Kim Ean Koh

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Project Description:
Performed simulation and design of the first in-house developed 11-kW EV wireless charging platform.

Responsibilities:

• Selected and designed LCC-LCC matching circuits to maximize transferred power and efficiencies of inverter and rectifier. Successfully increased the DC-DC efficiency from 92% to 95% and subsequently, reduced the number of paralleled power devices for converter size reduction.
• Simulated harmonic voltages and currents in the inverter, rectifier, matching circuit, and coils using Matlab and PLECS.
• Calculated losses in the DC/DC converter, inverter, and rectifier.
• Designed soft-switching operations for inverter and synchronous rectifier.
• Performed calculations of tolerances using Monte Carlo simulations.
• Debugged the embedded program especially on the power controller parts.

Project Descriptions:
Established, managed and lead an R&D start-up project to develop new wireless charging products.

Responsibilities:

• Established an R&D Department of Wireless Charging with a team of five engineers. Set up a laboratory, carried out budget planning, instrument selections, and purchasing.
• Selected and designed wireless charging systems: the coils, inverter, rectifier, and DC/DC converter. Performed tests, integration, and power device selections for these converters.
• Calculated the internal resistance, temperature rise, self-inductance, and mutual inductance of coils. Calculated the loss of power converters and selected suitable heat sinks.

Project Descriptions:
Designed, developed and patented a 100 W wireless charging system for fire trucks of Singapore Civil Defence Force (SCDF) as part of a collaboration between a university's start-up and SCDF. The 100-W system is for charging batteries that power equipment in fire trucks.

Responsibilities:

• Designed and developed a 100-W wireless power transfer system according to SCDF's requirements.
• Developed and patented our prototype to enable commercialization for the start-up.

Project Description:
Developed a wireless charging system for powering sensors in the moving column of the ship propeller.

Responsibilities:

• Tested the performance of the wireless charging in an oil-immersed environment.
• Designed a test fixture to hold coils around the propeller column.
• Designed a frequency control algorithm.
• Wrote the embedded program.

Project Description:

Transferred new products from R&D departments to production lines using Six Sigma quality standard. Developed automated test systems for multiple products such as hand-held digital multimeters, current clamps, LCR meters, bench-top digital multimeters, and data acquisition modules.

Responsibilities:

• Developed automated test and calibration systems for new product introduction (NPI).
• Performed characterization tests; defined measurement uncertainties and production margins for setting specifications of the products.
• Defined qualification methods and wrote test documents to ensure ISO90001 and ISO17025 compliance.
• Developed automated statistical process control (SPC) monitoring for test time and cost reduction projects.
• Performed Gauge R&R for comparing different testers of the same product.