An interview with James Hitchcock, a general manager of Keithley Instruments a Tektronix Company, shed light upon the recent acquisition of Elektro-Automatik (EA), a supplier of high-power electronic test solutions.
EA’s principal application space lies in energy storage, mobility, hydrogen, and renewable energy applications where their bidirectional programmable DC power supplies can double up as both the power supply and electronic load with their unique regenerative feature and bidirectionality. Many tests involve the necessity to dump large amounts of power in the form of heat through passive/resistive load banks or electronic loads, including battery cycling and burn-in tests. On a massive scale, handling this amount of heat is a significant undertaking, where the proper HVAC and even liquid cooling may be necessary. Instead, EA power supplies take that energy and transfer it back to the grid, recycling otherwise wasted energy and eliminating any cooling costs (Figure 1).
Figure 1: The process of energy recovery for EA’s regenerative bidirectional programmable power supplies in a testing scenario connected with the unit under test (UUT). Source: EA, a Tektronix Company
The principal application space for many Tektronix instruments lie in signal integrity and precision high frequency testing with an offering of high-end mixed signal oscilloscopes, signal generators, and spectrum analyzers. Keithley source measure units (SMUs), and precision measure instruments offer solutions for semiconductor characterization and quality control. Outside of this, the MSO oscilloscopes and IsoVu probes are geared towards power electronics performance analysis. However, how does any of this mix with EA’s high power test equipment portfolio?
Test solutions for the EV powertrain
“The primary motivation for acquiring EA and combining the solutions of Tektronix was focused around the battery emulation capabilities of EA and the applications focused on power inverters and motor drives primarily in the automotive space” says James, “where the EA sources can test the batteries but also emulate them in the designs of the vehicles and the Tektronix 4 and 5 series MSO scopes are well-suited for the AC signal analysis to drive the motor that is powered by these battery systems”. As shown in Figure 2, select EA power supplies can simulate a set of battery cells at a specific state of charge (SOC) in a few minutes. Typically, these tests involve hours of preparation, charging and discharging multiple batteries and different SOCs before beginning DUT validation.
Figure 2: The ability to both source and sink power enables EA’s power supplies to simulate battery behavior and accurately reproduce a battery’s voltage and current characteristics to test devices.
The Keithley data acquisition (DAQ) systems and digital multimeters (DMM) have played a role in this space for many years, monitoring the temperature and voltage control of the batteries in battery management systems (Figure 3). “So across the entire engineering workflow of designing the powertrain for an EV the Tektronix-, Keithley-, and EA-branded products work together for a solution.”
Figure 3: Keithley DAQ systems have long been leveraged in environmental monitoring, burn-in/accelerated life testing, as well as failure analysis for automotive applications. Source: Keithley, a Tektronix company
Power inverter and fuel cell testing
“There are other opportunities in power inverters in renewables, especially converting voltage from the DC side with solar panels to AC,” says James. The testing space expands beyond this with fuel cells testing for heavier duty electric mobility solutions such as large trucks, construction equipment, trains, and boats. Fuel cells are also increasingly used in energy security, providing a backup source of power in the event a black out or brownout occurs. “This is an area that EA is very good at and Tektronix can get involved in designing the precision electronics needed to control this type of testing.”
A gap in market for a unified testing solution
“Our Keithley source measurement units (SMUs) are well-suited to individual cell design,” says James “Our sourcing capabilities with our SMUs stop at about 5 kW of power (Figure 4). We have a 300 V solution and several hundred amp pulsing solutions with our SMUs and we found engineers were moving to higher powers with the evolution of new battery chemistries, new drive trains, and motors.”
Figure 4: The Keithley 2650 series SMU is a high power instrument designed for characterizing high power electronics such as diodes, FETs, IGBTs, etc., with up to 3000 V or 2000 W of pulse current power. Source: Keithley, a Tektronix company
Tektronix intends to support this trend of moving to higher voltage electrification system in EVs and more energy dense battery chemistries to reach parity with internal combustion engineer (ICE) vehicles, “there was a gap in the market where the suppliers were offering the power solutions or the measurement solutions but no one was really offering the full capability to serve the engineer across that full power portfolio”.
In the near term, Tektronix intends to bring the EA products into their software umbrella, providing unified testing solutions for engineers across the power spectrum from low-power embedded IoT designs to ultra-high power energy storage, mobility, and hydrogen fuel applications.
Aalyia Shaukat, associate editor at EDN, has worked in the design publishing industry for eight years. She holds a Bachelor’s degree in electrical engineering from Rochester Institute of Technology, and has published works in EE journals and trade magazines.
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