Electrical machinery, apparatus, equipment and consumables; lighting

Tender description

This requirement is for a pulsed power supply for the ISIS injection dipole. The new power supply will give a 15 kA pulsed output with a rise and fall time of 100 µs and a nominal flat top of 500 µs. The designated load is described in AW18-2. The supplier will specify the output cable to be used. The cable is expected to be a significant proportion of the load. The flat top, fall time and zero current stability of the pulsed output are critical to operational needs. A ‘Start Trigger’ will signal the beginning of the rise time. This will occur before the proton beam is present and is therefore of lower importance. The pulsed output is expected to be at operating current and stable by the time the beam is injected. A ‘Stop Tigger’ will then signal the beginning of the fall time. During this time the proton beam will be circulating in the synchrotron and passing through the magnets. The magnet current will fall to zero within 100 µs before acceleration of the protons begins. The current must then be stable at zero, when measured with no beam, for the remainder of the cycle. The power supply will be used at an operational facility and must have high performance, reliability and availability. It will be based on proven technology that is established in service. STFC staff will be trained by the supplier in the operation, maintenance, fault finding and repair of the power supply. The supplier will advise on a complete set of suitable spares, which will be quoted for as a separate item. STFC will consider purchase of the spares after successful testing of the power supply and cable. The requirement is for one power supply to provide current to the four injection dipole magnets in series, plus a complete set of spare parts. A summary of the specification is given below: — Fed from a nominal 230/400 VRMS AC, 3-phase, 50 Hz sinusoidal, 300 A per phase supply — 15 000 Amp pulse current output at flat top (plateau) — 1 000 ppm stability in magnet currents — 100 µs rise time, 500 µs flat top, 100 µs fall time — The output voltage across any one magnet must not exceed 1000 V — The output cable and connector type will be specified by the supplier — The power supply topology will be specified by the supplier — Manual isolation and automatic protection — A local user interface and ability to communicate to a remote user interface — A soft start function will gradually increase the output current to an operational level — Galvanic isolation between electrical supply, internal power circuits, control electronics and monitoring points — High reliability and minimal maintenance — Earthed enclosures and noise rejection — Designed to relevant British and International standards, with CE Marking as appropriate — Performance will be tested at ISIS to confirm the specification is met — Designs will be reviewed by STFC at several stages — Drawings, risk assessments, procedures and descriptions will be supplied Full details of the requirements can be found in the Emptoris e-sourcing platform.