CN204286646U - Main transformer of transformer substation thermometric loop fault detecting device - Google Patents

Abstract

The utility model discloses a fault detector for a temperature measuring circuit of a main transformer in a substation, which relates to the technical field of substation maintenance; it includes an adjustable resistance and a resistance R1, and the adjustable resistance and the resistance R1 are connected in parallel to a temperature transmitter; The multimeter is used to detect the resistance value or the voltage across the adjustable resistor, and the voltage across the temperature transmitter. The utility model facilitates the detection of the temperature measurement failure of the main transformer, and can directly locate the fault point, avoiding that the staff is forced to climb the live transformer due to the unclear fault point, and greatly reduces the possibility of live work, greatly improving The safety factor of on-site operations has been improved.

Description

Fault Detector for Temperature Measuring Circuit of Main Transformer in Substation

technical field

The utility model relates to the technical field of substation maintenance.

Background technique

The main transformer is one of the most important equipment for power transformation and load transmission in substations. Under long-term, high-load, and high-temperature environments, the insulation performance of the main transformer will decline with the rise of temperature, which will accelerate the aging of the insulation performance of the main transformer, and then affect the main transformer. Once the service life of the transformer runs in a high-temperature environment without monitoring and air cooling, the safe operation of the main transformer will be endangered, and then the turn-to-turn short circuit accident of the main transformer will be caused.

In order to avoid the above-mentioned accidents, the main transformer is equipped with a main transformer temperature measurement circuit for monitoring, that is, the resistance value of the Pt100 thermometer is uploaded to the temperature converter, and after the temperature converter converts it into a 0-5V CPU to collect the voltage value, It is sent to the measurement and control device and the background to provide the operating personnel with temperature monitoring data and operations of stopping, turning on air cooling, and compressing load.

At present, the fault detection of the main transformer temperature measurement circuit basically adopts the comparison method, because the temperature value at a certain moment is fixed, and the thermistor value is also fixed, so it can only be compared and adjusted based on the temperature displayed at that time, and it is difficult to carry out the whole process The adjustment of hidden defects and wiring and setting errors cannot be discovered in time, which has buried hidden dangers for operation. For such abnormal situations, we can only check each component of the circuit one by one, and compare it with the resistance value of another thermometer on the same main transformer, so as to avoid forced work due to inexperienced operators and inaccurate positioning. Personnel are forced to climb the main transformer that is running live, and replace the thermometer or thermometer probe to eliminate abnormalities.

Utility model content

The technical problem to be solved by the utility model is to provide a fault detector for the temperature measurement circuit of the main transformer of the substation, which facilitates the detection of the temperature measurement fault of the main transformer, and can directly locate the fault point, avoiding the failure of the staff due to the unclear fault point. Climbing the live-running transformer minimizes the possibility of live work and greatly improves the safety factor of on-site work.

In order to solve the problems of the technologies described above, the technical solution adopted by the utility model is:

A temperature measuring loop fault detector for a main transformer in a substation, comprising an adjustable resistor and a resistor R1, the adjustable resistor is connected in parallel with the resistor R1 and then connected to a temperature transmitter; it also includes a multimeter for detecting the adjustable resistor The resistance value or the voltage at both ends, and the voltage at both ends of the temperature transmitter.

In a further technical solution, the resistance value of the resistor R1 is 200 ohms.

In a further technical solution, the adjustable resistor is a potentiometer Rf2 with a switch, the potentiometer Rf2 is installed in the multimeter, and the potentiometer Rf2 is connected between the ground and the 200 ohm gear of the multimeter, so that the multimeter has both In order to display the function of output resistance, the multimeter pen is connected with the temperature transmitter.

The beneficial effect of adopting the above technical scheme is that the adjustable resistor replaces the thermocouple resistance of the thermometer, can flexibly adjust the resistance value and the change value of temperature, check the whole process of main transformer temperature acquisition and display, and detect the circuit wiring. Whether it is correct or not, it is convenient to find the fault point of the temperature measurement circuit of the main transformer; it can directly locate the fault point, and avoid forcing the staff to climb the live transformer to replace the probe and thermometer due to unknown reasons, or make the staff electrified to make a thermometer probe The functional test of temperature minimizes the possibility of live work and greatly improves the safety factor of on-site work; when performing equipment debugging and defect handling, the wiring is simple and the positioning is accurate, replacing the previous live-climbing main transformer. Remove the temperature probe, reintroduce the power supply, and use the heating plate to heat the test method, which improves the work efficiency; at the same time, using the 200Ω gear of the multimeter, it can display the output 0-200Ω resistance value, and can output while measuring, changing the multimeter to only measure the input , there is no output function. The utility model has the advantages of low cost, simple structure, easy manufacture and good operability, and can be widely used in debugging and fault finding of the temperature measuring circuit of the main transformer.

Description of drawings

Fig. 1 is the structural principle diagram of the utility model embodiment 1;

Fig. 2 is the parameter setting description corresponding to the RCS-9703 measurement and control device in embodiment 1;

Fig. 3 is the structural principle diagram of the utility model embodiment 2;

Fig. 4 is the temperature measurement curve of the main transformer in embodiment 2.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described in further detail.

Example 1

As shown in Figure 1, the fault detector of the temperature measurement circuit of the main transformer of the substation uses an adjustable resistor Rf1 to replace the temperature measurement elements in the temperature measurement circuit of the main transformer, such as thermocouple resistance, and connects it to the temperature transmitter. Among them, the temperature transmitter is connected with the measurement and control device. The adjustable resistor Rf1 is connected in parallel with the 200Ω resistor R1. Set several different resistance values according to the thermocouple and temperature comparison table, check the background temperature values respectively, refer to Table 1, and judge the fault location.

Table 1 Industrial platinum thermal resistance graduation table

Judgment principles are as follows:

(1) Adjust the adjustable resistor Rf1, and use a multimeter to detect the resistance value of the adjustable resistor Rf1, look up Table 1, and get the temperature value corresponding to the tested resistance value, if the temperature value corresponds to the display value of the temperature measurement circuit, then The problem usually lies with the thermometer.

(2) If the test temperature value in (1) does not correspond to the displayed temperature value, adjust the adjustable resistor Rf1, and use a multimeter to check whether the output voltage of the temperature transmitter changes when the resistance value is different. If there is no change, the preliminary It is judged that the temperature transmitter is damaged. Swap the voltage output terminal of the variable resistor Rf1 with the measurement and control device, and check the temperature change of the temperature measurement circuit. If the temperature display is correct, it can be determined that the temperature transmitter is damaged.

(3) Use the test resistance gear or the voltage output terminal of the variable resistor Rf1 to exchange with the measurement and control device to check the temperature change of the temperature measurement circuit. If the temperature display of the temperature measurement circuit is incorrect, please check the monitoring parameters in the measurement and control device. Whether the selected temperature transmitter type is correct, whether the parameter settings are correct, and whether the temperature correlation of the temperature measurement loop is correct, as shown in Figure 3.

Example 2

Since the resistance value of the adjustable resistor Rf1 in the embodiment 1 needs to be measured with a multimeter, the operation is inconvenient. The difference from the embodiment 1 is that a digital display temperature fault detector is produced with a multimeter and a potentiometer Rf2.

As shown in Figure 3, the potentiometer Rf2 with a switch is connected in parallel with the 200Ω resistor R1 so that the output resistance is less than 200Ω, and then installed in the digital multimeter, connected between the ground and the 200Ω range. The test line of the multimeter directly outputs an adjustable resistance of 0-180Ω, and then connects with the switch K2 and then connects with the temperature transmitter to simulate the temperature change resistance of the main transformer thermometer. The output resistance value is adjusted by the potentiometer Rf2 and displayed on the display screen of the multimeter.

When in use, turn the gear of the multimeter to 200Ω, turn on the switch K1 of the potentiometer Rf2, adjust the resistance value of the potentiometer Rf2 according to the test temperature, and simulate the temperature curve, as shown in Figure 4. Close the anti-disturbance switch K2 and monitor the temperature change of the temperature measuring circuit. After the work is completed, turn off the potentiometer Rf2 switch K1, and the functions of the multimeter can still be used normally.

The utility model can simulate the actual trend of the temperature of the main transformer, and prevent incorrect background temperature measurement caused by wiring errors, damaged thermometers, incorrect options of temperature transmitters, and incorrect settings of background temperature correlation points.

The utility model can facilitate on-site debugging and finding of temperature measurement faults. The 200Ω gear of the multimeter can display and output the resistance value of 0-200Ω, and can output while measuring. The multimeter only has the function of measuring input and not output. A thermocouple temperature comparison table was made to facilitate on-site reference and comparison. Through resistance 0-180Ω transformation, simulate the resistance output value of Pt100 thermometer in various environments, check the whole process of main transformer temperature acquisition and display, check the correctness of circuit and measurement and control, background setting, and detection circuit wiring. The utility model has the advantages of low cost, simple manufacture, simple wiring, flexible experimental method, good operability, and no impediment to implementation, and can be widely used in debugging and fault finding of the temperature measurement circuit of the main transformer. , in line with the requirements of safe operation, can well solve the practical problems of production.

Claims (3)

1. a substation main transformer temperature measurement loop fault detector is characterized in that comprising adjustable resistor and resistance R1, described adjustable resistor is connected with temperature transmitter after being connected in parallel with resistance R1; Also comprises multimeter, is used for It is used to detect the resistance value or the voltage across the adjustable resistor, and to detect the voltage across the temperature transmitter. 2. The fault detector for the temperature measuring circuit of the main transformer of a substation according to claim 1, characterized in that the resistance value of the resistor R1 is 200 ohms. 3. The substation main transformer temperature measuring circuit fault detector according to claim 1, wherein said adjustable resistor is a potentiometer Rf2 with a switch, said potentiometer Rf2 is installed in a multimeter, and the potentiometer Rf2 is connected between the ground and the 200 ohm gear of the multimeter, and the multimeter pen is connected with the temperature transmitter.