Engineering Design

Water-Cooled VVVF
Ringway has taken a fresh aproach to implementing Flux Vector (VVVF) drives in underground mining applications. Initial installations have been integrated into the Substation / Starter and relied on airconditioning as the cooling medium. By individually housing the drives and cooling them with a water to air heat exchanger Ringway has allowed the units to be mounted up close to the drive motor under control. This approach greatly reduces capacitive coupling to ground in the motor cable and enables drives to be moved in and out of service individually (as required). Better engineering has resulted in dust free enclosures, reduced maintenance issues (no air filters, no gas)and improved asset utilisation (drives are only installed where they are needed - less drives required to maintain the mining cycle). The Ringway design is engineered to minimise undesireable side effects that are inherent characteristics of VVVF technology. Side effects accounted for include RF, earth leakage, dv/dt, harmonic distortion and heating.

2MVA Mobile Substaion / Belt Starter
In conjuction with the dual 500kW VVVF drives constructed for Tahmoor Ringway has designed and built 2 x 2MVA Substation / Belt starters - with another due for delivery. The mobile substations had several design constrictions including height length and 'Form 4' construction.