Transformer temperature control device tester
By designing a transformer temperature control device tester including temperature sensor, A/D module and heating furnace, the problem of lack of special detection equipment in the prior art is solved, accurate detection and functional verification of transformer temperature control devices is achieved, and the safe operation quality of the transformer is improved.
Patent Information
- Application Number
- CN202421081742.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-05-17
AI Technical Summary
The prior art lacks special testing equipment to test the transformer temperature control device, which makes it impossible to effectively detect whether the transformer's temperature control device is working normally, which in turn affects the safe operation of the transformer.
Design a transformer temperature control device tester, including temperature sensor, A/D module, microcontroller module, D/A module, solid-state relay, heating furnace, touch screen and switching power supply module, to detect the function and stability of the temperature control device by precisely controlling the temperature.
Accurate detection of the transformer temperature control device is achieved, ensuring the normal operation of fan start-up, high temperature alarm and over-temperature tripping functions, reducing the risk of transformer damage caused by temperature control device failure, and improving the operating quality and safety and reliability of the transformer.
Smart Images
Figure CN222580441U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of transformer online monitoring, in particular to a transformer temperature control device tester. Background Art
[0002] In the power operation system, the temperature control measures for 10kV dry-type power transformers mainly rely on the supporting fan equipment for cooling. When the transformer is running at high load or is continuously heated up due to the influence of ambient temperature, when the temperature reaches a certain level, the fan will be started to blow air to cool the transformer.
[0003] Therefore, the research on the new transformer temperature control device tester is mainly aimed at testing the transformer temperature control device. The transformer temperature control device mainly uses the temperature thermistor probe equipped with it to detect the temperature of the transformer winding in real time to determine whether to start the relevant transformer protection function. The main functions of the temperature control device include fan start and stop, high temperature alarm, over-temperature trip and real-time temperature monitoring.
[0004] The new transformer temperature control device tester uses its own heating device to accurately program and control the heating output of the temperature probe thermistor of the transformer temperature control device to ensure that the corresponding protection temperature action is consistent with the set value output signal of the temperature control device. At the same time, it detects whether the relationship between the resistance value and temperature of the temperature probe thermistor meets the linear requirements of the product design.
[0005] Therefore, the new transformer temperature control device tester can not only solve the problem of no special testing equipment to test the transformer temperature control device, but also provide another technical means to protect the safe operation of the transformer. Utility Model Content
[0006] The technical problem to be solved by the utility model is to provide a transformer temperature control device tester in view of the deficiencies of the background technology.
[0007] The utility model adopts the following technical solutions to solve the above technical problems:
[0008] A transformer temperature control device tester comprises a temperature sensor, an A / D module, a microcontroller module, a D / A module, a solid-state relay, a heating furnace, a touch screen and a switching power supply module; the output end of the temperature sensor is connected to the input end of the A / D module, the output end of the A / D module is connected to the input end of the microcontroller module, the output end of the microcontroller module is connected to the input end of the D / A module, the output end of the D / A module is connected to the input end of the solid-state relay, the output end of the solid-state relay is connected to the input end of the heating furnace, and the output end of the heating furnace is connected to the input end of the temperature sensor; the touch screen and the switching power supply module are respectively connected to the microcontroller module.
[0009] As a further preferred embodiment of a transformer temperature control device tester of the utility model, the switching power supply module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth resistor, a first inductor, a second inductor, a third inductor, a first diode, a second diode, a Schottky diode, a first transistor, and a second transistor; wherein, the live wire L end is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the first capacitor, one end of the second resistor, one end of the third resistor, and one end of the first inductor, the other end of the first capacitor is respectively connected to the positive electrode of the first diode and grounded, the negative electrode of the first diode is connected to the neutral wire N end, the other end of the second resistor is connected to the collector of the first transistor, and the other end of the third resistor is respectively connected to The other end of the first inductor and the collector of the second transistor are connected, the base of the first transistor is respectively connected to one end of the fifth resistor and one end of the fourth resistor, the other end of the fifth resistor is connected to the positive electrode of the Schottky diode, the negative electrode of the Schottky diode is respectively connected to one end of the third capacitor, one end of the seventh resistor, and one end of the second inductor, the other end of the third capacitor is respectively connected to the other end of the seventh resistor, the emitter of the first transistor and grounded, the other end of the second inductor is connected to the negative electrode of the third diode and one end of the tenth resistor, the other end of the tenth resistor is connected to the other end of the second capacitor, the positive electrode of the third diode is grounded, one end of the third inductor is respectively connected to one end of the fourth capacitor, one end of the ninth resistor, and the positive output end of 5V, the other end of the fourth capacitor is respectively connected to the positive electrode of the second diode, the other end of the ninth resistor, and the negative output end of 5V, and the negative electrode of the second diode is connected to the other end of the third inductor.
[0010] As a further preferred solution of the transformer temperature control device tester of the utility model, it also includes a sensor signal conditioning circuit, a current signal conditioning circuit, a voltage signal conditioning circuit, an analog switch unit, and a voltage divider follower filter unit; the temperature sensor is connected to the A / D module in sequence through the sensor signal conditioning circuit, the current signal conditioning circuit, the voltage signal conditioning circuit, the analog switch unit, and the voltage divider follower filter unit.
[0011] As a further preferred embodiment of a transformer temperature control device tester of the utility model, the sensor signal conditioning circuit includes an analog signal input terminal, a resistor R1, a resistor R2, a capacitor C1, and an operational amplifier U1. The analog signal input terminal is respectively connected to one end of the resistor R1 and one end of the resistor R2, the other end of the resistor R2 is connected to one end of the capacitor C1, the other end of the capacitor C1 is respectively connected to the other end of the resistor R1 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1.
[0012] As a further preferred solution of the transformer temperature control device tester of the utility model, the current signal conditioning circuit adopts the ACS714 chip of Allegro, which is a current-isolated current sensor with common-mode field effect suppression, and is composed of a high-precision low-bias linear Hall sensor.
[0013] As a further preferred embodiment of a transformer temperature control device tester of the utility model, the voltage signal conditioning circuit includes a voltage signal input end, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, and an operational amplifier U2. The voltage signal input end is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, the other end of the capacitor C2 is respectively connected to the other end of the resistor R4 and the positive input end of the operational amplifier U1, and the negative input end of the operational amplifier U2 is connected to the output end of the operational amplifier U2.
[0014] As a further preferred solution of the transformer temperature control device tester of the utility model, the analog switch unit adopts an ADG706 chip.
[0015] As a further preferred embodiment of a transformer temperature control device tester of the utility model, the voltage divider follower filter unit includes an operational amplifier U3, a resistor R11, a resistor R12, an operational amplifier U4, a resistor R13, and a capacitor C7. The output end of the operational amplifier U3 is connected to one end of the resistor R12, and the other end of the resistor R12 is respectively connected to one end of the resistor R11 and the positive input end of the operational amplifier U4. The output end of the operational amplifier U4 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to one end of the capacitor C7 and the A / D conversion unit. The other end of the capacitor C7 is grounded, and the other end of the resistor R11 is connected to the current signal conditioning circuit.
[0016] Compared with the prior art, the utility model adopts the above technical solution and has the following technical effects:
[0017] The utility model discloses a transformer temperature control device tester, which comprises a temperature sensor, an A / D module, a microcontroller module, a D / A module, a solid-state relay, a heating furnace, and a switching power supply module. During the test, the temperature of the temperature control device tester is changed by electronic temperature adjustment, the temperature is accurately controlled, the solid-state relay outputs, the temperature is stable, and the resistance of the transformer temperature controller temperature sensing probe is measured. At different temperatures, the resistance value increases with the increase of temperature;
[0018] 2. Through precise temperature control, detect the accurate temperature action value of fan start-up, high temperature alarm and over-temperature tripping of the temperature control device; detect the stability and accuracy of the transformer temperature control device, reduce the risk of transformer damage caused by failure of the temperature control device, and improve the operation quality and safety reliability of the transformer.
[0019] 3. The utility model collects multi-channel sensor signals, voltage signals, and current signals. The collected signals are processed successively through signal conditioning, analog switches, voltage follower, and anti-aliasing filtering, and the link establishment time is analyzed. Successive approximation AD chips are then used for conversion. The data collection accuracy is verified by cooperating with the host computer, and the circuit design is optimized. The collected signals are more accurate, stable, and reliable. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a plan view of the overall structure of the utility model transformer temperature control device tester;
[0021] Figure 2 This is the principle diagram of the utility model transformer temperature control device tester;
[0022] Figure 3 This is the temperature control principle diagram of the utility model;
[0023] Figure 4 It is a circuit diagram of the switching power supply module of the utility model;
[0024] Figure 5 This is the principle diagram of sensor data preprocessing of the utility model;
[0025] Figure 6 It is a circuit diagram of the sensor signal conditioning circuit of the utility model;
[0026] Figure 7 It is a circuit diagram of the voltage signal conditioning circuit of the utility model;
[0027] Figure 8 The utility model is a circuit diagram of a voltage-dividing follower filtering unit. DETAILED DESCRIPTION
[0028] The technical solution of the utility model is further described in detail below in conjunction with the accompanying drawings:
[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0030] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present disclosure will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.
[0031] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring various aspects of the present disclosure.
[0032] A transformer temperature control device tester, such as Figure 1 and Figure 2 and Figure 3 As shown, it includes a temperature sensor, an A / D module, a microcontroller module, a D / A module, a solid-state relay, a heating furnace, a touch screen, and a switching power supply module; the output end of the temperature sensor is connected to the input end of the A / D module, the output end of the A / D module is connected to the input end of the microcontroller module, the output end of the microcontroller module is connected to the input end of the D / A module, the output end of the D / A module is connected to the input end of the solid-state relay, the output end of the solid-state relay is connected to the input end of the heating furnace, and the output end of the heating furnace is connected to the input end of the temperature sensor; the touch screen and the switching power supply module are respectively connected to the microcontroller module.
[0033] The new transformer temperature control device tester controls the temperature through a PID temperature regulation and control closed-loop system. The following is the process of PID temperature regulation and control:
[0034] The temperature of the heater is set on the touch screen, and the solid-state relay is controlled by the PLC to energize the heater. The heater heats up, and the temperature sensor transmits the heat to the PID.
[0035] Proportional control: Proportional control generates an output signal proportional to the deviation between the actual temperature and the set temperature to change the control amount of the system. The advantage of proportional control is fast response speed, but it may cause overshoot or oscillation in the system.
[0036] Integral control: The deviation signal is accumulated through integral control, and the output signal of the controller is adjusted according to the size of the accumulated deviation. The purpose of integral control is to eliminate the steady-state error of the system, but it may cause system overshoot and oscillation.
[0037] Differential control: The output signal of the controller is adjusted according to the rate of change of the deviation through differential control to predict the response trend of the system. The advantage of differential control is that it can enhance the stability and anti-interference ability of the system, but it may also cause the amplification of system noise.
[0038] The PID controller of the new transformer temperature control device tester continuously adjusts these control signals and combines their weights to achieve the best tracking performance, thereby achieving temperature maintenance near the target temperature. The PID controller calculates the adjustment value of the control amount based on the deviation between the actual temperature and the set temperature and its own parameters, and feeds it back to the actuator, such as the heater, to control the temperature change. This process forms a closed-loop feedback control system, ensuring the accurate temperature control of the new transformer temperature control device tester and achieving accurate test results.
[0039] like Figure 4 As shown, the switching power supply module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth resistor, a first inductor, a second inductor, a third inductor, a first diode, a second diode, a Schottky diode, a first transistor, and a second transistor; wherein, the live wire L end is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the first capacitor, one end of the second resistor, one end of the third resistor, and one end of the first inductor, the other end of the first capacitor is respectively connected to the positive electrode of the first diode and grounded, the negative electrode of the first diode is connected to the neutral wire N end, the other end of the second resistor is connected to the collector of the first transistor, and the other end of the third resistor is respectively connected to the other end of the first inductor, the second The collector of the transistor and the base of the first transistor are respectively connected to one end of the fifth resistor and one end of the fourth resistor, the other end of the fifth resistor is connected to the positive electrode of the Schottky diode, the negative electrode of the Schottky diode is respectively connected to one end of the third capacitor, one end of the seventh resistor, and one end of the second inductor, the other end of the third capacitor is respectively connected to the other end of the seventh resistor and the emitter of the first transistor and grounded, the other end of the second inductor is connected to the negative electrode of the third diode and one end of the tenth resistor, the other end of the tenth resistor is connected to the other end of the second capacitor, the positive electrode of the third diode is grounded, one end of the third inductor is respectively connected to one end of the fourth capacitor, one end of the ninth resistor, and the 5V positive output end, the other end of the fourth capacitor is respectively connected to the positive electrode of the second diode, the other end of the ninth resistor, and the 5V negative output end, and the negative electrode of the second diode is connected to the other end of the third inductor.
[0040] like Figure 5 As shown, it also includes a sensor signal conditioning circuit, a current signal conditioning circuit, a voltage signal conditioning circuit, an analog switch unit, and a voltage divider follower filter unit; the temperature sensor is connected to the A / D module through the sensor signal conditioning circuit, the current signal conditioning circuit, the voltage signal conditioning circuit, the analog switch unit, and the voltage divider follower filter unit in sequence.
[0041] like Figure 6 As shown, the sensor signal conditioning circuit includes an analog signal input terminal, a resistor R1, a resistor R2, a capacitor C1, and an operational amplifier U1. The analog signal input terminal is respectively connected to one end of the resistor R1 and one end of the resistor R2, the other end of the resistor R2 is connected to one end of the capacitor C1, the other end of the capacitor C1 is respectively connected to the other end of the resistor R1 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1.
[0042] As the key component of the conditioning circuit, the utility model selects the AD8608 operational amplifier chip of ADI Company. The chip combines many excellent characteristics, has four-rail input and output while being powered by a single power supply, and can ensure high speed while also ensuring extremely low noise and input bias current, and is widely applicable to various circuits;
[0043] Since the input impedance of the op amp is generally very high, it is very susceptible to external interference when the input pin is left floating. Therefore, setting the resistor R2 can form a loop between the input end and the analog ground when the input pin is left floating, thereby ensuring the stability of the op amp.
[0044] like Figure 7 As shown, the voltage signal conditioning circuit includes a voltage signal input terminal, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, and an operational amplifier U2. The voltage signal input terminal is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, the other end of the capacitor C2 is respectively connected to the other end of the resistor R4 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2.
[0045] The analog switch unit adopts ADG706 chip.
[0046] Rail-to-rail op amps can maximize the input and output voltage swings to be close to the power supply voltage value, but there is also a large deviation under high current conditions. Since the input voltage range of AD8608 is 0-0.5V, resistors R3 and R5 are set to form a voltage divider circuit to reduce the input voltage to below 5V.
[0047] According to the size of the current and the difference between AC and DC, the corresponding current collection methods are also different. Commonly used current collection methods include coaxial shunt method, current transformer method, Rogowski coil method, Hall sensor method and sampling resistor method, etc. The Hall sensor method is suitable for measuring both AC and DC currents, and can measure large currents. The current signal conditioning circuit adopts the ACS714 chip of Allegro, which is a current-isolated current sensor with common-mode suppression field effect, composed of high-precision low-bias linear Hall sensors.
[0048] like Figure 8 As shown, the voltage divider follower filter unit includes an operational amplifier U3, a resistor R11, a resistor R12, an operational amplifier U4, a resistor R13, and a capacitor C7. The output end of the operational amplifier U3 is connected to one end of the resistor R12, and the other end of the resistor R12 is respectively connected to one end of the resistor R11 and the positive input end of the operational amplifier U4. The output end of the operational amplifier U4 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to one end of the capacitor C7 and the A / D conversion unit. The other end of the capacitor C7 is grounded, and the other end of the resistor R11 is connected to the current signal conditioning circuit.
[0049] The signal passes through the analog switch and then passes through the voltage divider % follower % filter circuit, and then is input into the AD converter. The voltage follower makes the circuit present high impedance input and low impedance output, improving the circuit's load capacity. The chip model of the operational amplifier U3 and the operational amplifier U4 is AD8031. The maximum sampling current of the ACS714 chip is 5A.
[0050] The above only describes some exemplary embodiments of the present invention by way of illustration. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.
Claims
1. A transformer temperature control device tester, characterized in that: It comprises a temperature sensor, an A / D module, a microcontroller module, a D / A module, a solid-state relay, a heating furnace, a touch screen, and a switching power supply module; the output end of the temperature sensor is connected to the input end of the A / D module, the output end of the A / D module is connected to the input end of the microcontroller module, the output end of the microcontroller module is connected to the input end of the D / A module, the output end of the D / A module is connected to the input end of the solid-state relay, the output end of the solid-state relay is connected to the input end of the heating furnace, and the output end of the heating furnace is connected to the input end of the temperature sensor; the touch screen and the switching power supply module are respectively connected to the microcontroller module; The switching power supply module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first inductor, a second inductor, a third inductor, a first diode, a second diode, a Schottky diode, a first transistor, and a second transistor; wherein, the live wire L end is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the first capacitor, one end of the second resistor, one end of the third resistor, and one end of the first inductor, the other end of the first capacitor is respectively connected to the positive electrode of the first diode and grounded, the negative electrode of the first diode is connected to the neutral wire N end, the other end of the second resistor is connected to the collector of the first transistor, the other end of the third resistor is respectively connected to the other end of the first inductor, the The collector, the base of the first transistor is respectively connected to one end of the fifth resistor and one end of the fourth resistor, the other end of the fifth resistor is connected to the positive electrode of the Schottky diode, the negative electrode of the Schottky diode is respectively connected to one end of the third capacitor, one end of the seventh resistor, and one end of the second inductor, the other end of the third capacitor is respectively connected to the other end of the seventh resistor and the emitter of the first transistor and grounded, the other end of the second inductor is connected to the negative electrode of the third diode and one end of the tenth resistor, the other end of the tenth resistor is connected to the other end of the second capacitor, the positive electrode of the third diode is grounded, one end of the third inductor is respectively connected to one end of the fourth capacitor, one end of the ninth resistor, and the 5V positive output terminal, the other end of the fourth capacitor is respectively connected to the positive electrode of the second diode, the other end of the ninth resistor, and the 5V negative output terminal, and the negative electrode of the second diode is connected to the other end of the third inductor; It also includes a sensor signal conditioning circuit, a current signal conditioning circuit, a voltage signal conditioning circuit, an analog switch unit, and a voltage-dividing follower filter unit; the temperature sensor is connected to the A / D module through the sensor signal conditioning circuit, the current signal conditioning circuit, the voltage signal conditioning circuit, the analog switch unit, and the voltage-dividing follower filter unit in sequence; The sensor signal conditioning circuit comprises an analog signal input terminal, a resistor R1, a resistor R2, a capacitor C1, and an operational amplifier U1, wherein the analog signal input terminal is respectively connected to one end of the resistor R1 and one end of the resistor R2, the other end of the resistor R2 is connected to one end of the capacitor C1, the other end of the capacitor C1 is respectively connected to the other end of the resistor R1 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1; The current signal conditioning circuit uses the ACS714 chip of Allegro, which is a current-isolated current sensor with common-mode field effect rejection, and is composed of a high-precision, low-bias linear Hall sensor; The voltage signal conditioning circuit comprises a voltage signal input terminal, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, and an operational amplifier U2, wherein the voltage signal input terminal is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, the other end of the capacitor C2 is respectively connected to the other end of the resistor R4 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2; The analog switch unit adopts ADG706 chip; The voltage divider follower filter unit includes an operational amplifier U3, a resistor R11, a resistor R12, an operational amplifier U4, a resistor R13, and a capacitor C7. The output end of the operational amplifier U3 is connected to one end of the resistor R12, and the other end of the resistor R12 is respectively connected to one end of the resistor R11 and the positive input end of the operational amplifier U4. The output end of the operational amplifier U4 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to one end of the capacitor C7 and the A / D conversion unit. The other end of the capacitor C7 is grounded, and the other end of the resistor R11 is connected to the current signal conditioning circuit.