High-speed train and lead–acid battery: what they have in common
- Step 1. High-speed train — has part — Pantograph. A current collector.
- Step 2. Pantograph — is part of — Electric locomotive. Current is collected by a pantograph.
- Step 3. Electric locomotive — has part — IGBT. Traction converters.
- Step 4. IGBT — is part of — Inverter. The power switches of inverters.
- Step 5. Inverter — is part of — Uninterruptible power supply. An inverter.
- Step 6. Uninterruptible power supply — has part — Lead–acid battery. A battery.