-digital (A/D) conversion, you guarantee correct knowledge even underneath high-frequency circumstances. This permits EV motor and inverter validation with effectivity measurements that differentiate between actual features and measurement inaccuracies—very important for efficiency tuning in automotive.
Determine 1: Electrical Automobile Powertrain Key Measurement And Effectivity Factors
Charged: Are you able to broaden on the instance of EV traction motor design? How precisely is a purpose-built energy analyzer used to enhance the tip product?
Cristian Loris: Effectivity immediately impacts the vary of EVs, which is a key issue for customers. Small enhancements in motor effectivity can considerably lengthen automobile vary and cut back power consumption. Correct measurements will optimize efficiency underneath numerous hundreds, and precision is particularly important when addressing complicated drive cycle situations.
It comes down to 2 key challenges. First is measuring energy to a identified, traceable and assured energy spec, which isn’t potential if you’re utilizing devices targeted on DC specs or AC RMS. AC energy—particularly noisy switched energy—requires integration at a excessive pattern fee, consideration of line filters and 0 crossings, and so on.
The second problem is that motors are an inductive load, which is able to at all times have some energy issue that may additional degrade measurement accuracy for those who use common instruments like oscilloscopes, DAQs and DMMs—as a lot as 30% or extra.
In contrast to general-purpose tools, energy analyzers can have devoted algorithms optimized for traction motor purposes, together with energy calculation over various load circumstances. For EV energy measurements, sign conditioning is essential to cut back noise and keep sign integrity, particularly in high-power techniques. Additionally, purpose-built analyzers are designed to log knowledge persistently over prolonged durations and supply traceable knowledge information for certification functions, which is necessary for EV powertrain testing that always entails long-duration measurements.
Harmonics and distortions in present and voltage waveforms result in power loss and will influence the efficiency of the EV motor. Energy analyzers that may precisely measure harmonic content material assist engineers mitigate these losses.
Coty Harrison: To elaborate on this instance, a number of key parameters have to be measured in traction motor growth. The primary is powertrain effectivity, and people measurements require correct voltage and present readings from the ability equipped to the traction motor, each from the battery and the inverter. The problem right here lies in measuring high-frequency switching waveforms precisely, as traction motors sometimes function in dynamic circumstances.
Then there may be the ability issue, which impacts the power switch from the battery to the motor. Making certain a better energy issue (as shut as potential to the best unitary worth) improves power effectivity and reduces losses and is due to this fact essential to measure and management.
Additionally, harmonics and distortions in present and voltage waveforms result in power loss and will influence the efficiency of the EV motor. Energy analyzers that may precisely measure harmonic content material assist engineers mitigate these losses.
Lastly, torque and velocity measurements are important to evaluate motor output precisely.
Combining the correct measurement of those parameters will present engineers with a whole image of a motor’s effectivity.
Charged: You talked about the validation stage of the event course of. Is that when energy analyzers are primarily used?
Cristian Loris: Sure, energy analyzers are primarily used through the validation stage of EV techniques to benchmark effectivity and guarantee merchandise meet efficiency expectations earlier than transferring into mass manufacturing.
Earlier than finalizing designs and transport elements to clients, producers will use energy analyzers to benchmark the elements with extraordinarily excessive accuracy. That is once they create a spec sheet for an element. Ballpark values are inadequate for this step. They should have precise energy measurements.
Coty Harrison: The validation section contains the part degree (i.e. chip makers), the preliminary system integration degree (i.e. Tier 1 suppliers), and the manufacturing degree (i.e. automobile OEMs)—to ensure the total manufacturing course of is working appropriately.
Typically, part producers can use gadgets with decrease accuracy (round 1%) whereas designing elements. After which earlier than finalizing designs and transport elements to clients, they may use energy analyzers to benchmark the elements with extraordinarily excessive accuracy. That is once they create a spec sheet for an element. Ballpark values are inadequate for this step. They should have precise energy measurements.
Charged: What Yokogawa merchandise do EV engineers sometimes use for energy analyzing?
Coty Harrison: Our Yokogawa WT sequence energy analyzers are designed for this goal. In contrast to common measurement instruments, our energy analyzers present each remoted voltage inputs and correct present measurement capabilities, that are important for precisely capturing cycle-by-cycle energy metrics. Instruments that lack AC sign testing will battle with measurements within the dynamic circumstances seen in EVs or different techniques with shifting energy components.
Cristian Loris: Because the automotive trade has embraced electrification, we’ve added options like help for multi-motor techniques and sooner sampling charges to deal with greater switching frequencies.
Our WT5000 helps as much as seven components that present correct present and voltage measurements. Present sensing is carried out utilizing a shunt resistor with temperature and frequency compensation. For the analysis of motor velocity, torque and mechanical energy, as much as eight enter channels (through two modules) can be found, enabling the analysis of 4 motor techniques concurrently.
Energy analyzers present each remoted voltage inputs and correct present measurement capabilities, that are important for precisely capturing cycle-by-cycle energy metrics. Instruments that lack AC sign testing will battle with measurements within the dynamic circumstances seen in EVs or different techniques with shifting energy components.
Charged: The place are energy analyzers used outdoors the EV Trade?
Cristian Loris: Whereas automotive purposes are driving loads of innovation within the house, our energy analyzers are additionally extensively utilized in industrial motor growth, which consumes roughly 60% of world electrical energy. So, enhancing effectivity in these techniques has a large influence on decreasing power utilization and prices.
Charged: Are you able to inform us extra about your roles at Yokogawa and the way you assist EV techniques engineers?
Coty Harrison: I’ve been with Yokogawa for eight years. I began as an software engineer, which is the place most of our technical employees start. Given the complexity of our take a look at tools, it’s necessary to realize hands-on expertise. From there, I transitioned into technical gross sales and ultimately grew to become the North American Gross sales Supervisor for our take a look at and measurement workforce.
Cristian Loris: I additionally began with the applying engineering workforce about two and a half years in the past. There, I helped combine our merchandise into clients’ testing setups, permitting me to see firsthand the trade’s challenges. Since then, I’ve transitioned into the position of Product Supervisor for our decarbonization and electrification product portfolio, together with our energy analyzers for the EV market.
We work intently with EV techniques engineers once they need assistance determining what testing merchandise will work greatest for his or her particular purposes, after which we assist them customise and implement them into their processes.
MORE: Watch this webinar by Yokogawa Take a look at&Measurement to be taught extra about learn how to successfully benchmark knowledge for and troubleshoot points with power effectivity in EV powertrains.
