TYPE CV & SV
34Pages

TECHNICAL DATA TYPE CV & SV OIL-IMMERSED ON-LOAD TAP CHANGER HM0.154.001 SHANGHAI HUAMING POWER EQUIPMENT CO., LTD.

TYPE CV & SV OIL-IMMERSED ON-LOAD TAP CHANGER TECHNICAL DATA 1. General⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯2 2. Technical specifications⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯2 3. Model explanation ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯4 4. Terms and definitions⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯6 5. Special Design ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯10 6. Motor drive unit ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11 7. OLTC operation controllers ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11 8. OLTC accessories⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯12 9....

1. General CV & SV on-load tap changer (hereinafter referred to as CV or CV OLTC) is a selector switch type of OLTC, CV is applied for oil-immersed regulating transformer. The design of CV contact system is of rolling type dual resistor transition structure. CV is mounted on the top of the transformer tank via head flange, which is divided into two mounting models namely bell-type and standard tank. CV OLTC is operated by motor drive unit through connection with head gear mechanism, driving shaft and bevel gear unit, it could be realized to operate OLTC locally or remotely. Three-phase CV...

Table 1 CV & SV Series OLTC Main Technical Specifications TYPE CV & SV OIL-IMMERSED ON-LOAD TAP CHANGER TECHNICAL DATA The max through current should be decreased to 350A and 300A, when the switching capacity are 525kVA and 420kVA

3. Model explanation 3.1 Designation of the model CV OLTC series specifications depend on number of phase, value of max. rated through current and highest voltage of equipment, as well as connection mode etc., the designation of CV OLTC shows above different parameters, please refer to below code example for details: CV III 350 D / 72.5 the highest voltage for equipment (kV) connection mode: Y for neutral point,D for any connection max. rated through current (A) number of phase: I-single phase, III-3 phases product type Fig.2 CV OLTC Type Explanation 3.2 Basic connections of selector switch...

TYPE CV & SV OIL-IMMERSED ON-LOAD TAP CHANGER TECHNICAL DATA Fig.4 OLTC Basic Connection Diagram

4. Terms and definitions 4.1 Rated through current (Iu), Rated step voltage (Ui) and step capacity (PStN) Fig.5 Curve of Rated Switching Capacity of 3-Phase OLTC TYPE CV & SV OIL-IMMERSED ON-LOAD TAP CHANGER TECHNICAL DATA Fig.6 Curve of Rated Switching Capacity of Single -Phase OLTC Acoording to above curve, the Max. rated through current and relevant step voltage is determined, except limited by switching capacity, the step voltage is also effected by OLTC interior insulation level. Thus summation of OLTC step voltages (UT ) has to meet below conditions: 10-contact pitch: UT=ΣUi≤ 13500V...

4.3. Contact life The main expected contact life of selector switch arcing contacts can be estimated based on the relevant load (Iu/Ium) shown in below Fig. 7. The selector switch arcing contact life also depends on many influencing factors, particularly the condition of switching. Therefore, only average data are given in the figure(not applicable to constant current service condition). n: number of operation Iu: Rated through current Ium: Maximum rated through current Fig.7 Estimated Mean Contact Life Under Average Load Conditions 4.4 Short-circuit current test According to IEC 60214-1:...

TYPE CV & SV OIL-IMMERSED ON-LOAD TAP CHANGER TECHNICAL DATA Table 2 OLTC Interior Insulation Level Note: a: between maximum tap and minimum tap of the same phase b: between any two taps of the different phase c: between the beginning of the coarse tap of different phase d: between the beginning and the end of coarse tap of the same phase f: to ground

The voltage gradient between the terminals of change-over selector and the upper terminals of the selector for the coarse regulation. (refer to Fig.9) Note: Because of the practical arrangement of the change-over selector, the voltage gradient between the terminal "0" of the change-over selector and the upper terminal of the selector corresponds to the insulation distance "a" (same phase) or the insulation distance "b" (phase to phase). The insulation distance between the fine regulation selector and the change-over selector is principally not to be considered. 4.7 OLTC insulation to earth...

5. Special design Potential connection of the tap winding For high voltage or wide regulation range on-load regulating transformer, during the operation of the change-over selector the tap winding is disconnected momentarily from the main winding, the regulating section will be broken away from the main coil and at status of "suspend", thus voltage regulating winding will gain the new potential that depends upon coupling capacities Ce (to ground) and Cw (between adjacent tap winding), refer to Fig.11. Generally this potential is different from the one of voltage regulating winding before...

6. Motor drive unit CV & SV OLTC may operated by SHM-III or CMA9 motor drive unit, it could be also driven by CMA7 motor drive unit according to the requirement. SHM-III motor drive unit is developed by Huaming with many advantages, the mechanism transmission system is installed into SHM-III cabinet, and control system is integrated inside HMK8 which is mounted in control room, thus to ensure the operation reliability. Please refer to table 4 for motor drive unit technical data. Table 4 Motor Drive Unit Technical Data Note: Please specify if special voltage required for motor, and control &...

HMK8 main technical data is as below, refer to HMK8 manual for more details. Working voltage: 380V, 3AC/N Power frequency: 50Hz/60Hz Maximum operation positions: 35 Environment temperature: -10℃ to 40℃ Indoor 7.2 HMC-3C position indicator HMC-3C OLTC position indicator is a support fitting for CMA7 and CMA9 motor drive unit, it can be used to indicate the OLTC position, and has the function of "1→ N", "STOP", "N→ 1" control as well as remote control indicator lamp, its input is decimal code and output is BCD code. Please refer to HMC-3C manual for details. 7.3 Automatic voltage regulator...