The substation must go through a comprehensive inspection before it is officially put into operation, and the early inspection and acceptance is an important guarantee for the long-term normal operation of the equipment. In the past, the hexagonal diagram test was carried out after the substation was put into operation, which not only delayed the operation time, but also buried hidden dangers for the safe operation of the primary and secondary equipment of the substation during the test period. Let's take a look at how to perform a hexagonal diagram test, check and check the wiring of the transformer before the substation is put into operation. The inspection work before the substation is put into operation - hexagonal diagram test
Test site:35kV substation in xx city.
Test Equipment:OneYD300B wireless telemetry hexagonal volt-ampere phase meter(referred to as YD300B phase meter), one unitYD-200-W Wireless Telemetry Hexagonal Diagram Voltammetry Phase Meter(referred to as YD-200-W outdoor unit).
Equipment Introduction:
YD300B phase meter is an intelligent multi-functional tester independently developed by Wuhan Halma Electric Power, which is developed according to the secondary test needs of power system substations, especially the secondary analog distribution measurement needs of intelligent substations, and has six basic functions:
Three-phase voltammetry phase meter.
Single-phase volt-ampere phase meter.
PT is a pressurized test, CT, and a through-flow test.
Dual-machine wireless telemetry.
Hexagonal diagram with load measurement.
Hexagonal diagram of pre-commissioning.
Test Method:
1. The ABC incoming line on the high-voltage side of the transformer is connected to the ABC terminal of the YD-200-W outdoor unit, and the ABC on the low-voltage side is short-circuited, and the relevant circuit breaker is disconnected, and the line through the transformer is disconnected from other main lines.
High-side inlet wire termination.
Low-voltage side wiring.
2. The YD300B phase meter is measured in the protective cabinet, and the yellow, green, red and black of the hexagonal diagram test line are connected to the ABC and common end of the CT secondary on the high-voltage side of the transformer, and the blue, white, brown and black are connected to the ABC and the common end of the CT secondary on the low-voltage side.
3. Click "Hexagon Diagram Before Operation" on the main interface of YD300B Phase Analyzer to enter the hexagonal diagram test system interface, and click "Parameter Settings" to set the following settings:
Click "Start Test", the window of whether to carry out automatic test will pop up, in automatic mode, the indoor unit will remotely control the outdoor unit to pressurize the high-voltage side of the transformer once, and automatically measure the secondary voltage at the same time. In manual mode, enter the "Hexagon Diagram Test" through the knob, and then select "AB", "BC", and "AC" to test separately.
The test results of the test in automatic mode are shown in the figure below, the three-phase current of ABC on the low-voltage side lags behind the three-phase current on the high-voltage side by 30° respectively, which is consistent with the expected results, indicating that the wiring from CT on the high-voltage side of the transformer to the terminal strip of the protective cabinet is correct.
It is important to note that the YD300B phase meter is used for traditional substation and smart substation testing when wiring is differentiated.
Conventional Substation Testing:A YD300B phase meter and a YD-200-W outdoor unit are required, and the yellow, green, red and black of the hexagonal diagram test line are connected to the ABC and common end of the CT secondary on the high-voltage side of the transformer respectively, and the blue, white, brown and black are connected to the ABC and common end of the CT secondary on the low-voltage side respectively.
Smart Substation Testing:Two YD300B phase meters and one YD-200-W outdoor unit are required, the YD300B phase meter that measures the CT secondary current on the high voltage side is used as the main control machine, and the YD300B phase analyzer that measures the CT secondary current on the low voltage side is connected to the wire, you only need to click to enter the "Hexagonal Diagram Before Operation" interface, and the YD300B phase meter that measures the CT secondary current on the high voltage side starts the test. The YD300B phase meter hexagonal diagram test line for measuring the CT secondary current on the high-voltage side corresponds to the CT secondary current on the high-voltage side, and the yellow, green, red, and black corresponds to the CT secondary current ABC and the common end on the high-voltage side, respectively. The YD300B phase meter hexagonal diagram test line for measuring the CT secondary current on the low-voltage side is connected to the corresponding CT secondary current ABC and the common terminal on the low-voltage side, respectively.