A bidirectional charging and discharging machine grid-connected abnormal working condition detection method and system for vehicle-network interaction

Abstract

The application relates to the technical field of power supply and distribution, and discloses a bidirectional charging and discharging machine grid-connected abnormal working condition detection method and system for vehicle-network interaction, wherein the method comprises the following steps: acquiring grid-connected operation sampling data composed of alternating current side current sampling signals and photovoltaic power data; adopting a threshold self-adaptive mechanism of power change feedforward and steady-state deviation cooperation to output a capture threshold; adopting a direction-related dead zone interlocking and monostable trigger mechanism to output a capture window enable signal; adopting a window-constrained pre-biased switched capacitor peak capture and junction capacitor error compensation mechanism to output a peak latching voltage; adopting a dynamic hysteresis trigger and isolation reading mechanism to output a latching event flag; and outputting protection and reset execution instructions according to the latching event flag and the peak latching voltage. The application can improve the accuracy and continuity of abnormal current peak capture, latching event verification and fault energy grading protection during grid-connected mode switching.

Description

Technical Field

[0001] This invention relates to the field of power supply and distribution technology, and in particular to a method and system for detecting abnormal grid connection conditions of a bidirectional charging and discharging machine for vehicle-to-grid interaction. Background Technology

[0002] Currently, in integrated photovoltaic-storage-charging microgrids, vehicle-to-grid (V2G) bidirectional charge / discharge machines need to rapidly switch charging and discharging modes based on the drastic fluctuations in photovoltaic power generation. The switching timing window is often compressed to less than 50ms. During this time, the AC current undergoes a rapid commutation, and the amplitude of the first half-wave transient surge becomes the core parameter for assessing the stress on power devices and triggering reliable overcurrent protection. Existing technologies typically use a microcontroller's internal analog-to-digital converter to acquire AC current at a fixed sampling rate and achieve overcurrent detection through software threshold comparison. Some designs also supplement this with a pure analog comparator to provide a fast trigger signal.

[0003] For example, when photovoltaic power suddenly drops due to cloud cover, the system instructs the bidirectional charger to switch from charging to discharging within 50ms. The direction of the alternating current reverses abruptly, and the first half of the surge can reach several times the rated current within microseconds. The total time for the microcontroller's ADC sampling conversion and software judgment exceeds 1 millisecond. Within this delay, the surge has already decayed, and the processor can only read the residual current, unable to capture the true surge peak. Using a pure analog comparator to output the overcurrent pulse can provide a fast response, but the pulse width is extremely narrow and lacks analog latching functionality. The processor cannot obtain peak amplitude information, and the overcurrent protection setting value deviates significantly from the actual stress level, creating a protection blind zone.

[0004] Therefore, there is an urgent need for a detection method that can transiently capture and latch the peak value of the first half of the surge current under the condition of rapid mode switching of photovoltaic-storage-charging microgrids without relying on real-time software interruption. This method would allow the transient peak value to be accurately latched in the form of analog voltage and safely isolated and transmitted to the digital processor for reading even when the surge signal disappears and there is no software intervention. This would enable complete recording of overcurrent events and fault energy assessment, thereby improving the time response accuracy of protection, the accuracy of fault energy assessment, and the overall reliability of grid-connected operation. Summary of the Invention

[0005] To address the aforementioned technical shortcomings, the purpose of this invention is to propose a bidirectional charging and discharging machine grid-connected abnormal operating condition detection method for vehicle-to-grid interaction. This method aims to solve the problems in existing technologies where the microcontroller's AD sampling delay prevents the capture of the first half of the surge peak, and the pure analog comparator lacks event latching functionality. In particular, it addresses the technical problem of being unable to achieve nanosecond-level transient peak capture and analog latching under conditions where the photovoltaic-storage-charging microgrid completes the mode switching from charging to discharging within 50ms and the AC side current undergoes a rapid commutation.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention provides a method for detecting abnormal grid connection conditions of bidirectional charging and discharging motors for vehicle-to-grid interaction.

[0007] The aforementioned method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction includes: Step S10: Obtain grid-connected operation sampling data composed of AC side current sampling signal and photovoltaic power data; based on the grid-connected operation sampling data, perform the capture threshold calculation task using a threshold adaptive mechanism that combines power change feedforward and steady-state deviation, and output the capture threshold. Step S20: Obtain the mode switching instruction, and based on the capture threshold and the mode switching instruction, execute the capture window generation task using the direction-related dead zone interlock and monostable triggering mechanism, and output the capture window enable signal; Step S30: Based on the capture window enable signal and the capture threshold, a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism is used to perform peak latch preprocessing tasks and output peak latch voltage. Step S40: Based on the peak latch voltage and the capture threshold, a dynamic hysteresis triggering and isolation reading mechanism is used to perform a latch event validity verification task, and the latch event flag is output; Step S50: Perform abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset according to the latching event flag and the peak latching voltage, and output protection and reset execution commands.

[0008] Preferably, in step S10, the steps of acquiring grid-connected operation sampling data composed of AC side current sampling signals and photovoltaic power data, performing a threshold calculation task based on the grid-connected operation sampling data using a threshold adaptive mechanism that combines power change feedforward and steady-state deviation, and outputting the capture threshold specifically include: Step S101: Extract the AC side current sampling signal and the photovoltaic power data from the grid-connected operation sampling data, process the photovoltaic power data according to a preset sliding time window, and obtain the real-time photovoltaic power, photovoltaic power change rate and long-term sliding average power; Step S102: Obtain the rated grid-connected current, current sensor transimpedance gain, preset mode switching surge coefficient, preset power change rate feedforward mapping coefficient, preset power deviation compensation mapping coefficient, and preset converter loss factor; determine the base threshold voltage based on the rated grid-connected current, the current sensor transimpedance gain, and the preset mode switching surge coefficient; determine the power change feedforward compensation amount based on the photovoltaic power change rate and the preset power change rate feedforward mapping coefficient; and determine the steady-state power deviation compensation amount based on the real-time photovoltaic power, the long-term moving average power, the preset power deviation compensation mapping coefficient, and the preset converter loss factor. Step S103: The base threshold voltage, the power change feedforward compensation amount, and the steady-state power deviation compensation amount are superimposed to obtain the candidate capture threshold. The candidate capture threshold is limited to the preset capture threshold lower limit and the preset capture threshold upper limit. The limited candidate capture threshold is then smoothly updated according to the preset threshold update cycle, and the capture threshold is output.

[0009] Preferably, step S20, which involves obtaining a mode switching instruction, executing a capture window generation task based on the capture threshold and the mode switching instruction using a direction-dependent dead-zone interlocking and monostable triggering mechanism, and outputting a capture window enable signal, specifically includes: Step S201: Perform transimpedance conversion on the AC side current sampling signal to obtain the sampling voltage; parse the mode switching command, determine the mode switching direction, mode switching start time and mode valid state, and generate a mode switching edge pulse according to the mode switching start time; Step S202: Determine the target dead time according to the mode switching direction, start dead timer in response to the mode switching edge pulse, compare the sampling voltage with the capture threshold after the dead timer reaches the target dead time, and trigger the monostable circuit to generate a capture window pulse when the sampling voltage crosses the capture threshold in an abnormally increasing direction. Step S203: Perform an interlock check between the capture window pulse and the mode valid state. When the interlock check passes, output the capture window enable signal. When the preset window duration is reached, the mode valid state fails, or a reset command is received, cancel the capture window enable signal.

[0010] Preferably, step S202, which involves determining the target dead time based on the mode switching direction, initiating dead time timing in response to the mode switching edge pulse, comparing the sampled voltage with the capture threshold after the dead time timing reaches the target dead time, and triggering a monostable circuit to generate a capture window pulse when the sampled voltage exceeds the capture threshold in an abnormally increasing direction, specifically includes: The target dead time is obtained by selecting the dead time corresponding to the mode switching direction from the preset dead time mapping relationship; The dead-time timing is started in response to the mode switching edge pulse, and the trigger input of the monostable circuit is blocked when the dead-time timing has not reached the target dead-time duration; When the dead timer reaches the target dead time, the shielding of the trigger input is released, and a high-speed comparator is used to detect whether the sampling voltage exceeds the capture threshold along the abnormal increase direction; When the sampling voltage exceeds the capture threshold along the abnormal increase direction, the monostable circuit enters a metastable state and maintains an effective level for the duration of the preset window, thus forming the capture window pulse; The monostable circuit is shielded from repeated triggering signals during the quasi-stable state, and the monostable circuit exits the quasi-stable state when the preset window duration is reached.

[0011] Preferably, step S30, which involves performing a peak latch preprocessing task based on the capture window enable signal and the capture threshold using a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism, and outputting the peak latch voltage, specifically includes: Step S301: When the capture window enable signal is invalid, disconnect the peak capture switch and turn on the pre-bias switch to pre-charge the energy storage capacitor to the preset bias voltage, thereby obtaining the energy storage capacitor in the pre-bias state. Step S302: When the capture window enable signal is valid, the pre-bias switch is turned off, and the sampled voltage is compared with the capture threshold by a high-speed comparator; when the sampled voltage exceeds the capture threshold, the peak capture switch is turned on, so that the charging current flows into the energy storage capacitor in the pre-bias state; when the sampled voltage stops increasing or the capture window enable signal fails, the peak capture switch is turned off to obtain the initial peak holding voltage. Step S303: Obtain the capacitance value of the energy storage capacitor and the junction capacitance value of the diode in the charging branch where the peak capture switch is located. Based on the preset bias voltage, the charging current, the capacitance value of the energy storage capacitor, the junction capacitance value, and the capture threshold, perform joint compensation of charge accumulation and junction capacitance charge distribution on the initial peak holding voltage, and output the peak latch voltage. The calculation formula for the peak latch voltage is:

[0012] in, The peak latch voltage, The preset bias voltage. Let be the capacitance value of the energy storage capacitor. The charging current, The peak capture switch is the on-time of the peak capture switch during the period when the capture window enable signal is valid. The time when the peak capture switch is turned off. Here is the junction capacitance value of the diode. The threshold voltage corresponding to the capture threshold; The integral of the charging current between the on-time and the off-time is used to characterize the cumulative charge input to the energy storage capacitor, and the ratio of the junction capacitance value to the capacitance value of the energy storage capacitor is used to characterize the charge distribution ratio caused by the diode junction capacitance when the peak capture switch is turned off.

[0013] Preferably, step S40, which involves performing a latch event validity verification task based on the peak latch voltage and the capture threshold using a dynamic hysteresis triggering and isolation reading mechanism, and outputting a latch event flag, specifically includes: Step S401: Obtain a preset high scaling factor and a preset low scaling factor; determine the rising edge trigger threshold of the Schmitt trigger based on the capture threshold and the preset high scaling factor; and determine the falling edge reset threshold of the Schmitt trigger based on the capture threshold and the preset low scaling factor, wherein the preset high scaling factor is greater than the preset low scaling factor; when the peak latch voltage exceeds the rising edge trigger threshold, enable the Schmitt trigger to output an active level, and isolate and transmit the active level to obtain a candidate latch event flag; Step S402: In response to the candidate latch event flag, a read pulse is generated, and the isolation read switch is turned on according to the read pulse. The peak latch voltage is read sequentially through the unity gain buffer and the analog-to-digital converter to obtain the peak voltage read value. Step S403: Compare the peak voltage reading with the preset validity check lower limit and the preset validity check upper limit respectively; when the peak voltage reading is between the preset validity check lower limit and the preset validity check upper limit, and the candidate latch event flag remains valid, output a latch event flag to characterize a valid latch event; otherwise, output a latch event flag to characterize an invalid latch event.

[0014] Preferably, step S50, which involves performing abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset based on the latched event flag and the peak latched voltage, and outputting protection and reset execution commands, specifically includes: Step S501: When the latching event flag indicates a valid latching event, obtain the preset bias voltage, the current sensor transimpedance gain, and the preset grid connection point equivalent inductance, determine the voltage difference between the peak latching voltage and the preset bias voltage, convert the voltage difference into an abnormal current peak value according to the current sensor transimpedance gain, and determine the fault energy according to the inductance energy storage relationship based on the abnormal current peak value and the preset grid connection point equivalent inductance. Step S502: Compare the fault energy with a preset first fault energy threshold and a preset second fault energy threshold, respectively, wherein the preset second fault energy threshold is greater than the preset first fault energy threshold; when the fault energy is less than the preset first fault energy threshold, generate a power reduction operation command; when the fault energy is greater than or equal to the preset first fault energy threshold and less than the preset second fault energy threshold, generate a drive pulse lockout command; when the fault energy is greater than or equal to the preset second fault energy threshold, generate the drive pulse lockout command and the AC contactor disconnect command. Step S503: After completing the protection action corresponding to the fault energy, a reset pulse is generated. According to the reset pulse, the capacitor discharge switch is turned on to discharge the energy storage capacitor to ground. The monostable trigger branch used to form the capture window enable signal, the peak latch branch used to form the peak latch voltage, and the Schmitt trigger branch used to form the latch event flag are reset. When the latch event flag indicates an invalid latch event, only the reset pulse is generated, and the protection and reset execution instructions are obtained by summarizing them.

[0015] This invention also provides a bidirectional charging and discharging motor grid-connected abnormal operating condition detection system for vehicle-to-grid interaction, comprising: The threshold adaptive module is used to acquire grid-connected operation sampling data composed of AC side current sampling signal and photovoltaic power data. Based on the grid-connected operation sampling data, a threshold adaptive mechanism that combines power change feedforward and steady-state deviation is used to perform the capture threshold calculation task and output the capture threshold. The window generation module is used to acquire the mode switching instruction, and based on the capture threshold and the mode switching instruction, it uses a direction-related dead zone interlocking and monostable triggering mechanism to execute the capture window generation task and outputs the capture window enable signal. The peak latch module is used to perform peak latch preprocessing tasks based on the capture window enable signal and the capture threshold using a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism, and outputs the peak latch voltage. The event verification module is used to perform a latch event validity verification task based on the peak latch voltage and the capture threshold using a dynamic hysteresis triggering and isolation reading mechanism, and output a latch event flag. The protection execution module is used to perform abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset based on the latched event flag and the peak latched voltage, and output protection and reset execution commands.

[0016] The present invention also provides a bidirectional charging and discharging machine grid connection abnormal operation condition detection device for vehicle-to-grid interaction. The bidirectional charging and discharging machine grid connection abnormal operation condition detection device for vehicle-to-grid interaction includes: a memory, a processor, and a bidirectional charging and discharging machine grid connection abnormal operation condition detection program for vehicle-to-grid interaction stored in the memory and executable on the processor. When the bidirectional charging and discharging machine grid connection abnormal operation condition detection program for vehicle-to-grid interaction is executed by the processor, the above-mentioned method is implemented.

[0017] The present invention also provides a computer program product, the computer program product including a bidirectional charging and discharging motor grid-connected abnormal operating condition detection program for vehicle-to-grid interaction, the bidirectional charging and discharging motor grid-connected abnormal operating condition detection program for vehicle-to-grid interaction implementing the above method when executed by a processor.

[0018] The beneficial effects of this invention are as follows: This invention incorporates photovoltaic power change rate, long-term average power, and mode switching surge characteristics into the capture threshold calculation, forming a power differential feedforward adaptive mechanism. This allows the threshold to be dynamically adjusted in real time to follow changes in photovoltaic output and switching conditions. This avoids false triggering of fixed thresholds during rapid power fluctuations and prevents peak missed capture due to threshold lag, thereby enhancing the environmental adaptability and threshold rationality of the detection.

[0019] By employing dead-zone interlocking and a monostable trigger window generation mechanism, the capture window is only opened after all power switching devices are completely turned off and the current decays to zero, effectively shielding freewheeling interference and switching noise. Combined with high-speed comparator-controlled pre-biased switched capacitor peak latching, nanosecond-level response and capacitor memory retention of the first half-wave overcurrent surge voltage are achieved, overcoming the peak loss problem caused by sampling delay in traditional microcontrollers. Furthermore, hysteresis verification by Schmitt triggers and isolation reading eliminate false latching events. Finally, protection and reset are performed based on fault energy classification, improving the targeting of protection actions and the continuity of system operation. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the first embodiment of a bidirectional charging and discharging motor grid-connected abnormal operating condition detection method for vehicle-to-grid interaction according to the present invention. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] Example 1: As Figure 1 The diagram shown is a flowchart of the first embodiment of a bidirectional charging and discharging motor grid-connected abnormal operating condition detection method for vehicle-to-grid interaction according to the present invention. The first embodiment of the bidirectional charging and discharging motor grid-connected abnormal operating condition detection method for vehicle-to-grid interaction according to the present invention is presented.

[0024] In the first embodiment, the method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction includes: Step S10: Obtain grid-connected operation sampling data composed of AC side current sampling signal and photovoltaic power data; based on the grid-connected operation sampling data, perform the capture threshold calculation task using a threshold adaptive mechanism that combines power change feedforward and steady-state deviation, and output the capture threshold. It should be noted that grid-connected operation sampling data refers to the data set formed by correlated collection of AC side current and photovoltaic output of the bidirectional charge-discharge machine within the same grid-connected operation cycle, including AC side current sampling signals and photovoltaic power data. The AC side current sampling signal is output by the current sensor at the grid-connected interface, and the transimpedance gain of the current sensor characterizes the correspondence between the current and the sampling voltage. The photovoltaic power data is processed according to a preset sliding time window to obtain the real-time photovoltaic power, the rate of change of photovoltaic power, and the long-term sliding average power. The threshold adaptive mechanism of power change feedforward and steady-state deviation coordination refers to first determining the base threshold voltage based on the rated grid-connected current, the transimpedance gain of the current sensor, and the preset mode switching surge coefficient; then forming a power change feedforward compensation amount reflecting the rate of change of power output based on the rate of change of photovoltaic power; and forming a steady-state power deviation compensation amount based on the deviation of the real-time photovoltaic power from the long-term sliding average power. The three are superimposed to obtain the candidate capture threshold, which is then restricted between the preset lower limit and the preset upper limit of the capture threshold, and smoothly updated according to the preset threshold update cycle to output the capture threshold for use in subsequent steps.

[0025] Understandably, this step utilizes information on rapid changes in photovoltaic power and deviations relative to long-term operating levels to correct the base threshold. This ensures the capture threshold can respond promptly to power surges caused by cloud cover and sunlight recovery, while preventing irregular jumps due to fluctuations in individual sampling points. The upper and lower thresholds prevent the compensation amounts from exceeding the usable input range of the comparator and subsequent latching circuits, and smooth updates limit the amplitude of changes between adjacent update cycles. Therefore, the capture threshold output in step S10 can simultaneously serve as the comparison benchmark for step S20 to determine if the sampling voltage has reached an abnormally high level, the amplitude benchmark for step S30 to control the peak capture switch, and the base quantity for step S40 to determine the dynamic hysteresis boundary, ensuring continuous connection between each step around the same capture boundary.

[0026] It should be understood that traditional solutions typically configure a fixed comparison threshold based on the rated grid-connected current, or temporarily adjust the threshold only based on the current amplitude. A fixed comparison threshold cannot distinguish between normal commutation surges caused by rapid changes in photovoltaic output and fault overcurrents. Setting the threshold too low can easily lead to false triggering, while setting it too high may miss abnormal peaks during low-power operation. Adjusting the threshold only based on the current current makes it difficult to reflect the trend of photovoltaic output changes before abnormal peaks occur. This step introduces power change feedforward compensation before the abnormal current actually exceeds the limit, and corrects the steady-state operating position based on the deviation between the real-time photovoltaic power and the long-term moving average power, matching the capture boundary with the current output level and direction of change, thereby reducing false captures and missed captures caused by mismatch in fixed settings.

[0027] For example, when the bidirectional charger is in a stable charging state, the real-time photovoltaic power is close to the long-term moving average power, and the power change rate is also small. At this time, the capture threshold is mainly determined by the rated grid-connected current, the transimpedance gain of the current sensor, and the preset mode switching surge coefficient. When the cloud layer moves away rapidly, causing the photovoltaic power to rise continuously, the power change feedforward compensation amount is increased first, and the steady-state power deviation compensation amount subsequently increases as the real-time power deviates from the long-term average value. The candidate capture threshold is appropriately increased and output after smoothing to avoid mistaking the expected commutation overshoot as a fault. When the cloud layer re-shades, causing the photovoltaic power to drop rapidly, the two types of compensation amounts adjust the capture threshold to a lower level, while still being constrained by the preset capture threshold lower limit, thereby maintaining the ability to identify abnormal current peaks under low power conditions.

[0028] Step S20: Obtain the mode switching instruction, and based on the capture threshold and the mode switching instruction, execute the capture window generation task using the direction-related dead zone interlock and monostable triggering mechanism, and output the capture window enable signal; It should be noted that the mode switching command refers to the control information used to instruct the bidirectional charger / discharger to switch between charging and discharging modes, including the mode switching direction, the mode switching start time, and the mode valid state. First, the AC side current sampling signal in step S10 undergoes transimpedance conversion to obtain a sampling voltage that can be directly compared with the capture threshold, and a mode switching edge pulse is generated based on the mode switching start time. Direction-related dead-zone interlocking refers to setting corresponding target dead-zone durations for charging-to-discharging and discharging-to-charging respectively, and selecting a duration matching the current mode switching direction from a preset dead-zone duration mapping relationship; the trigger input of the monostable circuit is shielded before the target dead-zone duration is reached, and the shielding is released after the target dead-zone duration is reached. Subsequently, a high-speed comparator determines whether the sampling voltage exceeds the capture threshold along the abnormally increasing direction corresponding to the current mode switching direction. If the condition is met, the monostable circuit enters a metastable state and generates a capture window pulse. The capture window pulse and the mode valid state are interlocked and verified. After the verification is successful, the capture window enable signal is output. The signal is canceled when the preset window duration is reached, the mode valid state is invalidated, or a reset command is received.

[0029] Understandably, this step incorporates the mode switching direction, dead-time timing state, sampling voltage exceeding the limit direction, and mode validity state into the window opening conditions simultaneously, ensuring that the capture window is generated only during the transition phase corresponding to the target switching direction. Shielding the trigger input during the dead-time phase avoids drive overlap, parasitic oscillations, and line freewheeling during the initial commutation of power devices. Detecting the sampling voltage exceeding the capture threshold along the abnormally increasing direction after the dead-time ends avoids identifying voltage swings opposite to the current switching direction as abnormal peaks. The monostable circuit maintains an effective level for the preset window duration and shields against repeated triggering during the quasi-stable state, providing step S30 with a clearly defined and non-repeatedly activated capture interval.

[0030] It should be understood that the traditional approach of directly opening the peak detection loop after a fixed delay cannot adapt to the differences in device turn-off tailing, line freewheeling direction, and sampling voltage polarity between charging-to-discharging and discharging-to-charging transitions. If the fixed delay is too short, the window may fall into a stage where switching noise has not yet decayed; if the fixed delay is too long, the first abnormal peak may have already appeared and disappeared. The approach of triggering the monostable circuit solely with the edge of the mode switching command may also generate invalid windows during mode command cancellation, repeated jittering, or reset. This step utilizes the direction-dependent target dead time and the valid mode state for dual constraints, and uses the actual sampling voltage exceeding the capture threshold as the trigger condition, ensuring that the window start time corresponds to the actual voltage change in the grid-connected circuit, reducing erroneous latching caused by premature opening, delayed opening, and repeated opening.

[0031] For example, when the bidirectional charger switches from charging mode to discharging mode, the control unit identifies the switching direction and start time from the mode switching command, generates a mode switching edge pulse, and selects a first dead time suitable for that direction from a preset dead time mapping relationship. During the dead time, even if a short-term spike occurs in the sampled voltage caused by device shutdown, the monostable circuit will not operate because the trigger input is shielded; after the dead time ends, the high-speed comparator only detects abnormal increases corresponding to the discharge establishment direction. When the sampled voltage exceeds the capture threshold output in step S10, the monostable circuit outputs a capture window pulse that lasts for a preset duration. If the mode is still valid at this time, a capture window enable signal is formed; if the upper-level control cancels the switching command before the window is formed, the interlock check fails, and the peak capture loop will not be invalidally opened.

[0032] Step S30: Based on the capture window enable signal and the capture threshold, a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism is used to perform peak latch preprocessing tasks and output peak latch voltage. It should be noted that the window constraint means that the peak capture switch is only on during the period when the capture window enable signal output in step S20 is valid, and remains off when the window is invalid. Pre-biased switch capacitor peak capture refers to the process where, when the capture window enable signal is invalid, the pre-bias switch is turned on to pre-charge the energy storage capacitor to a preset bias voltage, forming an energy storage capacitor in a pre-biased state; after the capture window enable signal becomes valid, the pre-bias switch is turned off, and the high-speed comparator compares the sampled voltage with the capture threshold. When the sampled voltage exceeds the capture threshold, the peak capture switch is turned on, allowing charging current to flow into the energy storage capacitor; when the sampled voltage stops increasing or the capture window enable signal fails, the peak capture switch is turned off, obtaining the initial peak holding voltage. Junction capacitance error compensation refers to obtaining the capacitance value of the energy storage capacitor and the junction capacitance value of the diode in the charging branch where the peak capture switch is located, and correcting the charge distribution deviation in the initial peak holding voltage based on the preset bias voltage, the accumulated charge formed by the charging current during switch conduction, the energy storage capacitor value, the junction capacitance value, and the threshold voltage corresponding to the capture threshold, outputting the peak latch voltage.

[0033] Understandably, the energy storage capacitor is pre-charged to a potential close to the capture threshold before the window opens. When an abnormal peak arrives, it only needs to replenish the amount of charge corresponding to the rise from the preset bias voltage to the actual peak value, thus shortening the time required for the capacitor to establish the peak holding voltage. The capture window enable signal imposes a time constraint on the peak capture switch, preventing the energy storage capacitor from continuing to respond to damped oscillations or subsequent switching noise after the window ends. Furthermore, by incorporating the charge distribution ratio caused by the diode junction capacitance into the compensation, the voltage shift caused by the release or absorption of charge by parasitic capacitance at the moment the peak capture switch is turned off can be corrected, making the output peak latch voltage closer to the true abnormal peak value within the capture window.

[0034] It should be understood that conventional peak hold circuits typically charge the energy storage capacitor from zero potential. When faced with the first surge peak, which has a short duration, the capacitor voltage may not have reached the actual peak value before the signal begins to fall back. Circuits using simple diode isolation are also affected by diode junction capacitance and charge injection during switch disconnection, leading to repeatable errors in the holding voltage, such as being too low or too high. Some other schemes, although incorporating pre-charging, do not limit the charging period through a capture window, allowing the energy storage capacitor to be recharged by subsequent oscillations, causing the latched result to no longer correspond to the first abnormal peak. This step simultaneously defines the initial pre-bias state, switch on-condition, switch off-condition, and junction capacitance error compensation basis, constraining the peak latching process in terms of both time and charge boundaries.

[0035] For example, when the capture threshold is set to 2 volts, the energy storage capacitor can be pre-charged to approximately 1.6 volts. Before the capture window opens, the peak capture switch remains open, and the energy storage capacitor stabilizes at the preset bias voltage. After the window opens, if the sampling voltage rapidly rises to 3.5 volts, the high-speed comparator activates the peak capture switch after the sampling voltage exceeds the capture threshold, and the energy storage capacitor quickly charges from the preset bias voltage. The peak capture switch is immediately deactivated when the sampling voltage stops increasing, obtaining the initial peak holding voltage. The control unit then combines the energy storage capacitor value, the diode junction capacitance value, and the charging status during this conduction period to correct the charge distribution deviation, ensuring that the final output peak latch voltage remains close to the level of the abnormal peak value. The secondary oscillation after the window ends will not change the latching result.

[0036] Step S40: Based on the peak latch voltage and the capture threshold, a dynamic hysteresis triggering and isolation reading mechanism is used to perform a latch event validity verification task, and the latch event flag is output; It should be noted that dynamic hysteresis triggering refers to obtaining a preset high proportional coefficient and a preset low proportional coefficient, and using the capture threshold output in step S10 as a common benchmark, determining the rising edge trigger threshold and falling edge reset threshold of the Schmitt trigger, where the preset high proportional coefficient is greater than the preset low proportional coefficient. When the peak latch voltage output in step S30 exceeds the rising edge trigger threshold, the Schmitt trigger outputs a valid level, which, after isolation transmission, forms a candidate latch event flag. Isolation reading refers to generating a read pulse in response to the candidate latch event flag, briefly turning on the isolation read switch with the read pulse, and sequentially reading the peak latch voltage through a unity-gain buffer and an analog-to-digital converter to obtain the peak voltage read value. Subsequently, the peak voltage read value is compared with the preset validity check lower limit and the preset validity check upper limit; only when the peak voltage read value is between the two and the candidate latch event flag remains valid, a latch event flag representing a valid latch event is output; otherwise, a latch event flag representing an invalid latch event is output.

[0037] Understandably, the rising edge trigger threshold and falling edge reset threshold change synchronously with the capture threshold, maintaining a hysteresis range adapted to the current capture boundary under different photovoltaic output and different mode switching conditions. After the peak latch voltage first exceeds the rising edge trigger threshold, the Schmitt trigger will only reset when it falls below a lower reset threshold, thus suppressing repeated toggling caused by minor leakage in the latch node and comparator noise. The isolation read switch is turned on only during the read pulse, and the unity-gain buffer handles high input impedance sampling and low output impedance driving, ensuring that the sampling process of the analog-to-digital converter does not directly consume the charge on the energy storage capacitor. The joint verification of the candidate flag and the peak voltage read value can also eliminate inconsistent events such as digital triggering without a reasonable peak voltage or abnormal voltage without the candidate flag being maintained.

[0038] It should be understood that the traditional approach of directly using the comparator output as the final event flag is prone to generating multiple narrow pulses near the threshold due to noise jitter, and it cannot confirm whether the actual holding voltage on the energy storage capacitor is within an acceptable range. Directly connecting the latched voltage to the analog-to-digital converter for continuous sampling increases the load on the latch node, causing the holding voltage to decay before the processor completes the read. A scheme relying solely on a software threshold to determine validity also struggles to identify excessively low coupling noise and abnormally high voltages exceeding the input range. This step uses dynamic hysteresis triggering to form stable candidate events, then obtains the peak voltage reading through isolated reading, and performs a joint judgment based on a preset lower validity check limit, a preset upper validity check limit, and the candidate flag holding state, thereby improving the consistency between the event flag and the actual latched voltage.

[0039] For example, when the capture threshold output in step S10 is 2V / 8, the rising edge trigger threshold of the Schmitt trigger can be set to approximately 2V / 94, and the falling edge reset threshold can be set to approximately 2V / 66. If the peak latch voltage reaches 3V / 1, the Schmitt trigger outputs a valid level and forms a candidate latch event flag. The read pulse then turns on the isolation read switch, and the analog-to-digital converter reads 3V / 09. If the preset validity check range covers this read value, and the candidate latch event flag remains valid during the read, a latch event flag representing a valid latch event is output. If electromagnetic interference only causes the latch node to rise briefly to a level below the rising edge trigger threshold, or if the read value exceeds the preset validity check upper limit, this change will not be passed to step S50 as a valid latch event.

[0040] Step S50: Perform abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset according to the latching event flag and the peak latching voltage, and output protection and reset execution commands.

[0041] It should be noted that when the latching event flag indicates a valid latching event, the preset bias voltage, the current sensor trans-resistance gain, and the preset grid-connected point equivalent inductance are obtained. First, the voltage difference between the peak latching voltage and the preset bias voltage is determined. Then, this voltage difference is converted into an abnormal current peak value according to the current sensor trans-resistance gain. The fault energy is determined based on the abnormal current peak value and the preset grid-connected point equivalent inductance according to the inductance energy storage relationship. The fault energy tiered protection includes three levels of judgment: when the fault energy is less than a preset first fault energy threshold, a power reduction operation command is generated; when the fault energy is greater than or equal to the preset first fault energy threshold but less than a preset second fault energy threshold, a drive pulse blocking command is generated; when the fault energy is greater than or equal to the preset second fault energy threshold, both a drive pulse blocking command and an AC contactor disconnect command are generated simultaneously. After completing the corresponding protection action, a reset pulse is generated. The reset pulse activates the capacitor discharge switch, discharging the energy storage capacitor to ground and resetting the monostable trigger branch, peak latching branch, and Schmitt trigger branch respectively. When the latching event flag indicates an invalid latching event, only a reset pulse is generated. The above instructions are summarized into protection and reset execution instructions.

[0042] Understandably, this step first deducts the base increase of the peak latching voltage due to the preset bias voltage, and then recovers the abnormal current peak value according to the transimpedance gain of the current sensor. This avoids mistakenly including the initial voltage formed by pre-charging in the fault current. By using the preset grid-connected point equivalent inductance and the abnormal current peak value to determine the fault energy, the protection action can be correlated with the electromagnetic energy level of the grid-connected circuit in this abnormality. The three levels of protection results correspond to maintaining grid connection but reducing power, stopping power device driving, and simultaneously stopping driving and physically disconnecting the AC circuit, respectively, so that the protection strength increases progressively with the increase of fault energy. After the protection action is completed, the energy storage capacitor and the three signal branches are uniformly reset, which can clear the charge and logic state left by the previous event and establish consistent initial conditions for the next mode switch.

[0043] Example 2: Furthermore, the present invention provides a bidirectional charger / discharger grid connection abnormal operation condition detection system for vehicle-to-grid interaction, employing a bidirectional charger / discharger grid connection abnormal operation condition detection method for vehicle-to-grid interaction provided in the above embodiments, which can solve the technical problem of detecting bidirectional charger / discharger grid connection abnormal operation conditions for vehicle-to-grid interaction. The beneficial effects of the bidirectional charger / discharger grid connection abnormal operation condition detection system for vehicle-to-grid interaction provided by the present invention are the same as the beneficial effects of the bidirectional charger / discharger grid connection abnormal operation condition detection method for vehicle-to-grid interaction provided in the above embodiments, and other technical features of the bidirectional charger / discharger grid connection abnormal operation condition detection system for vehicle-to-grid interaction are the same as the features disclosed in the methods of the above embodiments, and will not be repeated here.

[0044] Example 3: This invention provides a bidirectional charger / discharger grid connection anomaly detection device for vehicle-to-grid interaction. The device includes at least one processor and a memory communicatively connected to the processor. The memory stores instructions executable by the processor, which are then executed to enable the processor to perform the bidirectional charger / discharger grid connection anomaly detection method described in Example 1. This bidirectional charger / discharger grid connection anomaly detection device can include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), and in-vehicle terminals (e.g., in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers. This bidirectional charger / discharger grid connection anomaly detection device is merely an example and should not be construed as limiting the functionality or scope of this invention. A bidirectional charging / discharging machine grid-connected abnormal operating condition detection device for vehicle-to-grid interaction may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes according to a program stored in a read-only memory or a program loaded from a storage device into a random access memory. The random access memory also stores various programs and data required for the operation of the bidirectional charging / discharging machine grid-connected abnormal operating condition detection device for vehicle-to-grid interaction. The processing unit, read-only memory, and random access memory are interconnected via a bus. An I / O interface is also connected to the bus. Typically, the following systems can be connected to the I / O interface: input devices including touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices including liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices including magnetic tapes, hard disks, etc.; and communication devices. The communication device allows the bidirectional charging / discharging machine grid-connected abnormal operating condition detection device for vehicle-to-grid interaction to exchange data with other devices wirelessly or via wired communication. While a bidirectional charging / discharging machine grid-connected abnormal operating condition detection device with various systems for vehicle-to-grid interaction has been described, it should be understood that implementation of all the described systems is not required. Alternatively, more or fewer systems may be implemented.

[0045] Example 4: This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method for detecting abnormal operating conditions of a bidirectional charger / discharger connected to the grid for vehicle-to-grid interaction. The computer program product provided by this invention can solve the technical problem of detecting abnormal operating conditions of a bidirectional charger / discharger connected to the grid for vehicle-to-grid interaction. Compared with the prior art, the beneficial effects of the computer program product provided by this invention are the same as those of the above-described method for detecting abnormal operating conditions of a bidirectional charger / discharger connected to the grid for vehicle-to-grid interaction, and will not be repeated here.

[0046] In particular, according to the embodiments disclosed in this invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device, or installed from a read-only memory. When the computer program is executed by a processing device, it performs the functions defined in the methods of the embodiments disclosed in this invention.

[0047] It should be understood that the various parts disclosed in this invention can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0048] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A method for detecting abnormal grid-connected operating conditions of a bidirectional charger / discharger for vehicle-to-grid interaction, characterized in that, The method includes: Step S10: Obtain grid-connected operation sampling data composed of AC side current sampling signal and photovoltaic power data; based on the grid-connected operation sampling data, perform the capture threshold calculation task using a threshold adaptive mechanism that combines power change feedforward and steady-state deviation, and output the capture threshold. Step S20: Obtain the mode switching instruction, and based on the capture threshold and the mode switching instruction, execute the capture window generation task using the direction-related dead zone interlock and monostable triggering mechanism, and output the capture window enable signal; Step S30: Based on the capture window enable signal and the capture threshold, a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism is used to perform peak latch preprocessing tasks and output peak latch voltage. Step S40: Based on the peak latch voltage and the capture threshold, a dynamic hysteresis triggering and isolation reading mechanism is used to perform a latch event validity verification task, and the latch event flag is output; Step S50: Perform abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset according to the latching event flag and the peak latching voltage, and output protection and reset execution commands.

2. The method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction as described in claim 1, characterized in that, In step S10, the following steps are taken: acquiring grid-connected operation sampling data composed of AC side current sampling signals and photovoltaic power data; performing a threshold calculation task based on the grid-connected operation sampling data using a threshold adaptive mechanism that combines power change feedforward and steady-state deviation; and outputting the capture threshold. Specifically, these steps include: Step S101: Extract the AC side current sampling signal and the photovoltaic power data from the grid-connected operation sampling data, process the photovoltaic power data according to a preset sliding time window, and obtain the real-time photovoltaic power, photovoltaic power change rate and long-term sliding average power; Step S102: Obtain the rated grid-connected current, current sensor transimpedance gain, preset mode switching surge coefficient, preset power change rate feedforward mapping coefficient, preset power deviation compensation mapping coefficient, and preset converter loss factor; determine the base threshold voltage based on the rated grid-connected current, the current sensor transimpedance gain, and the preset mode switching surge coefficient; determine the power change feedforward compensation amount based on the photovoltaic power change rate and the preset power change rate feedforward mapping coefficient; and determine the steady-state power deviation compensation amount based on the real-time photovoltaic power, the long-term moving average power, the preset power deviation compensation mapping coefficient, and the preset converter loss factor. Step S103: The base threshold voltage, the power change feedforward compensation amount, and the steady-state power deviation compensation amount are superimposed to obtain the candidate capture threshold. The candidate capture threshold is limited to the preset capture threshold lower limit and the preset capture threshold upper limit. The limited candidate capture threshold is then smoothly updated according to the preset threshold update cycle, and the capture threshold is output.

3. The method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction as described in claim 1, characterized in that, Step S20, which involves obtaining a mode switching instruction, executing a capture window generation task based on the capture threshold and the mode switching instruction using a direction-dependent dead-zone interlocking and monostable triggering mechanism, and outputting a capture window enable signal, specifically includes: Step S201: Perform transimpedance conversion on the AC side current sampling signal to obtain the sampling voltage; parse the mode switching command, determine the mode switching direction, mode switching start time and mode valid state, and generate a mode switching edge pulse according to the mode switching start time; Step S202: Determine the target dead time according to the mode switching direction, start dead timer in response to the mode switching edge pulse, compare the sampling voltage with the capture threshold after the dead timer reaches the target dead time, and trigger the monostable circuit to generate a capture window pulse when the sampling voltage crosses the capture threshold in an abnormally increasing direction. Step S203: Perform an interlock check between the capture window pulse and the mode valid state. When the interlock check passes, output the capture window enable signal. When the preset window duration is reached, the mode valid state fails, or a reset command is received, cancel the capture window enable signal.

4. The method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction as described in claim 3, characterized in that, In step S202, the steps of determining the target dead time based on the mode switching direction, starting dead time timing in response to the mode switching edge pulse, comparing the sampled voltage with the capture threshold after the dead time timing reaches the target dead time, and triggering the monostable circuit to generate a capture window pulse when the sampled voltage exceeds the capture threshold in an abnormally increasing direction, specifically include: The target dead time is obtained by selecting the dead time corresponding to the mode switching direction from the preset dead time mapping relationship; The dead-time timing is started in response to the mode switching edge pulse, and the trigger input of the monostable circuit is blocked when the dead-time timing has not reached the target dead-time duration; When the dead timer reaches the target dead time, the shielding of the trigger input is released, and a high-speed comparator is used to detect whether the sampling voltage exceeds the capture threshold along the abnormal increase direction; When the sampling voltage exceeds the capture threshold along the abnormal increase direction, the monostable circuit enters a metastable state and maintains an effective level for the duration of the preset window, thus forming the capture window pulse; The monostable circuit is shielded from repeated triggering signals during the quasi-stable state, and the monostable circuit exits the quasi-stable state when the preset window duration is reached.

5. The method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction as described in claim 4, characterized in that, Step S30, which involves performing a peak latch preprocessing task based on the capture window enable signal and the capture threshold using a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism, and outputting the peak latch voltage, specifically includes: Step S301: When the capture window enable signal is invalid, disconnect the peak capture switch and turn on the pre-bias switch to pre-charge the energy storage capacitor to the preset bias voltage, thereby obtaining the energy storage capacitor in the pre-bias state. Step S302: When the capture window enable signal is valid, the pre-bias switch is turned off, and the sampled voltage is compared with the capture threshold by a high-speed comparator; when the sampled voltage exceeds the capture threshold, the peak capture switch is turned on, so that the charging current flows into the energy storage capacitor in the pre-bias state; when the sampled voltage stops increasing or the capture window enable signal fails, the peak capture switch is turned off to obtain the initial peak holding voltage. Step S303: Obtain the capacitance value of the energy storage capacitor and the junction capacitance value of the diode in the charging branch where the peak capture switch is located. Based on the preset bias voltage, the charging current, the capacitance value of the energy storage capacitor, the junction capacitance value, and the capture threshold, perform joint compensation of charge accumulation and junction capacitance charge distribution on the initial peak holding voltage, and output the peak latch voltage. The calculation formula for the peak latch voltage is: in, The peak latch voltage, The preset bias voltage. Let be the capacitance value of the energy storage capacitor. The charging current, The peak capture switch is the on-time of the peak capture switch during the period when the capture window enable signal is valid. The time when the peak capture switch is turned off. This refers to the junction capacitance value of the diode. The threshold voltage corresponding to the capture threshold; The integral of the charging current between the on-time and the off-time is used to characterize the cumulative charge input to the energy storage capacitor, and the ratio of the junction capacitance value to the capacitance value of the energy storage capacitor is used to characterize the charge distribution ratio caused by the diode junction capacitance when the peak capture switch is turned off.

6. The method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction as described in claim 1, characterized in that, Step S40, which involves performing a latch event validity verification task based on the peak latch voltage and the capture threshold using a dynamic hysteresis triggering and isolation reading mechanism, and outputting the latch event flag, specifically includes: Step S401: Obtain a preset high scaling factor and a preset low scaling factor; determine the rising edge trigger threshold of the Schmitt trigger based on the capture threshold and the preset high scaling factor; and determine the falling edge reset threshold of the Schmitt trigger based on the capture threshold and the preset low scaling factor, wherein the preset high scaling factor is greater than the preset low scaling factor; when the peak latch voltage exceeds the rising edge trigger threshold, enable the Schmitt trigger to output an active level, and isolate and transmit the active level to obtain a candidate latch event flag; Step S402: In response to the candidate latch event flag, a read pulse is generated, and the isolation read switch is turned on according to the read pulse. The peak latch voltage is read sequentially through the unity gain buffer and the analog-to-digital converter to obtain the peak voltage read value. Step S403: Compare the peak voltage reading with the preset validity check lower limit and the preset validity check upper limit respectively; when the peak voltage reading is between the preset validity check lower limit and the preset validity check upper limit, and the candidate latch event flag remains valid, output a latch event flag to characterize a valid latch event; otherwise, output a latch event flag to characterize an invalid latch event.

7. The method for detecting abnormal grid connection conditions of a bidirectional charger / discharger for vehicle-to-grid interaction as described in claim 1, characterized in that, Step S50, which involves performing abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset based on the latched event flag and the peak latched voltage, and outputting protection and reset execution commands, specifically includes: Step S501: When the latching event flag indicates a valid latching event, obtain the preset bias voltage, the current sensor transimpedance gain, and the preset grid connection point equivalent inductance, determine the voltage difference between the peak latching voltage and the preset bias voltage, convert the voltage difference into an abnormal current peak value according to the current sensor transimpedance gain, and determine the fault energy according to the inductance energy storage relationship based on the abnormal current peak value and the preset grid connection point equivalent inductance. Step S502: Compare the fault energy with a preset first fault energy threshold and a preset second fault energy threshold, respectively, wherein the preset second fault energy threshold is greater than the preset first fault energy threshold; when the fault energy is less than the preset first fault energy threshold, generate a power reduction operation command; when the fault energy is greater than or equal to the preset first fault energy threshold and less than the preset second fault energy threshold, generate a drive pulse lockout command; when the fault energy is greater than or equal to the preset second fault energy threshold, generate the drive pulse lockout command and the AC contactor disconnect command. Step S503: After completing the protection action corresponding to the fault energy, a reset pulse is generated. According to the reset pulse, the capacitor discharge switch is turned on to discharge the energy storage capacitor to ground. The monostable trigger branch used to form the capture window enable signal, the peak latch branch used to form the peak latch voltage, and the Schmitt trigger branch used to form the latch event flag are reset. When the latch event flag indicates an invalid latch event, only the reset pulse is generated, and the protection and reset execution instructions are obtained by summarizing them.

8. A bidirectional charging / discharging motor grid-connected abnormal operating condition detection system for vehicle-to-grid interaction, applied to the bidirectional charging / discharging motor grid-connected abnormal operating condition detection method for vehicle-to-grid interaction as described in any one of claims 1 to 7, characterized in that, The bidirectional charging and discharging motor grid-connected abnormal operating condition detection system for vehicle-to-grid interaction includes: The threshold adaptive module is used to acquire grid-connected operation sampling data composed of AC side current sampling signal and photovoltaic power data. Based on the grid-connected operation sampling data, a threshold adaptive mechanism that combines power change feedforward and steady-state deviation is used to perform the capture threshold calculation task and output the capture threshold. The window generation module is used to acquire the mode switching instruction, and based on the capture threshold and the mode switching instruction, it uses a direction-related dead zone interlocking and monostable triggering mechanism to execute the capture window generation task and outputs the capture window enable signal. The peak latch module is used to perform peak latch preprocessing tasks based on the capture window enable signal and the capture threshold using a window-constrained pre-biased switched capacitor peak capture and junction capacitance error compensation mechanism, and outputs the peak latch voltage. The event verification module is used to perform a latch event validity verification task based on the peak latch voltage and the capture threshold using a dynamic hysteresis triggering and isolation reading mechanism, and output a latch event flag. The protection execution module is used to perform abnormal current peak conversion, fault energy classification protection, and energy storage capacitor discharge reset based on the latched event flag and the peak latched voltage, and output protection and reset execution commands.

9. A bidirectional charging / discharging motor grid-connected abnormal operating condition detection device for vehicle-to-grid interaction, characterized in that, The bidirectional charging and discharging machine grid connection abnormal operation condition detection device for vehicle-to-grid interaction includes: a memory, a processor, and a bidirectional charging and discharging machine grid connection abnormal operation condition detection program for vehicle-to-grid interaction stored in the memory and executable on the processor. When the bidirectional charging and discharging machine grid connection abnormal operation condition detection program for vehicle-to-grid interaction is executed by the processor, it implements the bidirectional charging and discharging machine grid connection abnormal operation condition detection method for vehicle-to-grid interaction according to any one of claims 1 to 7.

10. A computer program product, characterized in that, The computer program product includes a bidirectional charging and discharging motor grid connection abnormal operation condition detection program for vehicle-to-grid interaction. When the bidirectional charging and discharging motor grid connection abnormal operation condition detection program for vehicle-to-grid interaction is executed by the processor, it implements a method for detecting bidirectional charging and discharging motor grid connection abnormal operation conditions for vehicle-to-grid interaction according to any one of claims 1 to 7.

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