Regenerative DC Power Testing for EV Battery Validation in India

Why the Workload Is Changing

India’s EV programmes, two-wheeler OEMs, automotive Tier-1 suppliers, battery pack assemblers, and the cell-to-pack manufacturers ramping in Bengaluru, Pune, Chennai, and Hyderabad, are scaling validation capacity alongside production capacity. At the centre of that validation lab sits a DC source-and-sink: the instrument that drives charge cycles into a battery pack and absorbs the discharge energy back out again, with the BMS and DC-DC converter under instrumentation throughout.

Traditional dissipative loads dump every absorbed watt into heat. For continuous battery cycling at the kilowatt-to-tens-of-kilowatts range that EV qualification requires, that translates into a meaningful electricity and HVAC line item, energy spent producing nothing except heat that the facility then pays again to remove.

Regenerative bidirectional platforms address both sides of that problem.

How a Regenerative Bidirectional Source-and-Sink Works

The architecture combines two functions in one chassis:

• A programmable DC source drives the DUT during charge cycles, fault simulation, or steady-state validation.
• A regenerative sink absorbs power during discharge cycles, converts the absorbed DC back to AC synchronised with the facility’s mains, and feeds it into the local electrical grid for use by other loads on the same distribution.

The transition between source and sink modes happens within the same instrument with no rewiring. For battery testing, the BMS sees a single DC bus that ramps positive and negative current as the test profile demands. For DC-DC converter testing, the source-and-sink covers both forward and reverse power paths required by bidirectional traction-drive converters.

Energy recovery is a function of the regenerative inverter stage’s efficiency. The exact recovered fraction depends on operating point and is published per platform, the architectural takeaway is that the heat dissipated and the net grid draw are both substantially smaller than for a dissipative load operating at the same power.

The GW Instek RBS Series

GW Instek’s regenerative bidirectional platform for this workload is the RBS Series. Key parameters:

Capability	Specification
Power per unit	5 / 10 / 15 kW (3U chassis)
Voltage models	100 V, 500 V, 750 V, 1000 V, 1500 V, 2250 V
Max current	Up to 510 A
Operation	Bidirectional source + regenerative sink
Battery models	8 chemistries (LMO, LCO, LFP, NCM, LTO, Pb, NiMH, NiCd) + 1 user-defined
PV simulation	EN50530, Sandia, SAS2, user-defined
MPPT testing	Static and dynamic, with cloud-shading / cloud-movement profiles

The voltage lineup spans the practical range of EV pack voltages, 100 V is appropriate for two-wheeler and three-wheeler packs; 500–1000 V covers passenger-vehicle and commercial-vehicle packs; 1500–2250 V reaches into utility-scale energy-storage qualification and high-voltage DC bus testing.

Indian EV Validation Workloads

Battery pack cycling. AIS 156 (electric power-train safety requirements) and AIS 038 (rechargeable energy storage system requirements) call for extensive charge-discharge cycling under controlled conditions. The RBS’s bidirectional behaviour runs both sides of the cycle from one instrument; the regenerative path makes 24/7 cycle work practical to operate and to fund.

BMS validation. Battery management systems need to be exercised against fault scenarios, cell overvoltage, undervoltage, overcurrent, temperature excursion, communication failure. The built-in chemistry models simulate the electrical behaviour of a real pack under each scenario, including charge and discharge transitions, without a physical pack on the bench.

DC-DC converter testing. EV powertrains use multiple DC-DC stages, high-voltage to 48 V auxiliary, 48 V to 12 V, and bidirectional converters that handle regenerative braking energy. Each stage must be validated at full power across its operating envelope. Bidirectional source-and-sink behaviour exercises both the forward path and the reverse path in one test setup.

Motor-drive and inverter testing. While the mechanical side of motor characterisation goes to a dynamometer, the DC bus side of an inverter still requires a controllable DC source-and-sink for hardware-in-the-loop and steady-state qualification. A regenerative platform on the DC bus absorbs the simulated regenerative-braking energy without dumping it as heat.

Solar inverter validation. The same chassis with EN50530 and Sandia profiles loaded covers MPPT verification for the solar-inverter side of the lab, useful for groups that span solar and EV charging infrastructure validation.

Thermal and Infrastructure Implications

Beyond the direct energy bill, regenerative loading reduces the cooling infrastructure each test station requires. A multi-kW dissipative load deposits its full rated power as heat into the test area; the equivalent regenerative platform deposits only the conversion losses. For Indian facilities running through summers where ambient routinely exceeds 35 °C, that translates directly into smaller HVAC capital expenditure and lower air-conditioning operating cost.

Rack density also improves. Dissipative loads are dominated by heatsinks and fans; regenerative platforms move the energy out through the AC cable, which lets them pack more tightly in a rack.

Buying GW Instek Regenerative Test Equipment in India

GSAS Micro Systems is GW Instek’s authorized partner in India. Application engineers in Bengaluru, Hyderabad, Chennai, Pune, Mumbai, Delhi NCR, and Visakhapatnam work on power-electronics test infrastructure, including instrument selection, rack integration, and SCPI-based test automation for EV battery and converter validation labs.

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