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cb4187fa-1f56-4e0a-802b-38148d143d40 · Contract

Rotary Frequency Converter

KBS Maritime Ltd

Estimated Value

£2,000,000 – £0

Deadline

10 July 2026

29 days remaining

Published

8 June 2026

Type

goods

Any regionGBCPV: 31121111 32552420

Overview

We require a rotating machine manufacturer to design, build and install a 5MVA 11kV 50Hz to 6.6kV 60Hz Rotary Frequency Convertor. Both machines shall be synchronous with a mechanical coupling joining the 10-pole motor to the 12-pole generator.

There is a requirement to be able to physically rotate the generator stator to enable manipulation of the phase and load angle via racking motor or actuator. The machine should come complete with a starting reactor and contactor connected to the neutral point of the motor, to limit the inrush current on startup to approximately 400A. Control of the machine starting reactor and racking equipment shall be by an external control system, which shall not form part of the machine scope of supply.

AI Analysis

Powered by AI — always verify against official documents

High Complexity

The UK government needs a specialist company to design, manufacture, and install a custom rotary frequency converter — a large rotating machine that converts electrical power from 50Hz (standard UK frequency) to 60Hz (used in some industrial applications). The machine must handle 5 megavolt-amps of power and convert voltage from 11,000V down to 6,600V, with adjustable components to fine-tune phase and load during operation.

Requirements

  • Must be a rotating machine manufacturer with design and build capability
  • Machine must be rated for 5MVA (megavolt-amp) capacity
  • Input: 11kV 50Hz (standard UK industrial supply)
  • Output: 6.6kV 60Hz (converted frequency)
  • Motor must be 10-pole synchronous machine
  • Generator must be 12-pole synchronous machine
  • Mechanical coupling required between motor and generator
  • Generator stator must be physically rotatable (via racking motor or actuator) to adjust phase and load angle
  • Supply must include starting reactor connected to motor neutral point
  • Supply must include contactor (electrical switch) connected to motor neutral point
  • Starting reactor must limit inrush current to approximately 400A on startup
  • Supplier responsible for design, build, and installation — control system is NOT part of this contract

Key Tasks & Deliverables

  • Design a complete 5MVA rotary frequency converter system meeting the electrical and mechanical specifications
  • Manufacture a 10-pole synchronous motor (11kV 50Hz input side)
  • Manufacture a 12-pole synchronous generator (6.6kV 60Hz output side)
  • Engineer and build mechanical coupling to join motor and generator shafts
  • Design and integrate a starting reactor sized to limit inrush current to ~400A
  • Design and integrate contactor switch on motor neutral point
  • Install rotating stator racking system on the generator to allow phase and load angle adjustment during operation
  • Procure or design racking motor or actuator for generator stator manipulation
  • Full on-site installation of the complete machine assembly
  • Provide interface specifications so external control system can operate the starting reactor and racking equipment

How to Read This Tender

  • 1Recognize this is a highly specialized engineering contract — they need a company that has actually built similar machines before, not a general electrical contractor. Check if you have or can access this expertise.
  • 2Pay close attention to the two different pole counts (10-pole motor, 12-pole generator) — this is technically critical and indicates a non-standard design. Ask the buyer's technical team for clarification if unclear.
  • 3The 'racking' requirement means the generator stator must physically move during operation to adjust electrical phase — this is unusual and requires mechanical precision. Understand exactly how much movement is needed.
  • 4Note that the 'external control system' is explicitly NOT your responsibility — don't bid to supply control electronics, software, or SCADA systems unless asked. The buyer will handle this separately.
  • 5The starting reactor and contactor specifications (limiting inrush to ~400A) are performance-critical — you'll need to calculate this precisely based on motor and system impedance. If this isn't your normal work, budget for specialist electrical design support.

Tips for Small Businesses

  • This is a niche market contract — if you're not currently a rotating machine manufacturer, consider forming a consortium or subcontracting partnership with a specialist firm that has frequency converter or synchronous machine experience. Many small engineering firms bid as the prime but partner with established manufacturers.
  • The mechanical racking system is a potential subcontract opportunity if the main bidder doesn't have in-house mechanical design capability — look for contracts where you can supply just the actuator system, bearings, or mechanical design work for the stator racking.
  • Request the full Invitation to Tender (ITT) documents early — this brief is highly technical and the full spec will likely include load profiles, duty cycles, cooling requirements, testing standards (probably IEC or IEEE), and installation site conditions. Small firms often underestimate scope because they only read the headline description.

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Buyer Profile

KBS Maritime Ltd
Typepublic body
RegionAny region
Total contracts11
Total spend£11,300,000
View buyer profile

Key Dates

Published

8 June 2026

Submission deadline

10 July 2026

Notice type

Contract

Source

contracts finder

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