High-pressure protection device, heat pump system and high-pressure detection method

Abstract

The invention relates to the technical field of heat pump control, and discloses a high-voltage protection device, a heat pump system and a high-voltage detection method.According to the method, a high-voltage switch module automatically cuts off a power source, a drive module outputs a heartbeat signal, and cooperative detection is conducted through a main control module, so that the problems of complex hardware and high communication dependency of a traditional scheme are solved; the system has the advantages that the system structure is simplified, communication line dependence is reduced, and the working state of the driving module is monitored in real time.

Description

Technical Field

[0001] This invention relates to the field of heat pump control technology, specifically a high-pressure protection device, a heat pump system, and a high-pressure detection method. Background Technology

[0002] In existing heat pump systems, to meet the safety requirements of UL certification (UL 60335) or CE certification (EN60335), a high-pressure protection scheme is added to the heat pump system. Currently, this high-pressure protection scheme is mainly implemented in the following two ways: The first method involves adding a high-pressure switch to the compressor's control circuit. This is done by connecting the high-pressure switch in series with a contactor in the control circuit, thereby disconnecting the control circuit when the pressure is high.

[0003] The second method involves controlling the compressor's on / off state by detecting the status of the high-pressure switch and outputting control commands.

[0004] While the above two methods can achieve high-voltage protection and control and meet the corresponding certification safety requirements, they rely too much on additional hardware structures and communication stability, resulting in low reliability. Summary of the Invention

[0005] This application proposes a high-pressure protection device, a heat pump system, and a high-pressure detection method, aiming to solve the problem that existing high-pressure protection schemes for heat pump systems rely on external detection circuits or communication stability, resulting in low reliability.

[0006] In a first aspect, the present invention provides a high-pressure protection device for use in a heat pump system, comprising: a high-pressure switch, a drive module, a main control module, and a heartbeat detection module; The high-voltage switch module is connected in series with the power supply terminal of the drive module, and is used to automatically disconnect the external power supply from the power supply terminal of the drive module when the refrigerant in the heat pump system is under high pressure. The drive module is connected to the main control module through the heartbeat detection module, and is used to provide a drive signal to the compressor in the heat pump system and output a heartbeat signal to the heartbeat detection module when the refrigerant does not have high pressure. The main control module identifies whether the heartbeat detection module has detected a heartbeat signal, and determines whether the heat pump has experienced a high-pressure fault based on the identification result.

[0007] In one embodiment of the first aspect, the heartbeat detection module is an optocoupler circuit, the input terminal of the optocoupler circuit is connected to the heartbeat signal output terminal of the drive module, and the output terminal of the optocoupler circuit is connected to the detection terminal of the main control module.

[0008] In one embodiment of the first aspect, the high-pressure switch module is also connected to the refrigerant supply channel in the heat pump system; The high-pressure switch module detects the refrigerant pressure in the refrigerant supply channel in real time and calculates whether the refrigerant pressure exceeds a preset safety threshold. If the refrigerant pressure value is greater than the safety threshold, the contact mechanism inside the high-pressure switch will activate, changing from a closed state to an open state, thus cutting off the electrical connection between the external power supply and the power supply terminal of the drive module. If the refrigerant pressure value is greater than the safety threshold, the contact mechanism inside the high-pressure switch remains short-circuited, thus maintaining the electrical connection between the external power supply and the power supply terminal of the drive module.

[0009] In one embodiment of the first aspect, the driving module is specifically used for: When the refrigerant is not under high pressure, its internal logic circuits or microcontrollers generate a heartbeat signal with a fixed frequency and duty cycle. The system generates six corresponding drive signals based on actual temperature requirements and outputs them to the compressor to control its operating status. The heartbeat signal and the six drive signals are simultaneously output through different output ports of the drive module.

[0010] In one embodiment of the first aspect, the optocoupler circuit is used for: When the heartbeat signal is received from the drive module, the heartbeat signal is converted into an optical signal using the photoelectric conversion principle and then transmitted in isolation internally. When the optical signal is transmitted to the output of the optocoupler circuit, it is converted back into an electrical signal and output as a detection signal to the detection terminal of the main control module.

[0011] In one embodiment of the first aspect, the main control module determines the operating status of the drive module and whether the heat pump system has experienced a high-pressure fault by detecting the presence or absence of the electrical signal and the characteristics of the electrical signal.

[0012] In one embodiment of the first aspect, the main control module is specifically used for: When the electrical signal is detected, the pulse pattern of the electrical signal within a single sampling period is analyzed, and it is determined whether the pulse pattern is the same as the pulse pattern of the heartbeat signal. If they are different, then the heat pump system is determined to have a high-pressure fault.

[0013] In one embodiment of the first aspect, it further includes: The high-pressure warning module, connected to the main control module, is used to send an early warning when a high-pressure fault occurs in the heat pump system.

[0014] In a second aspect, the present invention provides a heat pump system, including a power supply device, a refrigerant device, and a high-pressure protection device as described above; The high-voltage switch module is connected in series between the power supply terminal of the drive module and the output terminal of the power supply device. The drive end of the refrigerant device is connected to the drive signal output end of the drive module.

[0015] Thirdly, the present invention provides a high-voltage detection method applied to the high-voltage protection device provided above, comprising: The heartbeat detection module detects whether a pulse signal is output at the heartbeat signal output terminal of the drive module. If present, the pulse signal is acquired, and it is identified whether the pulse signal follows a preset pulse pattern. Based on the identification results, it is determined whether the heat pump system has experienced a high-pressure fault.

[0016] The embodiments of the present invention bring the following beneficial effects: This invention provides a high-pressure protection device, a heat pump system, and a high-pressure detection method. The device includes a high-pressure switch, a drive module, a main control module, and a heartbeat detection module. The high-pressure switch module is connected in series with the power supply terminal of the drive module and is used to automatically disconnect the external power supply from the power supply terminal of the drive module when high pressure occurs in the refrigerant of the heat pump system. The drive module is connected to the main control module through the heartbeat detection module and is used to provide a drive signal to the compressor in the heat pump system and output a heartbeat signal to the heartbeat detection module when high pressure does not occur in the refrigerant. The main control module identifies whether the heartbeat detection module detects a heartbeat signal and determines whether the heat pump has experienced a high-pressure fault based on the identification result. By automatically disconnecting the power supply through the high-pressure switch module, outputting the heartbeat signal from the drive module, and coordinating detection with the main control module, the problems of complex hardware and high communication dependence in traditional solutions are solved.

[0017] Other features and advantages of the invention will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a high-voltage protection device provided in an embodiment of the present invention; Figure 2 A circuit diagram of a high-voltage protection device provided in an embodiment of the present invention; Figure 3 A schematic diagram of a heat pump system provided in an embodiment of the present invention; Figure 4 This is a flowchart of a high-voltage detection method provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0023] In related technologies, high-pressure protection schemes for heat pump systems typically employ either a high-pressure switch connected in series in the compressor control circuit or control commands output by detecting the status of the high-pressure switch. While these methods meet safety certification requirements, they suffer from issues such as complex hardware structures and reliance on communication stability, leading to insufficient system reliability. For example, in scenarios involving prolonged compressor operation or frequent refrigerant pressure fluctuations, relying solely on contact mechanisms or signal transmission is prone to malfunctions or failures due to poor contact, circuit interference, or other factors, making it impossible to accurately determine the high-pressure fault status.

[0024] Please see Figure 1 This application provides a specific embodiment of a high-voltage protection device applied to a heat pump system. The device includes a high-voltage switch module 110, a drive module 120, a main control module 130, and a heartbeat detection module 140.

[0025] It is understood that the high-voltage switch module 110 refers to a switch device that responds to changes in refrigerant pressure by mechanical or electronic means. Specifically, it can be implemented by a mechanical switch with a pressure sensor and contact mechanism or an electronic switch with an integrated comparator. Its function is to directly cut off the power circuit when the pressure exceeds the threshold.

[0026] The drive module 120 refers to the circuit unit that controls the operation of the compressor. Specifically, it can use logic circuits or microcontrollers to generate drive signals and heartbeat signals. The heartbeat signal is used to characterize the real-time working status of the drive module.

[0027] The main control module 130 refers to a control unit with signal analysis capabilities. Specifically, it can be a microprocessor with analog-to-digital converter and logic judgment functions, which can determine whether the system has malfunctioned by detecting parameters such as the frequency and duty cycle of the heartbeat signal.

[0028] The heartbeat detection module 140 refers to a circuit used to transmit and isolate electrical signals. Specifically, an optocoupler circuit can be used to convert the heartbeat signal output by the drive module into an optical signal and transmit it to the main control module to achieve electrical isolation and status feedback.

[0029] In this embodiment, the high-voltage switch module 110 is connected in series with the power supply terminal of the drive module 120, and is used to automatically disconnect the external power supply from the power supply terminal of the drive module 120 when the refrigerant in the heat pump system is under high pressure. The drive module 120 is connected to the main control module 130 through the heartbeat detection module 140, and is used to provide a drive signal to the compressor in the heat pump system and output a heartbeat signal to the heartbeat detection module 140 when the refrigerant does not have high pressure. The main control module 130 identifies whether the heartbeat detection module 140 has detected a heartbeat signal, and determines whether the heat pump has a high-pressure fault based on the identification result.

[0030] In practical applications, when the refrigerant pressure is normal, the drive module 120 continuously outputs a heartbeat signal at a fixed frequency, which is transmitted to the main control module 130 via the heartbeat detection module 140. The main control module 130 confirms that the drive module 120 is in normal working condition by periodically detecting the pulse pattern of the heartbeat signal. At this time, the high-pressure switch module 110 remains on, the external power supply powers the drive module 120, and the compressor operates normally according to the drive signal. When the refrigerant pressure exceeds the safety threshold, the high-pressure switch module 110 immediately cuts off the power, causing the drive module 120 to stop working, and the heartbeat signal disappears. If the main control module 130 does not detect a heartbeat signal that matches the expected pattern within a preset time, it determines that a high-pressure fault has occurred in the heat pump system and triggers the protection mechanism. If the heartbeat signal is abnormal due to poor wiring contact but the high-pressure switch module 110 does not activate, the main control module 130 can also determine the potential fault through the signal loss, achieving dual protection.

[0031] Compared with existing technologies, this embodiment integrates hardware disconnection and signal monitoring mechanisms to verify the operating status of the drive module simultaneously with power disconnection. This effectively distinguishes between genuine high-voltage faults and false triggering, solving the reliability issues of existing high-voltage protection devices that rely on a single detection mechanism. It achieves dual verification of power disconnection and drive module status, ensuring the accuracy of high-voltage fault diagnosis. Simultaneously, continuous monitoring of the heartbeat signal can promptly detect poor line contact or drive module abnormalities, preventing system-wide failure due to localized faults.

[0032] In one specific embodiment, the high-voltage switch module 110 includes: A pressure sensor, installed in the refrigerant supply channel, is used to detect the refrigerant pressure value in real time. Specifically, the pressure sensor can be understood as a device that can convert refrigerant pressure into an electrical signal. It can be implemented using a piezoelectric sensor or a capacitive sensor to monitor pressure changes in the refrigerant supply channel in real time.

[0033] The comparator, connected to the pressure sensor, is used to compare the detected refrigerant pressure value with a preset safety threshold. Specifically, the comparator can be understood as an electronic component with voltage comparison function, which can be implemented using an operational amplifier or a dedicated comparator chip to determine whether the refrigerant pressure exceeds the safety threshold.

[0034] The drive mechanism drives the contact mechanism to operate based on the output of the comparator, thereby controlling the on / off state of the power supply. Specifically, the drive mechanism can be understood as a device that converts electrical signals into mechanical actions. It can be implemented using an electromagnetic coil or a stepper motor to control the on / off state of the contact mechanism.

[0035] The status feedback circuit is used to feed back the status of the contact mechanism to the main control module 130 so that the main control module 130 can monitor the working status of the high-voltage switch in real time. Specifically, the status feedback circuit can be understood as a circuit that can collect the status of the contact mechanism and generate feedback signals. It can be implemented by combining a micro switch and a voltage divider circuit to transmit the real-time working status of the high-voltage switch to the main control module.

[0036] In practical applications, after a pressure sensor is installed in the refrigerant supply channel, its output analog pressure signal is transmitted to the comparator input. The comparator compares the pressure value with an internally stored safety threshold. When the detected value exceeds the threshold, the comparator outputs a high-level signal to trigger the drive mechanism. Upon receiving the high-level signal, the drive mechanism drives the contact mechanism to perform a mechanical action, disconnecting the external power supply from the drive module 120. Simultaneously, the status feedback circuit generates a feedback signal by detecting changes in the physical position of the contact mechanism. This signal is then transmitted to the input port of the main control module 130 after level conversion, forming a complete closed-loop control link.

[0037] In one specific embodiment, the heartbeat detection module 140 is an optocoupler circuit. The input terminal of the optocoupler circuit is connected to the heartbeat signal output terminal of the drive module 120, and the output terminal of the optocoupler circuit is connected to the detection terminal of the main control module 130.

[0038] Understandably, this optocoupler circuit refers to a circuit that uses the photoelectric conversion principle to achieve signal isolation and transmission. Specifically, it can be implemented using integrated devices containing light-emitting diodes and phototransistors, such as optocouplers like the PC817 and TLP521. The input terminal refers to the port that receives the output signal from the driver module. This can be achieved by connecting to the pulse width modulation signal output pin of the driver module 120, for example, receiving a square wave signal with a frequency of 1kHz and a duty cycle of 50%. The output terminal refers to the port that converts the optical signal into an electrical signal. This can be achieved by connecting to the general-purpose input / output interface of the main control module 130, for example, transmitting the level signal to the GPIO detection pin of the STM32 series microcontroller.

[0039] Specifically, when the heartbeat signal output by the driver module 120 is transmitted to the input terminal of the optocoupler circuit, the light-emitting diode inside the optocoupler is lit and generates a light signal. This light signal passes through the insulating layer and illuminates the phototransistor, causing it to conduct and generate a corresponding electrical signal. The electrical signal is transmitted to the main control module through the output terminal and converted into a digital signal for pulse pattern analysis. If the frequency and duty cycle of the detected electrical signal match the preset heartbeat signal parameters, the driver module is determined to be in normal working condition; if an abnormal or missing signal is detected, the high-voltage fault protection mechanism is triggered.

[0040] Furthermore, the optocoupler circuit is used to: when receiving the heartbeat signal output by the drive module 120, convert the heartbeat signal into an optical signal using the photoelectric conversion principle, and transmit it in isolation internally; when the optical signal is transmitted to the output terminal of the optocoupler circuit, it is converted back into an electrical signal and output as a detection signal to the detection terminal of the main control module 130.

[0041] The photoelectric conversion principle refers to the process of converting electrical signals into optical signals through a light-emitting element, specifically a light-emitting diode (LED). When the heartbeat signal output by the driving module 120 is applied to the LED, its internal PN junction emits light under forward bias. Isolation transmission refers to the technical means of physically isolating the input and output circuits, specifically using a phototransistor and LED optical coupling structure to block direct electrical connections between high and low voltage circuits. Electrical signal re-conversion refers to restoring the optical signal to a voltage signal recognizable by the main control module 130, specifically achieved through the photoelectric effect of the phototransistor. When the optical signal illuminates the base region of the phototransistor, a conducting current is formed between its collector and emitter.

[0042] Specifically, when the heartbeat signal output by the drive module 120 is transmitted to the input of the optocoupler circuit, the light-emitting diode is activated and emits a pulsed light signal synchronized with the heartbeat signal. This light signal passes through the isolation medium and is received by the phototransistor, generating an electrical signal corresponding to the original heartbeat signal at the output through the photoelectric effect. During this process, the physical isolation structure inside the optocoupler circuit effectively blocks electrical interference between the high-voltage side and the low-voltage control circuit, while fully preserving the frequency and duty cycle characteristics of the heartbeat signal. The main control module 130 continuously monitors the presence and waveform parameters of this electrical signal through the detection terminal to determine whether the drive module 120 is in normal working condition.

[0043] This application effectively solves the technical defects of traditional high-voltage protection schemes, such as susceptibility to signal transmission interference and poor communication stability. The isolation transmission mechanism of the optocoupler circuit physically isolates the high-voltage detection signal from the low-voltage control loop, ensuring system safety and improving signal transmission reliability. Simultaneously, the photoelectric conversion process fully preserves the original characteristics of the heartbeat signal, enabling the main control module to perform fault diagnosis based on precise waveform parameters, significantly reducing false alarm and missed alarm rates.

[0044] In this embodiment, as Figure 2 As shown, the optocoupler circuit includes: The light-emitting diode is used to receive the heartbeat signal output by the driver module 120 and emit light when current passes through it; specifically, it can be implemented using an LED device with a forward conduction voltage of 1.2V to 2.0V. Its function is to convert the heartbeat signal output by the driver module 120 into a light signal to achieve electrical isolation.

[0045] A phototransistor, positioned opposite to a light-emitting diode (LED), is used to receive the light signal emitted by the LED and convert it into an electrical signal for output to the main control module 130. Specifically, it can be implemented using an NPN type phototransistor with no base lead, whose function is to convert the light signal back into an electrical signal for transmission to the main control module 130.

[0046] A current-limiting resistor, connected in series in a light-emitting diode (LED) circuit, is used to limit the current passing through the LED and protect the optocoupler circuit from overcurrent damage. Specifically, a metal film resistor with a resistance of 1kΩ to 5kΩ can be used to achieve this. Its function is to prevent the LED from being damaged by overcurrent by limiting the current.

[0047] A pull-up resistor is connected between the output terminal of the phototransistor and the power supply to ensure that the output terminal of the phototransistor remains at a high level when there is no light signal input. Specifically, a carbon film resistor with a resistance of 10kΩ to 50kΩ can be used to achieve this. Its function is to ensure that the output terminal of the phototransistor maintains a certain logic state when there is no light input by providing a stable high level.

[0048] It should be noted that the heartbeat signal output by the driving module 120 is input to the light-emitting diode (LED). When current flows through the LED, it emits a light signal synchronized with the heartbeat signal. The phototransistor and the LED are isolated by an insulating material. After the light signal is received by the phototransistor, it triggers the collector-emitter junction to conduct, thereby generating a corresponding electrical signal at the output terminal. A current-limiting resistor is connected in series in the LED circuit to limit the maximum current value and prevent device overload damage. One end of the pull-up resistor is connected to the positive terminal of the power supply, and the other end is connected to the output terminal of the phototransistor. When the phototransistor is not conducting, the output terminal is pulled to a high level through the pull-up resistor to avoid misjudgment caused by a floating signal.

[0049] In one specific embodiment, the high-voltage switch module 110 is also connected to the refrigerant supply channel in the heat pump system; wherein, the refrigerant supply channel refers to the pipeline or cavity that transmits refrigerant in the heat pump system, which can be implemented using a metal pipe or a pressure-resistant plastic pipe, and its function is to provide a physical carrier for pressure detection.

[0050] The high-pressure switch module 110 detects the refrigerant pressure value in the refrigerant supply channel in real time and calculates whether the refrigerant pressure value is greater than the preset safety threshold. In practical applications, the refrigerant pressure value refers to the pressure value generated when the refrigerant flows in the channel, which can be specifically measured by converting the pressure sensor into an electrical signal.

[0051] If the refrigerant pressure value is greater than the safety threshold, the contact mechanism inside the high-pressure switch module 110 will activate, changing from a closed state to an open state, thus cutting off the electrical connection between the external power supply and the power supply terminal of the drive module 120. The safety threshold refers to a pre-set pressure critical value, which can be set through a comparator circuit or software parameters. Its function is to provide a reference for judging the high-pressure state.

[0052] The contact mechanism refers to a component that achieves circuit switching through mechanical action. Specifically, it can be implemented using an electromagnetic relay or a bimetallic strip structure. Its function is to directly cut off or maintain the power connection based on the pressure detection result.

[0053] If the refrigerant pressure value is greater than the safety threshold, the contact mechanism inside the high-pressure switch module 110 remains short-circuited, and the electrical connection between the external power supply and the power supply terminal of the drive module 120 is established.

[0054] Specifically, the high-pressure switch module 110 collects pressure data in the refrigerant supply channel in real time through a pressure sensor and compares this data with a preset safety threshold. When the pressure exceeds the safety threshold, the comparator outputs a trigger signal, and the drive mechanism controls the contact mechanism to switch from a closed state to an open state, thereby cutting off the connection between the external power supply and the drive module 120. If the pressure does not exceed the safety threshold, the contact mechanism remains closed, maintaining the connection between the power supply and the drive module 120. This process does not rely on external communication or complex control logic; it achieves rapid response solely through physical detection and mechanical action. This enables rapid triggering of high-pressure protection actions, reduces the risk of misjudgment due to communication failures or hardware malfunctions, simplifies the system structure, and meets the requirements of hardware redundancy and independence for safety certification.

[0055] In this embodiment, the driving module 120 is specifically used for: When the refrigerant is not under high pressure, its internal logic circuit or microcontroller generates a heartbeat signal with a fixed frequency and duty cycle. Here, the logic circuit or microcontroller refers to an electronic control unit that can generate periodic electrical signals. Specifically, it can be implemented using programmable logic devices or embedded controllers, which generate square wave signals with specific frequencies and duty cycles through preset programs.

[0056] The system generates six corresponding drive signals based on actual temperature requirements and outputs them to the compressor to control its operating status. The heartbeat signal and the six drive signals are simultaneously output through different output ports of the drive module 120.

[0057] Understandably, the six drive signals refer to the multi-phase drive waveforms used to control the windings of a three-phase compressor. Specifically, this can be achieved using complementary symmetrical PWM signals, adjusting the pulse width and phase difference to control the compressor speed and torque. Different output ports refer to physically isolated signal channels, which can be implemented using independent pins or isolated driver chips to avoid crosstalk and coupling between signals.

[0058] When the system is in normal operation, the control unit inside the drive module 120 continuously generates a heartbeat signal. This signal is designed as a square wave with a fixed frequency, such as 10kHz with a 50% duty cycle. Simultaneously, based on real-time data from the temperature sensor, the required operating parameters for the compressor are dynamically calculated, generating six drive signals with specific timing relationships. These six signals are output to the compressor's power module through independent ports, directly driving the motor windings to form a rotating magnetic field. The heartbeat signal and drive signals are output in parallel in the time dimension, for example, through a time-division multiplexing bus or parallel interface to achieve synchronous transmission, ensuring that there are no timing conflicts between the two signals during transmission.

[0059] In this embodiment, the main control module 130 determines the working status of the drive module 129 and whether the heat pump system has a high-pressure fault by detecting the presence or absence of the electrical signal and the characteristics of the electrical signal.

[0060] Understandably, the presence or absence of this electrical signal refers to whether the detection signal output by the optocoupler circuit is continuously present. Specifically, it can be implemented using a voltage detection circuit or a current detection circuit to determine whether the drive module is outputting a heartbeat signal normally.

[0061] The characteristics of this electrical signal refer to its frequency, duty cycle, or number of pulses. Specifically, it can be implemented using a timer or a pulse counter to verify whether the heartbeat signal conforms to a preset pulse pattern.

[0062] Specifically, the main control module 130 receives the electrical signal output from the optocoupler circuit through the detection terminal. If the electrical signal completely disappears, it indicates that the power supply to the drive module 120 has been cut off, and it can be determined that the high-voltage switch has been triggered. If the electrical signal exists but the frequency or duty cycle deviates from the preset range, it indicates that the drive module 120 may have distorted the heartbeat signal due to abnormal interference or hardware failure, and it can be determined that there is a high-voltage fault in the system. During this process, the pulse pattern of the electrical signal is periodically sampled, for example, by counting the number of pulses in a fixed time window and comparing it with a preset threshold, thereby avoiding misjudgment caused by instantaneous interference.

[0063] Assume the frequency of the heartbeat signal is fh, and the sampling window time is Tw. Under normal circumstances, the main control module 130 should detect N = fh × Tw. If the number of detected pulses is N_detected = 0, then a high-voltage fault is determined.

[0064] Furthermore, the main control module 130 is specifically used to: when the electrical signal is detected, analyze the pulse pattern of the electrical signal within a single sampling period, and determine whether the pulse pattern is the same as the pulse pattern of the heartbeat signal; if they are not the same, determine that the heat pump system has a high-pressure fault.

[0065] It should be noted that the pulse pattern refers to the periodic change characteristics of an electrical signal within a unit of time. Specifically, it can be quantified and described by frequency, duty cycle, and number of pulses. For example, a heartbeat signal can be set as a square wave with a fixed frequency of 10kHz and a duty cycle of 50%.

[0066] The sampling period refers to the time window during which the main control module 130 continuously acquires electrical signals. Specifically, it can be set to any value within the range of 10ms to 100ms. This period needs to cover the complete cycle of the heartbeat signal in order to accurately capture its pattern.

[0067] The main control module 130 acquires the electrical signal output from the optocoupler circuit in real time through an electrical signal detection circuit and converts it into a digital signal. Time-domain analysis is performed on the digital signal, for example, by using a Fast Fourier Transform to extract frequency components or by counting the number of pulses using a counter. If the frequency of the electrical signal deviates from a preset value (e.g., an allowable error range of ±5%), or if the duty cycle differs significantly from the heartbeat signal (e.g., a duty cycle below 40% or above 60%), the pulse pattern is determined to be abnormal. At this time, the main control module 130 triggers a high-voltage fault protection mechanism, such as cutting off the compressor power supply or activating the alarm module.

[0068] This application solves the problem of insufficient reliability caused by relying on a single signal for on / off judgment in the prior art. It achieves accurate identification of high-voltage faults through dynamic signal feature analysis, avoiding system shutdown caused by communication interference or hardware malfunction, thereby improving the stability and safety of heat pump system operation.

[0069] In one specific embodiment, the main control module 130 includes: An electrical signal detection circuit is used to detect the electrical signal output by the optocoupler circuit and convert it into a digital signal. This electrical signal detection circuit can be implemented using a combination of an operational amplifier and an analog-to-digital converter to eliminate noise interference during signal transmission and improve detection sensitivity.

[0070] The main control chip is used to analyze the frequency, duty cycle and pulse number of the electrical signal based on the digital signal, determine the pulse pattern of the electrical signal, and determine whether the pulse pattern is the same as the pulse pattern of the heartbeat signal. Based on the judgment result, it determines whether the heat pump system has a high-pressure fault. The main control chip can be implemented by a microcontroller or a digital signal processor. It performs pattern matching on the pulse characteristics through a preset algorithm to determine whether the drive module 120 is in normal working condition.

[0071] Specifically, after receiving the level signal output from the optocoupler, the electrical signal detection circuit removes high-frequency interference components through a filtering circuit, and then generates digital waveform data via an analog-to-digital converter. The main control chip captures this data at a fixed sampling period and compares it with the preset standard parameter range of the heartbeat signal by calculating the number of pulse rising edges, the proportion of high-level duration, and waveform period parameters per unit time. When a pulse frequency deviation exceeding a threshold, an abnormal duty cycle, or a mismatch in the number of pulses is detected, it is determined that the high-voltage switch has triggered a protection action, causing the drive module to lose power. At this time, the main control chip immediately generates a fault lockout signal.

[0072] In summary, the above technical solution addresses the reliability issues of existing high-voltage protection devices that rely on a single detection mechanism, achieving dual verification of power disconnection and drive module status, thus ensuring the accuracy of high-voltage fault diagnosis. Simultaneously, continuous monitoring of the heartbeat signal enables timely detection of poor line contact or drive module malfunctions, preventing system-wide failure due to localized faults.

[0073] like Figure 3 The image shows an embodiment of a heat pump system provided in this application. The heat pump system includes a power supply device 310, a refrigerant device 320, and a high-pressure protection device 330 as provided in the above embodiment. The high-voltage switch module is connected in series between the power supply terminal of the drive module and the output terminal of the power supply device 310. The drive end of the refrigerant device 320 is connected to the drive signal output end of the drive module.

[0074] In this embodiment, the refrigerant device 320 is actually a compressor and a compressor IPM. The drive module outputs six drive signals to the compressor IPM to control the compressor IPM to drive the compressor to run.

[0075] It should be noted that the structure and function of the high-pressure protection device 330 have been described in detail in the above embodiments and will not be repeated here. Therefore, this heat pump system also has the function of the aforementioned high-pressure protection device.

[0076] like Figure 4The image shows an embodiment of a high-voltage detection method proposed in this application based on the high-voltage protection device provided in the above embodiments. The method includes the following steps: S410, heartbeat signal output detection.

[0077] Specifically, the heartbeat detection module monitors the heartbeat signal output of the drive module in real time to determine whether a pulse signal is output.

[0078] In this embodiment, the heartbeat detection module is implemented using an optocoupler circuit. The input terminal of the optocoupler circuit is tightly connected to the heartbeat signal output terminal of the drive module. Under normal operating conditions where the refrigerant is not under high pressure, the internal logic circuit or microcontroller of the drive module generates a heartbeat signal with a fixed frequency and duty cycle according to preset rules, and outputs it to the outside through the heartbeat signal output terminal.

[0079] When the LED in the optocoupler circuit receives the heartbeat signal from the driver module, current flows through it, causing it to emit light. At this time, the phototransistor positioned opposite the LED receives this light signal and converts it into an electrical signal. The main control module determines whether a pulse signal is output by detecting the level at the output of the optocoupler circuit. If the level at the output of the optocoupler circuit changes, it indicates that a pulse signal is output from the driver module's heartbeat signal output; if the level at the output of the optocoupler circuit remains unchanged, it indicates that no pulse signal is output.

[0080] S420, pulse signal acquisition and recognition.

[0081] If a pulse signal is detected at the heartbeat signal output terminal of the drive module, the main control module immediately starts the pulse signal acquisition program to acquire the pulse signal and identify whether the pulse signal conforms to the preset pulse pattern.

[0082] The electrical signal detection circuit in the main control module acquires the electrical signal output by the optocoupler circuit and converts it into a digital signal. Subsequently, the fault diagnosis algorithm within the main control module analyzes and processes the acquired digital signal.

[0083] The preset pulse pattern refers to the characteristics that the heartbeat signal output by the drive module should possess under normal operating conditions of the heat pump system, including parameters such as pulse frequency, duty cycle, and pulse count. The main control module compares each parameter of the acquired pulse signal with the preset pulse pattern one by one.

[0084] For example, the preset pulse pattern specifies a heartbeat signal frequency of 10 pulses per second and a duty cycle of 50%. After acquiring the pulse signal, the main control module counts the number of pulses per unit time and calculates the high-level and low-level times of each pulse to determine the pulse frequency and duty cycle. If the acquired pulse signal frequency is 10 pulses per second and the duty cycle is 50%, it indicates that the pulse signal conforms to the preset pulse pattern; if the frequency or duty cycle deviates from the preset value, it indicates that the pulse signal does not conform to the preset pulse pattern.

[0085] To improve the accuracy of pulse signal recognition, the main control module samples and averages the electrical signal multiple times. Within a single sampling period, the main control module acquires the pulse signal multiple times and averages the acquired data to eliminate the influence of transient interference on the pulse signal parameters.

[0086] S430, high-voltage fault confirmed.

[0087] Specifically, based on the pulse signal identification results, the main control module determines whether the heat pump system has experienced a high-pressure fault.

[0088] If the acquired pulse signal is identified as conforming to a preset pulse pattern, the main control module determines that the heat pump system is in normal working condition and no high-pressure fault has occurred. At this time, the main control module continues to monitor the signal output by the heartbeat detection module in real time to ensure the stable operation of the system.

[0089] If the acquired pulse signal is found to deviate from the preset pulse pattern, the main control module will further analyze the anomaly. Considering the possibility of transient interference causing brief pulse signal anomalies, this implementation incorporates a fault delay judgment mechanism. The main control module monitors the pulse signal over multiple consecutive sampling periods. If the pulse signal deviates from the preset pulse pattern across multiple sampling periods, a high-pressure fault is determined in the heat pump system.

[0090] Once a high-pressure fault is detected in the heat pump system, the main control module will immediately execute protective actions. For example, the main control module will send a stop signal to the drive module, causing the drive module to stop outputting drive signals to the compressor, thereby stopping the compressor's operation. Simultaneously, the main control module will also control the high-pressure switch module to activate, cutting off the electrical connection between the external power supply and the drive module's power supply terminal, ensuring system safety. Furthermore, the main control module will record fault information, including the time of the fault occurrence and abnormal parameters of the pulse signals, for subsequent fault analysis and repair.

[0091] This embodiment can detect poor line contact or abnormal drive module in a timely manner by continuously monitoring the heartbeat signal, thus solving the problem of insufficient reliability of existing high-voltage protection devices due to their reliance on a single detection mechanism.

[0092] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-pressure protection device, applied to a heat pump system, characterized in that, include: High-voltage switch, drive module, main control module, and heartbeat detection module; The high-voltage switch module is connected in series with the power supply terminal of the drive module, and is used to automatically disconnect the external power supply from the power supply terminal of the drive module when the refrigerant in the heat pump system is under high pressure. The drive module is connected to the main control module through the heartbeat detection module, and is used to provide a drive signal to the compressor in the heat pump system and output a heartbeat signal to the heartbeat detection module when the refrigerant does not have high pressure. The main control module identifies whether the heartbeat detection module has detected a heartbeat signal, and determines whether the heat pump has experienced a high-pressure fault based on the identification result.

2. The high-voltage protection device according to claim 1, characterized in that, The heartbeat detection module is an optocoupler circuit. The input terminal of the optocoupler circuit is connected to the heartbeat signal output terminal of the drive module, and the output terminal of the optocoupler circuit is connected to the detection terminal of the main control module.

3. The high-voltage protection device according to claim 1, characterized in that, The high-voltage switch module is also connected to the refrigerant supply channel in the heat pump system; The high-pressure switch module detects the refrigerant pressure in the refrigerant supply channel in real time and calculates whether the refrigerant pressure exceeds a preset safety threshold. If the refrigerant pressure value is greater than the safety threshold, the contact mechanism inside the high-pressure switch will activate, changing from a closed state to an open state, thus cutting off the electrical connection between the external power supply and the power supply terminal of the drive module. If the refrigerant pressure value is greater than the safety threshold, the contact mechanism inside the high-pressure switch remains short-circuited, thus maintaining the electrical connection between the external power supply and the power supply terminal of the drive module.

4. The high-voltage protection device according to claim 1, characterized in that, The driving module is specifically used for: When the refrigerant is not under high pressure, its internal logic circuits or microcontrollers generate a heartbeat signal with a fixed frequency and duty cycle. The system generates six corresponding drive signals based on actual temperature requirements and outputs them to the compressor to control its operating status. The heartbeat signal and the six drive signals are simultaneously output through different output ports of the drive module.

5. The high-voltage protection device according to claim 2, characterized in that, The optocoupler circuit is used for: When the heartbeat signal is received from the drive module, the heartbeat signal is converted into an optical signal using the photoelectric conversion principle and then transmitted in isolation internally. When the optical signal is transmitted to the output of the optocoupler circuit, it is converted back into an electrical signal and output as a detection signal to the detection terminal of the main control module.

6. The high-voltage protection device according to claim 5, characterized in that, The main control module determines the operating status of the drive module and whether the heat pump system has experienced a high-pressure fault by detecting the presence or absence of the electrical signal and the characteristics of the electrical signal.

7. The high-voltage protection device according to claim 6, characterized in that, The main control module is specifically used for: When the electrical signal is detected, the pulse pattern of the electrical signal within a single sampling period is analyzed, and it is determined whether the pulse pattern is the same as the pulse pattern of the heartbeat signal. If they are different, then the heat pump system is determined to have a high-pressure fault.

8. The high-voltage protection device according to any one of claims 1-7, characterized in that, Also includes: The high-pressure warning module, connected to the main control module, is used to send an early warning when a high-pressure fault occurs in the heat pump system.

9. A heat pump system, characterized in that, Includes a power supply unit, a refrigerant unit, and a high-voltage protection device as described in any one of claims 1-8; The high-voltage switch module is connected in series between the power supply terminal of the drive module and the output terminal of the power supply device. The drive end of the refrigerant device is connected to the drive signal output end of the drive module.

10. A high-voltage detection method applied to the high-voltage protection device according to any one of claims 1-8, characterized in that, The method includes: The heartbeat detection module detects whether a pulse signal is output at the heartbeat signal output terminal of the drive module. If present, the pulse signal is acquired, and it is identified whether the pulse signal follows a preset pulse pattern. Based on the identification results, it is determined whether the heat pump system has experienced a high-pressure fault.

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