A multi-channel controlled heating device

Abstract

This utility model discloses a multi-channel controlled heating device, including a rectifier and filter module, a temperature detection module, a current detection module, a microcontroller, a drive module, and a switch module. The rectifier and filter module rectifies AC mains power into DC power to supply the switch module. The switch module includes multiple power switches, each connected to a preset heating load. This utility model uses the temperature detection module to detect the real-time temperature values ​​of the multiple heating loads and the real-time temperature values ​​of the multiple power switches, and the current detection module to detect the real-time current values ​​of the multiple heating loads. The microcontroller outputs multiple PWM waves with corresponding duty cycles based on the real-time temperature values ​​of the heating loads, and provides overcurrent protection for the power switches based on the real-time temperature values ​​of the power switches and the real-time current values ​​of the heating loads. This achieves stepless adjustment of the equivalent power output to the heating loads, eliminating contact arcing and surge current problems, effectively improving temperature regulation accuracy and extending equipment lifespan.

Description

Technical Field

[0001] This utility model relates to the field of frequency converter technology, and in particular to a multi-channel control heating device. Background Technology

[0002] Currently, most heating equipment sold on the market uses electromagnetic contactors or relays as the main control components. When these devices are working, the contacts snap together instantly, directly connecting the heating element to the AC 220V power supply, resulting in inaccurate temperature regulation. Secondly, each time power is applied, an extremely high inrush current is generated. This inrush current not only impacts the power grid but also causes severe electrolytic erosion and thermal shock to the contactor contacts and the heating element itself, significantly shortening the equipment's service life. Utility Model Content

[0003] The technical problems to be solved by this utility model are inaccurate temperature regulation and short equipment life. In view of the above-mentioned defects of the prior art, a multi-channel control heating device is provided.

[0004] This utility model proposes a multi-channel control heating device, which includes a rectifier and filter module, a temperature detection module, a current detection module, a microcontroller, a drive module, a switch module, and a human-machine interaction module; The input terminal of the rectifier and filter module is connected to a preset AC mains power supply, and the output terminal of the rectifier and filter module is connected to the input terminal of the switch module. The rectifier and filter module is equipped with a varistor device, which is used to suppress surges so that the AC mains power supply is converted into a stable DC power supply and to power the switch module. The switching module includes multiple power switches, and the output terminals of the power switches are respectively connected to multiple preset heating loads; The temperature detection module includes multiple sets of thermocouple acquisition chips and NTC thermistors, and is used to detect the real-time temperature values ​​of multiple heating loads and multiple power switches respectively. The current detection module includes a multi-channel isolated current detection chip, and is used to detect the real-time current values ​​of multiple heating loads respectively. The microcontroller is communicatively connected to the temperature detection module, the current detection module, and the drive module, and is used to output multiple PWM waves with corresponding duty cycles according to the real-time temperature value of the heating load, and to provide overcurrent protection for the power switch according to the real-time temperature value of the power switch and the real-time current value of the heating load. The input terminal of the drive module is connected to the microcontroller, and the output terminal is connected to the drive terminal of the switch module. It is used to provide electrical isolation and amplify the power of the PWM wave. The PWM wave is used to control the on and off of the power switch to control the on and off of the heating load.

[0005] Furthermore, the temperature detection module includes a voltage divider circuit, which contains multiple NTC thermistors located around the power switch, and the resistance value of the NTC thermistors is negatively correlated with the temperature of the corresponding power switch.

[0006] Furthermore, the microcontroller includes a PID control module, a PWM output module, an AD conversion module, a communication module, and an auxiliary module. The voltage divider circuit is used to convert the resistance value into an analog voltage value and send it to the AD conversion module.

[0007] Furthermore, the AD conversion module is used to convert the analog voltage value into a digital voltage value, and restore the digital voltage value to obtain the real-time temperature value corresponding to the power switch.

[0008] Furthermore, the PID control module is used to call a preset PID control algorithm, which obtains multiple control outputs based on the real-time temperature value of the heating load.

[0009] Furthermore, the PWM output module outputs multiple PWM waves with corresponding duty cycles according to the control output quantity.

[0010] Furthermore, the driving module includes a high-speed optocoupler, an RC network filter, and a bipolar buffer MOSFET. The high-speed optocoupler is used to provide electrical isolation, the RC network filter is used to filter out noise, and the bipolar buffer MOSFET is used to amplify the power of the PWM wave to control the on / off state of the power switch.

[0011] Furthermore, the auxiliary module includes a cooling control output interface and a relay control output interface. The fan control interface is used to control a preset cooling system, and the relay control output interface is used to control the on / off state of auxiliary power supplies or alarm devices.

[0012] Furthermore, the rectifier and filter module includes a rectifier bridge, an electrolytic capacitor, and a varistor device. The rectifier bridge is used to convert AC mains power into pulsating DC power, the electrolytic capacitor is used to smooth the pulsating DC power into stable DC power, and the varistor device is used to suppress surges.

[0013] Furthermore, the human-machine interaction module is used to acquire input commands. The microcontroller communicates with the human-machine interaction module through the communication module and is used to receive the input commands and send the operating parameters of the heating load to the human-machine interaction module for display.

[0014] This utility model has the following beneficial effects: This invention first rectifies the AC mains power into stable DC power through a rectifier and filter module, and then uses a switching module to quickly control the on and off states using high-frequency chopping. By precisely modulating the duty cycle of the switching module, stepless adjustment of the equivalent voltage output to the heating load is achieved, realizing soft start and contactless switching of the load, completely eliminating contact arcing and surge current problems, and effectively improving the accuracy of temperature regulation and the service life of the equipment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is an overall structural diagram of a multi-channel controlled heating device according to one embodiment of the present invention. Detailed Implementation

[0016] 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.

[0017] Please refer to Figure 1This utility model proposes a multi-channel controlled heating device, including a rectifier and filter module, a temperature detection module, a current detection module, a microcontroller, a drive module, a switch module, and a human-machine interface module. The input terminal of the rectifier and filter module is connected to a preset AC mains power supply, and the output terminal of the rectifier and filter module is connected to the input terminal of the switch module, and is used to convert the AC mains power supply into a stable DC power supply to power the switch module. The switch module includes multiple power switches, and the output terminals of the power switches are respectively connected to multiple preset heating loads. The temperature detection module includes multiple sets of thermocouple acquisition chips and NTC thermistors, and is used to detect the real-time temperature values ​​of multiple heating loads and multiple power switches respectively. The current detection module includes multiple... A channel-isolated current sensing chip is used to detect the real-time current values ​​of multiple heating loads respectively. The microcontroller is communicatively connected to the temperature sensing module, the current sensing module, and the drive module respectively, and is used to output multiple PWM waves with corresponding duty cycles according to the real-time temperature value of the heating load, and to provide overcurrent protection for the power switch according to the real-time temperature value of the power switch and the real-time current value of the heating load. The input terminal of the drive module is connected to the microcontroller, and the output terminal is connected to the drive terminal of the switch module, and is used to provide electrical isolation and power amplification of the PWM waves. The PWM waves are used to control the on and off of the power switch respectively, so as to control the on and off of the heating load respectively.

[0018] In this embodiment, a multi-channel controlled heating device includes a rectifier and filter module, a temperature detection module, a current detection module, a microcontroller, a drive module, a switch module, and a human-machine interface module. The microcontroller includes a PID control module, a PWM output module, an AD conversion module, a communication module, and an auxiliary module. The input terminal of the rectifier and filter module is connected to a preset AC mains power supply, and the output terminal of the rectifier and filter module is connected to the input terminal of the switch module. The rectifier and filter module includes a rectifier bridge, an electrolytic capacitor, and a varistor. The rectifier bridge converts the AC mains power into pulsating DC mains power, the electrolytic capacitor smooths the pulsating DC mains power into a stable DC mains power supply, and the varistor suppresses surges, thus converting the AC mains power into a stable DC mains power supply to the switch module. The switch module includes multiple power switches, and the output terminals of the power switches are respectively connected to multiple preset heating loads. In this embodiment, the power switches use IGBTs (Insulated Gate Bipolar Transistors), which have the advantages of simple driving and fast switching speed. The temperature detection module includes multiple thermocouple acquisition chips for detecting the real-time temperature values ​​of the heating loads. It also includes a voltage divider circuit containing multiple NTC thermistors located near the power switches, with their resistance values ​​negatively correlated with the temperature of the corresponding power switches. The voltage divider circuit converts the resistance values ​​into analog voltage values ​​and sends them to the AD conversion module. The AD conversion module converts the analog voltage values ​​into digital voltage values ​​and then reconstructs the digital voltage values ​​to obtain the real-time temperature value of the corresponding power switches. The current detection module includes multi-channel isolated current detection chips for detecting the real-time current values ​​of multiple heating loads. The PID control module calls a preset PID control algorithm, which generates multiple control outputs based on the real-time temperature values ​​of the heating loads. The PWM output module outputs multiple PWM waves with corresponding duty cycles based on the control outputs. The drive module includes a high-speed optocoupler, an RC network filter, and a bipolar buffer MOSFET. The high-speed optocoupler provides electrical isolation, the RC network filter filters out noise, and the bipolar buffer MOSFET amplifies the PWM wave to control the on / off state of the power switch, thereby enabling separate control of the heating load's on / off state. The microcontroller provides overcurrent protection for the power switch based on the real-time temperature value of the power switch and the real-time current value of the heating load. In one specific embodiment, when the real-time temperature value of the power switch and the real-time current value of the heating load exceed a set range, the microcontroller controls the device to stop operating, improving the safety of device operation.

[0019] This invention replaces the traditional relay control method with IGBT power switching devices and combines it with a high-frequency PWM control strategy to achieve rapid on / off control of the heating load, effectively reducing the inrush current of the equipment, improving response speed and control accuracy, and significantly extending the service life of the entire unit. This invention uses an optocoupler-isolated drive circuit to control IGBT conduction, enhancing the electrical isolation between the control system and the power system, and improving safety and anti-interference performance. This invention integrates both thermocouple and NTC dual temperature detection devices to achieve real-time monitoring and protection of the heating load and IGBT devices, ensuring the equipment can operate under prolonged high-temperature conditions. Stable operation under various conditions; This utility model integrates a multi-channel current detection circuit, which can collect the current data of each heating load in real time, providing an accurate detection basis for closed-loop control. At the same time, it can realize overcurrent protection, circuit breaker detection and other functions, improving the reliability of system operation; This utility model provides an RS485 communication module, which can realize industrial bus communication with the host computer system or PLC, supports remote parameter setting and operation status reading, and is suitable for various industrial control scenarios; This utility model has a highly modular and integrated structural design, which manages various input and output signals in a unified manner through a microcontroller, reduces the number of peripheral components, effectively reduces system costs, and improves the reliability and maintainability of the whole machine.

[0020] Please refer to Figure 1 The input terminal of the rectifier and filter module is connected to the preset AC mains power, and the output terminal of the rectifier and filter module is connected to the input terminal of the switch module. The rectifier and filter module includes a rectifier bridge, an electrolytic capacitor, and a varistor. The rectifier bridge is used to convert the AC mains power into pulsating DC mains power, the electrolytic capacitor is used to smooth the pulsating DC mains power into stable DC mains power, and the varistor is used to suppress surges, thereby converting the AC mains power into stable DC mains power to supply power to the switch module.

[0021] In practical implementation: The rectifier and filter module includes a rectifier bridge, an electrolytic capacitor, and a varistor. The input terminal of the rectifier bridge is connected to the AC mains and is used to convert the AC mains into pulsating DC mains. In this embodiment, the AC mains is 220V. The output terminal of the rectifier bridge is connected to the input terminal of the electrolytic capacitor, which is used to smooth the pulsating DC mains into a stable DC mains. The output terminal of the electrolytic capacitor is connected to the input terminal of the varistor. The resistance value of the varistor changes drastically with the change of the voltage across its terminals. Under normal voltage, it exhibits a high resistance state, almost equivalent to an open circuit, and has no effect on the circuit. When encountering a sudden high-voltage surge, its resistance value drops sharply, approaching a short circuit state, thereby quickly dissipating the surge energy, suppressing the surge, and protecting the precision components at the downstream end. The output terminal of the varistor is connected to the input terminal of the switching module, realizing the conversion of the AC mains into a stable DC mains to power the switching module.

[0022] Please refer to Figure 1 The switching module includes multiple power switches, each with its output connected to a preset heating load. The temperature detection module includes multiple thermocouple acquisition chips to detect the real-time temperature of each heating load. The temperature detection module also includes a voltage divider circuit containing multiple NTC thermistors located near the power switches, with the resistance of each thermistor negatively correlated with the temperature of its corresponding power switch. The voltage divider circuit converts the resistance value into an analog voltage value and sends it to the AD conversion module. The AD conversion module converts the analog voltage value into a digital voltage value and then restores the digital voltage value to obtain the real-time temperature value of the corresponding power switch. The current detection module includes a multi-channel isolated current detection chip to detect the real-time current values ​​of the multiple heating loads. In practical implementation: The switching module includes multiple power switches, each with its output connected to a heating load. In this embodiment, there are five power switches and five heating loads. The power switches are IGBTs (Insulated Gate Bipolar Transistors), which have the advantages of simple driving and fast switching speed. Each IGBT controls the on / off state of one heating load, forming a five-way controlled heating system. The temperature detection module includes multiple thermocouple acquisition chips, each connected to one heating load and used to detect the real-time temperature value of the heating load. In this embodiment, the thermocouple acquisition chip is the MAX6675. The temperature detection module also includes a voltage divider circuit containing multiple NTC thermistors. The number of NTC thermistors is the same as the number of power switches, and each thermistor is located near a power switch. The resistance value of the NTC thermistor is negatively correlated with the temperature of the corresponding power switch; as the temperature of the power switch rises, the resistance value of the NTC thermistor decreases. The voltage divider circuit converts the resistance value into an analog voltage value and sends it to the AD conversion module. The AD conversion module converts the analog voltage value into a digital voltage value and restores the digital voltage value to obtain the real-time temperature value of each power switch. The current detection module includes a multi-channel isolated current detection chip. The multi-channel isolated current detection chip simultaneously detects the real-time current value of each heating load, obtaining the real-time current value of each heating load. In this embodiment, the multi-channel isolated current detection chip uses an ACPL-C790 to detect the operating current of each heating load, determine whether there is an abnormal overcurrent or open circuit fault, and return the detection data to the microcontroller. This invention integrates thermocouples and NTC dual temperature detection devices to achieve real-time monitoring and protection of heating loads and IGBT devices, ensuring stable operation of the equipment under long-term high-temperature conditions. Through a multi-channel current detection circuit, it can collect the current data of each heating load in real time, providing an accurate detection basis for closed-loop control. At the same time, it can realize overcurrent protection, circuit breaker detection and other functions, improving the reliability of system operation.

[0023] Please refer to Figure 1 The PID control module calls a preset PID control algorithm, which generates multiple control outputs based on the real-time temperature of the heating load. The PWM output module outputs multiple PWM waves with corresponding duty cycles based on the control outputs. The drive module includes a high-speed optocoupler, an RC network filter, and a bipolar buffer MOSFET. The high-speed optocoupler provides electrical isolation, the RC network filter filters out noise, and the bipolar buffer MOSFET amplifies the PWM waves to control the on / off state of the power switch, thereby enabling separate control of the heating load's on / off state.

[0024] In specific implementation: The microcontroller includes a PID control module and a PWM output module. In this embodiment, the microcontroller uses an integrated 32-bit MCU (Microcontroller Unit) chip, which has multiple PWM outputs, AD sampling, external communication, and interrupt handling functions. The PID control module is used to call a preset PID control algorithm, which calculates multiple control outputs based on the real-time temperature value of the heating load. The PWM output module outputs multiple PWM waves with corresponding duty cycles based on the control outputs. The drive module includes a high-speed optocoupler, an RC network filter, and a bipolar buffer MOSFET. The high-speed optocoupler is used to electrically isolate the low-voltage side of the microcontroller from the high-voltage main circuit, improving safety and anti-interference performance. In this embodiment, the high-speed optocoupler uses a TLP5701, which has a shorter propagation delay and higher switching speed, and can reliably transmit high-frequency PWM signals. The RC network filter refers to a combination of resistors and capacitors that can form a low-pass filter, effectively filtering out high-frequency noise from the previous stage or entering the drive circuit through spatial coupling, preventing the IGBT from being falsely triggered due to noise interference. The bipolar buffer MOSFET is used to amplify the power of the PWM wave. Each PWM wave controls the on / off state of each power switch, and each power switch controls the on / off state of the heating load. This invention uses IGBT power switching devices to replace the traditional relay control method, combined with a high-frequency PWM control strategy, to achieve rapid on / off control of the heating load, effectively reducing the inrush current of the equipment, improving the response speed and control accuracy, and significantly extending the service life of the entire machine.

[0025] Please refer to Figure 1 The human-machine interface module is used to acquire input commands. The microcontroller communicates with the human-machine interface module through the communication module and is used to receive input commands and send the operating parameters of the heating load to the human-machine interface module for display. The auxiliary module includes a cooling control output interface and a relay control output interface. The fan control interface is used to control the preset cooling system, and the relay control output interface is used to control the on / off of auxiliary power supplies or alarm devices.

[0026] In practical implementation: The microcontroller also includes a communication module and an auxiliary module. The communication module, based on the VP3082 chip, constructs an RS485 bus interface for bidirectional communication with external host systems or PLC devices. It supports standard protocols such as Modbus RTU and allows for remote parameter setting and operational status reading, making it suitable for various industrial control scenarios. Users input commands through the human-machine interface module (HMI). The microcontroller unit receives temperature adjustment commands or operating mode settings from the HMI through this communication module, and simultaneously transmits real-time operating parameters such as heating status, current, voltage, and temperature to the HMI. In one specific embodiment, the HMI can be a touchscreen. The auxiliary module includes a cooling control output interface and a relay control output interface. The fan control interface is used to control the preset cooling system, and the relay control output interface is used to control the on / off state of auxiliary power supplies or alarm devices.

[0027] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A multi-channel controlled heating device, characterized in that, It includes a rectifier and filter module, a temperature detection module, a current detection module, a microcontroller, a driver module, a switch module, and a human-machine interface module; The input terminal of the rectifier and filter module is connected to a preset AC mains power supply, and the output terminal of the rectifier and filter module is connected to the input terminal of the switch module. The rectifier and filter module is equipped with a varistor device, which is used to suppress surges so that the AC mains power supply is converted into a stable DC power supply and to power the switch module. The switching module includes multiple power switches, and the output terminals of the power switches are respectively connected to multiple preset heating loads; The temperature detection module includes multiple sets of thermocouple acquisition chips and NTC thermistors, and is used to detect the real-time temperature values ​​of multiple heating loads and multiple power switches respectively. The current detection module includes a multi-channel isolated current detection chip, and is used to detect the real-time current values ​​of multiple heating loads respectively. The microcontroller is communicatively connected to the temperature detection module, the current detection module, and the drive module, and is used to output multiple PWM waves with corresponding duty cycles according to the real-time temperature value of the heating load, and to provide overcurrent protection for the power switch according to the real-time temperature value of the power switch and the real-time current value of the heating load. The input terminal of the drive module is connected to the microcontroller, and the output terminal is connected to the drive terminal of the switch module. It is used to provide electrical isolation and amplify the power of the PWM wave. The PWM wave is used to control the on and off of the power switch to control the on and off of the heating load.

2. The multi-channel controlled heating device according to claim 1, characterized in that, The temperature detection module includes a voltage divider circuit containing multiple NTC thermistors. The NTC thermistors are located around the power switch, and the resistance value of the NTC thermistors is negatively correlated with the temperature of the corresponding power switch.

3. The multi-channel controlled heating device according to claim 2, characterized in that, The microcontroller includes a PID control module, a PWM output module, an AD conversion module, a communication module, and an auxiliary module. The voltage divider circuit is used to convert the resistance value into an analog voltage value and send it to the AD conversion module.

4. The multi-channel controlled heating device according to claim 3, characterized in that, The AD conversion module is used to convert the analog voltage value into a digital voltage value, and then restore the digital voltage value to obtain the real-time temperature value corresponding to the power switch.

5. The multi-channel controlled heating device according to claim 4, characterized in that, The PID control module is used to call a preset PID control algorithm, which obtains multiple control outputs based on the real-time temperature value of the heating load.

6. The multi-channel controlled heating device according to claim 5, characterized in that, The PWM output module outputs multiple PWM waves with corresponding duty cycles according to the control output quantity.

7. The multi-channel controlled heating device according to claim 6, characterized in that, The drive module includes a high-speed optocoupler, an RC network filter, and a bipolar buffer MOSFET. The high-speed optocoupler provides electrical isolation, the RC network filter filters out noise, and the bipolar buffer MOSFET amplifies the PWM wave to control the on / off state of the power switch.

8. The multi-channel controlled heating device according to claim 7, characterized in that, The auxiliary module includes a cooling control output interface and a relay control output interface. The cooling control output interface is used to control a preset cooling system, and the relay control output interface is used to control the on / off state of the auxiliary power supply or alarm.

9. The multi-channel controlled heating device according to claim 1, characterized in that, The rectifier and filter module includes a rectifier bridge, an electrolytic capacitor, and a varistor device. The rectifier bridge is used to convert AC mains power into pulsating DC power. The electrolytic capacitor is used to smooth the pulsating DC power into stable DC power. The varistor device is used to suppress surges.

10. The multi-channel controlled heating device according to claim 3, characterized in that, The human-machine interaction module is used to acquire input commands. The microcontroller communicates with the human-machine interaction module through the communication module and is used to receive the input commands and send the operating parameters of the heating load to the human-machine interaction module for display.

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