Case studies
Specifications
: 12 kV; 1 600 A; 40 kA /1s
Delivery date
: 02.04.2019
Destination
: Rusko
I want similar solution
Challenge
For a pumping station project in Russia, the customer required a medium-voltage bypass switching solution that would allow safe switching between the grid and the converter output. The key requirement was to completely eliminate any possibility of feeding grid voltage into the converter output, even in the event of operator error.
In the initial phase, two technically feasible solutions were discussed in detail:
- a solution using a simple disconnector,
- a solution using a changeover disconnector.
Selection of the Technical Solution
Both variants were feasible in terms of dimensions and design (cabinet width approx. 800 mm). However, the fundamental difference lay in the level of inherent safety:
- With a simple disconnector, complex interlocking would be required to prevent grid voltage from being applied to the converter output.
- A changeover disconnector mechanically prevents this undesirable condition, independently of the control system.
Based on this analysis, a solution with a changeover disconnector was selected and supplemented with additional safety and signaling devices.
Implemented Solution
IVEP supplied an indoor MV switchgear with a changeover switch of type MSVI-CH, intended for secondary power distribution.
Technical Specifications
- Rated voltage: 12 kV
- Rated current: 1,600 A
- Short-circuit withstand: 40 kA / 1 s
The switchgear is designed as a free-standing cabinet for bottom cable entry on both sides. The structure is made of galvanized steel with a powder-coated finish. The insulation is air-based, with natural cooling supported by fans. For operation at low ambient temperatures, the cabinet is equipped with internal electric heating.
Safety, Interlocking, and Signaling
The solution includes:
- mechanical protection against switching into hazardous states,
- prevention of operation under load,
- interlocking solenoids,
- position contacts,
- voltage indication,
- polycarbonate windows allowing visual inspection of the changeover disconnector position.
Result
- Safe and unambiguous switching between sources without the risk of back-feeding the converter.
- Minimized dependence of safety on operator actions and the control system.
- A compact indoor solution adapted to pumping station operation.
- The equipment was delivered on April 2, 2019 and successfully commissioned.
IVEP Value
This project confirms IVEP’s ability to act as a technical partner already at the design stage. Thanks to a detailed evaluation of alternatives and a strong focus on mechanical safety, the resulting solution is robust, clear in layout, and safe over the long term.