Description

ĐẦU PHÁT STAMFORD P7

The STAMFORD P7 has a maximum continuous rating of 2800 kVA at 60Hz (2,325 kVA at 50Hz) and a voltage output of 380-690 volts.

The STAMFORD P7 is a very popular product because of its high efficiency and good electrical performances, making it a preferred product for grid code applications and combined heat and power. The P7 alternator’s proven design in the marine market makes it a preferred product for meeting the demanding marine societies’ performance standards.

PI734E
SPECIFICATIONS & OPTIONS

STANDARDS:

Stamford industrial generators meet the requirements of BS EN 60034 and the relevant sections of other national and international standards such as BS5000, VDE 0530, NEMA MG1-32, IEC60034, CSA C22.2-100, AS1359.
Other standards and certifications can be considered on request.

DESCRIPTION:

The STAMFORD PI range of synchronous ac generators are brushless with a rotating field. They are separately excited by the STAMFORD Permanent Magnet Generator (PMG).
This is a shaft mounted, high frequency, pilot exciter which provides a constant supply of clean power via the Automatic Voltage Regulator (AVR) to the main exciter. The main exciter output is fed to the main rotor, through a full wave bridge rectifier, protected by surge suppression.

VOLTAGE REGULATORS:

The PI range generators, complete with a PMG, are available with one of two AVRs. Each AVR has soft start voltage build up and built in protection against sustained over-excitation, which will de-excite the generator after a minimum of 8 seconds.
Underspeed protection (UFRO) is also provided on both AVRs. The UFRO will reduce the generator output voltage proportional to the speed of the generator below a pre- settable level.

The MX341 AVR is two phase sensed with a voltage regulation of ± 1 %. (see the note on regulation). The MX321 AVR is 3 phase rms sensed with a voltage regulation of 0.5% rms (see the note on regulation). The UFRO circuit has adjustable slope and dwell for controlled recovery from step loads. An over voltage protection circuit will shutdown the output device of the AVR, it can also trip an optional excitation circuit breaker if required. As an option, short circuit current
limiting is available with the addition of current transformers.

Both the MX341 and the MX321 need a generator mounted current transformer to provide quadrature droop characteristics for load sharing during parallel operation. Provision is also made for the connection of the STAMFORD power factor controller, for embedded applications, and a remote voltage trimmer.

WINDINGS & ELECTRICAL PERFORMANCE:

All generator stators are wound to 2/3 pitch. This eliminates triplen (3rd, 9th, 15th …) harmonics on the voltage waveform and is found to be the optimum design for trouble-free supply of non-linear loads. The 2/3 pitch design avoids excessive neutral currents sometimes seen with higher winding pitches. A fully connected damper winding reduces oscillations during paralleling. This winding, with the 2/3 pitch and carefully selected pole and tooth designs, ensures very low levels of voltage waveform distortion.

TERMINALS & TERMINAL BOX:

Standard generators feature a main stator with 6 ends brought out to the terminals, which are mounted on the frame at the non-drive end of the generator. A sheet steel terminal box contains the AVR and provides ample space for the customers’ wiring and gland arrangements. It has removable panels for easy access.

SHAFT & KEYS:

All generator rotors are dynamically balanced to better than BS6861:Part 1 Grade 2.5 for minimum vibration in operation. Two bearing generators are balanced with a half key.

INSULATION/IMPREGNATION:

The insulation system is class ‘H’, and meets the requirements of UL1446. All wound components are impregnated with materials and processes designed specifically to provide the high build required for static windings and the high mechanical strength required for rotating components.

QUALITY ASSURANCE:
Generators are manufactured using production procedures having a quality assurance level to BS EN
ISO 9001.

NOTE ON REGULATION:

The stated voltage regulation may not be maintained in the presence of certain radio transmitted signals. Any change in performance will fall within the limits of Criteria ‘B’ of EN 61000-6-2:2001. At no time will the steady-state voltage regulation exceed 2%.

DERATES:

All values tabulated on page 8 are subject to the following reductions 5% when air inlet filters are fitted. 10% when IP44 Filters are fitted. 3% for every 500 metres by which the operating altitude exceeds 1000 metres above mean sea level.
3% for every 5°C by which the operational ambient temperature exceeds 40°C.

*Note: Requirement for operating in an ambient temperature exceeding 60°C must be referred to the factory.

**Note: Continuous development of our products entitles us to change specification details without notice, therefore they must not be regarded as binding.