Overheating detection method and system for electric fireplace

Abstract

The invention relates to the technical field of electric appliance safety monitoring, and discloses an overheating detection method and system for an electric fireplace, and the method comprises the steps: collecting an initialization reference and real-time operation data, carrying out the denoising and alignment processing, and obtaining synchronous operation monitoring data; calculating a theoretical temperature rise difference value and an actual temperature rise difference value according to the synchronous operation monitoring data to obtain a thermoelectric response deviation degree; performing dual abnormality verification on the synchronous operation monitoring data and the thermoelectric response deviation degree to obtain an overheating risk judgment result; and performing graded protection according to the overheating risk judgment result, and performing closed-loop verification based on secondary current feedback. According to the method, the overheating hidden danger can be accurately identified through the thermoelectric coupling model, a closed-loop feedback mechanism is utilized to prevent adhesion failure of the relay, and the equipment safety is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of electrical safety monitoring technology, and in particular to an overheat detection method and system for electric fireplaces. Background Technology

[0002] Currently, with the rapid development of IoT technology and smart homes, users have put forward higher requirements for the safety performance of electric heating equipment. Introducing the mature industrial field of Prognostics and Health Management (PHM) technology concepts into home appliances has become an important direction for industry technology upgrading.

[0003] In existing technologies, overheat protection schemes for electric fireplaces typically rely on independent physical thermostats (such as bimetallic switches) or threshold judgment logic based on a single thermistor (NTC). Their working principle involves real-time acquisition of temperature data from the furnace cavity or air vents. Once the detected temperature exceeds a factory-preset fixed safety limit (e.g., 105°C), the control circuit directly cuts off the power to the heating element to prevent fire. However, existing technologies lack effective closed-loop detection methods for fatal actuator failures such as relay contact oxidation and adhesion, easily leading to an uncontrolled situation where "the command has been issued but heating has not stopped," posing a serious safety hazard.

[0004] Existing technologies lack the ability to dynamically perceive the health status of equipment. Summary of the Invention

[0005] This invention provides a method and system for detecting overheating in electric fireplaces, addressing the lack of dynamic sensing capabilities for the health status of equipment in existing technologies.

[0006] In a first aspect, to solve the above-mentioned technical problems, the present invention provides an overheat detection method for an electric fireplace, comprising: During the power-on initialization phase of the electric fireplace, ambient temperature data and current zero-point drift are collected to establish initial reference parameters for the system, including ambient reference temperature and current zero-point reference. The real-time operating temperature and real-time load current of the electric fireplace are collected, and noise reduction processing is performed in combination with the initial reference parameters of the system, and reference alignment processing is performed to obtain synchronous operation monitoring data. Based on the real-time load current and the preset heating coefficient, the theoretical temperature rise at the current moment is calculated, and the actual temperature rise relative to the ambient reference temperature is calculated. The difference between the theoretical temperature rise and the actual temperature rise is calculated to obtain the thermoelectric response deviation. The synchronous operation monitoring data and the thermoelectric response deviation are subjected to dual anomaly verification to determine whether the real-time operating temperature exceeds the preset absolute safety threshold and whether the thermoelectric response deviation shows a continuous divergence trend, so as to obtain the overheating risk judgment result. If the overheating risk assessment result indicates that there is a risk, a heating interruption command with the highest priority is generated and written into the power control unit to cut off the heating output; Within a preset delay time after the heating interruption command is executed, the real-time load current is collected a second time. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered.

[0007] In one optional implementation, during the power-on initialization phase of the electric fireplace, the process of collecting ambient temperature data and current zero-point drift to establish initial system reference parameters including an ambient reference temperature and a current zero-point reference includes: When the main control unit of the electric fireplace is started and the heating element is not powered on, the temperature sensor values ​​are continuously read and the arithmetic average is calculated. Determine whether the arithmetic mean is within a preset reasonable ambient temperature range. If it is within the range, then set it as the ambient reference temperature. If the temperature exceeds the range, the pre-stored historical default ambient temperature will be used as the ambient reference temperature. The original voltage signal of the current sensor is read synchronously, the static noise floor value of the original voltage signal is extracted, and the static noise floor value is set as the current zero point reference. The ambient reference temperature and the current zero-point reference are stored in a non-volatile memory as the initial reference parameters of the system for this operating cycle.

[0008] In one optional implementation, the real-time operating temperature and real-time load current of the electric fireplace are collected, and noise reduction processing is performed in conjunction with the initial reference parameters of the system, followed by reference alignment processing, to obtain synchronous operation monitoring data, including: The original temperature sequence and the original current sequence are obtained at a preset sampling frequency, and the electromagnetic interference noise in the original current sequence is filtered out using a moving average filtering algorithm. Subtract the current zero-point reference from the current value after noise filtering to obtain the net load current value; Subtract the ambient reference temperature from the values ​​in the original temperature sequence to obtain the relative temperature rise value; By correlating the net load current value and the relative temperature rise value at the same timestamp in a time sequence, the synchronous operation monitoring data containing the current-temperature rise correspondence is constructed.

[0009] In one optional implementation, the step of calculating the theoretical temperature rise at the current moment based on the real-time load current and a preset heating coefficient, and calculating the actual temperature rise of the real-time operating temperature relative to the ambient reference temperature, and performing a difference calculation between the theoretical temperature rise and the actual temperature rise to obtain the thermoelectric response deviation includes: Read the net load current value from the synchronous operation monitoring data, and calculate the estimated input power value at the current moment based on Joule's law; Obtain the relative temperature rise value from the synchronous operation monitoring data, and directly use the relative temperature rise value as the actual temperature rise value; Using the preset heating coefficient and thermal inertia time constant, a discretized first-order thermal response equation is constructed; Substitute the estimated input power into the first-order thermal response equation, and perform iterative accumulation calculations based on the theoretical temperature rise value calculated at the previous moment to generate the theoretical temperature rise value at the current moment. Calculate the algebraic difference between the actual temperature rise and the theoretical temperature rise, and take the absolute value of the algebraic difference as the thermoelectric response deviation.

[0010] In one optional implementation, the step of performing dual anomaly checks on the synchronous operation monitoring data and the thermoelectric response deviation to determine whether the real-time operating temperature exceeds a preset absolute safety threshold and whether the thermoelectric response deviation shows a continuous divergence trend, thereby obtaining an overheating risk assessment result, includes: The device reads the preset limit melting temperature threshold as the absolute safety threshold, compares the real-time operating temperature with the limit melting temperature threshold, and simultaneously calculates the difference between the current thermoelectric response deviation and the deviation at a preset historical time to obtain the deviation change slope. If the real-time operating temperature is greater than the ultimate melting temperature threshold, or if the slope of the deviation change is monitored to remain positive for a continuous preset number of sampling periods and the value of the thermoelectric response deviation at the current moment exceeds the preset tolerance range, then it is determined that the current state is high-risk, and an overheating risk determination result indicating the presence of risk is generated.

[0011] In one optional implementation, the step of generating a highest-priority heating interruption command if the overheating risk assessment result indicates a risk, and writing the heating interruption command into the power control unit to cut off the heating output, includes: If the overheating risk assessment result indicates that there is a risk, the user terminal's control input signal and timed task signal will be immediately blocked. Based on the preset physical driving characteristics of the power switching device, a digital logic level or control register configuration value corresponding to the open circuit state is constructed and defined as the heating interruption instruction; The heating interruption command is written into the microcontroller's PWM register or relay control pin to force the power switching device to disconnect and stop supplying power to the heating element.

[0012] In one optional implementation, within a preset delay time after executing the heating interruption command, the real-time load current is sampled a second time. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered, including: A millisecond-level countdown timer is started after the heating interrupt command is issued; When the countdown timer reaches the preset delay time, the real-time feedback value of the current sensor is read. If the real-time feedback value is greater than the preset shutdown residual tolerance threshold, it is determined to be a power device adhesion fault, and the buzzer or fault indicator light is driven to issue a continuous secondary hardware forced protection alarm.

[0013] Secondly, the present invention provides an overheat detection system for an electric fireplace, comprising: The initialization calibration module is used to collect ambient temperature data and current zero-point drift during the power-on initialization phase of the electric fireplace, and to establish initial reference parameters for the system, including ambient reference temperature and current zero-point reference. The data monitoring and processing module is used to collect the real-time operating temperature and real-time load current of the electric fireplace, and to perform noise reduction and reference alignment processing in combination with the initial reference parameters of the system to obtain synchronous operation monitoring data. The thermoelectric model analysis module is used to calculate the theoretical temperature rise at the current moment based on the real-time load current and the preset heating coefficient, and to calculate the actual temperature rise of the real-time operating temperature relative to the ambient reference temperature. The difference between the theoretical temperature rise and the actual temperature rise is calculated to obtain the thermoelectric response deviation. The dual logic verification module is used to perform dual anomaly verification on the synchronous operation monitoring data and the thermoelectric response deviation, to determine whether the real-time operating temperature exceeds the preset absolute safety threshold, and to determine whether the thermoelectric response deviation shows a continuous divergence trend, so as to obtain the overheating risk judgment result. The graded protection execution module is used to generate a heating interruption command with the highest priority if the overheating risk assessment result indicates that there is a risk, and write the heating interruption command into the power control unit to cut off the heating output; The closed-loop verification module is used to collect the real-time load current a second time within a preset delay time after the execution of the heating interruption command. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention collects real-time load current and constructs a thermoelectric coupling model based on Joule's law and the first-order thermal response equation to calculate the thermoelectric response deviation between theoretical temperature rise and actual temperature rise in real time. This method fundamentally breaks the passive protection limitation of traditional technology that relies only on a single fixed temperature threshold. It can deeply analyze the physical causes of temperature changes, thereby keenly capturing the early heat accumulation trend (i.e. "soft fault") caused by covering or poor ventilation. It can achieve accurate early warning (PHM) before the temperature reaches the limit melting value, which significantly improves the active safety protection capability of the equipment.

[0015] (2) This invention introduces a reasonable temperature range judgment and zero-point calibration mechanism during the power-on initialization stage, and performs dual anomaly verification by combining the absolute safety threshold and the deviation divergence trend; effectively avoids the algorithm failure caused by the false high reference or sensor noise drift due to "hot engine restart"; at the same time, by using the trend quantification judgment of continuous sampling period, it successfully filters out transient electromagnetic interference and normal thermal fluctuations, solves the technical problem that the existing technology is prone to false alarms or missed alarms under complex and variable working conditions, and ensures the high robustness and high signal-to-noise ratio of the detection system.

[0016] (3) By introducing a secondary current acquisition and closed-loop circuit breaking verification mechanism with millisecond delay after issuing the heating interruption command, the present invention can directly monitor the actual disconnection state of the power circuit. Once the residual current exceeds the tolerance threshold, it is immediately determined that the power device (such as the relay) is stuck and a secondary hardware forced alarm is triggered, thereby completely solving the fatal safety blind spot of "the command has been issued but the heating has not stopped" caused by the physical failure of the actuator in the traditional solution, and constructing a complete safety closed loop from software logic decision to hardware execution feedback. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of an overheat detection method for an electric fireplace provided in the first embodiment of the present invention; Figure 2 This is a schematic diagram of an overheat detection system for an electric fireplace provided in the second embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Reference Figure 1 The first embodiment of the present invention provides a method for detecting overheating in an electric fireplace, comprising the following steps: S11, During the power-on initialization phase of the electric fireplace, ambient temperature data and current zero-point drift are collected to establish initial reference parameters of the system, including ambient reference temperature and current zero-point reference. S12, collect the real-time operating temperature and real-time load current of the electric fireplace, and perform noise reduction processing in combination with the initial reference parameters of the system, and perform reference alignment processing to obtain synchronous operation monitoring data; S13. Calculate the theoretical temperature rise value at the current moment based on the real-time load current and the preset heating coefficient, and calculate the actual temperature rise value of the real-time operating temperature relative to the ambient reference temperature. Perform a difference calculation between the theoretical temperature rise value and the actual temperature rise value to obtain the thermoelectric response deviation. S14, perform dual anomaly verification on the synchronous operation monitoring data and the thermoelectric response deviation, determine whether the real-time operating temperature exceeds the preset absolute safety threshold, and determine whether the thermoelectric response deviation shows a continuous divergence trend, and obtain the overheating risk judgment result. S15, if the overheating risk determination result indicates that there is a risk, generate a heating interruption command with the highest priority, and write the heating interruption command into the power control unit to cut off the heating output; S16. Within a preset delay time after the heating interruption command is executed, the real-time load current is collected a second time. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered.

[0020] In step S11, during the power-on initialization phase of the electric fireplace, ambient temperature data and current zero-point drift are collected to establish initial system reference parameters including ambient reference temperature and current zero-point reference, including: When the main control unit of the electric fireplace is started and the heating element is not powered on, the temperature sensor values ​​are continuously read and the arithmetic average is calculated. Determine whether the arithmetic mean is within a preset reasonable ambient temperature range. If it is within the range, then set it as the ambient reference temperature. If the temperature exceeds the range, the pre-stored historical default ambient temperature will be used as the ambient reference temperature. The original voltage signal of the current sensor is read synchronously, the static noise floor value of the original voltage signal is extracted, and the static noise floor value is set as the current zero point reference. The ambient reference temperature and the current zero-point reference are stored in a non-volatile memory as the initial reference parameters of the system for this operating cycle.

[0021] It should be noted that data acquisition during the process of starting the electric fireplace's main control unit but before the heating element is powered on is achieved using the power-on reset logic of the microcontroller (MCU). Before executing the main loop program, the microcontroller first executes an initialization subroutine. This subroutine detects the drive level of the heating relay through GPIO pins. After confirming that it is at a low level (i.e., off state), it starts the analog-to-digital converter (ADC) to sample the temperature and current sensors. Continuously reading the temperature sensor values ​​and calculating the arithmetic mean means continuously acquiring N (e.g., 10) temperature samples at a preset initialization sampling frequency (e.g., 100Hz) and calculating their arithmetic mean to eliminate random quantization noise caused by circuit instability in a single sampling.

[0022] It is worth noting that the determination of the preset initial sampling frequency and the number of samples N is based on the noise convergence analysis of the sensor circuit during the cold start phase. The system collects a large number of raw sensor signals at the moment of power-on in a laboratory environment, calculates the standard error of the mean (SEM) as the number of samples increases, and constructs an error convergence curve. The point where the absolute value of the derivative of this curve is lower than a preset stability threshold is selected as the number of samples N. The preset stability threshold is determined based on the quantization error limit of the analog-to-digital converter (ADC). Specifically, the minimum resolution voltage value of the ADC (i.e., the voltage corresponding to 1 LSB) is calculated, and 50% of this voltage value is set as the preset stability threshold. This setting means that when the error reduction due to increasing the number of samples is less than 0.5 LSBs, further sampling is physically unable to distinguish between the effective signal and quantization noise (i.e., the marginal contribution is negligible), thus determining the optimal number of samples N. Simultaneously, combined with the maximum allowable delay time for system power-on initialization (e.g., 200ms perceptible to the user), the formula is used... The minimum frequency required to complete N data acquisitions within a limited time is calculated and used as the preset initial sampling frequency. This setting ensures that the most statistically stable initial readings are obtained without affecting the user's boot-up experience.

[0023] It should be noted that the above method for determining the initial sampling parameters (N and sampling frequency) through error convergence analysis and back-calculation elucidates the theoretical principle of parameter optimization. In the actual engineering implementation of this invention, to simplify development, the initial sampling quantity N can be directly preset to an empirical value, such as 8, 10, or 16. This value must ensure that the acquisition is completed within the time it takes for the sensor output to stabilize after electrolytic reset on the MCU. The initial sampling frequency can be set to a typical usable frequency of the MCU ADC module when handling other tasks, such as 100Hz to 1kHz. As long as a stable average ambient temperature and zero current value can be obtained, the specific sampling parameters can be adjusted according to the actual hardware performance under the guidance of the theoretical principle.

[0024] It is worth noting that the preset reasonable ambient temperature range is determined based on statistical analysis of historical cold-state start-up data of the electric fireplace. The system collected initial temperature data from all normal starts (i.e., the last shutdown time exceeding 2 hours) of this model of electric fireplace over the past year, and constructed a probability distribution model of the start-up temperature. The 99% confidence interval of this distribution (e.g., [0℃, 45℃]) was selected as the preset reasonable ambient temperature range. This setting aims to identify hot-start scenarios (i.e., restarting immediately after the user has turned off the fireplace) and prevent the reference temperature from being artificially high due to residual heat from the sensor, thus masking the subsequent true temperature rise. The pre-stored historical default ambient temperature (e.g., 25℃) is the mathematical expectation value of this probability distribution.

[0025] It should be noted that extracting the static noise floor value refers to reading the output voltage value of the Hall current sensor or shunt when no current flows through the heating circuit. This voltage value is not theoretically 0V, but includes the noise floor caused by the op-amp offset voltage and ADC zero-point drift. Setting this as the current zero-point reference means that all subsequent current readings will be subtracted from this reference value, thereby achieving zero-point calibration at the hardware level.

[0026] For example, when the electric fireplace is powered on, the initialization program detects that the relay control pin is at a low level. The system continuously collects temperature data 10 times and calculates an average value of 65℃. The system determines that 65℃ exceeds the reasonable ambient temperature range of [0℃, 45℃] (determining it as a warm-up restart), and therefore forcibly uses 25℃ as the ambient reference temperature. Simultaneously, the current sensor voltage is collected as 0.02V (theoretically it should be 0V), and this is set as the current zero-point reference. Finally, the parameter combination {T_base=25.0, I_zero=0.02} is written into the EEPROM as the reference for this operation.

[0027] In step S12, the real-time operating temperature and real-time load current of the electric fireplace are collected, and noise reduction processing is performed in conjunction with the initial reference parameters of the system. Reference alignment processing is then performed to obtain synchronous operation monitoring data, including: The original temperature sequence and the original current sequence are obtained at a preset sampling frequency, and the electromagnetic interference noise in the original current sequence is filtered out using a moving average filtering algorithm. Subtract the current zero-point reference from the current value after noise filtering to obtain the net load current value; Subtract the ambient reference temperature from the values ​​in the original temperature sequence to obtain the relative temperature rise value; By correlating the net load current value and the relative temperature rise value at the same timestamp in a time sequence, the synchronous operation monitoring data containing the current-temperature rise correspondence is constructed.

[0028] It should be noted that acquiring the original temperature and current sequences at a preset sampling frequency is achieved by triggering a dual-channel analog-to-digital converter (ADC) via a timer interrupt from the microcontroller. The system is configured with a high-precision timer that triggers an interrupt at fixed time intervals (e.g., 100 milliseconds). This fixed time interval is based on spectral analysis of the load current changes in the electric fireplace. The system collects current waveform data from the electric fireplace under laboratory conditions when it frequently switches between different power levels, performs a Fast Fourier Transform (FFT) on the data, and identifies the highest cutoff frequency (e.g., 5Hz) of the effective load dynamic change. Subsequently, according to the Nyquist-Shannon Sampling Theorem, the sampling frequency is set to more than twice this cutoff frequency (i.e., greater than 10Hz), thus determining the 100-millisecond sampling interval. This setting ensures that the rapid changes in heating power are fully captured while avoiding the data processing burden caused by excessively high sampling rates. In the interrupt service routine, the system simultaneously reads the register values ​​from both the temperature and current sensors. This synchronous triggering mechanism ensures strict alignment of temperature and current data in the time dimension from the hardware level, effectively avoiding timing jitter caused by software polling.

[0029] It is worth noting that the preset sampling frequency (e.g., 10Hz, i.e., sampling once every 100 milliseconds) was determined based on spectral analysis of the thermal inertia time constant and current mutation characteristics of the electric fireplace. The system collects historical operating data and performs Fast Fourier Transform (FFT) on the frequency components of the current load change. According to the Nyquist sampling theorem, the sampling frequency should be at least twice the highest effective frequency of the signal. Considering that the current load fluctuates at the millisecond level at the moment the relay is activated, but the thermal effect is an integral process at the second level, selecting 10Hz can capture the rapid switching of heating power (such as PWM dimming or power level switching) while avoiding data redundancy caused by excessively high frequencies.

[0030] It should be noted that the moving average filtering algorithm is used to filter out electromagnetic interference noise, aiming to eliminate instantaneous spikes caused by relay operation or power grid fluctuations. This algorithm maintains a length of... (For example, 5) First-In-First-Out (FIFO) queue. The length The determination of the value is based on a balance analysis of the pulse interference suppression ratio and response delay of historical current data. Through simulation testing of the response speed and attenuation capability of different window sizes for step signals, the smallest integer value that can attenuate the amplitude of a single pulse interference to within 10% of the original amplitude, and whose introduced phase delay does not exceed the system control cycle (e.g., 500ms), is selected as the preset value. For each newly acquired current sampling point... The system pushes the sampled data into a queue and removes the oldest sampled point. Then, it calculates the arithmetic mean of all elements in the queue as the filtered output value. The calculation formula is: in, As a moving average index, this operation has low-pass filtering characteristics, which can smooth high-frequency electromagnetic interference and restore the true load current level.

[0031] It is worth noting that the window size of the moving average filtering algorithm... The determination of (e.g., 5) is based on a balance analysis of historical signal-to-noise ratio (SNR) and response delay. Raw current waveforms with typical electromagnetic interference (such as mobile phone signal interference and relay spark interference) are acquired and filtered using different window sizes (e.g., 3, 5, 10). The residual noise amplitude and the phase delay time of the signal response after filtering are calculated. The smallest window size that can attenuate the noise amplitude to within 10% of the original amplitude and introduce a phase delay not exceeding the system control cycle (e.g., 500ms) is selected as the preset window size.

[0032] It should be noted that the time-series correlation between the net load current value and the relative temperature rise value at the same timestamp is the process of constructing a structured data frame. The system allocates a circular buffer in memory to store the data after S11 reference correction (subtracting...). and The clean data after that is packaged into a set of time-state tuples. .in, This represents the actual heating current after deducting background noise. This represents the actual temperature rise caused by the work done by the current. This data structure provides a standardized input interface for the thermoelectric model calculation based on energy conservation in the subsequent step S13.

[0033] It is worth noting that the preset current sensor sensitivity coefficient The determination of the sensitivity coefficient is based on standard linearity calibration of the Hall current sensor. In a laboratory environment, the system uses a high-precision constant current source to output a series of standard current values ​​covering the range (e.g., from 0A to 20A, in 0.5A increments), simultaneously recording the voltage response at the sensor output. Linear regression analysis is performed on the acquired current-voltage data using the least squares method, and the slope of the fitted straight line is extracted as the sensitivity coefficient. Compared to directly using the nominal values ​​from the datasheet, this method can effectively eliminate individual differences caused by device manufacturing tolerances, ensuring the accuracy of physical quantity conversion.

[0034] For example, in At this time, the timer triggers sampling. The initial temperature reading is 55.0℃, and the initial current sensor voltage reading is 0.05V (corresponding to an uncalibrated voltage value). At this point, the reference parameters determined in S11 are... ℃, V. First, the current and voltage values ​​enter a sliding filter queue of length 5, and the filtered voltage is calculated to be 0.048V. Next, reference alignment and physical quantity conversion are performed, and the net voltage difference is calculated. V; Call the preset current sensor sensitivity coefficient (For example, 0.01V / A, this parameter is determined by the datasheet of the selected Hall sensor), calculate the net load current. A; simultaneously, calculate the relative temperature rise. ℃. Finally, the system constructs a synchronous running monitoring data frame {Timestamp:10500ms,Current_Net:2.8A,Temp_Rise:30.0C} and stores it in the buffer.

[0035] In step S13, based on the real-time load current and the preset heating coefficient, the theoretical temperature rise at the current moment is calculated, and the actual temperature rise relative to the ambient reference temperature is calculated. The difference between the theoretical temperature rise and the actual temperature rise is calculated to obtain the thermoelectric response deviation, including: Read the net load current value from the synchronous operation monitoring data, and calculate the estimated input power value at the current moment based on Joule's law; Obtain the relative temperature rise value from the synchronous operation monitoring data, and directly use the relative temperature rise value as the actual temperature rise value; Using the preset heating coefficient and thermal inertia time constant, a discretized first-order thermal response equation is constructed; Substitute the estimated input power into the first-order thermal response equation, and perform iterative accumulation calculations based on the theoretical temperature rise value calculated at the previous moment to generate the theoretical temperature rise value at the current moment. Calculate the algebraic difference between the actual temperature rise and the theoretical temperature rise, and take the absolute value of the algebraic difference as the thermoelectric response deviation.

[0036] It should be noted that the estimated input power value calculated based on Joule's law at the current moment is the net load current value obtained in S12. The square root is a physical quantity characterizing the heating power of the system. This is due to the resistance of the heating wire in the electric fireplace. It is relatively stable at high temperatures, according to Joule's law. The input power is proportional to the square of the current. In this embodiment, to simplify calculations and reduce floating-point operations, the estimated input power value is directly defined. .

[0037] It should be noted that the discretized first-order thermal response equation is constructed based on a physical model established using Newton's law of cooling and the law of conservation of energy. This model considers the electric fireplace to be a first-order thermally inertial system, whose temperature change depends on the difference between the input heat and the dissipated heat. This embodiment uses the forward Euler method to convert the continuous differential equation... Discretization yields the following recursive formula: in, This represents the theoretical temperature rise at the current moment. This is the theoretical temperature rise value from the previous moment. This is the sampling time interval (i.e., 100ms in S12). The preset heating coefficient is... The preset thermal inertia time constant is given.

[0038] It is worth noting that the preset heating coefficient With the thermal inertia time constant The determination was based on a standard step response test of the electric fireplace. Specifically, in a standard laboratory environment (no wind, 25°C), a constant rated current was applied to the electric fireplace. Record its temperature rise curve until thermal steady state is reached. Read the limiting temperature rise at thermal steady state. ,calculate This coefficient characterizes the final steady-state temperature rise capability generated by a unit current square. Find the temperature rise value on the temperature rise curve when it reaches... The time difference between that moment and the start of heating is _____. This constant characterizes the system's thermal response rate. Once these two parameters are determined, they are embedded in the program as inherent thermal fingerprint parameters of the device.

[0039] It should be noted that the iterative accumulation operation refers to the system maintaining a static variable `Last_Theory_Temp` in memory. Whenever a new data frame arrives from S12, the system calculates a new `Current_Theory_Temp` using the above equation and updates `Last_Theory_Temp`, thus achieving dynamic simulation of the heat accumulation process. This variable is reset to 0 during system startup initialization.

[0040] For example, suppose that the heating coefficient of a certain electric fireplace has been measured. Thermal inertia time constant Seconds (60000ms), sampling interval ms. Theoretical temperature rise at the previous moment. ℃. At the current moment, the net load current transmitted from S12 is... A (i.e., the estimated input power is 225), actual temperature rise ℃. Substitute into the equation to calculate the current theoretical temperature rise: Calculate the thermoelectric response deviation: The value of 4.98℃ will be sent to step S14 to determine whether there is obstructed heat dissipation or abnormal overheating trend.

[0041] In step S14, a dual anomaly check is performed on the synchronous operation monitoring data and the thermoelectric response deviation to determine whether the real-time operating temperature exceeds a preset absolute safety threshold and whether the thermoelectric response deviation shows a continuous divergence trend, thereby obtaining an overheating risk assessment result, including: The device reads the preset limit melting temperature threshold as the absolute safety threshold, compares the real-time operating temperature with the limit melting temperature threshold, and simultaneously calculates the difference between the current thermoelectric response deviation and the deviation at a preset historical time to obtain the deviation change slope. If the real-time operating temperature is greater than the ultimate melting temperature threshold, or if the slope of the deviation change is monitored to remain positive for a continuous preset number of sampling periods and the value of the thermoelectric response deviation at the current moment exceeds the preset tolerance range, then it is determined that the current state is high-risk, and an overheating risk determination result indicating the presence of risk is generated.

[0042] It should be noted that the preset limit melting temperature threshold of the reading device refers to retrieving this parameter from the protected area of ​​the microcontroller's read-only memory (Flash) or EEPROM. This limit melting temperature threshold serves as the system's physical safety baseline; regardless of the calculation model, once the actual temperature reaches this line, a forced shutdown must be initiated. The comparison between the real-time operating temperature and the limit melting temperature threshold is achieved using a simple greater-than (>) logical operation.

[0043] It is worth noting that the ultimate fusing temperature threshold (e.g., 105°C) is determined based on the heat distortion temperature (HDT) of the electric fireplace housing material and the fusing parameters of the built-in physical thermal fuse. The system selects the smaller value between 90% of the softening temperature of the housing material (such as ABS or PP) and 95% of the rated operating temperature of the physical fuse as the preset ultimate fusing temperature threshold. This setting ensures that software protection precedes physical damage, providing a recoverable level of protection.

[0044] It should be noted that the difference between the thermoelectric response deviation at the current moment and the deviation at a preset historical moment, to obtain the slope of the deviation change, is achieved using a differential calculation method. The system indexes into the circular buffer... Thermoelectric response deviation stored one sampling period ago (i.e., the preset historical time) And obtain the deviation calculated at the current time S13. The calculation formula is: Due to sampling interval and span Since it is a constant, in engineering implementations, the algebraic difference is usually calculated directly. To characterize the direction of the slope.

[0045] It is worth noting that the preset historical time (i.e., span) The determination of (e.g., 10 cycles, corresponding to 1 second) is based on the spectral analysis of the deviation signal. To avoid high-frequency measurement noise causing jitter in the slope calculation, a time span that covers the main frequency period of the noise is selected, which is equivalent to smoothing the derivative.

[0046] It should be noted that the monitoring of the slope of the deviation change remaining positive within a preset number of sampling periods is achieved using a counter accumulation mechanism. The system sets a software counter, Trend_Counter, which increments the slope of the current period. (i.e., the deviation is increasing), then Trend_Counter is incremented by 1; if If the deviation converges or remains constant, Trend_Counter is cleared to zero. Only when the value of Trend_Counter exceeds the preset number of consecutive sampling periods (e.g., 50, corresponding to 5 seconds) is the continuous divergence condition considered met. This mechanism effectively filters out instantaneous positive slope jumps caused by occasional sensor fluctuations.

[0047] It is worth noting that the determination of the continuously preset number of sampling periods (e.g., 50) is based on ROC curve (Receiving Controller Characteristic) analysis. By replaying historical fault data and normal perturbation data, the true positive rate (TPR) and false positive rate (FPR) at different counting thresholds are tested. The threshold that maximizes the Youden index (TPR-FPR) is selected to balance response speed and anti-interference ability.

[0048] It should be noted that the preset tolerance range (e.g., ±5℃) is determined based on statistical analysis of thermal fluctuations under normal steady-state operation of the system. The system statistically analyzes the deviation distribution of the electric fireplace during stable operation at rated power and calculates its standard deviation. . The interval The preset tolerance range is set. This ensures that an alarm is triggered only when the deviation is not only increasing (with a positive slope) but also when the absolute value has significantly exceeded the normal thermal noise range, preventing false alarms caused by slight model mismatch in the early stages of cold start-up.

[0049] For example, the current real-time temperature is 95℃, which is below the threshold of 105℃ (first-level verification passed). The system calculates the deviation slope; the current deviation is 12℃, and the deviation one second ago was 11.8℃, a difference of +0.2℃ (positive). Since the slope is positive, the counter increments by 1, and the current count reaches 51 (exceeding the preset 50). The current deviation of 12℃ is greater than the preset tolerance limit of 5℃. Based on this, although the absolute temperature is not exceeded, the system determines it as a high-risk condition due to persistent and excessively large deviations (e.g., obstructed heat dissipation), generating an overheating risk assessment result RISK_LEVEL_HIGH.

[0050] In step S15, if the overheating risk assessment result indicates a risk, a heating interruption command with the highest priority is generated, and the heating interruption command is written to the power control unit to cut off the heating output, including: If the overheating risk assessment result indicates that there is a risk, the user terminal's control input signal and timed task signal will be immediately blocked. Based on the preset physical driving characteristics of the power switching device, a digital logic level or control register configuration value corresponding to the open circuit state is constructed and defined as the heating interruption instruction; The heating interruption command is written into the microcontroller's PWM register or relay control pin to force the power switching device to disconnect and stop supplying power to the heating element.

[0051] It should be noted that immediately blocking user-side control input signals and timed task signals is achieved using the forced jump logic of a software state machine (FSM). A global state variable, System_State, is defined in the system's main loop or interrupt service routine. When the RISK_LEVEL_HIGH result is received, the system immediately switches System_State from NORMAL_RUN (normal operation state) to EMERGENCY_LOCK (emergency lock state). In the EMERGENCY_LOCK state, all key scanning functions, infrared remote control receiving functions, and timer callback functions (such as a preset 2-hour automatic shutdown countdown) are bypassed or directly returned, no longer responding to any new user commands. This prevents the user from unknowingly reactivating the faulty device through accidental remote control operations (such as powering on or increasing the power level).

[0052] It should be noted that the heating interrupt instruction, constructed based on the preset physical drive characteristics of the power switching device, is implemented through the configuration of the Hardware Abstraction Layer (HAL). During the initialization phase, the system reads the hardware configuration file stored in Flash, which defines the specific type of the power control unit (relay or thyristor) and its effective drive level (Active-High or Active-Low). If the device is a relay, and the physical drive characteristic is defined as "low level to engage, high level to disengage," then the digital logic level constructed by the system is GPIO_PIN_SET (high level). If the device is a triac, and the physical drive characteristic is defined as "PWM duty cycle controls the conduction angle," then the control register configuration value constructed by the system is TIM_CCR_VAL=0 (0% duty cycle). These two forms of control data constitute the heating interrupt instruction.

[0053] It is worth noting that the determination of the physical driving characteristics of the preset power switching devices is based on the circuit design schematic and the power device datasheet, which are pre-fixed during the firmware development stage. For example, the base connection method (NPN or PNP) of the relay driver transistor is confirmed according to the schematic, and combined with the transistor's saturation conduction condition, it is determined what level of output of the MCU pin can de-energize the relay coil.

[0054] It should be noted that writing the heating interrupt instruction to the microcontroller's PWM register or relay control pin performs the final physical cut-off action. This operation is implemented by directly manipulating the MCU's underlying registers (Direct RegisterAccess) to ensure maximum execution efficiency. For example, for relay control, the system calls GPIO_WriteBit(PORT_HEATER,PIN_RELAY,Bit_SET); for PWM control, the system calls TIM_SetCompare1(TIM_HEATER,0). To prevent program crashes that could cause the I / O port state to toggle, this operation is usually combined with a watchdog refresh mechanism and repeatedly executed in a safe loop to force the power switching device (relay contacts open or SCR cut off), thereby physically cutting off the 220V / 110V main circuit current flowing to the heating element.

[0055] For example, the system detects an overheating risk. The global state is set to LOCK. When the user presses the heating button on the remote control, the system detects the LOCK state and ignores the button event. Reading the configuration, it knows that the currently controlled object is a relay, and the drive circuit is low-active. Therefore, to disconnect, a high-level instruction needs to be constructed. The MCU writes logic 1 (3.3V) to a control pin (e.g., PA5). The transistor cuts off, the relay coil is de-energized, the normally open contact pops open, and the heating wire is de-energized.

[0056] In step S16, within a preset delay time after executing the heating interruption command, the real-time load current is sampled a second time. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered, including: A millisecond-level countdown timer is started after the heating interrupt command is issued; When the countdown timer reaches the preset delay time, the real-time feedback value of the current sensor is read. If the real-time feedback value is greater than the preset shutdown residual tolerance threshold, it is determined to be a power device adhesion fault, and the buzzer or fault indicator light is driven to issue a continuous secondary hardware forced protection alarm.

[0057] It should be noted that starting a millisecond-level countdown timer after issuing the heating interrupt command is to reserve buffer time for the physical action of the power switching device. Whether it's a mechanical relay or a solid-state relay, there is an inherent mechanical delay or turn-off delay from receiving a control level change to the complete disconnection of the physical contacts or the cutoff of the conduction channel. If the current is read immediately upon issuing the command, residual current that has not been completely cut off is likely to be read, leading to misjudgment. This embodiment utilizes the microcontroller's hardware timer to configure a single-trigger interrupt event.

[0058] It is worth noting that the preset delay time (e.g., 500 milliseconds) is determined based on a joint analysis of the datasheet parameters of the selected power devices and actual aging test data. Specifically, the maximum release time (e.g., 10ms) in the relay specifications is consulted, taking into account the tendency of contacts to oxidize and stick after long-term use and the arc extinguishing time. The system selects 50 times the maximum release time as a safety redundancy delay to ensure that the normal physical shutdown process has necessarily ended when secondary data acquisition is performed.

[0059] It should be noted that reading the real-time feedback value from the current sensor involves restarting the ADC to sample the current loop. This sampling no longer requires the complex moving average filtering performed in S12; instead, it uses a single fast sampling or a short-window (e.g., 3 times) average to obtain the transient current state, which is the aforementioned real-time feedback value.

[0060] It should be noted that if the real-time feedback value exceeds the preset shutdown residual tolerance threshold, it is determined to be a power device sticking fault. This is a logical judgment based on physical facts. In S15, a disconnect command has already been issued; theoretically, the circuit should be open and the current should be zero. If the current still exists at this time (and is significantly greater than the noise floor), the only physical reason is that the power device (relay contact or thyristor) has undergone physical welding or short-circuiting, resulting in an inability to disconnect under control. This fault is called sticking, and it is the most dangerous runaway mode in electric heating equipment.

[0061] It is worth noting that the preset shutdown residual tolerance threshold (e.g., 0.1A) is determined based on statistical process control (SPC) analysis of the circuit board's static leakage current and sensor zero-point drift. The system collects a large amount of system current noise floor data in the shutdown state and calculates its mean. and standard deviation .Will Set to the aforementioned shutdown residual tolerance threshold. This setting tolerates the sensor's own slight zero drift while still being able to sensitively detect any substantial load current (the operating current of an electric fireplace heating wire is typically above 5A, much greater than 0.1A).

[0062] It should be noted that the continuous secondary hardware forced protection alarm emitted by the driving buzzer or fault indicator light is the highest level of user alarm mechanism. The system drives a passive buzzer via a PWM module to emit a high-frequency (e.g., 3kHz) high-duty-cycle sharp beep, while simultaneously controlling the red fault indicator light to flash at a high frequency (e.g., 5Hz). This continuous alarm aims to convey an emergency signal to the user that "the equipment is out of control; please unplug the power cord immediately," until the system is completely powered off. Because in the case of an adhesion fault, the MCU's software control is ineffective, and only manual physical power disconnection can eliminate the fire hazard.

[0063] In summary, this invention constructs a full-chain overheat detection process, from establishing initial reference parameters during the power-on initialization phase, denoising and aligning real-time data, to iterative calculation of theoretical temperature rise and acquisition of thermoelectric response deviation based on the discretized first-order thermal response equation, to performing dual anomaly checks including absolute safety threshold determination and deviation divergence trend monitoring, and finally generating a heating interruption command and performing closed-loop circuit breaking verification based on secondary current acquisition. This achieves real-time dynamic monitoring and proactive fault defense of the thermoelectric energy conversion process of electric fireplaces, effectively solving the safety hazards caused by the lag in single temperature threshold determination and the inability to identify power device adhesion faults in existing technologies, and significantly improving the fault prediction capability and operational safety of electric fireplace systems.

[0064] Reference Figure 2 The second embodiment of the present invention provides an overheat detection system for an electric fireplace, comprising: The initialization calibration module is used to collect ambient temperature data and current zero-point drift during the power-on initialization phase of the electric fireplace, and to establish initial reference parameters for the system, including ambient reference temperature and current zero-point reference. The data monitoring and processing module is used to collect the real-time operating temperature and real-time load current of the electric fireplace, and to perform noise reduction and reference alignment processing in combination with the initial reference parameters of the system to obtain synchronous operation monitoring data. The thermoelectric model analysis module is used to calculate the theoretical temperature rise at the current moment based on the real-time load current and the preset heating coefficient, and to calculate the actual temperature rise of the real-time operating temperature relative to the ambient reference temperature. The difference between the theoretical temperature rise and the actual temperature rise is calculated to obtain the thermoelectric response deviation. The dual logic verification module is used to perform dual anomaly verification on the synchronous operation monitoring data and the thermoelectric response deviation, to determine whether the real-time operating temperature exceeds the preset absolute safety threshold, and to determine whether the thermoelectric response deviation shows a continuous divergence trend, so as to obtain the overheating risk judgment result. The graded protection execution module is used to generate a heating interruption command with the highest priority if the overheating risk assessment result indicates that there is a risk, and write the heating interruption command into the power control unit to cut off the heating output; The closed-loop verification module is used to collect the real-time load current a second time within a preset delay time after the execution of the heating interruption command. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered.

[0065] It should be noted that the overheat detection system for an electric fireplace provided in this embodiment of the invention is used to execute all the process steps of the overheat detection method for an electric fireplace in the above embodiment. The working principles and beneficial effects of the two are one-to-one, so they will not be described again.

[0066] This invention also provides an electronic device. The electronic device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, such as an overheat detection program for an electric fireplace. When the processor executes the computer program, it implements the steps in the various embodiments of the overheat detection method for an electric fireplace described above, for example... Figure 1 The step S11 shown. Alternatively, when the processor executes the computer program, it implements the functions of each module / unit in the above system embodiments, such as initializing the calibration module.

[0067] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the electronic device.

[0068] The electronic device may be a desktop computer, laptop, handheld computer, or smart tablet, etc. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above components are merely examples of electronic devices and do not constitute a limitation on the electronic device. It may include more or fewer components than described above, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0069] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the electronic device, connecting all parts of the electronic device via various interfaces and lines.

[0070] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0071] If the modules / units integrated into the electronic device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or system capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0072] It should be noted that the system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the system embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for detecting overheating in an electric fireplace, characterized in that, include: During the power-on initialization phase of the electric fireplace, ambient temperature data and current zero-point drift are collected to establish initial reference parameters for the system, including ambient reference temperature and current zero-point reference. The real-time operating temperature and real-time load current of the electric fireplace are collected, and noise reduction processing is performed in combination with the initial reference parameters of the system, and reference alignment processing is performed to obtain synchronous operation monitoring data. Based on the real-time load current and the preset heating coefficient, the theoretical temperature rise at the current moment is calculated, and the actual temperature rise relative to the ambient reference temperature is calculated. The difference between the theoretical temperature rise and the actual temperature rise is calculated to obtain the thermoelectric response deviation. The synchronous operation monitoring data and the thermoelectric response deviation are subjected to dual anomaly verification to determine whether the real-time operating temperature exceeds the preset absolute safety threshold and whether the thermoelectric response deviation shows a continuous divergence trend, so as to obtain the overheating risk judgment result. If the overheating risk assessment result indicates that there is a risk, a heating interruption command with the highest priority is generated and written into the power control unit to cut off the heating output; Within a preset delay time after the heating interruption command is executed, the real-time load current is collected a second time. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered.

2. The overheat detection method for an electric fireplace according to claim 1, characterized in that, During the power-on initialization phase of the electric fireplace, ambient temperature data and current zero-point drift are collected to establish initial system reference parameters that include ambient reference temperature and current zero-point reference, including: When the main control unit of the electric fireplace is started and the heating element is not powered on, the temperature sensor values ​​are continuously read and the arithmetic average is calculated. Determine whether the arithmetic mean is within a preset reasonable ambient temperature range. If it is within the range, then set it as the ambient reference temperature. If the temperature exceeds the range, the pre-stored historical default ambient temperature will be used as the ambient reference temperature. The original voltage signal of the current sensor is read synchronously, the static noise floor value of the original voltage signal is extracted, and the static noise floor value is set as the current zero point reference. The ambient reference temperature and the current zero-point reference are stored in a non-volatile memory as the initial reference parameters of the system for this operating cycle.

3. The overheat detection method for an electric fireplace according to claim 1, characterized in that, The real-time operating temperature and real-time load current of the electric fireplace are collected, and noise reduction processing is performed in conjunction with the initial reference parameters of the system. Reference alignment processing is then performed to obtain synchronous operation monitoring data, including: The original temperature sequence and the original current sequence are obtained at a preset sampling frequency, and the electromagnetic interference noise in the original current sequence is filtered out using a moving average filtering algorithm. Subtract the current zero-point reference from the current value after noise filtering to obtain the net load current value; Subtract the ambient reference temperature from the values ​​in the original temperature sequence to obtain the relative temperature rise value; By correlating the net load current value and the relative temperature rise value at the same timestamp in a time sequence, the synchronous operation monitoring data containing the current-temperature rise correspondence is constructed.

4. The overheat detection method for an electric fireplace according to claim 1, characterized in that, The process involves calculating the theoretical temperature rise at the current moment based on the real-time load current and a preset heating coefficient, and calculating the actual temperature rise relative to the ambient reference temperature. The difference between the theoretical and actual temperature rise is then calculated to obtain the thermoelectric response deviation, including: Read the net load current value from the synchronous operation monitoring data, and calculate the estimated input power value at the current moment based on Joule's law; Obtain the relative temperature rise value from the synchronous operation monitoring data, and directly use the relative temperature rise value as the actual temperature rise value; Using the preset heating coefficient and thermal inertia time constant, a discretized first-order thermal response equation is constructed; Substitute the estimated input power into the first-order thermal response equation, and perform iterative accumulation calculations based on the theoretical temperature rise value calculated at the previous moment to generate the theoretical temperature rise value at the current moment. Calculate the algebraic difference between the actual temperature rise and the theoretical temperature rise, and take the absolute value of the algebraic difference as the thermoelectric response deviation.

5. The overheat detection method for an electric fireplace according to claim 1, characterized in that, The process of performing dual anomaly checks on the synchronous operation monitoring data and the thermoelectric response deviation to determine whether the real-time operating temperature exceeds a preset absolute safety threshold and whether the thermoelectric response deviation shows a continuous divergence trend, thereby obtaining an overheating risk assessment result, includes: The device reads the preset limit melting temperature threshold as the absolute safety threshold, compares the real-time operating temperature with the limit melting temperature threshold, and simultaneously calculates the difference between the current thermoelectric response deviation and the deviation at a preset historical time to obtain the deviation change slope. If the real-time operating temperature is greater than the ultimate melting temperature threshold, or if the slope of the deviation change is monitored to remain positive for a continuous preset number of sampling periods and the value of the thermoelectric response deviation at the current moment exceeds the preset tolerance range, then it is determined that the current state is high-risk, and an overheating risk determination result indicating the presence of risk is generated.

6. The overheat detection method for an electric fireplace according to claim 1, characterized in that, If the overheating risk assessment result indicates a risk, a heating interruption command with the highest priority is generated, and the heating interruption command is written to the power control unit to cut off the heating output, including: If the overheating risk assessment result indicates that there is a risk, the user terminal's control input signal and timed task signal will be immediately blocked. Based on the preset physical driving characteristics of the power switching device, a digital logic level or control register configuration value corresponding to the open circuit state is constructed and defined as the heating interruption instruction; The heating interruption command is written into the microcontroller's PWM register or relay control pin to force the power switching device to disconnect and stop supplying power to the heating element.

7. The overheat detection method for an electric fireplace according to claim 1, characterized in that, Within a preset delay time after executing the heating interrupt command, the real-time load current is collected a second time. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered, including: A millisecond-level countdown timer is started after the heating interrupt command is issued; When the countdown timer reaches the preset delay time, the real-time feedback value of the current sensor is read. If the real-time feedback value is greater than the preset shutdown residual tolerance threshold, it is determined to be a power device adhesion fault, and the buzzer or fault indicator light is driven to issue a continuous secondary hardware forced protection alarm.

8. An overheat detection system for an electric fireplace, characterized in that, include: The initialization calibration module is used to collect ambient temperature data and current zero-point drift during the power-on initialization phase of the electric fireplace, and to establish initial reference parameters for the system, including ambient reference temperature and current zero-point reference. The data monitoring and processing module is used to collect the real-time operating temperature and real-time load current of the electric fireplace, and to perform noise reduction and reference alignment processing in combination with the initial reference parameters of the system to obtain synchronous operation monitoring data. The thermoelectric model analysis module is used to calculate the theoretical temperature rise at the current moment based on the real-time load current and the preset heating coefficient, and to calculate the actual temperature rise of the real-time operating temperature relative to the ambient reference temperature. The difference between the theoretical temperature rise and the actual temperature rise is calculated to obtain the thermoelectric response deviation. The dual logic verification module is used to perform dual anomaly verification on the synchronous operation monitoring data and the thermoelectric response deviation, to determine whether the real-time operating temperature exceeds the preset absolute safety threshold, and to determine whether the thermoelectric response deviation shows a continuous divergence trend, so as to obtain the overheating risk judgment result. The graded protection execution module is used to generate a heating interruption command with the highest priority if the overheating risk assessment result indicates that there is a risk, and write the heating interruption command into the power control unit to cut off the heating output; The closed-loop verification module is used to collect the real-time load current a second time within a preset delay time after the execution of the heating interruption command. If the real-time load current does not return to zero, a secondary hardware forced protection alarm is triggered.

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