A compressor variable frequency drive circuit suitable for frequency control

Abstract

The utility model belongs to the technical field of electronic circuit, specifically is a kind of compressor variable frequency drive circuit suitable for frequency control, including receiving external control signal and generating frequency control signal, according to input signal adjustment output frequency;For the frequency control signal generated by main control module is converted into high frequency or low frequency power signal for driving compressor, the protection module includes overvoltage protection circuit, undervoltage protection circuit, overcurrent protection circuit and over-temperature protection circuit;With external equipment carries out data interaction, the communication module supports at least one communication protocol, realizes remote monitoring and parameter setting;The environmental parameter detection module includes temperature sensor, humidity sensor and vibration sensor, the working environment of compressor is monitored in real time and feedback to main control module;The frequency regulation module includes PID regulator or fuzzy logic controller, realizes accurate frequency control and dynamic response, with the effect of realizing efficient, low interference variable frequency control.

Description

Technical Field

[0001] This utility model relates to the technical field of electronic circuits, specifically a compressor frequency converter drive circuit suitable for frequency control. Background Technology

[0002] Generally, refrigerators control compressor speed via frequency signals. Existing solutions typically use a power chip and transformer to generate a non-isolated voltage, usually 18V, to power the power chip and inverter circuit. However, the inverter circuit typically operates at 15V, and the MCU requires 5V. Current circuits use an LDO circuit to convert 18V to 15V, and another LDO circuit to convert 15V to 5V to meet circuit requirements. However, existing circuits suffer from high standby power consumption and high power loss in the LDO circuits. Furthermore, these circuits operate continuously in both compressor operating and non-operating modes, resulting in significant power loss. The new circuit improves upon this design. When the compressor needs to operate, the speed sensor receives the speed signal, and an optocoupler converts the 18V to 18V. The 18V to 15V conversion circuit is then replaced with a single transistor step-down converter, and the 15V to 5V conversion uses a DC-DC converter. This significantly reduces power loss due to voltage reduction when the compressor is running. When the compressor is not in operation, SPEED does not receive a signal, and the 18V1 voltage cannot be converted to 18V, preventing the subsequent circuitry from functioning. This reduces power loss caused by voltage conversion when the compressor is not operating.

[0003] In modern industrial and household environments, compressors are among the most widely used devices, primarily in refrigeration equipment such as air conditioners and refrigerators. Traditional compressors operate at a fixed speed, which often leads to unnecessary energy waste and low refrigeration efficiency. With technological advancements, variable frequency technology has been gradually incorporated into compressor design. By adjusting the compressor's operating frequency to adapt to different environmental demands, it can improve energy efficiency and effectively extend the compressor's lifespan.

[0004] Traditional variable frequency drive circuits are relatively complex, mainly including rectification, filtering, control, and inversion stages. This not only increases manufacturing costs, but the complex circuit design also makes them prone to failure, reducing system reliability and lifespan. Furthermore, these circuits have weak immunity to electromagnetic interference (EMI), easily causing interference to other electronic devices, and may also be susceptible to EMI generated by other electronic devices. Therefore, designing a compressor variable frequency drive circuit that simplifies circuit structure, improves reliability, and reduces electromagnetic interference has become an important research direction in the current technological field.

[0005] Against this backdrop, the design of a compressor variable frequency drive circuit suitable for frequency control is particularly urgent. This circuit aims to achieve efficient and low-interference variable frequency control by optimizing the design and integration of various functional modules. By reducing unnecessary circuit components and simplifying signal processing, it can significantly reduce manufacturing costs and system complexity, while also improving system stability and its ability to cope with extreme environmental conditions, providing reliable support for the efficient operation of the compressor.

[0006] To address the aforementioned technical shortcomings, a solution for a compressor variable frequency drive circuit suitable for frequency control is proposed. Utility Model Content

[0007] To solve the above problems, this utility model provides the following technical solution:

[0008] A compressor variable frequency drive circuit suitable for frequency control includes:

[0009] The main control module is used to receive external control signals and generate frequency control signals. The main control module includes a microcontroller or a programmable logic controller and adjusts the output frequency according to the input signal.

[0010] A power drive module is used to convert the frequency control signal generated by the main control module into a high-frequency or low-frequency power signal to drive the compressor. The power drive module includes at least one power amplifier or IGBT module, which adjusts the output power according to the frequency control signal.

[0011] The protection module is used to detect and protect the compressor from abnormal conditions during operation. The protection module includes an overvoltage protection circuit, an undervoltage protection circuit, an overcurrent protection circuit, and an overtemperature protection circuit. When an abnormality is detected, it automatically cuts off the power supply or issues an alarm signal.

[0012] A communication module is used for data interaction with external devices. The communication module supports at least one communication protocol to enable remote monitoring and parameter setting.

[0013] An environmental parameter detection module is used to detect parameters of the compressor's operating environment. The environmental parameter detection module includes a temperature sensor, a humidity sensor, and a vibration sensor, which monitor the compressor's working environment in real time and feed it back to the main control module.

[0014] The frequency regulation module is used to dynamically adjust the output frequency according to the load requirements of the compressor. The frequency regulation module includes a PID controller or a fuzzy logic controller to achieve precise frequency control and dynamic response.

[0015] Furthermore, the main control module includes a microcontroller for system control via an 8-bit or 32-bit microcontroller, a digital signal processor for complex control algorithms and high-frequency signal processing, and a programmable logic controller suitable for industrial control scenarios, supporting multiple input / output and communication protocols.

[0016] Set up input interfaces to receive external control signals, including digital inputs (buttons, switches, relay contacts), analog inputs (0-10V, 4-20mA signals) for receiving frequency setting, pressure, and temperature analog signals, and communication inputs (receiving remote control signals via RS485, CAN bus, Modbus, and other protocols).

[0017] Set the output interface to send the processed control signal to the power drive module. This is usually a pulse width modulation signal, including PWM output, which is used to control IGBT and MOSFET power devices in the power drive module, and relay output, which is used to control the start and stop of external devices.

[0018] Furthermore, the power drive module includes a power amplifier, which amplifies the weak control signal output by the main control module to give it sufficient energy to drive the compressor motor.

[0019] Linear amplifiers are suitable for low-power applications but are less efficient, while switching amplifiers are suitable for high-power applications and are more efficient but require complex control circuits.

[0020] Inverters are installed to convert DC power to AC power to meet the needs of the compressor. These include full-bridge inverters, which consist of four power switching devices that generate alternating positive and negative AC signals, and half-bridge inverters, which consist of two power switching devices and are suitable for symmetrical loads.

[0021] Power switching devices are used for fast switching to generate the required AC signal. IGBTs are suitable for high-voltage, high-current applications, with fast switching speed and good thermal stability. MOSFETs are suitable for high-frequency applications, with fast switching speed and low on-resistance. GTOs are suitable for high-power applications, but have a slower switching speed.

[0022] The circuit is equipped with protection circuits to prevent damage to the compressor or drive module due to overcurrent or overvoltage abnormalities. These circuits include overcurrent protection, which uses a current sensor to detect the current and quickly cuts off the power supply when the current exceeds a set value; overvoltage protection, which uses a voltage sensor to detect the voltage and takes appropriate protective measures when the voltage is too high; and short-circuit protection, which detects short circuits and quickly cuts off the power supply.

[0023] Furthermore, the power drive module also includes filtering and buffering circuits to reduce electromagnetic interference generated by high-frequency switching and protect power devices from overvoltage damage. The filter is composed of inductors and capacitors to filter out high-frequency noise and ensure the stability of the output signal. The buffering circuit is composed of resistors, capacitors and diodes to absorb voltage spikes generated during the switching process.

[0024] The feedback circuit is set up to monitor the status of the output signal in real time and feed the information back to the main control module for adjusting the control signal to achieve more precise control. Voltage feedback is used to detect the output voltage through a voltage sensor to ensure that the output voltage is stable. Current feedback is used to detect the output current through a current sensor to ensure that the output current is within a safe range.

[0025] An auxiliary power supply is set up to provide a stable power supply for the internal circuits, ensuring that each module works normally. This includes the DC-DC converter, which steps down and regulates the main power supply to provide a power supply suitable for the internal circuits. The regulated power supply ensures that the output voltage is stable and is not affected by input voltage fluctuations.

[0026] A heat dissipation system is set up to ensure that power devices do not overheat under high power conditions. This includes heat sinks, which accelerate heat dissipation by increasing surface area; fans, which improve heat dissipation efficiency by forcing air circulation; and heat pipes, which efficiently transfer heat through phase change heat transfer.

[0027] The control interface is configured to communicate with the main control module, receive control signals and send feedback signals, including a PWM interface to receive pulse width modulation signals and control the switching frequency of the power switching devices, a digital signal interface to receive digital signals and control the switching state of the power switching devices, and an analog signal interface to receive analog signals and adjust the output voltage or current of the power switching devices.

[0028] Furthermore, the protection module includes overcurrent protection, which detects that the current exceeds the safe value and quickly cuts off the power supply to prevent the equipment from overheating or burning out, using a current sensor and a circuit breaker or fuse.

[0029] Overvoltage protection detects excessively high voltage to prevent equipment damage caused by excessive voltage, using voltage sensors and relays or circuit breakers;

[0030] Undervoltage protection detects low voltage to prevent equipment from malfunctioning or being damaged due to insufficient voltage. It uses voltage sensors and control circuits.

[0031] Over-temperature protection detects excessively high internal temperatures of the equipment to prevent damage caused by overheating, using temperature sensors and control circuits.

[0032] Short circuit protection detects short circuits in the circuit and quickly cuts off the power supply to prevent excessive current from damaging equipment or causing a fire. Circuit breakers or fuses are used.

[0033] Furthermore, the communication module includes a wired communication module RS232, a serial communication interface suitable for short-distance data transmission; RS485, which supports multi-point communication and is suitable for industrial automation environments; Ethernet, which provides high-speed data transmission and supports LAN and WAN communication; and CAN bus, which is used for high-reliability communication in the automotive and industrial control fields.

[0034] Wireless communication module: Wi-Fi, wireless network communication based on IEEE 802.11 standard; Bluetooth, short-range wireless communication technology, suitable for simple data exchange between devices; ZigBee, low-power, low-data-rate wireless communication protocol, suitable for IoT applications; Cellular network: 2G, 3G, 4G, 5G, supports wide area network communication; LoRa, long-range, low-power wireless communication technology, suitable for remote monitoring.

[0035] Fiber optic communication modules, specifically fiber optic transceivers, convert electrical signals into optical signals, enabling long-distance, high-speed data transmission.

[0036] Furthermore, the environmental parameter detection module includes a temperature sensor to measure the ambient temperature and is equipped with a thermistor, a thermocouple, and an infrared sensor.

[0037] Humidity sensor, which measures ambient humidity, is equipped with both resistive and capacitive humidity sensors;

[0038] A light sensor measures light intensity and is equipped with a photoresistor and a photodiode.

[0039] An air quality sensor that detects the concentration of harmful gases is equipped with metal oxide semiconductor and electrochemical sensors;

[0040] Pressure sensors measure ambient pressure and include both piezoresistive and piezoelectric sensors.

[0041] Gas flow sensor, which measures gas flow rate, is equipped with both thermal and ultrasonic sensors.

[0042] Furthermore, the environmental parameter detection module also includes software and firmware, controls the module's operation, processes data, and performs system settings, and includes data acquisition software, configuration tools, and drivers;

[0043] The user interface displays measurement data and system status, and is equipped with an LCD screen, LED indicators, and a touch screen.

[0044] The alarm and warning system issues an alarm when parameters exceed the set range, and is equipped with sound alarm, light alarm and SMS notification;

[0045] Remote monitoring function, which enables remote monitoring and management through the Internet or wireless communication technology, and is equipped with cloud platform, mobile APP and web interface;

[0046] Data storage and recording: Stores the collected data for subsequent analysis and traceability, and is equipped with SD card, cloud storage and database;

[0047] Energy harvesting and power supply: In the absence of an external power source, the module is powered by solar energy and vibration energy.

[0048] Furthermore, the frequency adjustment module's frequency detection circuit monitors the system's current frequency in real time using a counter, frequency meter, or dedicated frequency detection chip.

[0049] The comparator compares the detected frequency with the set target frequency to determine whether adjustment is needed and sets up the analog and digital logic circuits.

[0050] The regulator adjusts the system frequency based on the comparator's output signal. In power systems, this involves adjusting the generator's speed or changing the transformer's taps; in electronic devices, it involves changing the frequency by adjusting the oscillator's parameters.

[0051] The feedback mechanism feeds the adjusted frequency information back to the frequency detection circuit, forming a closed-loop control to ensure frequency stability. The adjusted frequency data is transmitted back to the detection circuit through the feedback loop to achieve continuous frequency monitoring and adjustment.

[0052] The control logic determines the specific rules and algorithms for frequency regulation. It typically employs a PID control algorithm to achieve precise frequency control and also includes over-frequency protection and under-frequency protection mechanisms.

[0053] Compared with the prior art, the beneficial effects of this utility model are:

[0054] 1. In this utility model, an external control signal is received and a frequency control signal is generated, and the output frequency is adjusted according to the input signal; the frequency control signal generated by the main control module is converted into a high-frequency or low-frequency power signal to drive the compressor; the protection module includes an overvoltage protection circuit, an undervoltage protection circuit, an overcurrent protection circuit, and an overtemperature protection circuit; data interaction with external devices is performed, and the communication module supports at least one communication protocol to realize remote monitoring and parameter setting; the environmental parameter detection module includes a temperature sensor, a humidity sensor, and a vibration sensor to monitor the compressor's working environment in real time and feed it back to the main control module; the frequency adjustment module includes a PID controller or a fuzzy logic controller to achieve precise frequency control and dynamic response, and has the effect of achieving efficient and low-interference variable frequency control.

[0055] 2. In this utility model, electromagnetic interference generated by high-frequency switching is reduced through filtering and buffering circuits, protecting power devices from overvoltage damage. The filter, composed of inductors and capacitors, filters out high-frequency noise and ensures the stability of the output signal. The buffer circuit, composed of resistors, capacitors, and diodes, absorbs voltage spikes generated during switching. A feedback circuit monitors the status of the output signal in real time and feeds the information back to the main control module for adjusting the control signal to achieve more precise control. Voltage feedback uses a voltage sensor to detect the output voltage, ensuring output voltage stability. Current feedback uses a current sensor to detect the output current, ensuring the output current is within a safe range. This design not only significantly reduces manufacturing costs and system complexity but also improves system stability and the ability to cope with extreme environmental conditions, providing reliable support for the efficient operation of the compressor. Attached Figure Description

[0056] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings;

[0057] Figure 1 This is a schematic diagram of the overall modules of this utility model;

[0058] Figure 2 This is a schematic diagram of the main circuit of this utility model;

[0059] Figure 3 This is a schematic diagram of the control circuit in this utility model;

[0060] Figure 4 This is a schematic diagram of the feedback circuit in this utility model. Detailed Implementation

[0061] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0062] like Figure 1-4 As shown, a compressor inverter drive circuit suitable for frequency control includes:

[0063] The main control module is used to receive external control signals and generate frequency control signals. The main control module includes a microcontroller or a programmable logic controller and adjusts the output frequency according to the input signal.

[0064] A power drive module is used to convert the frequency control signal generated by the main control module into a high-frequency or low-frequency power signal to drive the compressor. The power drive module includes at least one power amplifier or IGBT module, which adjusts the output power according to the frequency control signal.

[0065] The protection module is used to detect and protect the compressor from abnormal conditions during operation. The protection module includes an overvoltage protection circuit, an undervoltage protection circuit, an overcurrent protection circuit, and an overtemperature protection circuit. When an abnormality is detected, it automatically cuts off the power supply or issues an alarm signal.

[0066] A communication module is used for data interaction with external devices. The communication module supports at least one communication protocol to enable remote monitoring and parameter setting.

[0067] An environmental parameter detection module is used to detect parameters of the compressor's operating environment. The environmental parameter detection module includes a temperature sensor, a humidity sensor, and a vibration sensor, which monitor the compressor's working environment in real time and feed it back to the main control module.

[0068] The frequency regulation module is used to dynamically adjust the output frequency according to the load requirements of the compressor. The frequency regulation module includes a PID controller or a fuzzy logic controller to achieve precise frequency control and dynamic response.

[0069] In one embodiment, the input power supply is processed and managed. The power management module includes a rectifier circuit, a filter circuit, and a voltage regulator circuit, providing a stable power supply to the system. Faults during compressor operation are diagnosed and located. The fault diagnosis module includes a fault code generator and a fault record storage device, capable of generating corresponding fault codes and storing fault information when a fault is detected. A human-machine interface is provided. The user interface module includes a display screen, buttons, and a touch screen, capable of displaying the compressor's operating status and parameters, and supporting user operation and settings. The compressor's energy consumption is optimized. The energy optimization module includes an energy monitoring circuit and an optimization algorithm, enabling efficient energy utilization while ensuring the compressor's normal operation. Through the coordinated operation of the above modules, the compressor's variable frequency drive circuit can achieve precise frequency control of the compressor, improving operating efficiency, extending equipment life, and providing comprehensive protection and monitoring functions.

[0070] Specifically, the main control module includes a microcontroller for system control via an 8-bit or 32-bit microcontroller, a digital signal processor for complex control algorithms and high-frequency signal processing, and a programmable logic controller suitable for industrial control scenarios, supporting multiple input / output and communication protocols.

[0071] Set up input interfaces to receive external control signals, including digital inputs (buttons, switches, relay contacts), analog inputs (0-10V, 4-20mA signals) for receiving frequency setting, pressure, and temperature analog signals, and communication inputs (receiving remote control signals via RS485, CAN bus, Modbus, and other protocols).

[0072] Set the output interface to send the processed control signal to the power drive module. This is usually a pulse width modulation signal, including PWM output, which is used to control IGBT and MOSFET power devices in the power drive module, and relay output, which is used to control the start and stop of external devices.

[0073] In one embodiment, the system operating status is monitored and protection functions are provided. Overvoltage protection detects excessively high power supply voltage and cuts off the power. Undervoltage protection detects excessively low power supply voltage and cuts off the power. Overcurrent protection detects excessively high current and cuts off the power. Overtemperature protection detects excessively high temperature and cuts off the power. Short circuit protection detects a short circuit and cuts off the power.

[0074] Provides a stable power supply to the main control module, ensuring its normal operation. A DC-DC converter transforms the input power into a voltage suitable for the processor and other modules (e.g., 5V, 3.3V). Filter capacitors remove noise from the power supply, improving its stability. Stores control programs, operating parameters, and historical data. EEPROM: Used to store user settings and operating parameters. Flash memory: Used to store control programs and firmware updates. SD card: Used to store operating data and logs.

[0075] The algorithm and software are used to implement the control logic and signal processing. Frequency control algorithms include PID control and fuzzy logic control. Vector control is used for precise control of motor torque and speed. Direct torque control is used for high-precision motor control. Energy optimization algorithms are used to improve energy efficiency.

[0076] The system includes clock and timing functions for system timing, task scheduling, and timestamp recording. A real-time clock provides a precise time reference. A timer module controls task execution time. Through the coordinated operation of these components, the main control module precisely controls the compressor's operating frequency, achieving efficient and stable operation. Depending on specific application requirements, the main control module can employ different hardware configurations and software algorithms to meet varying performance and functional requirements.

[0077] Specifically, the power drive module includes a power amplifier, which amplifies the weak control signal output by the main control module to give it sufficient energy to drive the compressor motor.

[0078] Linear amplifiers are suitable for low-power applications but are less efficient, while switching amplifiers are suitable for high-power applications and are more efficient but require complex control circuits.

[0079] Inverters are installed to convert DC power to AC power to meet the needs of the compressor. These include full-bridge inverters, which consist of four power switching devices that generate alternating positive and negative AC signals, and half-bridge inverters, which consist of two power switching devices and are suitable for symmetrical loads.

[0080] Power switching devices are used for fast switching to generate the required AC signal. IGBTs are suitable for high-voltage, high-current applications, with fast switching speed and good thermal stability. MOSFETs are suitable for high-frequency applications, with fast switching speed and low on-resistance. GTOs are suitable for high-power applications, but have a slower switching speed.

[0081] The circuit is equipped with protection circuits to prevent damage to the compressor or drive module due to overcurrent or overvoltage abnormalities. These circuits include overcurrent protection, which uses a current sensor to detect the current and quickly cuts off the power supply when the current exceeds a set value; overvoltage protection, which uses a voltage sensor to detect the voltage and takes appropriate protective measures when the voltage is too high; and short-circuit protection, which detects short circuits and quickly cuts off the power supply.

[0082] Specifically, the power drive module also includes filtering and buffering circuits to reduce electromagnetic interference generated by high-frequency switching and protect power devices from overvoltage damage. The filter is composed of inductors and capacitors to filter out high-frequency noise and ensure the stability of the output signal. The buffering circuit is composed of resistors, capacitors and diodes to absorb voltage spikes generated during the switching process.

[0083] The feedback circuit is set up to monitor the status of the output signal in real time and feed the information back to the main control module for adjusting the control signal to achieve more precise control. Voltage feedback is used to detect the output voltage through a voltage sensor to ensure that the output voltage is stable. Current feedback is used to detect the output current through a current sensor to ensure that the output current is within a safe range.

[0084] An auxiliary power supply is set up to provide a stable power supply for the internal circuits, ensuring that each module works normally. This includes the DC-DC converter, which steps down and regulates the main power supply to provide a power supply suitable for the internal circuits. The regulated power supply ensures that the output voltage is stable and is not affected by input voltage fluctuations.

[0085] A heat dissipation system is set up to ensure that power devices do not overheat under high power conditions. This includes heat sinks, which accelerate heat dissipation by increasing surface area; fans, which improve heat dissipation efficiency by forcing air circulation; and heat pipes, which efficiently transfer heat through phase change heat transfer.

[0086] The control interface is configured to communicate with the main control module, receive control signals and send feedback signals, including a PWM interface to receive pulse width modulation signals and control the switching frequency of the power switching devices, a digital signal interface to receive digital signals and control the switching state of the power switching devices, and an analog signal interface to receive analog signals and adjust the output voltage or current of the power switching devices.

[0087] Specifically, the protection module includes overcurrent protection, which detects that the current exceeds the safe value, quickly cuts off the power supply, and prevents the equipment from overheating or burning out, using a current sensor and a circuit breaker or fuse.

[0088] Overvoltage protection detects excessively high voltage to prevent equipment damage caused by excessive voltage, using voltage sensors and relays or circuit breakers;

[0089] Undervoltage protection detects low voltage to prevent equipment from malfunctioning or being damaged due to insufficient voltage. It uses voltage sensors and control circuits.

[0090] Over-temperature protection detects excessively high internal temperatures of the equipment to prevent damage caused by overheating, using temperature sensors and control circuits.

[0091] Short circuit protection detects short circuits in the circuit and quickly cuts off the power supply to prevent excessive current from damaging equipment or causing a fire. Circuit breakers or fuses are used.

[0092] Specifically, the communication module includes a wired communication module RS232, a serial communication interface suitable for short-distance data transmission; RS485, which supports multi-point communication and is suitable for industrial automation environments; Ethernet, which provides high-speed data transmission and supports LAN and WAN communication; and CAN bus, which is used for high-reliability communication in the automotive and industrial control fields.

[0093] Wireless communication module: Wi-Fi, wireless network communication based on IEEE 802.11 standard; Bluetooth, short-range wireless communication technology, suitable for simple data exchange between devices; ZigBee, low-power, low-data-rate wireless communication protocol, suitable for IoT applications; Cellular network: 2G, 3G, 4G, 5G, supports wide area network communication; LoRa, long-range, low-power wireless communication technology, suitable for remote monitoring.

[0094] Fiber optic communication modules, specifically fiber optic transceivers, convert electrical signals into optical signals, enabling long-distance, high-speed data transmission.

[0095] In one embodiment, the communication protocol stack includes: TCP / IP (the foundational protocol for internet communication); HTTP / HTTPS (data transfer for web services); FTP (file transfer protocol); MQTT (lightweight IoT communication protocol); and Modbus (a commonly used communication protocol in industrial automation).

[0096] The interface and adapter include a USB port for connecting external devices and supporting data transfer; an HDMI port for high-definition video and audio transmission; and a fiber optic port for fiber optic communication connections.

[0097] The communication controller includes an MCU (Microcontroller): responsible for processing communication data and controlling the operation of the communication modules. An FPGA (Field-Programmable Gate Array): used to implement complex communication logic and protocols.

[0098] The communication software includes communication protocol software: a software stack that implements various communication protocols; data transmission software: used to manage data sending and receiving; and network management software: used to monitor and manage the communication network.

[0099] The security module includes an encryption module to encrypt communication data and ensure data transmission security. The authentication module is used for device and user authentication.

[0100] Through the coordinated operation of the aforementioned components, the communication module enables efficient and reliable data transmission, meeting communication needs in various scenarios. Whether in industrial automation, the Internet of Things, or home networks, the communication module is a core component ensuring smooth information transmission.

[0101] Specifically, the environmental parameter detection module includes a temperature sensor to measure the ambient temperature and is equipped with a thermistor, thermocouple, and infrared sensor.

[0102] Humidity sensor, which measures ambient humidity, is equipped with both resistive and capacitive humidity sensors;

[0103] A light sensor measures light intensity and is equipped with a photoresistor and a photodiode.

[0104] An air quality sensor that detects the concentration of harmful gases is equipped with metal oxide semiconductor and electrochemical sensors;

[0105] Pressure sensors measure ambient pressure and include both piezoresistive and piezoelectric sensors.

[0106] Gas flow sensor, which measures gas flow rate, is equipped with both thermal and ultrasonic sensors.

[0107] Specifically, the environmental parameter detection module also includes software and firmware, controls the module to run, process data and perform system settings, and includes data acquisition software, configuration tools and drivers;

[0108] The user interface displays measurement data and system status, and is equipped with an LCD screen, LED indicators, and a touch screen.

[0109] The alarm and warning system issues an alarm when parameters exceed the set range, and is equipped with sound alarm, light alarm and SMS notification;

[0110] Remote monitoring function, which enables remote monitoring and management through the Internet or wireless communication technology, and is equipped with cloud platform, mobile APP and web interface;

[0111] Data storage and recording: Stores the collected data for subsequent analysis and traceability, and is equipped with SD card, cloud storage and database;

[0112] Energy harvesting and power supply: In the absence of an external power source, the module is powered by solar energy and vibration energy.

[0113] Specifically, the frequency adjustment module's frequency detection circuit monitors the system's current frequency in real time using a counter, frequency meter, or dedicated frequency detection chip.

[0114] The comparator compares the detected frequency with the set target frequency to determine whether adjustment is needed and sets up the analog and digital logic circuits.

[0115] The regulator adjusts the system frequency based on the comparator's output signal. In power systems, this involves adjusting the generator's speed or changing the transformer's taps; in electronic devices, it involves changing the frequency by adjusting the oscillator's parameters.

[0116] The feedback mechanism feeds the adjusted frequency information back to the frequency detection circuit, forming a closed-loop control to ensure frequency stability. The adjusted frequency data is transmitted back to the detection circuit through the feedback loop to achieve continuous frequency monitoring and adjustment.

[0117] The control logic determines the specific rules and algorithms for frequency regulation. It typically employs a PID control algorithm to achieve precise frequency control and also includes over-frequency protection and under-frequency protection mechanisms.

[0118] In one embodiment, frequency control of the compressor is achieved by receiving control signals. The following is an explanation of the circuit's operation:

[0119] Optical coupler PC1 (EL817): Used for signal isolation and transmission.

[0120] Electrolytic capacitor E2: Used for energy storage and filtering.

[0121] Transistors Q1 and Q2 are used for voltage conversion and signal amplification.

[0122] Zener diode: Used for voltage regulation.

[0123] DC-DC chip U1: Used for voltage conversion.

[0124] Resistors R1-R12 and inductor L1 are used for voltage division, current limiting, and filtering.

[0125] Diode D1: Used for rectification and protection.

[0126] (1) When the compressor needs to work (SPEED signal is received)

[0127] Optocoupler PC1 is on:

[0128] When the SPEED signal receives the control signal, the primary light-emitting diode (LED) of the optocoupler PC1 is lit after current limiting by resistor R4.

[0129] When the secondary circuit of optocoupler PC1 is turned on, the output signal is used to control the subsequent circuit.

[0130] Voltage conversion and energy storage:

[0131] The 18V power supply charges the electrolytic capacitor E2 through resistor R3 and diode D1.

[0132] Meanwhile, E2 provides a bias voltage to transistor Q2 through resistor R7, causing Q2 to conduct.

[0133] After Q2 is turned on, the 18V1 power supply turns on transistor Q1 through R5 and R6, thereby converting the 18V1 power supply to 18V.

[0134] 18V to 15V:

[0135] The 18V power supply is stabilized at 15V through resistor R1 and a 16V Zener diode.

[0136] 15V to 5V:

[0137] The 15V power supply is converted to 5V through the DC-DC chip U1.

[0138] Resistors R10 and R12 are used to adjust the output voltage of the DC-DC chip (adjusted to 5V here).

[0139] Inductor L1 is used for filtering to reduce the ripple of the output voltage.

[0140] (2) When the compressor does not need to work (the SPEED signal is not received)

[0141] When the SPEED signal does not receive a control signal, the primary LED of optocoupler PC1 cannot light up.

[0142] The secondary circuit of optocoupler PC1 cannot conduct, causing subsequent circuits to malfunction.

[0143] The 18V1 power supply cannot charge E2 through R3 and D1, and Q2 and Q1 cannot conduct either, so the 18V1 power supply cannot be converted to 18V.

[0144] Therefore, the entire circuit is in the off state, and the compressor stops working.

[0145] The function of optocoupler PC1 is to achieve signal isolation and transmission through optocoupler, and to avoid interference from the main circuit to the control signal.

[0146] The function of electrolytic capacitor E2 is to store energy and filter it, ensuring stability during voltage conversion.

[0147] The functions of transistors Q1 and Q2 are: to convert voltage and amplify signals, ensuring that subsequent circuits can function properly.

[0148] The function of DC-DC chip U1 is to convert 15V power to 5V power, providing a stable low-voltage power supply for the control circuit.

[0149] The function of resistors R10 and R12 is to adjust the output voltage of the DC-DC chip and ensure that the output voltage is stable at 5V.

[0150] The function of inductor L1 is to filter, reduce output voltage ripple, and improve power quality.

[0151] Signal isolation: Signal isolation is achieved through optocouplers to prevent interference from the main circuit to the control signals.

[0152] Flexible voltage conversion: Through multi-stage voltage conversion (18V1→18V→15V→5V), it meets the voltage requirements of different circuit modules.

[0153] Filtering and voltage regulation: The stability and reliability of the power supply are ensured through electrolytic capacitors, inductors, and Zener diodes.

[0154] This circuit is suitable for compressor systems that require frequency control. It can dynamically adjust the compressor's operating frequency according to external control signals to achieve energy saving and efficient operation.

[0155] When the press needs to work:

[0156] When SPEED receives a signal, resistor R4 limits the current, causing the primary LED of optocoupler PC1 (EL817) to light up. This turns on the secondary side of the optocoupler, allowing 1) 18V1 to charge electrolytic capacitor E2 through resistor R3 and diode D1. Simultaneously, E2 turns on transistor Q2 through resistor R7. At this time, resistors R5 and R6 are active, causing transistor Q1 to conduct, thus converting 18V1 to 18V.

[0157] The 18V voltage is turned on by resistor R1 and a 16V Zener diode, causing transistor V1 to conduct. At this point, the 18V is converted to 15V.

[0158] The 15V is converted to 5V by the DC-DC chip U1. Resistors R10 and R12 are used to adjust the output voltage (here adjusted to 5V), and the output ripple is adjusted by the inductor L1.

[0159] When the press is not in operation:

[0160] Since SPEED did not receive a signal, the primary LED of PC1 (EL817) could not light up, and the subsequent components could not function properly.

[0161] The working principle of this utility model is as follows: It receives external control signals and generates frequency control signals, adjusting the output frequency according to the input signals; it converts the frequency control signals generated by the main control module into high-frequency or low-frequency power signals to drive the compressor; the protection module includes overvoltage protection circuit, undervoltage protection circuit, overcurrent protection circuit, and overtemperature protection circuit; it interacts with external devices, and the communication module supports at least one communication protocol to achieve remote monitoring and parameter setting; the environmental parameter detection module includes temperature sensors, humidity sensors, and vibration sensors to monitor the compressor's working environment in real time and feed it back to the main control module; the frequency adjustment module includes a PID controller or a fuzzy logic controller to achieve precise frequency control and dynamic response, achieving efficient and low-interference variable frequency control. By employing filtering and buffering circuits, electromagnetic interference generated by high-frequency switching is reduced, protecting power devices from overvoltage damage. The filter, composed of inductors and capacitors, removes high-frequency noise, ensuring output signal stability. The buffer circuit, consisting of resistors, capacitors, and diodes, absorbs voltage spikes generated during switching. A feedback circuit monitors the output signal status in real time and feeds this information back to the main control module for adjusting the control signal, achieving more precise control. Voltage feedback uses a voltage sensor to detect the output voltage, ensuring stability. Current feedback uses a current sensor to detect the output current, ensuring it remains within a safe range. This system not only significantly reduces manufacturing costs and system complexity but also improves system stability and the ability to cope with extreme environmental conditions, providing reliable support for the efficient operation of the compressor.

[0162] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A compressor variable frequency drive circuit suitable for frequency control, characterized by, include: The main control module is used to receive external control signals and generate frequency control signals. The main control module includes a microcontroller or a programmable logic controller and adjusts the output frequency according to the input signal. A power drive module is used to convert the frequency control signal generated by the main control module into a high-frequency or low-frequency power signal to drive the compressor. The power drive module includes at least one power amplifier or IGBT module, which adjusts the output power according to the frequency control signal. The protection module is used to detect and protect the compressor from abnormal conditions during operation. The protection module includes an overvoltage protection circuit, an undervoltage protection circuit, an overcurrent protection circuit, and an overtemperature protection circuit. When an abnormality is detected, it automatically cuts off the power supply or issues an alarm signal. A communication module is used for data interaction with external devices. The communication module supports at least one communication protocol to enable remote monitoring and parameter setting. An environmental parameter detection module is used to detect parameters of the compressor's operating environment. The environmental parameter detection module includes a temperature sensor, a humidity sensor, and a vibration sensor, which monitor the compressor's working environment in real time and feed it back to the main control module. The frequency regulation module is used to dynamically adjust the output frequency according to the load requirements of the compressor. The frequency regulation module includes a PID controller or a fuzzy logic controller to achieve precise frequency control and dynamic response.

2. A compressor variable frequency drive circuit suitable for frequency control as defined in claim 1, wherein, The main control module includes a microcontroller, which uses an 8-bit or 32-bit microcontroller for system control; a digital signal processor, which is used for complex control algorithms and high-frequency signal processing; and a programmable logic controller, which is suitable for industrial control scenarios and supports multiple input / output and communication protocols. Set up input interfaces to receive external control signals, including digital inputs (buttons, switches, relay contacts), analog inputs (0-10V, 4-20mA signals) for receiving frequency setting, pressure, and temperature analog signals, and communication inputs (receiving remote control signals via RS485, CAN bus, Modbus, and other protocols). Set the output interface to send the processed control signal to the power drive module. This is usually a pulse width modulation signal, including PWM output, which is used to control the IGBT and MOSFET power devices in the power drive module, and relay output, which is used to control the start and stop of external devices.

3. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 1, wherein, The power drive module includes a power amplifier, which amplifies the weak control signal output by the main control module to give it sufficient energy to drive the compressor motor. Linear amplifiers are suitable for low-power applications but are less efficient, while switching amplifiers are suitable for high-power applications and are more efficient but require complex control circuits. Inverters are installed to convert DC power to AC power to meet the needs of the compressor. These include full-bridge inverters, which consist of four power switching devices that generate alternating positive and negative AC signals, and half-bridge inverters, which consist of two power switching devices and are suitable for symmetrical loads. Power switching devices are used for fast switching to generate the required AC signal. IGBTs are suitable for high-voltage, high-current applications, with fast switching speed and good thermal stability. MOSFETs are suitable for high-frequency applications, with fast switching speed and low on-resistance. GTOs are suitable for high-power applications, but have a slower switching speed. The circuit is equipped with protection circuits to prevent damage to the compressor or drive module due to overcurrent or overvoltage abnormalities. These circuits include overcurrent protection, which uses a current sensor to detect the current and quickly cuts off the power supply when the current exceeds a set value; overvoltage protection, which uses a voltage sensor to detect the voltage and takes appropriate protective measures when the voltage is too high; and short-circuit protection, which detects short circuits and quickly cuts off the power supply.

4. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 3, wherein, The power drive module also includes filtering and buffering circuits to reduce electromagnetic interference generated by high-frequency switching and protect power devices from overvoltage damage. The filter is composed of inductors and capacitors to filter out high-frequency noise and ensure the stability of the output signal. The buffering circuit is composed of resistors, capacitors and diodes to absorb voltage spikes generated during the switching process. The feedback circuit is set up to monitor the status of the output signal in real time and feed the information back to the main control module for adjusting the control signal to achieve more precise control. Voltage feedback is used to detect the output voltage through a voltage sensor to ensure that the output voltage is stable. Current feedback is used to detect the output current through a current sensor to ensure that the output current is within a safe range. An auxiliary power supply is set up to provide a stable power supply for the internal circuits, ensuring that each module works normally. This includes the DC-DC converter, which steps down and regulates the main power supply to provide a power supply suitable for the internal circuits. The regulated power supply ensures that the output voltage is stable and is not affected by input voltage fluctuations. A heat dissipation system is set up to ensure that power devices do not overheat under high power conditions. This includes heat sinks, which accelerate heat dissipation by increasing surface area; fans, which improve heat dissipation efficiency by forcing air circulation; and heat pipes, which efficiently transfer heat through phase change heat transfer. The control interface is configured to communicate with the main control module, receive control signals and send feedback signals, including a PWM interface to receive pulse width modulation signals and control the switching frequency of the power switching devices, a digital signal interface to receive digital signals and control the switching state of the power switching devices, and an analog signal interface to receive analog signals and adjust the output voltage or current of the power switching devices.

5. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 4, wherein, The protection module includes overcurrent protection, which detects that the current exceeds the safe value and quickly cuts off the power supply to prevent the equipment from overheating or burning out, using a current sensor and a circuit breaker or fuse. Overvoltage protection detects excessively high voltage to prevent equipment damage caused by excessive voltage, using voltage sensors and relays or circuit breakers; Undervoltage protection detects low voltage to prevent equipment from malfunctioning or being damaged due to insufficient voltage. It uses voltage sensors and control circuits. Over-temperature protection detects excessively high internal temperatures of the equipment to prevent damage caused by overheating, using temperature sensors and control circuits. Short circuit protection detects short circuits in the circuit and quickly cuts off the power supply to prevent excessive current from damaging equipment or causing a fire. Circuit breakers or fuses are used.

6. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 5, wherein, The communication module includes a wired communication module RS232, a serial communication interface suitable for short-distance data transmission; RS485, which supports multi-point communication and is suitable for industrial automation environments; Ethernet, which provides high-speed data transmission and supports LAN and WAN communication; and CAN bus, which is used for high-reliability communication in the automotive and industrial control fields. Wireless communication module: Wi-Fi, wireless network communication based on IEEE 802.11 standard; Bluetooth, short-range wireless communication technology, suitable for simple data exchange between devices; ZigBee, low-power, low-data-rate wireless communication protocol, suitable for IoT applications; Cellular network: 2G, 3G, 4G, 5G, supports wide area network communication; LoRa, long-range, low-power wireless communication technology, suitable for remote monitoring. Fiber optic communication modules, specifically fiber optic transceivers, convert electrical signals into optical signals, enabling long-distance, high-speed data transmission.

7. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 6, wherein, The environmental parameter detection module includes a temperature sensor to measure the ambient temperature and is equipped with a thermistor, thermocouple and infrared sensor. Humidity sensor, which measures ambient humidity, is equipped with both resistive and capacitive humidity sensors; A light sensor measures light intensity and is equipped with a photoresistor and a photodiode. An air quality sensor that detects the concentration of harmful gases is equipped with metal oxide semiconductor and electrochemical sensors; Pressure sensors measure ambient pressure and include both piezoresistive and piezoelectric sensors. Gas flow sensor, which measures gas flow rate, is equipped with both thermal and ultrasonic sensors.

8. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 7, wherein, The environmental parameter detection module also includes software and firmware, which control the module to run, process data and perform system settings. It is equipped with data acquisition software, configuration tools and drivers. The user interface displays measurement data and system status, and is equipped with an LCD screen, LED indicators, and a touch screen. The alarm and warning system issues an alarm when parameters exceed the set range, and is equipped with sound alarm, light alarm and SMS notification; Remote monitoring function, which enables remote monitoring and management through the Internet or wireless communication technology, and is equipped with cloud platform, mobile APP and web interface; Data storage and recording: Stores the collected data for subsequent analysis and traceability, and is equipped with SD card, cloud storage and database; Energy harvesting and power supply: In the absence of an external power source, the module is powered by solar energy and vibration energy.

9. A variable frequency drive circuit for a compressor suitable for frequency control as defined in claim 8, wherein, The frequency adjustment module's frequency detection circuit monitors the system's current frequency in real time using a counter, frequency meter, or dedicated frequency detection chip. The comparator compares the detected frequency with the set target frequency to determine whether adjustment is needed and sets up the analog and digital logic circuits. The regulator adjusts the system frequency based on the comparator's output signal. In power systems, this involves adjusting the generator's speed or changing the transformer's taps; in electronic devices, it involves changing the frequency by adjusting the oscillator's parameters. The feedback mechanism feeds the adjusted frequency information back to the frequency detection circuit, forming a closed-loop control to ensure frequency stability. The adjusted frequency data is transmitted back to the detection circuit through the feedback loop to achieve continuous frequency monitoring and adjustment. The control logic determines the specific rules and algorithms of frequency adjustment, usually adopts PID control algorithm to realize the accurate control of frequency, and also includes over frequency protection and low frequency protection protection mechanism.

Images