Transition resistance effect on aircraft and spacecraft onboard cable network shielding efficiency

Аuthors

Zhukov P. A.^1*, Marchenko M. V.^1**, Kirillov V. Y.^2***

1. Moscow Experimental Design Bureau “Mars”, 1-st Shemilovsky lane 16, building 2, Moscow, 127473, Russia
2. ,

*e-mail: terran35@mail.ru
**e-mail: m-fallout@yandex.ru
***e-mail: kaf309@mai.ru

Abstract

To ensure the specified shielding efficiency electromagnetic screen should be homogenous to the maximum.

The uniformity of the shield depends on the resistance between the cable shield, the electrical connector and the onboard device case, i. e. transition resistances. High shielding efficiency can be ensured with small values of transition resistances.

The transition resistance is not a constant and can variable significantly during the life cycle of a product. These variations are caused by the effect of various factors: shields and cases bonding and connecting techniques; temperature and environmental conditions; operating conditions.

The results of the experiment that simulating a stay in a tropical climate revealed, that the magnitude of the transition resistance has increased up to 8 mOm, and in some cases it increased from 1 to 26 mOm, which significantly exceeds the standard value.

While temperature fluctuations effect testing, cable connectors subjected to thermal shock by immersion in liquid nitrogen with subsequent heating to 290°C by the stream of hot air. The results of this experiment demonstrate, that the transition resistance of the heated connector increases from 1 to 6 mOm.

In all these experiments, significant changes of transition resistances values in the direction to increase without returning to the initial values were observed. The reason for this consists in the thermal deformation of the parts' shape and contact failure due to the emergence of the oxidized layer.

The results of the shielding effectiveness study show that the magnitude of the transition resistance affects significantly the levels of induced interference voltage at the load, connected to the onboard instrument simulator cable.

Transient resistance value increasing reduces the onboard cables shielding efficiency. Thus, while electromagnetic shields designing, it is necessary to account for in shielding efficiency decrease on exposure to thermal and climatic factors during the life cycle of the product.

Keywords:

shielding efficiency, aircraft and spacecraft onboard cables, transient resistance, electrical connectors, cable life cycle

References

1. Grodnev I.I., Sergeichuk K.Ya. Ekranirovanie apparatury i kabelei svyazi (Shielding of equipment and cables), Moscow, Svyaz'izdat, 1960, 316 p.

2. Kirillov V.Yu., Tomilin M.M. Vestnik Moskovskogo aviatsionnogo instituta, 2011, vol. 18, no. 1, pp. 121-125.

3. Gainutdinov R.R., Chermoshentsev S.F. Izvestiya vysshikh uchebnykh zavedenii. Aviatsionnaya tekhnika, 2016, no. 4, pp. 155-160.

4. Zhegov N.A., Kirillov V.Yu., Klykov A.V., Tomilin M.M. Vestnik Moskovskogo aviatsionnogo instituta, 2015, vol. 22, no. 4, pp. 142-148.

5. Sredstva obespecheniya zashchity izdelii raketnoi i raketno-kosmicheskoi tekhniki ot staticheskogo elektrichestva. Obshchie trebovaniya k metallizatsii i zazemleniyu. GOST 19005-81, 07.01.1982 (Means of ensuring protection of products of rocket and space equipment from static electricity. General requirements to the metallization and earthing. State Standart 19005-81), Moscow, Standarty, 1993, 38 p.

6. Kirillov V.Yu., Marchenko M.V., Tomilin M.M. Elektromagnitnaya sovmestimost' bortovoi kabel'noi seti letatel'nykh apparatov (Electromagnetic compatibility of onboard cable network of the aircraft), Moscow, MAI, 2014, 178 p.

7. Kirillov V.Yu., Marchenko M.V. Tekhnologii elektromagnitnoi sovmestimosti, 2012, no. 1, pp. 10-14.

8. Sovmestimost' tekhnicheskikh sredstv elektromagnitnaya. Ustoichivost' k elektrostaticheskim razryadam. Trebovaniya i metody ispytanii. GOST R 51317.4.2-99, 24.12.1999 (Compatibility of technical equipment. Resistance to electrostatic discharge. Requirements and test methods. State Standart R 51317.4.2-99, 24.12.1999), Moscow, Standarty, 2000, 20 p.

9. D'yakov A.F., Maksimov B.K., Borisov R.K., Kuzhekin I.P., Zhukov A.V. Elektromagnitnaya sovmestimost' v elektroenergetike i elektrotekhnike (Electromagnetic compatibility in power industry and electrical engineering), Moscow, Energoatomizdat, 2003, 768 p.