Testing of Electrical and Hybrid Drives
The Instrumentation from HBM at the Heart of the GreenMot Strategy
GreenMot is a young French company located near Lyon specializing in the testing of internal combustion engines, propulsion systems and energy systems, in particular in the field of automotive, heavy goods vehicles, railways and industrial equipment (cooling systems, power generation systems, etc.).
Established in October 2010, it has enjoyed rapid success with a turnover of close to EUR 1 million from the first year. If GreenMot has also succeeded in establishing itself equally rapidly on the market, that is thanks to its unique position, explains Stéphane Londos, its President and founder:
"We adapt our instrumentation to the products to be tested, not vice versa. By carrying out non-intrusive tests, we obtain far more reliable results. Another of the strengths of our company is being able to define the tests to be carried out according to the results required and analyzing the results obtained. We can therefore make suggestions to our clients for improvements to be made in their products in order to improve their performance."
The decision for suitable instrumentation
This positioning has several implications for the instrumentation. HBM had all the trumps to establish itself with GreenMot and rapidly became the preferred partner. There are several reasons for this:
- First there are the types of measurement to be carried out. GreenMot carries out large numbers of torque measurements, a domain where HBM is practically indispensable.
- Then there's the acquisition system. When it comes to measurements on mobile equipment (automobiles, trains, heavy goods vehicles) or stationary systems (on a test bench or industrial site), GreenMot utilizes an embedded acquisition system which is furthermore able to collect data from a wide variety of measurements (torque, deformation, rotational speed, temperature, pressure, humidity, air flow rate, etc.).
With its modular QuantumX system, HBM has the solution to all these requirements. But for Stéphane Londos, other crucial factors also speak in favor of HBM:
"We work in the field of applied research which is far more demanding in terms of the measurement quality. The HBM products meet the metrological requirements here, whether in terms of measurement uncertainty, repeatability, synchronization of the measurements. And I've kept the best for last: HBM is able to produce "tailor-made" sensors that we need for installation of the instruments on the structures and for carrying out non-intrusive measurements. We have therefore gone over to regularly co-developing together with the German company. We are very appreciative of the attention that HBM has given us since our very beginnings, a company of international standing."
In order to carry out these non-intrusive measurements, and therefore to possibly design customized sensors, GreenMot bases its development on the arithmetic model of the equipment to be tested. Even before having access to the real equipment, the company is therefore able to prepare the tests, the positioning of the sensors, the routing of the cables, etc., and possibly to study the design of the customized sensors. The time savings are enormous.
A Genesis HighSpeed DAQ for testing electric motors
The cooperation with HBM which is already firmly established recently underwent a new development. Since the very beginning, GreenMot has worked on complete systems, taking their environment into consideration. Hybrid cars which combine traditional internal combustion engines with electric motors have led the society to become interested in electric motors which unquestionably have an impact on the behavior and performance of the vehicles.
The tests on these motors present a new challenge when it comes to measurement because the electric power supply comes in the form of a stream of electric pulses of several hundred volts with complex form at a frequency of 1 to 25 kHz. This pulse train comprises several very rapid transients with variable intensity which have to be recorded reliably in order to be able to analyze the performance of the motor, and to understand the influence of the power supplies on the speed and torque delivered by the motor.
This led GreenMot to examine the systems available on the market. The company even tested a high-tech system specially developed for analyzing disturbances on the power grid. But this system did not allow long-term data acquisition while recording all the details of the signal. Once again, HBM appeared to be the best choice.
"We decided in favor of the GEN3i system from the Genesis HighSpeed series which is capable of recording high-voltage signals and of operating at sampling frequencies of up to 100 MS/s – more than enough to allow the details of the signals to be analyzed," explains Stéphane Londos.
It is worth noting in passing that the purchase of GEN3i by GreenMot in addition to that of QuantumX, confirms the pertinence of the decision by Spectris (the parent company of HBM) of having entrusted HBM with the modernization of the range of acquisition systems "salvaged" as a result of the takeover of LDS in 2008.
GEN3i (just like QuantumX) is used as an acquisition front-end. The digitized measurements are transferred via an optical GigabitEthernet link to a workstation where they are visualized, stored and analyzed. The optical link permits perfect insulation between the supply voltage to the motors (up to 700 V) and the workstation. The data processing is assured by the Perception software package developed by HBM for high-speed data acquisition which is capable of visualizing 10 GB of data in 10 seconds.
GreenMot intends to strengthen its cooperation with HBM which meets the expectations both with respect to products and to service (in particular the development of customized sensors).
"It is also a question of leveraging the material and intellectual investments that we have made in the products and computers,"
comments Stéphane Londos. Several projects are in process. The GEN3i bought by the French company will be fitted with supplementary measurement channels in order to be able to handle applications which employ several electric motors (one of the trends in hybrid vehicles). In the near future GreenMot plans to test a solution proposed by HBM for synchronizing the measurements performed with QuantumX with those performed with GEN3i. HBM is therefore more than ever a key partner for allowing the French company to handle more and more complex systems and for strengthening its reputation with the manufacturers of powered industrial equipment.