1、BRITISH STANDARD BS G174:1959 Invertors forsecondary electrical supplies for aircraft UDC 621.314.58:629.13.066BSG174:1959 This BritishStandard, having been approved by the Aircraft Industry Standards Committee and endorsed by the Chairman ofthe Engineering Divisional Council, was published under th
2、eauthority of the General Council of the Institution on 31March1959 BSI02-2000 The following BSI references relate to the work on this standard: Committee reference ACE/42 Draft for comment CX(ACE)4464 ISBN 0 580 34530 0 Foreword In this BritishStandard the aim has been to provide not only for inver
3、tors for general use on aircraft, but also as far as practicable for those suitable for aircraft applications requiring a more closely controlled output. To this end the performance and test requirements are appropriately differentiated as being for general purposes and for special purpose machines.
4、 They are also differentiated according to the classification of an invertor by the altitude for which it is suited. Owing to the wide variety of uses of aircraft invertors, and because of the need for taking account, in such a general specification, of the penalties of weight and size likely to be
5、involved in achieving a very closely controlled output, some of the performance requirements for special purpose invertors are necessarily a compromise between the needs of applications requiring different degrees of accuracies. The environmental performance requirements of the standard are related
6、to the acceleration, climatic and vibration requirements of the 1952 edition of BSG100. These are currently under review in the light of conditions obtaining on modern high-performance aircraft, but it is believed that the publication of this BritishStandard in its present form will nevertheless ser
7、ve a useful purpose. Its requirements will be reviewed as soon as the impending changes in BS G100 take place. NOTEWhere metric equivalents have been given, the figures in British units are to be regarded as the standard. The metric conversions are approximate. More accurate conversions should be ba
8、sed on the tables in BS350 “Conversion factors and tables.” A British Standard does not purport to include 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
9、legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to19 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 fron
10、t cover. Amendments issued since publication Amd. No. Date CommentsBSG174:1959 BSI 02-2000 i Contents Page Foreword Inside front cover 1 Scope 1 2 Definitions 1 Section 1. General requirements 3 Classes of invertor 1 4 Supply voltage 1 5 Output voltage and frequency 1 6 Voltage balance 1 7 Wave form
11、 of output voltage 1 8 Modulation of output voltage 2 9 Control of voltage and frequency 2 10 Adjustment of voltage and frequency 2 11 Regulation response 3 12 Synchronous impedance 3 13 Protection 3 14 Vibration, acceleration and climatic proofing 3 15 Flameproofness 3 16 General construction 3 Sec
12、tion 2. Particular requirements 17 Arrangement and construction 3 18 Phase sequence 3 19 Suppression of radio interference 4 20 Brushgear 4 21 Starting 4 22 Cooling 4 23 Arrangement and construction of control panels 4 24 Declaration of performance 5 25 Marking 5 Section 3. Tests 26 General 5 27 Pre
13、paration for test 6 28 Resistance test 6 29 Overspeed test 6 30 Control characteristics 6 31 Starting test 6 32 Heating test 6 33 Insulation tests 7 34 Acceleration, vibration and climatic tests 7 35 Water-proofing tests 7 36 Flame-proof test 7 37 High voltage and insulation resistance tests 7 38 Co
14、ld test 8 39 Acceleration, vibration and climatic tests 8 40 Water-proofing tests 8 40 Flame-proof test 8 42 Heating test 8 43 Starting tests 9 44 Regulation test 9BSG174:1959 ii BSI 02-2000 Page 45 Transient response test 9 46 Commutation test 9 47 Wave form and modulation 9 48 Acceleration, vibrat
15、ion and climatic tests 9 49 Endurance tests 10 50 Radio noise test 10 51 Dimensional check for wear 10 52 General 10 53 Preparation for test 10 54 Resistance test 10 55 Overspeed test 10 56 Control characteristics 10 57 Efficiency test 10 58 Insulation tests 10 59 Preliminary run 11 60 Performance c
16、haracteristics 11 61 Insulation tests 11 62 Sampling 11 63 Testing 11 Appendix A Instrumentation for invertor tests 14 Appendix B Test for radio interference 17 Appendix C Water spray box 19 Figure 1 Limits of atmospheric conditions 13 Figure 2 Circuit diagram for wave form analysis of115V400c/s sup
17、ply 15 Figure 3 Circuit diagram for sub-harmonic analysis on115V400c/s supply 16 Figure 4 Line stabilizing network for radio noise measurement 18 Figure 5 Test arrangement for radio noise measurement 19 Table 1 Load conditions 2 Table 2 17BSG174:1959 BSI 02-2000 1 1 Scope This BritishStandard covers
18、 the general design and test procedure for apparatus for deriving alternating current at controlled voltage and frequency from an aircraft d.c. supply. 2 Definitions For the purposes of this BritishStandard the definitions in BS205, “Glossary of electrical terms”, shall apply, except those defined i
19、n the following list: 2.1 invertor a dynamo electric machine and necessarily associated control apparatus for deriving alternating current at a sensibly constant voltage and frequency from a direct current supply 2.2 rating the operating limitations assigned to the invertor by the manufacturer 2.3 r
20、ated output the output at the nominal voltage and nominal frequency declared by the manufacturer. In the case of a three-phase output, the output voltage of the invertor is the average of the three line voltages 2.4 time rating the declared operating time of the invertor at rated output 2.5 type inv
21、ertor an invertor which is representative of others identical in design, construction and rating 2.6 type tests tests to which type invertors are subjected to establish the declared performance of invertors of the same type 2.7 production tests tests to which an invertor identical with a type invert
22、or is subjected in order to ascertain that it is electrically and mechanically sound and in working order 2.8 quality tests tests to which sample invertors are subjected to ensure that the standard of reliability and workmanship is maintained Section 1. General requirements 3 Classes of invertor a)
23、Two classes of invertor are dealt with in this BritishStandard: Class1 Suitable for use up to an altitude of20,000ft (6,100m) or at an equivalent air pressure, Class2 Suitable for use up to whatever altitude is assigned to it by the manufacturer. b) Each class is sub-divided into two groups: Group A
24、 Special purpose, for use where closely controlled output is necessary. Group B General purpose. 4 Supply voltage Unless otherwise required by the individual specification, the invertor shall be capable of operating over an input voltage range of2529volts on a nominal28V d.c. supply, or over a range
25、 of100116volts on a nominal112V d.c. supply. 5 Output voltage and frequency a) Voltage. The nominal output voltage, from the respective input voltages, shall be115V and200V r.m.s. line to line. b) Frequency. The nominal output frequency shall be400c/s. 6 Voltage balance For a three-phase invertor, o
26、n balanced linear non-reactive load, the maximum difference between individual line to line voltages shall not exceed the following values: Group A2per cent of nominal voltage. Group B3per cent of nominal voltage. 7 Wave form of output voltage a) Group A. When the invertor is supplying the loads ind
27、icated in Table 1, the voltage wave at constant frequency shall be such that: i) the mean value of the voltage lies between88.6per cent and91.3per cent of the measured r.m.s. voltage, ii) the divergence of corresponding ordinates from those of the sine wave of the equivalent r.m.s. value does not ex
28、ceed four per cent of the measured r.m.s. voltage, and iii) the r.m.s. value of the total harmonic content does not exceed4per cent of the measured r.m.s. voltage.BSG174:1959 2 BSI 02-2000 b) Group B. At all balanced linear non-reactive loads between15per cent and100per cent of full load the ratio o
29、f peak to r.m.s. value of the voltage shall be within the limits1.41 10per cent, and the individual and total harmonic content shall not exceed the following values: three-phase invertors individual3 1 / 2 per cent, total5per cent. Single-phase invertors individual3 1 / 2 per cent, total7per cent. 8
30、 Modulation of output voltage a) At all balanced linear non-reactive loads between15per cent and100per cent of full load the percentage modulation of the output voltage shall not exceed the values given below when calculated from where a 1and a 2are the maximum and minimum amplitudes of the modulate
31、d wave. These maximum values are: Group A0.15 Group B0.5 b) For Group B machines the manufacturer shall declare the amplitude and frequency of any modulation below100cycles per second. 9 Control of voltage and frequency a) Voltage. At all balanced loads between15per cent and100per cent and at power
32、factors between0.8lag and0.95 lead, each line to line r.m.s. voltage shall be within the following limits: Group A 2per cent of nominal. Group B 3per cent of nominal. For three-phase invertors the manufacturer shall declare the departure from this tolerance when the load is unbalanced to the extent
33、that any one line current differs from the average by1amp or15per cent of the average, whichever is the greater. b) Frequency. At all loads between15per cent and 100per cent and at power factors between0.8lag and 0.95 lead, the frequency shall be within the following limits: Group A 2per cent of nom
34、inal. Group B 5per cent of nominal. 10 Adjustment of voltage and frequency Trimmers shall be provided to allow adjustment of terminal voltage between105per cent and98per cent of nominal, in addition to providing for the correction of voltage and frequency drift throughout the life of the invertor. T
35、able 1 Load conditions a 1 a 2 a 1 a 2 + -100 Number of phases Basic load Auxiliary load Volts Rectifier Resistance Capacitance Inductance 3 Balanced three-phase load at0.8 power factor (lagging) 0.375W kilowatts Three-phase full wave ohms ohms 7W4F 7W4F henry with a d.c. resistance of 33ohms/henry.
36、 henry with a d.c. resistance of 100ohms/henry. 115 200 1 Unity power factor load 0.375W kilowatts Full wave ohms ohms 7W4F 7W4F henry with a d.c. resistance of 13ohms/henry. henry with a d.c. resistance of 43ohms/henry. 115 200 NOTE a) W =rated output of invertor in kilowatts. b) The three componen
37、ts of the auxiliary load are connected in parallel across the output of the rectifier. c) The auxiliary load component values should be within five per cent of the figures quoted. 195 W - 580 W - 1.5 W - 1.5 W - 80 W - 260 W - 1.5 W - 1.5 W -BSG174:1959 BSI 02-2000 3 11 Regulation response a) When r
38、esistive load is switched from100per cent to15per cent, or vice versa, the voltage and frequency shall be restored to within their normal tolerances within0.1 and0.5seconds respectively. b) For Group A machines only, during the first two cycles after such switching, or during starting, the peak valu
39、e of the voltage shall not exceed225per cent of the nominal r.m.s. value, and during the remainder of the surge period it shall be between165per cent and115per cent of the nominal r.m.s. value. c) For Group B machines during such switching, or during starting, the peak value of the voltage shall not
40、 exceed300per cent of the nominal r.m.s. value. 12 Synchronous impedance The synchronous impedance shall not exceed200per cent. 13 Protection Unless otherwise required by the individual specification, means shall be provided for automatic shut-down of the invertor if the output voltage or frequency
41、exceeds125per cent of the nominal values; inherent protection against low voltage or low frequency shall not in general be provided. 14 Vibration, acceleration and climatic proofing The design and construction of the invertor shall be such as to meet the requirements of BS G100 1)in respect of: a) v
42、ibration, to the performance grading declared by the manufacturer; b) acceleration, Grade I; c) climatic test, Grade I or Grade II, as declared by the manufacturer. 15 Flameproofness Where the invertor or any part of it is specified to be flame-proof, it shall comply under any operating conditions w
43、ith the requirements of BS G100 for flame-proof equipment. 16 General construction The invertor shall be sound, suitable for its purpose, and its design and construction shall comply with the relevant requirements of BS G100 1) . Section 2. Particular requirements 17 Arrangement and construction a)
44、There should preferably be no limitation in the performance of the invertor in respect of the attitude in which it may be mounted. Equipment for control of voltage, frequency and wave form may be housed separately and connected to the machine by screened cables. It is preferable that any components
45、for the suppression of radio noise and any requisite starting equipment should be capable of being mounted on the machine. Any separate control apparatus shall be capable of use with any appropriate dynamo electric machine and vice versa. For Group A machines, after initial build-up the output side
46、of the machine shall provide its own excitation. b) The design and construction of the invertor shall be such that it is capable of1,000hours operation before requiring maintenance. c) The invertor shall be capable of operating from a fully insulated system, but provision shall be made by means of a
47、n internal and easily accessible link for earthing the negative terminal on the input side. A gland suitable for screened cable shall be provided for use where a negative lead is an installational requirement. The output winding shall be insulated from the frame of the invertor. d) The input and out
48、put windings shall be on separate armatures and insulated from each other. Where the star point is required to be brought out, it shall be stated in the individual specification. e) Any limitations of the requirements of a) to d) shall be declared. f) Input terminals shall be marked positive and neg
49、ative as appropriate (red and blue where colours are used). Output terminals shall be marked A, B, C or1,2,3 (red, white and blue where colours are used). If a star point is provided it shall be marked “N”. 18 Phase sequence The phase sequence shall be such that the terminal voltages measured from an artificial star point shall reach their maxima in the order A, B, C (red, white and blue respectively). 1) BS G100 “General requirements for electrical equipment an
