Breakdown Voltage SF6 Versus CF3CHCl2 Gas as Alternative for Gas Insulation Applied

Sulfur Hexafluoride Gas is a filling gas in Gas Insulated Switchgear equipment whose existence starts to be limited and reduced in accordance with amendments to the Kyoto Protocol. The utilization of new gas included in the list of recommendations for the Kyoto Protocol enters the implementation and application phases. Dichlorotriflouroethane gas has equivalent capability even better than SF6 gas so it is feasible to be recommended as a potential gas for SF6 gas replacement. Experimental HV testing showed the gas capability to withstand breakdown voltage reaching 837 kV and had a technoeconomic value 0.2 times cheaper than SF6 gas. In the future CF3CHCl2 gas is very feasible and can be recommended as an environmentally friendly gas and is feasible as a potential alternative gas substitute for circuit breaker equipment in substation equipment that uses gas as a substitute for SF6 gas. Keyword SF6, Gas Insulated Switchgear, Protocol Kyoto, Techno-economic

Breakdown mechanism of different sulphur hexafluoride gas mixtures.
Onal, E. 2018 In Table II, there was much research that supports the Kyoto protocol but still used old SF 6 gas as the main medium to fill GIS, while to support the Kyoto Protocol program they used mixed gas as an active measure in reducing the amount of use of SF 6 . The use of CF 3 CHCl 2 gas as the main medium for substituting SF 6 gas is a pure effort to replace the total gas used in GIS equipment.

II. SPECIFICATION AND CHARACTERISTICS CF 3 CHCL 2
The Kyoto Protocol recommended the utilization of one gas from the HCFC (Hydro Chloro Floro Carbons) family was CF 3 CHCl 2 (Dichlorotriflouroethane) gas could be seen in Table I. The selection of Dichlorotriflouroethane gas was because it had the specifications, characteristics and capabilities such as SF 6 gas. The four requirements were recommended by the Protocol as alternative gases could be met by Dichlorotriflouroethane gas. In addition to the four conditions that must be met by gas as a substitute for alternative gas, a more important requirement was the availability of gas in the market. The ease of gas procurement was very important so that market surveys were needed to see gas availability. Dichlorotriflouroethane gas had elements VII-A (Halogen group) in its constituent chemical compounds, namely elements F (Flor) and Cl (Clor). The VIIA element was known to have electronegativity in its chemical structure elements. The elements were needed in the process of electric arc outages. We could see the capabilities and properties of Dichlorotriflouroethane gas in the discussion below.

A. High Voltage (HV) Tests for CF 3 CHCl 2
A breakdown voltage test was to obtain a real value of Dichlorotriflouroethane gas if given voltage. Gas testing was carried out in a high voltage laboratory with equipment and set up of equipment as follows: 1. Prepare the test equipment was shown in Fig. 1 Figure 1 showed the S1 and S2 automatically switches, AT Autotrafo, V Voltmeter, Rp Bump Resistor, Thermo-controlled, P Pressure (Bar), B Chamber Gas using feeder and outfeeder gas. 3. Preparing the chamber gas was by making a vacuum. 4. Test the CF 3 CHCl 2 gas in the chamber was by adjusting the pressure (P), and the electrode gap (d) in the chamber. 5. Gives a voltage to the gas in space gradually from 0 kV was to increase until a breakdown occurs. The output voltage of the gas in the chamber was 2 kV/s. The breakdown voltage in gas using Paschen law was an equation that provides breakdown voltage that was the voltage needed to start an electric arc between two electrodes in a gas as a function of pressure and gap [21] - [24].

B. Electronegativity in CF 3 CHCl 2
Electronegativity was a number that showed the ability of an atom in a molecule to pull electrons into the atomic structure. The greater the electronegativity value of a compound was the greater the ability of the gas to extinguish the electric arc. Electronegativity was the affinity of an atom to attract electrons in a bond. Electronegativity affects polar pole formation in a chemical compound [22]- [25]. SF 6 gas and CF 3 CHCl 2 gas had Halogen group elements which were groups of elements that had the greatest electronegativity value. Chemical elements found in SF 6 gas and CF 3 CHCl 2 gas were elements F (Flor), Cl (Clor). Electronegativity values of the VIIA group were Flor 3.98, Clor 3.16, Brom 2.96, Iod 2.66, Astantin 2.2. We used the following equation to find the electronegativity value of a compound (6).
The electronegativity difference between two atoms A and B could be calculated by: Dissociation Energy (Ed) A -B, A -A and B-B was expressed in electron volts. Factor (eV) ½ was inserted to produce dimensionless values. Ed AB Ed AA Ed BB 2 (6)

C. Kyoto Protocol in CF3CHCl2
The Kyoto Protocol was an amendment to the United Nations Framework Convention on Climate Change, an international agreement on global warming. The results of the Kyoto Protocol Convention recommend replacement gas that was more environmentally friendly according to Table I. In addition to recommending a list of gases that were more environmentally friendly, the amendments also recommend the value of Global Warming Potential, Ozone Depleting potential and atmosphere live-time. The three conditions above were the conditions that must be owned by a replacement gas.
The gas value used a value base: 1. Global Warming Potential (GWP) was an index system that compares the potential of a greenhouse gas to heat the earth, compared to the potential of carbon dioxide [26]. The GWP value could be obtained by the equation (7): TH 0 a r t dt (7) RFi = Radiative forcing (RF) for element i, RFr = Radiative forcing the reference gas (CO 2 ), TH = the time horizon, Ci = the time-dependent abundance of the element i, ai = the RF per unit mass increased in atmospheric abundance of component i (radiative efficiency), ar = the RF per unit mass increased in atmospheric abundance of reference component. 2. Ozone Depleting Potential (ODP) was a relative measure of the ozone layer degradation caused by a compound. ODP was the comparative value of ozone layer degradation of a compound in certain mass units of CFC-11 with the same mass [27]. Calculate the ODP value with the equation (8) as follows: ODP Global ∆O 3 due to substance i Global ∆O 3 due to CFC 11 (8) 3. Atmosphere Live-time (ALT) was the average time that a molecule resided in the atmosphere before it was removed by the chemical reaction or deposition reaction [28], [29]. This could also be thought of as the time that it took after the environment had returned to natural levels. Greenhouse gas live-times could range from a few years to a few thousand years. ALT values could be obtained by equation (9) ALT mass removal rate m F out L D (9) m = mass (kg), F out = Flow of substance x out the box (kg/year), L = loss of substance x (kg/year), D = deposition of substance x (kg/year) D. Techno-Economic SF 6 Versus CF 3 CHCl 2 The use of new gas as a substitute for SF6 gas could not be separated from the economic value considered by the market to accept CF 3 CHCl 2 gas as a new medium for SF 6 gas substitution [30], [31]. Economic values that form the basis of consideration were: 1.The price of providing replacement gas materials. 2.Price/transportation costs from producers to consumers. 3.Availability/ease of material on the market. 4. Reliability of new gas.
One of the main components of techno-economic values were procurement costs, availability of material in the market and reliability of gas replacement. The factor of procurement of gas materials was very vital because it involved 40% of the costs incurred by consumers. Prices were based on prevailing market price standards. The benchmark gas market price could be shown in Table III.  The benchmark for gas procurement prices could be seen in Table III, which was a benchmark price for some gas in the territory of the Republic of Indonesia. Table IV.

Results of HV Tests were shown in
The results of data collection during the test 5 times obtained the average value of the voltage disturbance CF 3 CHCl 2 in Table IV  3. Testing by changing the temperature in the room did not show a significant change. Testing by changing/affecting the chamber temperature could be ignored because it did not show significant changes, Comparison of testing experimental and theoretical details emphasizes according to Paschen's law with equations (1) -(5) was shown in Table V.  [34]. If both gases (SF 6 and CF 3 CHCl 2 ) were inserted into the chamber on GIS equipment with a 7 Bar gas pressure then the breakdown voltage for SF 6 gas was 630 kV and the breakdown voltage for CF 3 CHCl 2 gas was 837 kV. Both gases were able to withstand breakdown voltages above 500 kV. Because it was able to withstand breakdown voltage above 500 kV, CF 3 CHCl 2 gas was very potential to be used as a substitute for SF 6 gas. 2. The electronegativity value obtained from equation (6) is that SF 6 gas had an electronegativity value of 3.98 while the CF 3 CHCl 2 gas had an electronegativity value of 7.14. The greater the electronegativity value of the material, the faster the material in the process of electric arc outages when switching on GIS equipment. The CF 3 CHCl 2 gas had the ability to reduce fire arcs 1.7 times compared to SF 6 gas. 3. The values of GWP, ODP, and Alt that were owned by SF 6 gas and CF 3 CHCl 2 gas were: a. The GWP value of two gases according to equation (7) was that SF 6 gas had a value of 23900 times that of CO 2 gas, while the GWP value of CF 3 CHCl 2 gas had a value of 23 times CO 2 gas. b. The ODP value of two gases according to equation (8) was that SF 6 gas has a value of 0.08 times that of CO 2 gas, while the ODP value of CF 3 CHCl 2 gas had a value of 0.016 times the gas from CO 2 gas. c. The Alt value of two gases according to equation (9) was that SF 6 gas had an Alt value of 3200 years while CF 3 CHCl 2 gas had an Alt value of 1.5 years. 4. For GIS tubes with 7 Bar pressure on substation equipment, 210 kg of gas was needed. Based on Table III, which was the price of gas in Indonesian currency, namely rupiah (IDR), the gas procurement price for SF 6 gas was 326,508,000 IDR, while the cost required to obtain CF 3 CHCl 2 gas was Rp. 63,000,000. The cost required to obtain gas for an operating voltage of 500 kV, CF 3 CHCl 2 gas was 0.2 times cheaper than SF 6 gas IV. CONCLUSION The CF 3 CHCl 2 gas is very feasible to be recommended as a new alternative gas to replace SF 6 gas for GIS equipment in substations.
The CF 3 CHCl 2 gas is very suitable to be used as a new alternative to replace SF 6 gas because it has the ability to withstand a breakdown voltage above 500 kV and has a better breakdown voltage than SF 6 gas, which is able to withstand breakage voltage of 1.3 times greater than SF 6 gas.
The CF 3 CHCl 2 gas has capabilities that are more environmentally friendly than SF 6 gas and in accordance with the requirements of the Kyoto protocol convention for environmentally friendly values which include the value of the Global Warming Potential, the Ozone Depleting Potential value and the live-time Atmosphere value. The overall value of CF 3 CHCl 2 gas has a better value than the value of SF 6 gas.
The techno-economic value in terms of procurement of goods shows that the procurement price of CF 3 CHCl 2 gas reaches IDR 63,000,000 is cheaper than compared to the procurement of SF 6 gas which reaches IDR 326,508,000.
In the future, CF 3 CHCl 2 gas is very potential, it is recommended for alternative replacements in GIS equipment and has the values needed as a requirement for gas insulation, fire arc extinguisher, ability to withstand penetrating stresses and values required as environmentally friendly gas compared to SF 6 gas.