A multifunctional automated test system and method for dry-type transformers

Abstract

The present invention relates to the field of dry-type transformer detection equipment, and specifically, to a multifunctional automatic test system and method for dry-type transformers, which includes a tester module, an industrial computer, a PLC controller, and a switching switch. The tester module is connected to the PLC industrial computer, and the industrial computer is electrically connected to the PLC controller; the tester module is used to collect electrical signals, the industrial computer is used to control the tester module to test and read the test result data, and the PLC controller is used to control the on and off of the switching switch. The present invention can connect a DC resistance tester, a voltage ratio tester, an insulation resistance tester, and a transformer characteristic tester to the high and low voltage terminals of the transformer respectively according to different experimental projects, and realize the required test wiring through the on and off control of the switching switch, thereby eliminating the need to frequently disassemble the transformer winding terminals and the wiring between the instruments, improving the test efficiency, and reducing the labor intensity of the operator.

Description

Technical Field

[0001] The invention relates to the field of dry-type transformer detection equipment, and in particular to a multifunctional automatic test system and method for dry-type transformers. Background Art

[0002] With the rapid economic growth, various electrical equipment are constantly being developed and applied to various occasions. Among them, dry-type transformers have become essential key equipment and are widely used in many occasions, such as airports, hospitals or shopping malls, where a large amount of power is required. Compared with oil-immersed transformers, dry-type transformers are transformers whose cores and high-voltage coils are not immersed in insulating liquids. They are generally used for local lighting and electronic circuits.

[0003] Before using a dry-type transformer, it is necessary to test its DC resistance, voltage ratio and insulation resistance. Currently, the most common testing method is manual testing, which requires manual connection of instruments such as DC resistance testers, voltage ratio testers and insulation resistance testers to the dry-type transformer. During the test, the transformer winding terminals and the side wiring between the instruments need to be frequently disassembled, resulting in poor detection efficiency. Summary of the invention

[0004] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0005] A multifunctional automatic test system for dry-type transformers comprises a tester module, an industrial computer, a PLC controller and a switching switch, wherein the switching switch comprises a switch QK1, contactor switches KM1~KM3 and KM19~KM20, and a three-phase switch KM7~KM18; the tester module is connected to the industrial computer, and the industrial computer is electrically connected to the PLC controller; the tester module comprises a DC resistance tester, a ratio group tester, an insulation resistance tester and a transformer loss parameter tester; the tester module is used to collect electrical signals, the industrial computer is used to control the tester module to test and read test result data, and the PLC controller is used to control the on and off of the switching switch.

[0006] The multifunctional automatic test system for dry-type transformers in the present invention can connect a DC resistance tester, a voltage ratio tester, an insulation resistance tester and a transformer characteristic tester to the high and low voltage terminals of the transformer respectively according to different experimental projects, and realize the required test wiring by switching the on-off control of the switch, thereby avoiding the frequent disassembly of the transformer winding terminals and the side wiring between the instruments, improving the test efficiency and reducing the labor intensity of the operators.

[0007] As a preferred embodiment of the present invention, the above-mentioned experimental system also includes a voltage regulating control module electrically connected to an industrial computer, the voltage regulating control module is electrically connected to a step-up transformer, and the step-up transformer is electrically connected to the tested transformer; the industrial computer is used to control the PLC controller and the voltage regulating control module to control the switching switch and the step-up transformer.

[0008] As a preferred embodiment of the present invention, the above-mentioned experimental system also includes a buck-boost voltage regulator and three single-phase current transformers CT1~CT3. The three single-phase current transformers are respectively connected to the high and low voltage windings of the tested transformer through contactor switches KM1 and KM2; the external three-phase power supply is connected to the experimental system through the buck-boost voltage regulator, and the three single-phase current transformers are used to collect line current.

[0009] As a preferred solution of the present invention, the insulation resistance tester is connected to the transformer winding terminal through another test cable, and the DC resistance tester is connected to the transformer winding terminal through the three-phase switch KM7~KM19.

[0010] As a preferred solution of the present invention, the transformation ratio tester is connected to the experimental system through six terminals of the high and low voltage windings.

[0011] As a preferred solution of the present invention, the switching switch further includes a switch QK1, and the switch QK1 is used to control the access of an external three-phase power supply.

[0012] The present invention also provides an experimental method based on the above-mentioned multifunctional automatic test system for dry-type transformers, which comprises the following steps:

[0013] Step 1: Connect the tester module, industrial computer, PLC controller and switch to the transformer under test;

[0014] Step 2: Connect the external three-phase power supply to the experimental system;

[0015] Step 3: Control the on and off of the switch through the industrial computer and PLC controller; then perform the test, and send the test data to the industrial computer;

[0016] Step 4: Industrial computer records test data and generates reports.

[0017] Through the above method, the required test wiring can be achieved by switching the on-off control of the switch, eliminating the need to frequently disassemble the transformer winding terminals and the wiring between the instruments, thereby improving the test efficiency and reducing the labor intensity of the operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a hardware architecture diagram of the multifunctional automated test system for dry-type transformers in Example 1.

[0019] Figure 2 This is a schematic diagram of the device connection in the multifunctional automated test system for dry-type transformers in Example 1.

[0020] Figure 3 This is a system schematic diagram of the multifunctional automated test system for dry-type transformers in Example 1.

[0021] Figure 4 This is the software system architecture of the multifunctional automatic test system for dry-type transformers in Example 1.

[0022] Figure 5 This is a schematic diagram of the interface of the dual-channel DC resistance tester in Example 1.

[0023] Figure 6 This is a schematic diagram of the interface of the transformation ratio tester in Example 1. DETAILED DESCRIPTION

[0024] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0025] Example 1

[0026] Combination Figure 1 As shown, this embodiment provides a multifunctional automated test system for dry-type transformers, which includes a tester module, an industrial computer, a PLC controller and a switching switch, the switching switch includes a switch QK1, contactor switches KM1~KM3 and KM19~KM20, and a three-phase switch KM7~KM18. The tester module is connected to the industrial computer, and the industrial computer is electrically connected to the PLC controller; the tester module includes a DC resistance tester, a ratio group tester, an insulation resistance tester and a transformer loss parameter tester; the tester module is used to collect electrical signals, the industrial computer is used to control the tester module to test and read the test result data, and the PLC controller is used to control the on and off of the switching switch.

[0027] The industrial computer carries the system software to realize the control function of the whole system. The industrial computer is directly connected with various measuring instruments in various tester modules. Through the RS232 interface, the instrument test is controlled and the test result data is read. The industrial computer is connected with the PLC controller through the TCP / IP network. According to the test items, the PLC controller controls the on and off of each switch to achieve the purpose of automatic wiring switching.

[0028] Combination Figure 2As shown, it also includes a voltage regulating control module electrically connected to the industrial computer, the voltage regulating control module is electrically connected to the step-up transformer, and the step-up transformer is electrically connected to the tested transformer; the industrial computer is used to control the PLC controller and the voltage regulating control module to control the switching switch and the step-up transformer. The data of each test instrument is summarized to the industrial computer, and the industrial computer processes it uniformly.

[0029] Combination Figure 3 As shown, the system also includes a step-up / down voltage regulator and three single-phase current transformers. The external three-phase power supply is connected to the experimental system through the step-up / down voltage regulator. The three single-phase current transformers are used to collect line current. The single-phase current transformers are connected to the high and low voltage windings of the tested transformer through two contactor switches KM1 and KM2. The three-phase voltage and current signals are input into the transformer loss parameter tester to calculate the no-load loss; the three-phase voltage and current signals are input into the transformer loss parameter tester; the three single-phase current transformers are connected to the high and low voltage windings of the tested transformer through the two contactor switches KM1 and KM2 in the switching switch. The insulation resistance tester is connected to the transformer winding terminal through another test cable, and the DC resistance tester is connected to the transformer winding terminal through 8 groups of three-phase switches (three-phase switches KM7~KM19) in the switching switch to complete the test.

[0030] The software system architecture of the system is as follows Figure 4 As shown, it includes a user interface layer, a test data layer, a test logic layer and a driver layer. The entire software realizes the test process control, test data recording and report generation of the device.

[0031] Combination Figure 3 As shown, the dry-type transformer comprehensive test system provides a stable three-phase voltage input through an external power supply, and controls the external power supply access through switch QK1. The device collects the current signal on the power supply side through current transformers CT1~3, and collects the voltage signal on the power supply side through the sampling voltage branch. Contactor switches KM1~20 are used to control each branch, and realize the wiring of different test items through a certain opening and closing combination.

[0032] DC resistance test process

[0033] The DC resistance tester is the main test instrument and does not require additional power input or additional electrical quantity collection. At this time, only KM2 needs to be switched on, and then the corresponding switches of the DC resistance tester need to be switched on. On the low-voltage side, KM7 and KM11, KM8 and KM12, KM9 and KM10 are switched on in sequence, and on the high-voltage side, KM13 and KM17, KM14 and KM18, KM15 and KM16 are switched on in sequence, and the resistance of ab, bc, ca, AB, BC, and CA lines can be measured respectively. Automatic line switching and measurement can be achieved by switching the switches with an industrial computer.

[0034] The performance parameter requirements of the DC resistance tester are as follows:

[0035]

[0036] At the beginning of the test, you must first check the items to be tested, and then set the corresponding parameters in the test parameters. The specific parameter setting range needs to be determined manually based on the capacity and parameters of the test product. The current range selection should not exceed 10% of the rated current, and the test resistance value should be less than 60% of the test current range.

[0037] After selecting the test items and setting the test parameters, select the test according to the current tap position of the test transformer: select the tap position number; click the test button, the system will automatically perform the corresponding test and pop up the test status information window; after the current high-voltage side tap position test is completed, the test data will be automatically displayed in the corresponding table, and the data will be calculated and judged accordingly. When testing the first set of high-voltage tap positions, the system will automatically perform the resistance position test on the low-voltage side, and will no longer test the resistance on the low-voltage side in the next tap position test. After the tap resistance test is completed, the system will automatically test the transformation ratio of the current tap position.

[0038] After the first set of tapping gears are tested, the tester needs to manually change the transformer tapping gear, then click the changed tapping gear with the mouse, and click the test button to measure the next tapping gear. Similarly, after all tapping gears are tested, the DC resistance and transformation ratio test is completed. The interface diagram of the dual-channel DC resistance tester is as follows: Figure 5 shown.

[0039] Ratio tester usage process

[0040] The ratio tester is the main test instrument and does not require additional power input or additional electrical quantity collection. At this time, keep KM2, K19 and K20 in operation to achieve correct wiring. The ratio tester can be controlled by an industrial computer to achieve ratio measurement. The interface diagram of the ratio tester is as follows Figure 6 shown.

[0041] The performance parameter requirements of the ratio tester are as follows:

[0042]

[0043] Insulation resistance measurement

[0044] The insulation resistance tester is the main test instrument and does not require additional power input or additional electrical quantity collection. To ensure the measurement effect, the original wiring of the transformer needs to be removed and the transformer needs to be rewired according to the insulation resistance test technical requirements. After the wiring is completed, the industrial computer can complete the automatic measurement.

[0045] The performance parameter requirements of the insulation resistance tester are as follows:

[0046]

[0047] Insulation resistance measurement is an independent manual test item, and the system does not support automatic testing.

[0048] 1. L terminal: "L" is the high voltage output terminal, called the line terminal, which is connected to the line end of the measured line by the high voltage cable. 2. G terminal: "G" is called the shield terminal, which is used to measure the volume resistance of insulating materials or cables by the three-electrode method. It is connected to the guard ring end of the three electrodes. 3. E terminal: "E" is called the ground terminal, which is connected to the ground and zero terminal of the object being measured. For example, the transformer core. Before the test, make sure that the transformer is well grounded; adjust the test voltage value, the test voltage value of 10kV power transformer is 2.5kV / 5kV; the absorption ratio will be calculated based on the measured value.

[0049] No load test

[0050] The no-load test is completed by the transformer loss parameter tester. During the no-load test, close KM1, disconnect KM2, connect the low-voltage side of the transformer to the output power supply of the voltage regulator, apply the rated low-voltage side voltage to the transformer through the voltage regulator, and measure the voltage side current. During the load test, close KM2 and KM3, disconnect KM1, apply voltage on the high-voltage side until the high-voltage side current reaches the rated value, and measure the load loss. The parameters of the transformer loss parameter tester are shown in the following table.

[0051]

[0052] The test process of no-load test in manual mode: After setting various parameters and confirming that there are no problems, you can conduct the test. First select test, then select the appropriate current gear (select according to the model of the transformer), then click on the switch, and then select the voltage increase or decrease and the voltage increase rate adjustment to finally reach the specified voltage.

[0053] The boost button is used to increase the voltage output by the test power supply. The operation mode is to click the button with the mouse. When the left mouse button is pressed, the voltage will continue to increase, and it will stop when the left mouse button is released.

[0054] The voltage reduction button is used to reduce the voltage output by the test power supply. The operation mode is to click the button with the mouse. When the left mouse button is pressed, the voltage will continue to be reduced, and it will stop when the left mouse button is released. During the voltage adjustment process, watch the data collected in the monitoring window and increase it to the specified test voltage. When the desired data is collected, click Lock. When the data is recorded, the voltage can be reduced. Click the Disconnect button, and then click the Stop button to end the test.

[0055] Power frequency withstand voltage test

[0056] This power frequency withstand voltage test system is an integrated structure, consisting of an isolated conversion power supply, a low voltage filter, a UPS uninterruptible power supply, an intelligent control system, an electric voltage regulator, a test transformer, a current limiting protection resistor, a coupling capacitor and a voltage divider, and a safe grounding discharge device for an injection capacitor. It is integrated and installed in a shielding cabinet, with a complete structure and reliable connection. The bottom of the shielding cabinet is equipped with movable universal wheels for easy movement; the shielding cabinet has safety interlocking protection. The power frequency withstand voltage test module is connected to the comprehensive intelligent control system to complete functions such as automatic voltage control and data access readback. The specific parameters of this power frequency withstand voltage test system are shown in the following table.

[0057]

[0058] In summary, through the above-mentioned multifunctional automatic test system for dry-type transformers, the DC resistance tester, voltage ratio tester, insulation resistance tester and transformer characteristic tester can be connected to the high and low voltage terminals of the transformer respectively according to different experimental projects, and the required test wiring can be achieved by switching the on-off control of the switch, which avoids frequent disassembly of the transformer winding terminals and the wiring between instruments, improves the test efficiency, and reduces the labor intensity of operators.

[0059] At the same time, the software part of the multifunctional automatic test system for dry-type transformers can realize the automatic saving of test results of each test item and the automatic generation of test reports, eliminating the tedious operations of test personnel such as recording and inputting, and improving the test efficiency.

[0060] Example 2

[0061] This embodiment provides an experimental method based on the above-mentioned multifunctional automatic test system for dry-type transformers, which includes the following steps: Step 1, connecting the tester module, industrial computer, PLC controller and switch to the tested transformer; Step 2, connecting an external three-phase power supply to the experimental system;

[0062] Step 3: Control the on and off of the switch through the industrial computer and PLC controller; then perform the test, and send the test data to the industrial computer;

[0063] Step 4: Industrial computer records test data and generates reports.

[0064] Through the above method, the required test wiring can be achieved by switching the on-off control of the switch, eliminating the need to frequently disassemble the transformer winding terminals and the instrument side wiring, thereby improving the test efficiency and reducing the labor intensity of the operator.

[0065] In conclusion, the above is only a preferred embodiment of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the patent of the present invention.

Claims

1. A multifunctional automatic test system for dry-type transformers, characterized in that: It includes a tester module, an industrial computer, a PLC controller and a switching switch; the switching switch includes a switch QK1, contactor switches KM1~ KM3 and KM19~KM20, and a three-phase switch KM7~ KM18; The tester module is connected to the industrial computer, and the industrial computer is electrically connected to the PLC controller; the tester module includes a DC resistance tester, a ratio group tester, an insulation resistance tester, and a transformer loss parameter tester; the tester module is used to collect electrical signals, the industrial computer is used to control the tester module to test and read the test result data, and the PLC controller is used to control the on and off of the switching switch; The industrial computer system software realizes the control function of the whole system. The industrial computer is directly connected to various measuring instruments in various tester modules, and controls the instrument test and reads the test result data through the RS232 interface. The industrial computer is connected to the PLC controller through the TCP / IP network. The PLC controller controls the on and off of each switch according to the test project to realize automatic wiring switching. The industrial computer system software includes the user interface layer, the test data layer, the test logic layer and the driver layer to realize the test process control, test data recording and report generation. It also includes a voltage regulating control module electrically connected to the industrial computer, the voltage regulating control module is electrically connected to a step-up transformer, and the step-up transformer is electrically connected to the tested transformer; the industrial computer is used to control the PLC controller and the voltage regulating control module to control the switching switch and the step-up transformer, and the data of each test instrument is summarized to the industrial computer, and the industrial computer processes uniformly; It also includes a step-up / step-down voltage regulator and three single-phase current transformers CT1-CT3. The three single-phase current transformers are connected to the high and low voltage windings of the tested transformer through contactor switches KM1 and KM2 respectively. The external three-phase power supply is connected to the experimental system through the step-up / step-down voltage regulator. The three single-phase current transformers are used to collect line currents. The three-phase voltage and current signals are input into the transformer loss parameter tester to calculate the no-load loss. The insulation resistance tester is connected to the transformer winding terminals through another test cable; The DC resistance tester is connected to the transformer winding terminals through three-phase switches KM7~KM18 to complete the test; The ratio tester is connected to the experimental system through the six terminals of the high and low voltage windings; The system provides stable three-phase voltage input through an external power supply, and controls the external power supply access through switch QK1; the device collects the current signal on the power supply side through current transformers CT1~CT3, and collects the voltage signal on the power supply side through the sampling voltage branch; switching switches KM1~KM3, KM7~KM20 are used to control each branch, and the wiring of different detection items is realized through a certain opening and closing combination.

2. The experimental method of a multifunctional automatic test system for dry-type transformers according to claim 1 is characterized in that: The following steps are involved: Step 1: Connect the tester module, industrial computer, PLC controller and switch to the transformer under test; Step 2: Connect the external three-phase power supply to the experimental system; Step 3: Control the on and off of the switch through the industrial computer and PLC controller; then perform the test, and send the test data to the industrial computer; Step 4: Industrial computer records test data and generates reports.

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