1、BRITISH STANDARD BS 2G124-2: 1966 Specification for A.C. generators for aircraft Part 2: Variable frequency UDC 629.13.066:621.313.3-8BS2G 124-2:1966 This British Standard, having been approved by the Aerospace Industry Standards Committee and endorsed by the Chairman ofthe Engineering Divisional Co
2、uncil, was published under theauthority of the General Council of the Institution on 30December 1966 BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference ACE/42 Draft for comment 66/7395 ISBN 0 580 34139 9 Amendments issued since publication Amd. No. Date
3、 CommentsBS2G 124-2:1966 BSI 04-2000 i Contents Page Foreword ii 1 Scope 1 Section 1. General requirements 2 General construction 1 3 Cooling arrangements 1 4 Mounting and drive 1 5 Terminal arrangement 1 Section 2. Particular requirements 6 Voltage, frequency, phases and waveform 1 7 Rating and ove
4、rload requirements 1 8 Efficiency 1 9 Excitation 1 10 Overspeed 1 11 Vibration, acceleration, climatic proofing, radio interference and compass interference 2 12 Declaration of performance 2 13 Nameplate 2 Section 3. Tests 14 General 2 15 Weight moment of inertia and centre of gravity 2 16 Initial c
5、heck 2 17 Open-circuit characteristic and losses 2 18 Short-circuit characteristic and losses 3 19 Voltage balance 3 20 Temperature tests 3 21 Insulation tests 3 22 Overspeed tests 3 23 Wave form 3 24 Determination of reactances and time constants 4 25 Containment test 4 26 Endurance and overload te
6、st 4 27 Radio interference test 4 28 Altitude test 4 29 Vibartion test 5 30 Acceleration test 5 31 Climatic tests 5 32 Compass interference test 5 33 Resistance of windings 5 34 Overspeed test 5 35 Open-circuit characteristic 5 36 Phase sequence and voltage balance 5 37 Short-circuit characteristic
7、5 38 Heat test 6 39 Insulation tests 6 40 Sampling 6 41 Testing 6BS2G 124-2:1966 ii BSI 04-2000 Foreword This standard has been prepared as part of a programme of work to bring the aircraft series British Standards for rotating machines up to date in relation to present-day and probable future requi
8、rements, and to experience gained in working to earlier issues of the standards. The standard is published in two parts, Part 1 dealing with constant frequency generators, being a revision of BS G 124:1950, and Part 2 with variable frequency machines. Reference is made in the standard to the followi
9、ng: BS 2G100, General requirements for electrical equipment and indicating instruments for aircraft. BS G102, General requirements for rotating electrical machines for aircraft 1) . BS , Methods of test for determining synchronous machine quantities 1) . A British Standard does not purport to includ
10、e all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i
11、 and ii, pages1 to 6 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In course of preparation.BS2G 124-2:1966 BSI 04-2000 1 1 Scope This part of BS G 124 specif
12、ies the general design and test procedure for generators for aircraft variable frequency a.c. power supply. It is intended to be read in conjunction with BS 2G 100 and BSG102. 2) Section 1. General requirements 2 General construction Unless otherwise stated, the design and construction of the machin
13、e shall comply with the relevant requirements of BS 2G 100 and BS G 102. 2) The design aim should be to achieve 3 000 (aircraft) hours operation of the machine before requiring maintenance. 3 Cooling arrangements a) The manufacturer and purchaser shall agree upon the cooling arrangements to be provi
14、ded for the machine. b) Cooling connections shall comply with the requirements of BS G 102. 2) 4 Mounting and drive The mounting and drive of the machine shall comply with the requirements of BS G 102. 2) 5 Terminal arrangement The machine terminals shall comply with the requirements of BS 2G 100-1,
15、 and of BS G 102. 2) Section 2. Particular requirements 6 Voltage, frequency, phases and waveform a) The full load voltage of the machine shall be120/208 volts for a nominal 115/200 volt a.c. system and the rated line current shall relate to rated kVA at the rated system volts. b) The voltage and it
16、s waveform, frequency, number and sequence of phases of the machineshall comply with the requirements ofBS 2G 100-3. 3) 7 Rating and overload requirements a) Unless otherwise stated, the machine shall be capable of providing rated output continuously over the whole speed range. b) The manufacturer s
17、hall declare the cooling requirements in the form of rating charts in accordance with BS G 102. 2) c) With the frequency maintained at 400 Hz following rated load operation at steady temperature conditions at the speed giving an output frequency of 400 Hz the machine shall: i) Maintain rated voltage
18、 for two minutes at150 per cent rated current and minimum ratedpower factor. ii) Withstand 200 per cent rated current for five seconds at minimum rated power factor. When agreed between the manufacturer and purchaser, the output voltage of the machine may fall to not less than90 per cent of rated vo
19、ltage. iii) Produce a symmetrical three-phase short-circuit current of at least300 per cent rated current. 8 Efficiency The manufacturer shall declare the power required to drive the machine at rated voltage, current, power factor at maximum, and minimum speeds, and at a speed for 400Hz. 9 Excitatio
20、n The excitation system shall be independent of any external electrical supply, and shall be capable of initial build-up without reference to any other supply. Supplement excitation may be employed by agreement between the manufacturer and purchaser. 10 Overspeed Consideration should be given to the
21、 highest speed at which the generator could be driven, in the applications for which it is intended, if all overspeed protection devices fail. If this speed is more than125per cent of the maximum rated speed, the machine shall be designed either to withstand the highest speed, or to fail at a lower
22、speed and to contain all its parts within the machine frame after failure. The containment requirements and the necessary proving tests shall be agreed between the manufacturer and the user. 2) In course of preparation. 3) BS 2G100-3:1960 is being revised to include requirements for variable frequen
23、cy a.c. systems.BS2G 124-2:1966 2 BSI 04-2000 11 Vibration, acceleration, climatic proofing, radio interference and compass interference The machine shall comply with the requirements of BS 2G 100-2 in respect of: 12 Declaration of performance In addition to the declarations required by BS2G100, the
24、 following information shall be provided by the manufacturer in regard to the machine: a) Continuous rated output under declared conditions of altitude and cooling. b) Cooling requirements for conditions other than those declared in a). c) Power required to drive the machine under the conditions spe
25、cified in Clause8. d) Method of measurement of temperature rise. 13 Nameplate a) A nameplate and a modification plate, which shall bear the serial number, shall be mounted on the body of the machine. b) The following information shall be marked on the nameplate: i) The number of this British Standar
26、d. ii) The manufacturers name or identification. iii) Serial number. iv) Type (or part) number. v) Rated kVA. vi) Rated power factor. vii) Frequency range. viii) Speed range. ix) Rated voltage. x) Phases. xi) Direction of rotation. xii) Stores reference number, when applicable. c) The modification p
27、late shall provide for ten modification references. Section 3. Tests 14 General a) Tests shall be made to prove compliance with all requirements of this British Standard. The tests required are as follows: the results obtained shall be recorded: Type tests. (Clauses15 to32) to be made on each partic
28、ular design of machine. Production routine tests. (Clauses33 to39) to be made on every machine manufactured to this British Standard. Production quality tests. (Clauses40 and41) to be made on batch sample or samples. b) More than one machine may be used for the type tests, provided that the tests pr
29、escribed in Clauses16, 17, 18, 19 d), 20, 21, and22 shall be performed on one machine. Every machine used for type test purposes shall previously have passed tests equivalent to the production routine tests. c) Unless otherwise specified, the tests shall be made at a temperature of 20 5 C, any depar
30、ture from this temperature being recorded. The manufacturer shall declare the method of measurement of temperature rise. Type tests 15 Weight moment of inertia and centre of gravity The weight of the machine, the moment of inertia of the rotor, and the distance of the centre of gravity from the moun
31、ting flange shall be determined. 16 Initial check The winding resistance shall be measured and corrected to a temperature of + 20 C. The brushes,if fitted, shall be bedded over the full arc for at least 80 per cent of their axial width and the brush spring pressures shall be measured. 17 Open-circui
32、t characteristic and losses a) The open-circuit characteristic and losses shall be determined at minimum and maximum speeds and at a speed for 400Hz, up to 130per cent rated voltage. b) The phase sequence shall be checked. a) Vibration to the performance grading declared by the manufacturer. b) Acce
33、leration c) Climatic d) Radio interference. e) Compass safe distance. BS2G 124-2:1966 BSI 04-2000 3 18 Short-circuit characteristic and losses The short-circuit characteristic and losses shall be determined at minimum and maximum speeds, and at a speed for400Hz, up to150per cent rated current. Excit
34、ation readings shall also be taken at200per cent and300per cent rated current. 19 Voltage balance The machine shall be run at a speed for400Hz rated voltage and load, and in addition under unbalanced loading to give line currents of approximately90, 100and110 per cent of the rated line current. Term
35、inal voltages shall be measured and shall comply with the requirements of BS 2G 100-3. 20 Temperature tests a) A test shall be performed under sea-level conditions at rated power factor, 400Hz, rated load, and at an ambient temperature of20 5 C, during which the coolant mass flow to the machine shal
36、l correspond to the value declared under Clause7. The run shall be continued for a period of one hour after steady temperature conditions have been reached. b) For the purpose of standardizing a test for production machines a further heat test shall beperformed under the same conditions as for a), e
37、xcept that the output terminals shall be short-circuited and the excitation adjusted to give rated output current. The coolant flow shall be the same as for a). The duration of the run shall be one hour. c) A series of tests shall be performed to enable the presentation of rating data charts over th
38、e whole speed range as required by Clause7. d) During the tests, records shall be kept of the following: i) Output: volts, amps and watts. ii) Excitation: volts and amps. iii) Mass flow rate, inlet and outlet temperatures and inlet and outlet pressures of coolant. iv) All other relevant temperatures
39、, including the ambient temperature and the temperature rise of the output winding measured by change of resistance. 21 Insulation tests Whilst still hot from the test in Clause 20 b) the machine shall be subjected to insulation tests in accordance with BS 2G 100-2, windings for less than100 volts b
40、eing also subjected to a voltage of500 volts a.c. r.m.s. The conditions applied shall be recorded. 22 Overspeed tests Immediately after the test in Clause21 and while still hot, the machine shall be run unexcited for three minutes at125 per cent of its maximum rated speed or at such higher speed as
41、may be agreed with the manufacturer (see Clause10). The machine shall be stripped and examined, and there shall be no signs of movement of the rotor parts, nor damage to the stator or rotor. The balance of the rotor shall also be checked for compliance with the requirements of BSG 102. 4) 23 Wave fo
42、rm Line voltage and phase voltage wave forms on rated load and quarter load at minimum and maximum speeds, and at a speed for 400Hz, shall be recorded by an oscillograph or other approved means. The wave forms of the voltages shall be analysedand shall comply with the requirements ofBS 2G 100-3 for
43、linear loads. 4) In course of preparation.BS2G 124-2:1966 4 BSI 04-2000 24 Determination of reactances and time constants The following parameters shall be determined by the methods described in BS. 5) , “Methods of test for determining synchronous machine quantities”, assuming rated frequency to be
44、 400 Hz: NOTE 1The tests in BS. have been prepared for conventional slip-ring machines and are not necessarily applicable without modification to machines having different forms of construction, for example, brushless machines. NOTE 2It is important that the contactor used to make the three-phase sh
45、ort circuit, when determining transient and subtransient reactances and time constants, be made to close all three contacts within 10 electrical. 25 Containment test The machine shall be subjected to a test to ensure that it complies with the requirements for containment specified in Clause10. 26 En
46、durance and overload test a) As applicable and practicable, parts liable to wear shall be dimensionally checked against the relevant drawings, the temperature being recorded. b) No maintenance or adjustments of any kind shall be performed on the machine in the course of this test, except that, if ne
47、cessary, new brushes may be fitted. The time taken to bed new brushes shall not constitute a part of the test, and a record shall be kept of wear of the brushes. c) The machine shall be run under rated cooling conditions for 1 000 hours in cycles of10 to20 hours duration, with sufficient shut-down t
48、ime between cycles to allow the machine to cool to room temperature. For the first100 hours of thetest the machine shall be run at rated load and 90per cent maximum speed, except that during the last cycle, and not less than five hours before the end of the last cycle, an over-load test shall be mad
49、e under the conditions specified in Clause7 c) i). At the end of the cycle, the machine shall be tested for compliance with Clause7 c) ii). For the remainder of the test the load may be reduced to 75per cent rated load. d) At the conclusion of the test insulation resistance shall be measured with the machine hot, and if it is less than 2 megohms, the machine shall be cleaned, without replacement of any parts, after which theinsulation resistance shall not be lessthan2 megohms. Failure to attain this value shall be investigated and a record made of any action
