At a large thermal power plant in Shandong, China, a 280 m belt conveyor moves raw coal to the boilers around the clock. The conveyor uses two 160 kW motors – one at the head end and one at the tail end. Its original asynchronous-motor and soft-starter configuration ran continuously at fixed speed, even when the conveyor was lightly loaded or idle.
The result was excessive no-load current (up to 190 A), high inrush current at startup, belt slip, accelerated mechanical wear, and a power factor of only 0.81. Coal-handling power consumption accounted for more than 60% of auxiliary-equipment losses at the plant.
The plant replaced the two soft starters with two 200 kW GK960 heavy-duty vector drives and upgraded to two 160 kW IE5 permanent-magnet synchronous direct-drive motors. The original large-diameter drive pulleys were retained.
| Metric | Before retrofit | After retrofit |
| No-load current | 190 A | 39 A |
| Full-load current | 300 A | 80 A |
| Annual electricity consumption | 1.92 million kWh | 1.28 million kWh |
| Power factor | 0.81 | ≥ 0.96 |
| Maintenance savings | — | RMB 80,000–100,000 / year |
GK960 is a high-performance vector engineering inverter. Featuring a book-type structure for side-by-side installation, it offers 1500Hz high-frequency output and 16K carrier, ideal for high-speed motors. Supporting GTLINK bus and EtherCAT servo control with ultra-fast response (62.5us current loop), it is widely used in high-end drives like hoisting and building materials.
