Transformer voltage test

Frequency voltage test equipment I. Overview frequency voltage withstand test is the most rigorous, the most effective and most direct method of identifying electrical equipment insulation strength. It can check out those more dangerous concentration of defects, determine the power equipment can continue to participate in the operation has a decisive role, it is to ensure that the equipment insulation level, an important means to avoid the occurrence of insulation accidents. The device is based on the latest national power industry and design, advanced performance of voltage test equipment for a variety of electrical products, electrical components, insulation material insulation strength test specified voltages to assess the product's insulation level found defective insulation products were tested, and measure the voltage over the capacity. Second, the product features monitoring functions: High voltage power low-voltage current zero indicates time counters indicate the operating instructions Protection: overcurrent protection, zero start protection, sound and light alarm to remind the language using the new time relays, timing broader (1S ~ 99H ) using the new current relay, more accurate, more reliable, to ensure personal and equipment safety. Test transformer high voltage winding cylindrical multi-tower, the value of the high-quality polyester enameled wire and high voltage insulation material around the system. Test transformer (5kVA above) is equipped with a movable iron wheel. Light weight, small size, easy to move, superior performance characteristics. Third, the device consisting of 1, selection Configuration Standard configuration □ split operation section: □ Box (less than 5kVA) / □ Desktop Capacity: kVA (less than 200kVA) input: □ AC220V / □ AC380V transformer test: □ AC / □ post DC □ oil change / □ dry change / □ gas transformer capacity: kVA (less than 200kVA) Output: AC kV (less than 300kVA) □ □-one box (no more than 20kV) / □ Desktop (less than 30kV) Capacity: kVA ( less than 300kVA) input: □ AC220V / □ AC380V Output: AC kV (not more than 30kV) matching customers standard high voltage divider □ □ □ protect the ball-gap discharge DC microammeter stick □ □ □ high-pressure water resistance protection filter capacitor 1, Conditions of use: (1) The workplace should not seriously affect the insulation gas, steam, chemical dust and other explosive and corrosive media. (2) Ambient temperature -20 ~ + 50 ℃ (3) Environmental humidity ≤85% RH (no condensation) 2, the control box (Taiwan) parameters General parameters as follows :() Specifications Capacity Input power supply output voltage Weight (kg ) Phase (V) (A) (V) (A) 2/220 2 1 220 10 0-250 8 14 3/220 3 1 220 15 0-250 12 16 5/220 5 1 220 25 0-250 20 18 10/220 10 1 220500-2504080 15/380 152 380 90 34.8 37.5 0-430 20/380 202380500-430 25/380 252 380 46.5 100 58.1 12 030 62.5 0-430 / 380 302380750-430 69.7 140 50/380 5023801250-430 100/380 100 116.2 160 232.5 250 23802500-430 Description: For special parameter requirements, user's technical parameters design. 3, test transformer parameters General parameters as follows :() Specifications Capacity kVA high side and low voltage side of the high pressure side (AC-DC transformer) ratio measured 60 minutes temperature ℃ Impedance Voltage% load current% by mass kg AC output voltage V Current A DC output voltage kV current and voltage kV Current 1.5 / 50 1.5 200 7.5 503 070 21.4 5,005,010 <4 19.5 3/50 320015506070 42.9 5,005,010 <427 5/50 5200255010070 71.4 5005010 <452 10/50 10200505020070 142.9 5,005,010 <480 15/50 15 400 37.5 5,030,070 214.3 500,508 <4120 20/50 20400505040070 285.7 50050 8 <4140 30/50 30400755060070 428.6 500 508 <4155 50/50 5,040,012,550,100,070 714.3 500 508 <4184 10/100 1,020,050,100,100,140 71.4 10005010 < 4135 15/100 15 400 37.5 100 150 140 107.1 1000508 <4150 20/100 2,040,050,100,200,140 142.9 1,000,508 <4215 30/100 3,040,075,100,300,140 214.3 1,000,508 <4250 50/100 50 400,125,100,500,140 357.1 1,000,508 <4290 10/150 1020050100 15005010 47.6 66.7 140 <4180 15/150 15 400 37.5 150 100 210 71.4 1,500,508 <420,020 / 1503040050150 133.3 210 95.2 1,500,508 <4220 30/150 3,040,075,150,200,210 142.9 1,500,508 <4280 50/150 50 400 125 150 333.3 210 238.1 1500508 <4340 Description: If Special parameters required, according to the user's technical parameters design. The weight of the table to test oil-immersed transformer, for example, is slightly different dry-type transformer test and inflatable test transformer. V. wiring and working principle 1, pressure regulator wiring and schematic portion by the control section and the test transformer. The control section is a contact and is controlled by the regulator, protection, measurement, signal circuit. Test transformer winding by the low pressure, high voltage winding, winding instrument consists of three parts. AC and DC test transformer to test transformer equipped with high voltage silicon stack (oil change, air into the built-in, dry becomes external), high-voltage AC and DC output. AC output requires access shorting bar (oil change, air change) or remove the external silicon stack (dry change); output DC, wring out the requirements shorting bar (oil change, air change), or add an external silicon stack (dry change) through the access frequency power to regulate the voltage regulator, high voltage test to obtain the desired value. When the test portion wiring and schematic do pressure test, control section, the ground terminal must be grounded and the high voltage transformer tail. Conditional case, please add frequency voltage withstand test work limiting resistor, standard high voltage divider, ball-gap protection resistor and protect the ball gap, as shown in Figure 3. Please do DC voltage test plus microammeter, microammeter must be connected between the stack and the silicon test, oil change or gas become general high head screwed on top (requires Unscrew shorting bar), dry variable twist In the external silicon stack above; in order to more accurately display high voltage DC leakage current, high-voltage divider set is connected between microammeter and silicon heap. Pressure test current limiting resistor R1 should be based on test transformer rated capacity to choose. A high-pressure side of the rated output current 100 ~ 300mA, the desirability of 0.5 ~ 1Ω / V (test voltage); when the high voltage side rated output current of 1A above, it is desirable 1Ω / V (test voltage). Common water resistance as a current-limiting resistor, tube length can be 150kV / m consider, pipe thickness should have sufficient heat capacity (water resistance liquid preparation methods: adding an appropriate amount of copper sulfate with distilled formulated into a variety of resistance). Ball protection gap and resistance: When the voltage exceeds ball gap setting value (usually take the test voltage of 110% to 120%), ball gap discharge, the protective effect of the test product. Ball gap protection resistors can be 1Ω / V (test voltage) selection. In the power frequency voltage withstand test, the low-voltage side measuring voltage (meter voltage) is not very accurate, which is due to the existence test transformer leakage inductance, leakage inductance on this there must drop or container liter, so test the voltage on the lower or higher than reflected on the low pressure side of the measuring voltage voltmeter. When frequency voltage withstand test, the test voltage is higher than the output voltage test transformer, that is, the so-called phenomenon liter capacity. When sensing pressure test, test transformer leakage inductance there must drop. In order to accurately measure the test voltage is applied, so often in the high-pressure side access standard high voltage divider to measure the voltage. Operation points (1) Before the test, the test voltage should be aware of the test items, while for other products were tested in pilot projects and previous test results. If they are defective or abnormal test should be conducted after the elimination of the pressure test. (2) The test site should be surrounded by good masking or ropes, hang nameplate, and sent people to care. (3) before the test, the test items should wipe clean surface that will be the test case and non-tested winding grounded. The new products were tested when flushing device shall "order," states the oil still some time to boost, for 110kV and below the oil-filled electrical equipment, in filled with oil after standing time should be less than 24 hours, for 220kV and 330kV oil-filled electrical equipment, the standing time should be at least 48 hours. (4) Connect the test connection after examination by experienced personnel before boosted confirmation. (5) prior to boosting, first check whether the regulator at zero. Regulator only boost at zero. (6) step process not only to monitor changes in voltmeter, ammeter should also monitor the changes, and changes in current test items. When boost to even boost, not too fast. When raised to the specified test voltage, counting time after time, slowly and evenly lower voltage. It does not allow the buck on the first jump on the power switch. (7) trial found that the hands swing or test is abnormal sound, smoke, etc. should immediately lower the voltage, the power-supply, after the high-pressure side hung grounding wire, and then pinpoint the cause. (8) should be measured before and after the pressure test is the test of the insulation resistance.