The mill runs polyester weaving lines. Winter is the expensive season: the process air heating is electric, and the air heating pulls a spike that lands on top of the normal weaving load during the morning startup window. Tariff in Zhejiang has a winter premium on top of the standard peak.
We delivered a 200 kW PCS matched to a 430 kWh LiFePO4 rack installed in the basement mechanical room. The rack was sized by the integrator, not by us — we worked to the DC current rating of the cabinet, which is what matters for the bidirectional IGBT stage.
What the cabinet does
- Peak shaving the morning winter spike (06:00–09:30)
- Charging from the grid overnight on off-peak tariff
- Standby mode during substation maintenance days (about once a month, the local utility calls ahead)
- Remote monitoring from the integrator’s NOC in Hangzhou
Things the customer asked about
Three questions came up at every meeting before the order: noise, footprint, and what happens during a blackout. The answers, in order: the cabinet fans are below 65 dB at one metre, which is acceptable in their basement; the cabinet is 1.2 m by 0.8 m, which fits where they wanted it; and during a blackout the cabinet goes into voltage-source mode and rides through with the local load for as long as the cell holds, which is roughly two and a half hours at the average morning load.
We did not oversell the ride-through. The cell energy is fixed, and so is the answer.
First winter results
Six months on, the cabinet has logged 178 peak cycles and one unplanned substation event that lasted three hours, both of which are in the normal envelope. The integrator sent us a one-page monthly summary. The interesting line: average peak cut was 184 kW, which is below the 200 kW cabinet rating, on purpose — the cabinet holds 16 kW of margin for the standby event so it never runs at full nameplate in normal peak shaving.
Contact: 58298175@qq.com / +86-181-5931-0123.
