Intelligent controller durability test protection system based on Internet of Things

Abstract

The invention discloses an intelligent controller durability test protection system based on the Internet of Things, which comprises an overtime detection unit and a cut-off circuit device connected in series on a durability test main loop of an intelligent controller, and is characterized in that when the overtime detection unit detects that the power-on time of the main loop reaches a set time threshold ttimeout, the cut-off circuit device cuts off the circuit when the power-on time of the main loop reaches the set time threshold ttimeout; controlling the cut-off circuit device to cut off the main loop; the timeout detection unit dynamically adjusts the time threshold ttimeout according to the surface temperature of the detected intelligent controller, and the higher the surface temperature is, the smaller the time threshold ttimeout is. According to the protection system, the overtime threshold value is dynamically adjusted according to the surface temperature of the intelligent controller, overtime protection can be triggered earlier when the surface temperature of the intelligent controller is too high, and the intelligent controller can be better protected against damage or other electrical accidents.

Description

Technical Field

[0001] The invention relates to the technical field of intelligent controller durability testing. Background Art

[0002] Smart controllers such as smart relays, smart switches, and smart thermostats are key components in household appliances and industrial equipment, widely used in scenarios such as circuit control, temperature regulation, and load switching. Their performance and reliability directly impact the normal operation and safety of equipment. Therefore, endurance testing of these components is crucial to ensuring their quality and lifespan.

[0003] Intelligent controller durability test main circuit Figure 1 As shown, the circuit mainly consists of a power supply, a load, and a test sample connected in series. For safety reasons, endurance testing requires the addition of a protection system. Traditional protection systems typically implement timeout protection by setting a fixed time threshold. This protection system includes a contactor connected in series with the main circuit. When the main circuit's power-on time exceeds the time threshold, the contactor disconnects the main circuit.

[0004] The time setting flexibility of the timeout protection function of the traditional protection system is poor and the protection effect is limited. Summary of the Invention

[0005] The purpose of the present invention is to upgrade the existing protection system to provide better protection functions.

[0006] The purpose of the present invention is achieved through the following technical solution: a durability test protection system for an intelligent controller based on the Internet of Things, which includes a timeout detection unit and a circuit-cutting device connected in series to the main circuit of the durability test of the intelligent controller, wherein the timeout detection unit detects that the power-on time of the main circuit reaches a set time threshold t timeout When the circuit breaker is turned off, the circuit breaker is controlled to turn off the main circuit;

[0007] It is characterized in that the timeout detection unit dynamically adjusts the time threshold t according to the surface temperature of the intelligent controller being measured. timeout The higher the surface temperature, the greater the time threshold t timeout The smaller.

[0008] The higher the surface temperature of the intelligent controller, the higher the time threshold t timeout The smaller it is, the earlier the timeout protection can be triggered when the surface temperature of the intelligent controller is too high, which is beneficial to better protect the intelligent controller from damage or avoid other electrical accidents.

[0009] Preferably, the time threshold t timeout The specific adjustments are as follows:

[0010] t timeout =t0*(1+kT now )

[0011] Where t0 represents the initial time threshold, T now Indicates the current sampled value of temperature, T now Less than the maximum temperature limit T max , k is the temperature correction coefficient, which is a negative value and can be determined through experiments;

[0012] And in T now Reaching the maximum temperature limit T max When, that is, T now ≧T max , the single chip microcomputer unit controls the circuit cut-off device to disconnect the main circuit.

[0013] When the surface temperature of the intelligent controller does not reach T max When the real-time sampling value of the surface temperature is used, the t timeout To control the on and off of the main circuit of the intelligent controller, if a test failure of the intelligent controller occurs (such as prolonged arcing or tin melting), even if its surface temperature fails to reach Tmax, the timeout protection time of the protection system can be kept within a controllable range, solving the problem of fixing the timeout threshold and aggravating sample damage when encountering abnormal situations during the test process.

[0014] Preferably, the timeout detection unit is composed of a single-chip microcomputer unit, a current acquisition module and a temperature acquisition module; the protection system further comprises a contact resistance acquisition module; the temperature acquisition module, the current acquisition module and the contact resistance acquisition module are all connected to the single-chip microcomputer unit; the current acquisition module is connected in series in the main circuit for collecting the current of the main circuit; the contact resistance acquisition module is connected to the switch contacts of the intelligent controller for collecting the contact resistance information of the switch contacts and outputting the collected current and resistance information to the single-chip microcomputer unit.

[0015] The change of contact resistance of switch contacts can predict the life of intelligent controller, so it is very important to monitor it.

[0016] The protection system also includes a server and a remote control terminal. The single-chip microcomputer unit uploads the collected data information and the test abnormality information determined thereby to the server. The server stores the information and displays it on the web page. The remote control terminal issues control instructions through the web page and transmits them to the single-chip microcomputer unit through the server for execution.

[0017] The protection system of the present invention uploads test data and saves it on the server side. The test data is traceable and the test process is automatically monitored by the single-chip microcomputer unit. The system has a high degree of automation and the staff can also remotely monitor and control the test process, solving the problem that traditional protection systems rely on manual local monitoring.

[0018] The single chip unit adopts a hierarchical monitoring strategy according to the current information collected by the current collection module, and adopts different corresponding measures for each level.

[0019] The protection system includes more than one protection device, each of which corresponds to the monitoring of the main circuit of the intelligent controller, including the cut-off protection device, the temperature acquisition module, the current acquisition module, the contact resistance acquisition module, and the voltage acquisition module. Some or all of these protection devices share one single-chip computer unit.

[0020] Beneficial effects:

[0021] 1) The protection system of the present invention dynamically adjusts the timeout threshold according to the surface temperature of the intelligent controller. When the surface temperature of the intelligent controller is too high, the timeout protection can be triggered earlier, which is conducive to better protecting the intelligent controller from damage or other electrical accidents.

[0022] 2) When the surface temperature of the intelligent controller does not reach Tmax, the on-off of the main circuit of the intelligent controller is controlled by adjusting ttimeout according to the real-time sampling value of its surface temperature. This ensures that if a test failure of the intelligent controller occurs (such as prolonged arcing or tin melting), even if its surface temperature does not reach Tmax, the timeout protection time of the protection system can be kept within a controllable range, thus solving the problem of a fixed timeout threshold and aggravating sample damage when encountering abnormal conditions during the test process.

[0023] 3) The test data of the protection system of the present invention is directly uploaded to the server, and the data traceability is strong;

[0024] 4) The single-chip microcomputer unit of the protection system automatically monitors the test process, reducing dependence on manual labor. The protection system test data of the present invention is uploaded in real time and supports remote operation, solving the problem of traditional protection systems relying on local monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the connection relationship between the protection system and the intelligent controller, i.e., the test sample in the figure, according to a preferred embodiment of the present invention;

[0026] Figure 2 A logic flow chart for the hierarchical monitoring of current by the microcontroller unit;

[0027] Figure 3This is the circuit schematic diagram of the current acquisition module;

[0028] Figure 4 This is a flowchart for adjusting the timeout threshold;

[0029] Figure 5 This is the circuit schematic diagram of the temperature acquisition module;

[0030] Figure 6 The logic diagram for detecting the contact resistance of switch contacts by injecting high-frequency signals;

[0031] Figure 7 This is the circuit schematic diagram of the contact resistance acquisition module;

[0032] Figure 8 This is the circuit schematic diagram of the voltage acquisition module;

[0033] Figure 9 This is a schematic diagram of the pin connections of the main control chip of the single-chip microcomputer unit;

[0034] Figure 10 is a signal processing block diagram of the protection system of this embodiment;

[0035] Figure 11 This is a processing flow chart of the protection system of this embodiment;

[0036] Figure 12 A schematic diagram of another system architecture of the protection system of the present invention;

[0037] Figure 13 for Figure 12 Block diagram of the protection device. DETAILED DESCRIPTION

[0038] like Figure 1 As shown, the protection system of this embodiment includes an ESP32 single-chip microcomputer unit and a temperature acquisition module, a voltage acquisition module, a contact resistance acquisition module, a current acquisition module and a Chint AC contactor respectively connected thereto. The Chint AC contactor serves as a circuit-cutting device in this embodiment. It is connected in series in the main circuit of the withstand voltage test of the test sample, that is, the intelligent controller, and is used to disconnect the main circuit under the control of the single-chip microcomputer unit. The main circuit is mainly composed of a power supply, a load, and a test sample in series. The current acquisition module is also connected in series in the main circuit to collect the current of the main circuit so that the single-chip microcomputer unit can use it to judge the power-on time of the main circuit and other matters. The above-mentioned temperature acquisition module, voltage acquisition module, and contact resistance acquisition module are respectively used to collect the surface temperature of the test sample, the voltage across the switch contacts, and the contact resistance of the switch contacts, and output them to the single-chip microcomputer unit.

[0039] The model of the Chint AC contactor used in this embodiment is CJX2-8011.

[0040] Compared with the technology, the protection system of this embodiment mainly adds the monitoring of the contact resistance and surface temperature of the switch contacts of the test sample. The change of the switch contact resistance can predict the life of the intelligent controller, and the surface temperature can reflect the working status of the intelligent controller, so their monitoring is very important.

[0041] When the test sample is powered on, the ESP32 microcontroller unit obtains information from the voltage acquisition module, current acquisition module, temperature acquisition module, and contact resistance acquisition module to determine whether the current exceeds the limit set by the user and whether the sample surface temperature exceeds the maximum temperature T set by the user. max , check whether there is any abnormality in the contact resistance of the sample switch contacts, etc.

[0042] In this embodiment, the single chip unit monitors the current it obtains in a graded manner and takes different measures, specifically, Figure 2 As shown:

[0043] The current acquisition module uses an ACS758-200B Hall effect sensor, which the microcontroller uses to acquire the test main circuit current, I. When I ≥ 1.5Ie, the test is interrupted, the abnormality information is uploaded (the upload path is described below), and the main test circuit is disconnected via a control contactor. If 1.5Ie > I ≥ 1.2Ie, only the abnormality information is uploaded and observation continues. The test ends normally when the test cycle is reached. Ie represents the rated current of the sample.

[0044] This embodiment adopts hierarchical monitoring of current, which is conducive to timely feedback of abnormalities and flexible handling of abnormalities of different degrees while ensuring equipment safety.

[0045] Figure 3 This is the circuit schematic diagram of the current acquisition module.

[0046] This embodiment uses the sample surface temperature in two ways: One is to use it to dynamically adjust the time threshold t of the protection system timeout protection. timeout , the higher the surface temperature, the greater the time threshold t timeout The smaller the value, the earlier the timeout protection can be triggered when the sample surface temperature is too high, that is, the earlier the contactor is triggered to cut off the main circuit, which is conducive to better protecting the sample from damage or other electrical accidents. In this embodiment, the single-chip microcomputer unit, the current acquisition module, and the temperature acquisition module together constitute the timeout detection unit of the protection system.

[0047] Another way to use the sample surface temperature is to monitor whether the surface temperature exceeds the maximum temperature T set by the user. max , the combination of the two methods is as follows Figure 4 As shown:

[0048] In this embodiment, the temperature acquisition module uses the MLX90614 infrared temperature sensor, and the single chip unit obtains the current surface temperature T of the sample through it. now , when T now ≧The maximum temperature value T set by the user max When the test is interrupted, the abnormal information is uploaded (the upload path is described below) and the test main circuit is cut off by controlling the contactor. Otherwise, t is dynamically adjusted according to the following formula timeout , until the end of the test cycle:

[0049] t timeout =t0*(1+kT now ).

[0050] Where t0 represents the initial time threshold, and k is the temperature correction coefficient, which is a negative value and can be determined through experiments.

[0051] The combination of the two methods of utilizing the sample surface temperature above makes the surface temperature instantly reach T when the sample fails. max When the sample surface temperature is lower than T max , t can be adjusted according to its real-time sampling value timeout To control the on-off of its main circuit, so that if the intelligent controller test failure (such as long-term arcing or tin melting) occurs, even if its surface temperature does not reach T max It can also keep the timeout protection time of the protection system within a controllable range, solving the problem of aggravating sample damage due to a fixed timeout threshold when encountering abnormal situations during the test process.

[0052] Figure 5 This is the circuit schematic diagram of the temperature acquisition module.

[0053] In this embodiment, the contact resistance acquisition module is connected to the sample switch contacts and detects the contact resistance of the sample switch contacts by injecting high-frequency signals. It includes a Howland current pump, an ISO124 isolation amplifier, an LC bandpass filter, and an ADS1115ADC module. The detection logic is as follows: Figure 6 As shown:

[0054] A Howland current pump is used to inject a sinusoidal current signal with a frequency of 1kHz and an amplitude of 50mA into the circuit. The main circuit is isolated from the measurement circuit by an ISO124 isolation amplifier. The isolated signal passes through a bandpass filter to filter out low-frequency signals or noise. Finally, it is input into the ADC module of the microcontroller unit. Combined with RMS (effective value) calculation, the voltage drop of the contact under the 1kHz, 50mA sinusoidal current is obtained. Finally, according to Ohm's law R = U / I (where U is the measured voltage drop and I is the injected 50mA current), the contact resistance of the contact is calculated.

[0055] Figure 7 This is the circuit schematic diagram of the contact resistance acquisition module.

[0056] The current pump circuit consists of the OPA548T operational amplifier U5 in the upper left corner. Resistors R6, R7, R4, and R5 implement the Howland current pump function, converting the input signal into a stable 1kHz, 50mA sinusoidal current signal and outputting it to both ends of the contact.

[0057] U6 in the upper right corner is the isolation amplifier ISO124. Its input is the signal at both ends of the contact. The input signal is electrically isolated by the isolation amplifier and then output, making the main circuit and the measurement circuit electrically independent of each other to avoid interference.

[0058] The circuit in the lower left corner, composed of L1, C2, C3, and L2, is a bandpass filter that filters the isolated signal, allowing only sinusoidal signals of around 1kHz to pass through, suppressing noise and interference signals of other frequencies, and making the signal output to subsequent circuits purer.

[0059] U7 in the lower right corner is the analog-to-digital converter ADS1115 of the microcontroller unit, which converts the filtered analog voltage signal into a digital signal, communicates with the microcontroller through the SDA and SCL pins, and transmits the digital signal to the microcontroller so that the microcontroller can perform RMS calculations and subsequent contact resistance solutions.

[0060] Figure 8 This is the circuit schematic diagram of the voltage acquisition module.

[0061] The voltage signal across the sample switch contacts is first connected to the HCPL-7840 optical isolator U4, which electrically isolates the input and output sides. The signal is then output to the INA826AIDR instrumentation amplifier via U4_VOUT+ and U4_VOUT-. The resistor configuration, such as R18 and R19, determines the amplification factor. The instrumentation amplifier amplifies the input signal, increasing its amplitude and making weak voltage signals easier to detect and process. The amplified signal passes through the voltage divider circuit formed by R1, R2, and R3, adjusting the signal amplitude to a range suitable for the ADC input. C1 provides filtering and stabilization. The final processed signal is connected to the ADC for subsequent processing and analysis by the microcontroller.

[0062] Figure 9 This is a schematic diagram of the pin connections of the main control chip of the microcontroller unit.

[0063] Figure 10 This is a signal processing block diagram of the protection system of this embodiment.

[0064] As shown in the figure, the temperature acquisition module communicates with the MCU via the IIC protocol. The MCU uses its built-in ADC converter to read the analog current signal output by the current acquisition module and the analog voltage signal output by the voltage acquisition module. The MCU also uses the IIC protocol to obtain resistance data collected by the contact resistance acquisition module. The MCU uses the acquired current information for the secondary protection process and the acquired temperature information for dynamic timeout threshold adjustment. The MCU also uploads the acquired information from each module to the server and displays it on the web page. This information includes the voltage across the contacts of the test main circuit, the sample surface temperature, and the contact resistance of the sample contacts.

[0065] Figure 11 This is a processing flow chart of the protection system in this embodiment.

[0066] 1) When the sample is powered on, the single-chip microcomputer unit first obtains information from the voltage acquisition module, current acquisition module, temperature acquisition module, and contact resistance acquisition module;

[0067] 2) The MCU unit uploads the acquired information of each module to the server and displays it on the web page;

[0068] 3) The single chip unit determines whether the current, temperature and resistance data it obtains exceed the graded protection current set by the user and whether the sample surface temperature exceeds the maximum temperature T set by the user. max 2. Check whether the contact resistance of the sample contacts is abnormal;

[0069] 4) If there is an abnormality, the single chip unit controls the contactor to cut off the test main circuit and upload the test abnormality information to the server and display it on the web page;

[0070] 5) If the user issues a command through the web page on the remote control terminal, the command is sent to the MCU unit through the server. The MCU unit unpacks the command and executes the corresponding action or updates the corresponding data;

[0071] 6) If the test cycle is completed, the single-chip microcomputer unit will upload the test completion information to the web page through the server for remote display and control to cut off the test main circuit;

[0072] 7) The single chip microcomputer unit stores the test data on the server.

[0073] Figure 12 Another system architecture of the protection system of the present invention is illustrated.

[0074] The protection system includes three protection devices, each of which corresponds to the main circuit monitoring of a sample. Each protection device includes a cut-off protection device, a temperature acquisition module, a current acquisition module, a contact resistance acquisition module, and a voltage acquisition module. Figure 13As shown in Figure 1, three protections share one MCU unit. This architecture helps reduce the number of MCUs used, thereby reducing the hardware cost of the system.

[0075] In addition to the advantages stated above, the protection system of the present invention also has the following effects:

[0076] The protection system of the present invention stores durability test data on a server, enhancing the traceability of sample test data. Furthermore, its remote monitoring and operation capabilities improve testing efficiency, resolving the issue of traditional protection systems relying on local monitoring. Furthermore, the single-chip microcomputer unit of the protection system of the present invention automatically monitors the testing process, reducing reliance on manual labor.

Claims

1. An IoT-based intelligent controller durability test protection system, comprising a timeout detection unit and a circuit-cutting device connected in series to the main circuit of the intelligent controller durability test. The timeout detection unit detects that the power-on time of the main circuit has reached a set time threshold t timeout When the circuit breaker is turned off, the circuit breaker is controlled to turn off the main circuit; It is characterized in that The timeout detection unit dynamically adjusts the time threshold t according to the surface temperature of the intelligent controller being measured. timeout The higher the surface temperature, the greater the time threshold t timeout The smaller.

2. The protection system according to claim 1, characterized in that The time threshold t timeout The specific adjustments are as follows: t timeout =t0*(1+kT now ) Where t0 represents the initial time threshold, T now Indicates the current sampled value of temperature, T now Less than the maximum temperature limit T max , k is the temperature correction coefficient, which is a negative value; And in T now Reaching the maximum temperature limit T max When, that is, T now ≧T max , the single chip microcomputer unit controls the circuit cut-off device to disconnect the main circuit.

3. The protection system according to claim 2, characterized in that The timeout detection unit is composed of a single-chip microcomputer unit, a current acquisition module and a temperature acquisition module. The protection system also includes a contact resistance acquisition module. The temperature acquisition module, the current acquisition module and the contact resistance acquisition module are all connected to the single-chip microcomputer unit. The current acquisition module is connected in series in the main circuit and is used to collect the current of the main circuit. The contact resistance acquisition module is connected to the switch contacts of the intelligent controller and is used to collect the contact resistance information of the switch contacts and output the collected current and resistance information to the single-chip microcomputer unit.

4. The protection system according to claim 1, 2 or 3, characterized in that: The protection system also includes a server and a remote control terminal. The single-chip microcomputer unit uploads the collected data information and the test abnormality information determined thereby to the server. The server stores the information and displays it on the web page. The remote control terminal issues control instructions through the web page and transmits them to the single-chip microcomputer unit through the server for execution.

5. The protection system according to claim 3, characterized in that The single chip unit adopts a hierarchical monitoring strategy according to the current information collected by the current collection module, and adopts different corresponding measures for each level.

6. The protection system according to claim 3, characterized in that The protection system includes more than one protection device, each of which corresponds to the monitoring of the main circuit of the intelligent controller, including the cut-off protection device, the temperature acquisition module, the current acquisition module, the contact resistance acquisition module, and the voltage acquisition module. Some or all of these protection devices share one single-chip computer unit.

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