NMX‑EMT‑350 / Rev 00 / DIN 1319 · IEC 60034 / Noida · India 2026 · Product Page

NMX-EMT-350 · ENGINEERED TO ORDER — E-MOTOR TEST BENCHES

Two machines, one shaft — the grid pays only the losses.

Name: E-Motor Test Bench
Brand: Neometrix

E-motor and powertrain test benches — four-quadrant, back-to-back, to the 350 kW class and EV-grade speeds. The motor under test and the load machine share one DC bus, so power circulates; a precision torque flange reads truth between them; and efficiency maps fall out across the whole speed–torque grid. With battery emulation for the inverter, a chamber for temperature, and production EOL testers for the factory floor. Engineered to order — the reference configuration on this page has not yet been built.

Enquire — e-motor test Capability sheet (PDF)

Illustrative image, not a delivered installation — an e-motor test bench: two electric machines mounted on a cast-iron T-slot bedplate, coupled through a guarded shaft with a torque flange at its centre, with orange high-voltage cables to a drive cabinet row behind and a small instrumentation mast beside the bed

Fig · 01 DUT and load machine on one bedplate, torque flange between them — illustrative, not a delivered installation

Power

350kW class

Quadrants

4motor & absorb

Torque

±0.03% repeatability

DC bus

1,000V emulation

DAQ

10kHz class

ISO 9001 / 14001 Engineered to order Torque metrology to DIN 1319 class Calibration & acceptance in scope of supply Noida · India

Overview

Range is won and lost in the efficiency map.

An EV’s range is not one number; it is the integral of the powertrain’s efficiency over every operating point a drive cycle visits. The map of those points — efficiency islands across the speed–torque plane — is the product this bench manufactures. Everything else on the page exists to make that map true.

Illustrative image, not a delivered installation — close-up of a precision torque flange in a guarded coupling between two shafts on a test bench, its polished measurement body between bolted flanges, with a speed encoder ring beside it and a safety guard partly visible

Fig · 02 The torque flange — where the bench’s truth is measured — illustrative, not a delivered installation

Back-to-back is the honest architecture. The motor under test drives; the load machine absorbs — and both sit on one DC bus, so the absorbed power feeds straight back to the driving side. The grid supplies only the losses. A 350 kW test that would otherwise demand 350 kW of supply and 350 kW of heat rejection instead draws tens of kilowatts. That is not a convenience; it is what makes full-power endurance affordable at all.

Torque is measured, not inferred. A precision flange in the shaft line — repeatability in the ±0.03 % class (DIN 1319), temperature compensated, IP54 — reads mechanical power directly, while power analysers read the electrical side. Divide one by the other and the efficiency map appears; get the flange wrong and every island on it moves.

The inverter is half the powertrain. A battery emulator (0–1,000 V class) stands in for the pack, with realistic source impedance, so motor, inverter and control software are proven together — and a motor emulator variant proves controllers with no rotating iron at all.

Speed matters twice: EV machines turn at tens of thousands of rpm, and at those speeds balance, alignment and guarding stop being mechanical details and become the design.

Engineered to Order

Sized to the machines and the duty

Power class, speed, inertia, emulation depth and chamber pairing follow from the machines being tested — hub motors to complete e-axles — and the standards they answer to. The reference envelope was engineered against India’s current EV-laboratory build-out, including a live national-lab requirement pairing a 350 kW bench with a gearbox and climatic chamber; no order followed, so no delivered bench is claimed.

Lab · Line

Development bench and EOL testers, one creed

The same measurement discipline scales from the R&D bench to the factory: no-load/load, back-EMF and Hall verification, stator surge, hipot/IR, Ke and phase resistance — production gates that catch a bad winding in seconds, not in a warranty claim.

Powertrain in Context

Chamber, dyno, EMC — the family closes

This bench pairs with the Neometrix climatic chambers for temperature, stands beside the chassis dynamometer for vehicle level, and its inverters get their EMC verdict in the EMI/EMC laboratory — the EV test family engineered as one line.

Architecture

A power loop on a bedplate, a map as the product.

The schematic below is the whole bench: the circulating power loop, the torque flange where mechanical truth is read, the emulators that stand in for pack and machine, and the safety chain wrapped around a shaft turning at EV speeds.

FIG · 03BENCH ARCHITECTURE · BACK-TO-BACK POWER LOOP · TORQUE-FLANGE METROLOGY · EMULATION · EOL LINE

Fig · 03 Power circulates between DUT and load machine; the grid tops up losses; the flange reads mechanical power; the analysers read electrical — efficiency is the ratio, mapped over the grid

Arc · 01

The Circulating Loop

DUT drive and load-machine drive share a common DC bus. Mechanical power crosses the shaft; electrical power returns through the bus; the active front end draws from the grid only the sum of losses. Full-power endurance runs become routine rather than events the utility notices.

Arc · 02

Metrology in the Shaft Line

The torque flange (±0.03 % class repeatability, temperature compensated) and encoder read mechanical power; precision power analysers read the electrical side at inverter input and output. Efficiency of motor, inverter and gearbox separate cleanly — each stage’s losses attributed, not lumped.

Arc · 03

Emulation, Both Directions

A battery emulator (0–1,000 V class, bidirectional) is the pack the inverter believes in — sag, impedance and regen acceptance included. A motor emulator is the machine the controller believes in — development and EOL testing of drives with no rotating hardware, no couplings, no risk.

Arc · 04

The Cell Around the Shaft

Guarded couplings and interlocked enclosures; overspeed and vibration trips; torque-limit supervision; E-stop philosophy defined before commissioning. With the bench coupled to a climatic chamber, the whole map re-runs at temperature — because a motor’s losses at −20 °C are not its losses at +40 °C.

Have an e-motor bench, e-axle rig or motor EOL requirement? Send it across — clause-by-clause compliance matrix within two working days · [email protected]

Send tender spec

Specifications

Reference bench, sized to your machines.

The parameters below describe a reference development bench and its production-line siblings. Power, speed, emulation and chamber pairing are settled against the machines and standards at design review.

Illustrative image, not a delivered installation — a production end-of-line motor test station: a small hub motor clamped in a quick-change fixture on a bench-top tester with a guarded coupling, a dark screen above, and a row of identical motors queued on a conveyor tray beside it

Fig · 04 The EOL station — the same measurement creed at line rate — illustrative, not a delivered installation

Where motor benches actually disappoint

Alignment that was “good enough” at commissioning and audible by month six; torque data quietly corrupted by temperature drift the flange never compensated; emulators too slow to reproduce the pack sag that breaks control software; and EOL stations that pass motors a warranty analysis later proves were marginal.

Hence the emphasis here: flange-class metrology with temperature compensation, emulation with honest dynamics, bedplate mechanics treated as precision work, and production gates — surge, BEMF, Hall, hipot — tuned to catch the marginal machine, not just the dead one.

Full specification — expand

System	E-motor / powertrain test bench — back-to-back dyno, torque-flange metrology, battery and motor emulation, gearbox/e-axle configurations, chamber integration, EOL variants · design, engineering, supply, installation, integration, commissioning, calibration and training
Configuration	Four-quadrant back-to-back: DUT and load machine on a common DC bus through a precision torque flange · power circulates; grid supplies losses only
Power & Speed	Reference 350 kW class, scaling down to hub-motor benches · speeds to the twenty-thousand-rpm order of EV traction machines · short-time overload headroom per duty
Torque Metrology	Flange-based · repeatability ±0.03 % class (DIN 1319) · temperature-effect compensated · IP54 · encoder speed/angle · shunt-calibration check built in
Efficiency Mapping	Automated sweeps across the speed–torque grid · motor, inverter and driveline efficiencies separated via simultaneous mechanical + electrical measurement · maps, islands and drive-cycle energy integration
Battery Emulation	Bidirectional DC source, 0–1,000 V class · programmable source impedance and sag · full regenerative acceptance · the inverter proven against the pack it will actually meet
Motor Emulation	Electronic machine model for controller/inverter test without rotating hardware · development and EOL duty · fault and limit cases run safely
Gearbox / E-Axle	Input–output configurations · transmission efficiency · complete e-axle characterisation under drive cycles · in-line torque measurement both sides where specified
Environmental	Bench coupled to a climatic chamber (see the Neometrix climatic & environmental test chamber line) · powertrain maps re-run across the temperature range
Data & Automation	DAQ over EtherCAT / CAN-class networks, sampling to the 10 kHz class · humidity/temperature instrumentation · automated test sequences, limit supervision, report generation · resume-after-interruption
EOL Variants	No-load & load test · back-EMF & Hall-sensor verification · stator surge comparison (windings >10 µH) · hipot & IR · Ke constant · phase resistance · quick-change fixtures at line rate
Safety	Guarded couplings · interlocked enclosures · overspeed & vibration trips · torque-limit supervision · defined E-stop philosophy · HV isolation practices at bus level
Standards Context	IEC 60034-1 (duty, temperature rise) · IEC 60034-2-1 (efficiency determination methods) · DIN 1319 metrology vocabulary for the flange class · AIS/CMVR context for vehicle programmes · calibration ISO/IEC 17025-traceable, in scope of supply
Sourcing	Load machines, drives, torque flanges and encoders are proprietary bought-in components of established manufacturers · Neometrix engineers and builds the bench — bedplate mechanics and alignment, common-bus power architecture, measurement chain, emulation integration, chamber coupling, automation, safety chain, installation and acceptance
Status	Engineered to order — reference configuration, not yet built · sized to the machines, duty and standards at design review

PDF · 1 page

E-Motor Test Bench — Capability Sheet

Tender Response

Send your specification — compliance matrix in two working days

Variants

Hub motor to e-axle, bench to line.

Tenders call these motor test benches, e-motor test rigs, powertrain dynos or motor EOL testers. What changes is the power, the speed, and whether the customer is proving a design or a production shift.

Var · 01

Development Bench (Reference)

Four-quadrant back-to-back to the 350 kW class with torque-flange metrology, battery emulation and full efficiency mapping — the machine a powertrain programme is built around.

Var · 02

Hub & Small-Motor Benches

The same architecture scaled to two- and three-wheeler machines — lower power, high channel turnover, quick-change fixtures, and the measurement creed intact.

Var · 03

Inverter & Controller Rigs

Battery emulator on one side, motor emulator on the other — the power electronics proven with realistic sources and loads, no rotating hardware, faults injected on purpose rather than discovered.

Var · 04

Production EOL Stations

Surge, BEMF/Hall, hipot/IR, no-load and load — the factory gates that measure every motor built, at line rate, with limits tuned to catch marginal machines before customers do.

Applications

Where it applies.

Anywhere electric torque is designed, built or certified.

A · 01EV traction motor & e-axle development and efficiency mapping

A · 02Inverter & motor-controller validation with battery and motor emulation

A · 03Two- and three-wheeler hub & drive motor production EOL

A · 04National laboratories & proving grounds — powertrain test infrastructure

A · 05Industrial & aerospace electric machines — efficiency to IEC 60034-2-1

A · 06Powertrain testing at temperature — bench-in-chamber programmes

FAQ

Common questions.

Plain-language answers from the engineering team.

Q · 01 What does “back-to-back” actually mean, and why does it matter?

It means the motor under test and the load machine are coupled on one shaft and fed from one shared DC bus. The DUT converts electrical power to mechanical; the load machine converts it straight back; the power goes round in a circle, and the grid connection only makes up the losses of the loop — typically a modest fraction of the circulating power. The alternative — absorbing full test power into resistors or a separate absorber and buying every kilowatt from the wall — multiplies both the supply installation and the cooling plant. For a 350 kW-class bench running endurance cycles around the clock, circulation is the difference between a laboratory feeder and a substation, which is why it is the default architecture here rather than an option.

Q · 02 Why measure torque with a flange instead of calculating it from current?

Because calculated torque inherits every error of the model it comes from. Estimating torque from motor current assumes you already know the machine’s parameters — but those parameters shift with temperature, saturation and ageing, and they are often exactly what the test is trying to determine. A torque flange in the shaft line measures the mechanical quantity itself, with repeatability in the ±0.03 % class and temperature compensation built into the sensor. With mechanical power measured at the shaft and electrical power measured at the terminals, efficiency becomes a ratio of two independent measurements — and when the map says 96.2 %, that number can survive an audit rather than an assumption.

Q · 03 What is a battery emulator, and why not just use a power supply?

A plain supply gives the inverter something no vehicle ever will: a stiff, tireless source that never sags, never absorbs, never changes. A battery emulator is a bidirectional DC source programmed to behave like the pack — its open-circuit voltage falling with state of charge, its impedance producing realistic sag under launch currents, and crucially its willingness to accept power during regenerative braking. Control software tuned against a stiff supply routinely misbehaves on a real pack; proving the inverter against emulated pack behaviour finds those failures on the bench. The emulator also makes tests repeatable in a way no physical pack can be — the “battery” is always at exactly the state of charge the test plan demands, thousands of times in a row.

Q · 04 What do the EOL tests catch that a running test would not?

The marginal machine — the one that runs today and fails in month eleven. A surge test fires matched pulses into windings and compares the ring-down against a golden reference: a single shorted turn, invisible to a resistance check and inaudible in a spin test, shows up as a changed waveform. Back-EMF and Hall verification confirm the magnets are charged, oriented and the sensors aligned — errors that a no-load spin can mask but that emerge as torque ripple and heat in service. Hipot and insulation resistance prove the winding-to-frame barrier before HV ever touches it in a vehicle. Each takes seconds in a quick-change fixture, which is the point: at line rate, the test must be faster than the assembly takt and stricter than the warranty department.

Q · 05 Why test a powertrain inside a climatic chamber?

Because the efficiency map is not one map — it is a family of maps indexed by temperature. Cold thickens lubricants, raises copper resistance at first then lowers it as windings warm, shifts magnet strength, and changes what the inverter’s semiconductors lose; heat does the reverse and adds derating behaviour on top. A powertrain that meets its range target at 25 °C can miss it badly on a winter morning, and the only way to know is to run the map at temperature. Coupling the bench to a climatic chamber — the same chamber line Neometrix builds — turns temperature from an excuse into an axis of the data, which is precisely how current national-laboratory requirements are being specified.

Q · 06 Do you build the load machines and drives yourselves?

No — load machines, drive units, torque flanges and encoders are proprietary products from established manufacturers, chosen for the duty rather than reinvented. What Neometrix engineers and builds is the bench: the bedplate mechanics and precision alignment on which everything else rests, the common-bus power architecture that makes circulation work, the measurement chain from flange to report, the emulation integration, the chamber coupling, the automation and the safety cell around a shaft turning at EV speeds — plus installation, calibration and acceptance. It is the same division of work as our chassis dynamometer and battery test pages. And to be straightforward: this configuration is engineered to order and has not yet been built, so nothing here is offered as a delivered reference.

↗

The EV test laboratory from Neometrix.

Powertrain, vehicle, battery and environmental qualification — engineered as one family at our Noida facility.

↗ Vehicle Test

Chassis Dynamometer

The whole vehicle’s turn — the road, indoors.

↗ Battery

EV Battery Test System

The energy source, proven cell to pack.

↗ Environmental

Climatic & Environmental Test Chambers

The temperature axis of every powertrain map.

Browse all Neometrix product lines.

Get a quotation

Send your machines
and your duty cycle.

The Projects desk replies within two working days with a clause-by-clause compliance matrix and a budgetary quotation. Write to [email protected] or use the form.

Enquire — e-motor test Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED TO ORDER — E-MOTOR TEST BENCHES DIN 1319 CLASS TORQUE · IEC 60034 ENGINEERED IN NOIDA · INDIA

Two machines, one shaft — the grid pays only the losses.

Range is won and lost in the efficiency map.

Sized to the machines and the duty

Development bench and EOL testers, one creed

Chamber, dyno, EMC — the family closes

A power loop on a bedplate, a map as the product.

The Circulating Loop

Metrology in the Shaft Line

Emulation, Both Directions

The Cell Around the Shaft

Reference bench, sized to your machines.

Where motor benches actually disappoint

Hub motor to e-axle, bench to line.

Development Bench (Reference)

Hub & Small-Motor Benches

Inverter & Controller Rigs

Production EOL Stations

Where it applies.

Common questions.

The EV test laboratory from Neometrix.

Chassis Dynamometer

EV Battery Test System

Climatic & Environmental Test Chambers

Send your machines
and your duty cycle.

Similar Products

Share This Page

Two machines, one shaft — the grid pays only the losses.

Range is won and lost in the efficiency map.

Sized to the machines and the duty

Development bench and EOL testers, one creed

Chamber, dyno, EMC — the family closes

A power loop on a bedplate, a map as the product.

The Circulating Loop

Metrology in the Shaft Line

Emulation, Both Directions

The Cell Around the Shaft

Reference bench, sized to your machines.

Where motor benches actually disappoint

Hub motor to e-axle, bench to line.

Development Bench (Reference)

Hub & Small-Motor Benches

Inverter & Controller Rigs

Production EOL Stations

Where it applies.

Common questions.

The EV test laboratory from Neometrix.

Chassis Dynamometer

EV Battery Test System

Climatic & Environmental Test Chambers

Send your machinesand your duty cycle.

Similar Products

Share This Page

Send your machines
and your duty cycle.