Electromagnetic heating system, heating method and laminating machine

Abstract

The invention provides an electromagnetic heating system, an electromagnetic heating method and a laminating machine, the electromagnetic heating system comprises a hot pressing plate, a rectifier bridge, a main control chip, a voltage reduction numerical control power supply and an inversion unit, and a heating coil is laid on the hot pressing plate; the second input end of the step-down numerical control power supply is coupled with the main control chip, and the step-down numerical control power supply adjusts the direct current input from the rectifier bridge under the control of the main control chip so as to output a target voltage; the output end of the inversion unit is coupled with the heating coil, and after the inversion unit converts the target voltage into high-frequency alternating current, the high-frequency alternating current is provided for the heating coil, so that the actual power of the heating coil reaches preset rated power; the electromagnetic heating system can effectively realize self-adaptive adjustment of the target voltage input to the inversion unit when the heating coil and / or the load are / is changed so as to be compatible with heating coils of different specifications and loads of different materials, the packaging requirements of solar cell modules of different sizes are met, the voltage regulation and control are accurate, and the voltage ripple is smaller.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic module production, and in particular to an electromagnetic heating system, an electromagnetic heating method and a laminator. Background Art

[0002] A laminator is a mechanical device used to press together multiple layers of material, primarily used for encapsulating solar cell modules. During operation, the laid-out solar modules are placed in a high-temperature, sealed, and evacuated chamber. Heating equipment, such as hot press plates, heats the modules while applying pressure to the modules under atmospheric pressure, achieving laminated encapsulation. Therefore, heating equipment and technology are crucial for solar modules. Currently, there are two main heating technologies: oil heating and electric heating tubes.

[0003] Traditional oil heating equipment uses electric heating tubes in the heating oil furnace to heat the thermal oil medium, and introduces the thermal oil medium in the heating oil furnace into the hot pressing plate through a circulating pump. The thermal oil medium is circulated in the hot pressing plate. However, in this method, the thermal oil preheating time is long and the energy consumption of heating the thermal oil is high.

[0004] Traditional electric heating tube heating equipment uses numerous mounting holes machined into the heat platen, into which numerous electric heating tubes are inserted. Heat from the heating tubes is then transferred to the heat platen to heat it. The sheer number of heating tubes and mounting holes significantly increases the difficulty and workload of installation and maintenance, and the heating tubes can cause significant heat loss when transferring heat to the heat platen.

[0005] Compared with the above-mentioned oil heating equipment and electric heating tube heating equipment, electromagnetic heating equipment has certain advantages in the solar module packaging process, such as fast heating response, simple installation and maintenance, and low heat loss.

[0006] Electromagnetic heating equipment is a device that uses the principle of electromagnetic induction to convert electrical energy into magnetic energy and then into thermal energy. Electromagnetic heating equipment generates a rapidly changing alternating magnetic field by passing a high-frequency, low-voltage, and high-current through the coil, causing the hot plate to cut the alternating magnetic lines of force and heat up. Because the hot platens used in the packaging of solar panels of different sizes have different sizes and materials (different loads), the coil sizes inside will also be different, so the corresponding working voltage and operating frequency of the coil will also have certain differences. Currently, a thyristor voltage regulator controller is usually used in the power supply circuit to reduce the voltage of the current connected to the rectifier bridge. However, it is only applicable to the heating system of a certain coil. When the coil or load is replaced, the accuracy and stability of the coil supply voltage will be reduced due to the inability to adaptively adjust the voltage regulation frequency. Therefore, the versatility of existing electromagnetic heating systems is poor.

[0007] Therefore, it is necessary to find an electromagnetic heating system with greater versatility. Summary of the Invention

[0008] The object of the present invention is to provide an electromagnetic heating system, a heating method and a laminator, which can achieve.

[0009] In order to achieve the above-mentioned object of the invention, the present invention proposes the following technical solutions:

[0010] In a first aspect, an electromagnetic heating system is provided, comprising:

[0011] A hot pressing plate, on which a heating coil is laid;

[0012] a rectifier bridge, wherein an input end of the rectifier bridge is connected to an external AC power source to convert the AC power input by the external AC power source into DC power;

[0013] A main control chip obtains the working current of the heating coil in real time;

[0014] a step-down digitally controlled power supply, wherein a first input terminal of the step-down digitally controlled power supply is coupled to the output terminal of the rectifier bridge, a second input terminal of the step-down digitally controlled power supply is coupled to the main control chip, and the step-down digitally controlled power supply adjusts the direct current input from the rectifier bridge under the control of the main control chip to output a target voltage;

[0015] An inverter unit, wherein the input end of the inverter unit is coupled to the output end of the step-down CNC power supply, and the output end of the inverter unit is coupled to the heating coil. After the inverter unit converts the target voltage into high-frequency alternating current, the high-frequency alternating current is provided to the heating coil so that the actual power of the heating coil reaches the predetermined rated power.

[0016] In a preferred embodiment, the step-down digital control power supply includes a BUCK circuit, and the main control chip is coupled to a first switch tube in the BUCK circuit to control the switching frequency and duty cycle of the first switch tube.

[0017] In a preferred embodiment, the electromagnetic heating system further includes a current transformer, which is coupled between the inverter unit and the heating coil to obtain the working current of the heating coil in real time;

[0018] The main control chip is coupled to the current transformer to obtain the working current of the heating coil in real time.

[0019] In a preferred embodiment, the main control chip is used to determine the real-time power of the heating coil based on the working current. When the real-time power is less than the rated power of the heating coil, the switching frequency and / or duty cycle of the first switching tube is increased to increase the output voltage of the step-down CNC power supply.

[0020] In a preferred embodiment, the inverter unit includes an H-bridge circuit and a corresponding driver stage;

[0021] The main control chip is also used to calculate and obtain the angle value of the phase difference between the output voltage of the step-down CNC power supply and the working current at the same time; determine whether the angle value of the phase difference is greater than 0°; and adjust the driving frequency of any driving level based on the judgment result so that the angle value of the phase difference is greater than 0°.

[0022] In a preferred embodiment, the electromagnetic heating system further includes a first comparator and a second comparator;

[0023] The positive input terminal of the first comparator is connected to a pin of the main control chip, and the signal output by the pin of the main control chip is related to the output voltage of the step-down digital control power supply;

[0024] The positive input terminal of the second comparator is connected to the output terminal of the current transformer, and the signal output by the output terminal of the current transformer is related to the current of the heating coil;

[0025] The main control chip calculates the angle value according to the output signal of the first comparator and the output signal of the second comparator.

[0026] In a preferred embodiment, the electromagnetic heating system further includes an impedance matching unit, which includes a transformer, wherein the primary coil included in the transformer is coupled to the output end of the inverter unit, and the secondary coil included in the transformer is connected to the heating coil.

[0027] In a preferred embodiment, the heating coil is arranged in a serpentine structure along the length direction of the hot pressing plate; or,

[0028] The heating coils are arranged in a serpentine structure along the width direction of the hot pressing plate.

[0029] In a preferred embodiment, the heating coil further includes a compensation coil wound around the lengthwise side and / or widthwise side of the heating plate.

[0030] In a preferred embodiment, the heating plate is provided with multiple rows or columns of grooves, and the heating coil is arranged in the grooves on the heating plate, or the heating plate is provided with a winding post, and the heating coil is wound on the heating plate through the winding post.

[0031] In a second aspect, an electromagnetic heating method is provided, wherein the electromagnetic heating method is used to control a heating coil to heat a heating plate, and the electromagnetic heating method comprises:

[0032] The rectifier bridge is used to convert the AC power input from the external AC power supply into DC power;

[0033] obtaining the operating current of the heating coil in real time;

[0034] Calculating a target voltage to be provided to the heating coil according to the operating current and the rated power of the heating coil;

[0035] regulating the DC power to obtain the target voltage;

[0036] After the target voltage is converted into high-frequency alternating current by an inverter unit, the high-frequency alternating current is provided to the heating coil so that the actual power of the heating coil reaches the rated power of the heating coil.

[0037] In a third aspect, a laminating machine is provided, comprising the electromagnetic heating system as described in any one of the first aspects.

[0038] In a preferred embodiment, the laminator further comprises a temperature sensor and a controller, wherein the temperature sensor is installed at the heating plate to sense the real-time temperature of the heating plate;

[0039] The controller is electrically connected to the temperature sensor to obtain the real-time temperature of the heating plate sensed by the temperature sensor;

[0040] The controller is also electrically connected to the electromagnetic heating system. When the real-time temperature of the heating plate exceeds a predetermined temperature, the controller controls the electromagnetic heating system to stop supplying power to the heating coil.

[0041] In a preferred embodiment, the laminator comprises a feeding mechanism, at least one laminating mechanism and a discharging mechanism sequentially arranged along a first horizontal direction, wherein:

[0042] The laminating mechanism includes a first frame, a lifting drive device, a flexible connector and a plurality of laminating units, wherein:

[0043] The first end of the flexible connector is arranged on the frame, and the second end of the flexible connector is transmission-connected to the lifting drive device;

[0044] A plurality of laminating units are arranged vertically at intervals, and the laminating units are detachably mounted on the flexible connector. Each laminating unit is capable of carrying a photovoltaic module and transporting the photovoltaic module along the first horizontal direction. Two adjacent laminating units can both laminate photovoltaic modules.

[0045] The lifting drive device is used to vertically drive the flexible connector to deform, so as to drive the adjacent lamination units to move closer or farther away. When two adjacent lamination units move closer to each other, the photovoltaic modules between them are laminated.

[0046] The feeding mechanism includes a second frame and a plurality of feeding and conveying units, wherein:

[0047] A plurality of the feeding and conveying units are vertically spaced apart and arranged on the second frame, and the feeding and conveying units are used to convey the photovoltaic components to be processed to the corresponding laminating units along the first horizontal direction;

[0048] The discharging mechanism includes a third frame and a plurality of discharging conveying units, wherein:

[0049] A plurality of discharge conveying units are vertically spaced apart and arranged on the third frame, wherein the discharge conveying units are used to receive the laminated photovoltaic modules outputted by the corresponding laminating units and output the laminated photovoltaic modules along the first horizontal direction;

[0050] The hot press plate and the heating coil in the electromagnetic heating system are disposed within the laminating unit.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention provides an electromagnetic heating system, an electromagnetic heating method and a laminating machine. The electromagnetic heating system includes a hot pressing plate, a rectifier bridge, a main control chip, a step-down digital control power supply and an inverter unit. A heating coil is laid on the hot pressing plate; the input end of the rectifier bridge is connected to an external AC power supply to convert the AC power input by the external AC power supply into DC power; the working current of the heating coil is obtained in real time; the first input end of the step-down digital control power supply is coupled to the output end of the rectifier bridge, the second input end of the step-down digital control power supply is coupled to the main control chip, and the step-down digital control power supply adjusts the DC power input from the rectifier bridge under the control of the main control chip to output a target voltage; the input end of the inverter unit is connected to the output end of the rectifier bridge, the second input end of the step-down digital control power supply is coupled to the main control chip, and the step-down digital control power supply adjusts the DC power input from the rectifier bridge under the control of the main control chip to output a target voltage; the input end of the inverter unit is connected to the output end of the rectifier bridge. The output end of the step-down digitally controlled power supply is coupled to the output end of the inverter unit, which is coupled to the heating coil. The inverter unit converts the target voltage into high-frequency alternating current, which is then supplied to the heating coil so that the actual power of the heating coil reaches the predetermined rated power. Through the cooperation of the step-down digitally controlled power supply and the main control chip, this electromagnetic heating system can effectively adaptively adjust the target voltage input to the inverter unit when the heating coil and / or load change. This allows for compatibility with heating coils of different specifications and loads of different materials, thereby meeting the packaging requirements of solar cell modules of different sizes. Compared to existing electromagnetic heating systems, this system offers more precise voltage regulation and less voltage ripple.

[0053] Furthermore, the electromagnetic heating system further includes an impedance matching unit, which includes a transformer, wherein the primary coil included in the transformer is coupled to the output end of the inverter unit, and the secondary coil included in the transformer is connected to the heating coil; when the step-down digital control power supply cannot step down the voltage to the target voltage so that the heating coil reaches the rated power, the electromagnetic heating system can further step down the voltage by providing the impedance matching unit, and at the same time, the transformer can effectively isolate the DC power, thereby effectively reducing energy consumption;

[0054] Furthermore, the heating coils are arranged in a serpentine structure along the length of the hot press plate; or, the heating coils are arranged in a serpentine structure along the width of the hot press plate. By laying the heating coils in a serpentine structure extending from one end to the other on the hot press plate, the electromagnetic heating system can form a magnetic field with equal strength at all locations, thereby achieving a uniform temperature at all locations on the hot press plate after heating.

[0055] Of course, the present invention only needs to achieve at least one of the above technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a schematic structural diagram of the electromagnetic heating system in Example 1;

[0057] Figure 2 It is a structural schematic diagram of the electromagnetic heating system in Example 2.

[0058] Markings in the figure:

[0059] 100-electromagnetic heating system, 10-heating coil, 20-hot press plate, 30-rectifier bridge, 50-step-down CNC power supply, 60-inverter unit, 70-current transformer, 80-impedance matching unit, 81-primary coil, 82-secondary coil. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0061] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "side", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0062] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0063] In one embodiment, the present application provides an electromagnetic heating system 100 for providing appropriate heating power to the heating coil 10. Figure 1 As shown, the electromagnetic heating system 100 includes a hot pressing plate 20, a rectifier bridge 30, a main control chip, a step-down digital control power supply 50 and an inverter unit 60, wherein the above-mentioned heating coil 10 is laid on the hot pressing plate 20, and the hot pressing plate 20 cuts the alternating magnetic field generated by the heating coil 10 and heats up to the target temperature. The hot pressing plate 20 performs hot pressing and packaging on the solar cell module based on high temperature, high pressure and a flat contact surface.

[0064] When the heating coil 10 is laid on the hot platen 20, it preferably extends uniformly from one end of the hot platen 20 to the other in a serpentine configuration. For example, the heating coil 10 may be arranged in a serpentine configuration along the length of the hot platen 20; or, alternatively, the heating coil 10 may be arranged in a serpentine configuration along the width of the hot platen 20. As a further improvement, the heating coil 10 may also include compensation coils wound around the longitudinal and / or width edges of the heating platen 20 to increase the temperature at the edges of the heating plate 20, further improving the temperature uniformity of the heating plate 20.

[0065] The compensation coil can be wound separately or set as an extension section of the heating coil. After the heating coil 10 is extended and arranged in a serpentine structure along the length direction of the hot press plate 20, it is then continued to be wound separately on the side of the length direction of the hot press plate 20. Or after the heating coil 10 is extended and arranged in a serpentine structure along the width direction of the hot press plate 20, it is then continued to be wound separately on the side of the width direction of the hot press plate 20. Or it can also be continued to be wound along the circumference of the already arranged heating coil 10.

[0066] In an optional embodiment, the temperature range of the wire used in the heating coil 10 is greater than 200°C, the wire diameter is greater than 0.5mm, and the wire spacing does not exceed 20 cm. The edges around the heating plate 20 can be wrapped with a coil, or it can be wrapped around the whole, or each edge of the heating plate 20 can be wound in a separate loop, and this embodiment does not limit this. In addition, the electromagnetic heating system 100 also includes a heat insulation plate, which is provided on the side of the heating coil 10 away from the heating plate 20, and is used to isolate the heating coil 10 from the outside world to reduce heat exchange. Of course, a temperature sensor is provided on the heating plate 20 to monitor its temperature in real time.

[0067] In a specific implementation, at least a portion of the heating coil 10 is embedded within the heating plate 20, or at least a portion of the heating coil 10 is wound on the surface of the heating plate 20. In one embodiment, the heating plate 20 is provided with multiple rows or columns of grooves, and the heating coil 10 is disposed within the grooves on the heating plate 20. In another embodiment, the heating plate 20 is provided with winding posts, and the heating coil 10 is wound around the heating plate 20 via the winding posts. Therefore, by providing grooves on the heating plate 20 or providing winding posts on the surface of the heating plate 20, the layout of the heating coil 10 on the heating plate 20 can be personalized and effectively fixed, ultimately improving the temperature control stability and uniformity of the heating plate 20.

[0068] When the size of the components to be heat-sealed varies, the size or shape of the corresponding heating plate 20 will also vary. Given the structure of the heating coil 10, in order to ensure that the actual power of the heating coil 10 reaches the rated power, it is necessary to regulate the target voltage input to the inverter unit 60, i.e., the output voltage of the rectifier bridge 30.

[0069] As mentioned above, the input end of the rectifier bridge 30 is connected to the external AC power supply to convert the AC power U1 input from the external AC power supply into high-voltage DC power U2 and output it.

[0070] In one implementation, the effective voltage of the AC power U1 is 380V, and the voltage of the high-voltage DC power U2 is The rectifier bridge 30 includes a three-phase rectifier bridge. Since any input end of the three-phase rectifier bridge is connected to the live wire, a fuse is connected in series at any input end of the three-phase rectifier bridge to improve equipment safety.

[0071] The first input terminal of the step-down digital control power supply 50 is coupled to the output terminal of the rectifier bridge 30. The aforementioned high-voltage DC power U2 serves as the input voltage of the step-down digital control power supply 50. The second input terminal of the step-down digital control power supply 50 is coupled to the main control chip. Under the control of the main control chip, the step-down digital control power supply 50 steps down the DC power U2 input from the rectifier bridge 30 to a target output voltage U3, which is a low-voltage DC power. In specific implementations, the target voltage is a low-voltage DC power in the range of 10V to 300V.

[0072] As a preference, Figure 1 As shown, the step-down digital control power supply 50 includes a step-down conversion circuit (hereinafter referred to as a BUCK circuit), and a first capacitor C1 and a first resistor R1 arranged in parallel, and the voltage is reduced by the BUCK circuit. Specifically, the first capacitor C1 is used to reduce the ripple of the high-voltage direct current U2 as the input voltage, so that the input voltage is smoother; R1 is used to serve as the load of the first capacitor C1 when a loop fault such as a short circuit or an open circuit occurs, forming a discharge loop to improve the safety of the equipment. The BUCK circuit includes a first switching tube, a diode, at least one second capacitor C2, an inductor L, etc. Among them, the first switching tube is preferably an insulated gate bipolar transistor (Insulate-Gate Bipolar Transistor, hereinafter referred to as IGBT). Among them, one output terminal of the main control chip is coupled to the first switching tube to control the switching frequency and duty cycle of the first switching tube, so as to achieve when the input voltage of the step-down digital control power supply 50 is a high-voltage direct current U2, output a stable low-voltage DC target voltage U3.

[0073] The input end of the inverter unit 60 is coupled to the output end of the step-down CNC power supply 50 to receive the target voltage U3 as its input voltage, and the output end of the inverter unit 60 is coupled to the heating coil 10 to output the obtained high-frequency alternating voltage U4 to the heating coil 10. Under the action of the high-frequency alternating voltage U4, the heating coil 10 generates a high-speed changing alternating magnetic field, and the hot press plate 20 cuts the alternating magnetic lines to generate heat energy and thus heat up. In this process, the high-frequency alternating voltage U4 output by the inverter unit 60 is provided to the heating coil 10 so that the actual power of the heating coil 10 reaches the predetermined rated power. It should be noted that the heating coil 10 and the heating plate 20 are usually a fixed combination, and the heating coil 10 has a certain rated power. When the actual power of the heating coil 10 reaches the rated power, it can usually meet the temperature requirement of the corresponding heating plate 20.

[0074] Specifically, the inverter unit 60 includes an H-bridge circuit and corresponding driver stages. The H-bridge circuit is composed of IGBTs or Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs). In one embodiment, the inverter unit 60 is composed of IGBT1, IGBT2, IGBT3, IGBT4, and corresponding driver stages. By designing each IGBT driver stage, two diagonally opposite IGBTs are alternately turned on at high frequency to achieve high-frequency AC voltage U4. Figure 1 As shown, in one state, IGBT1 and IGBT4 are turned on, and IGBT2 and IGBT3 are not turned on; in another state, IGBT1 and IGBT4 are not turned on, and IGBT2 and IGBT3 are turned on. In these two states, the high potential and low potential of the two output terminals of the inverter unit 60 change alternately, that is, Figure 1 The potentials of M and N in the circuit always change alternately, and the heating coil 10 generates an alternating current with a corresponding changing frequency.

[0075] Furthermore, the electromagnetic heating system 100 further includes a current transformer 70 , which is coupled between the inverter unit 60 and the heating coil 10 to obtain the operating current It of the heating coil 10 in real time.

[0076] One pin of the main control chip is coupled to the current transformer 70 to obtain the real-time operating current It of the heating coil 10. Based on the operating current It, the main control chip determines the real-time power Pt of the heating coil 10. When the real-time power Pt is less than the rated power of the heating coil 10, the main control chip increases the switching frequency and / or duty cycle of the first switching transistor to increase the output voltage of the step-down digital control power supply 50. That is, because the real-time power Pt of the heating coil 10 varies, this embodiment adjusts the real-time power Pt of the heating coil 10 by adjusting the output target voltage U3 through the main control chip.

[0077] In addition, the main control chip is also used to calculate and obtain the angle value of the phase difference between the output voltage U3 of the step-down CNC power supply 50 and the working current It at the same time, determine whether the angle value of the phase difference is greater than 0°, and adjust the driving frequency of any driving level based on the judgment result so that the angle value of the phase difference between the two is greater than 0°.

[0078] Any IGBT in the inverter unit 60 can operate in the resonant, capacitive, or inductive regions. When in the resonant or capacitive regions, the IGBT consumes a certain amount of power and generates heat. This requires sufficient heat dissipation time, preventing a high drive frequency. Consequently, the drive frequency is significantly limited. When the IGBT is in the inductive region, the drive frequency is unaffected by heat dissipation requirements.

[0079] Specifically, the power P consumed by the IGBT in the working state is calculated according to the following formula (1):

[0080] P=UIcosΔΨ (1)

[0081] Where U represents the instantaneous operating voltage of the corresponding IGBT, I represents the instantaneous operating current of the corresponding IGBT, and ΔΨ represents the phase difference between the output voltage U3 of the step-down digital control power supply and the operating current It of the heating coil 10 at the same moment. When ΔΨ > 0, the IGBT is in the inductive region, its own power consumption P is low, and the influence of heat dissipation time is generally not considered in the design. To this end, the electromagnetic heating system 100 can automatically lock the phase to maintain ΔΨ > 0.

[0082] To this end, the electromagnetic heating system 100 further includes a first comparator and a second comparator. The positive input of the first comparator is connected to a pin of the main control chip, and the negative input of the first comparator is connected to a reference signal. The signal output by the corresponding pin of the main control chip is related to the output voltage U3 of the step-down digital control power supply 50, and is output from a pin of the main control chip. The positive input of the second comparator is connected to the output of the current transformer 70, and the negative input of the second comparator is connected to the reference signal. The signal output by the output of the current transformer 70 is related to the current It of the heating coil 10. The main control chip calculates the angle value ΔΨ based on the output signals of the first comparator and the second comparator.

[0083] Furthermore, the phase difference angle value ΔΨ is calculated based on the two output signals of the two comparators. Specifically, the two output signals are connected to the pulse capture modules ECAP1 and ECAP2 included in the main control chip, and the time difference between ECAP1 and ECAP2 is detected. The time difference is divided by the pulse width modulation (PWM) period T of the IGBT and multiplied by 360 degrees to obtain the phase difference angle value ΔΨ.

[0084] In the state of ΔΨ>0, when the current It of the heating coil 10 is too low, the PWM frequency of the IGBT is reduced. When the current It of the heating coil 10 is too high, the PWM frequency of the IGBT is increased, and finally the frequency matching is achieved so that the actual power reaches the rated power, which is usually 10kw.

[0085] As mentioned above, the electromagnetic heating system provided in the present application can effectively realize the adaptive adjustment of the target voltage input to the inverter unit when the heating coil and / or load changes through the cooperation of the step-down digital control power supply and the main control chip, so as to be compatible with heating coils of different specifications and loads of different materials, thereby meeting the packaging requirements of solar cell modules of different sizes. Compared with the existing electromagnetic heating system, the voltage regulation is more precise, the voltage ripple is smaller, and the automatic phase locking of the entire circuit and automatic power matching can be achieved.

[0086] like Figure 2 As shown, the present application also provides another electromagnetic heating system 100, which further includes an impedance matching unit 80, which includes a transformer. The transformer includes a primary coil 81 and a secondary coil 82. The primary coil 81 is coupled to the output end of the inverter unit 60, and the secondary coil 82 is connected to the heating coil 10. The primary coil 81 has more turns than the secondary coil 82, thereby further reducing the voltage.

[0087] Furthermore, one or more primary capacitors are provided at the input end of the primary coil 81, and multiple secondary capacitors are provided at the output end of the secondary coil 82. These secondary capacitors are connected in series and in parallel. The provision of primary and secondary capacitors effectively blocks DC signals, improving device safety.

[0088] Therefore, by setting the impedance matching unit 80, the voltage provided to the heating coil 10 is further reduced to avoid overload when the output voltage value of the step-down CNC power supply is too large, and by setting multiple capacitors, a DC isolation effect is played, thereby improving equipment safety.

[0089] In one implementation, the present application provides an electromagnetic heating method, which is implemented based on the electromagnetic control system described in Example 1 or 2, and is used to control the heating coil to heat the heating plate. The electromagnetic heating method includes:

[0090] S1, uses the rectifier bridge to rectify the AC power U1 input from the external AC power supply into DC power U2. Among them, U1 is the AC power with an effective value of 380V, and U2 is the voltage value of of high voltage direct current.

[0091] S2. Obtain the operating current of the heating coil in real time. Specifically, obtain the operating current It of the heating coil through a current transformer.

[0092] S3. Calculate the target voltage U3 to be provided to the heating coil according to the operating current and the rated power of the heating coil;

[0093] S4, the step-down digital control power supply regulates the voltage of the DC power U2 under the control of the digital control power supply to obtain the target voltage U3;

[0094] S5. After the target voltage U3 is converted into high-frequency alternating current U4 by the inverter unit, the high-frequency alternating current U4 is provided to the heating coil so that the actual power of the heating coil reaches the rated power of the heating coil.

[0095] By combining the step-down CNC power supply with the main control chip, heating coils corresponding to different specifications and heating plates of different materials are obtained, achieving adaptive matching and effectively improving equipment compatibility.

[0096] In one implementation, the present application further provides a laminating machine comprising the electromagnetic heating system of Example 1 or Example 2. Furthermore, the laminating machine further comprises a temperature sensor and a controller, wherein the temperature sensor is mounted on the heating plate to sense the real-time temperature of the heating plate. The controller is electrically connected to the temperature sensor to obtain the real-time temperature of the heating plate sensed by the temperature sensor. The controller is also electrically connected to the electromagnetic heating system, and when the real-time temperature of the heating plate exceeds a predetermined temperature, the controller controls the electromagnetic heating system to stop supplying power to the heating coil.

[0097] Furthermore, the laminator includes a feeding mechanism, at least one laminating mechanism and a discharging mechanism sequentially arranged along a first horizontal direction, wherein:

[0098] The laminating mechanism includes a first frame, a lifting drive device, a flexible connector and a plurality of laminating units, wherein:

[0099] The first end of the flexible connector is arranged on the frame, and the second end of the flexible connector is transmission-connected to the lifting drive device;

[0100] A plurality of laminating units are arranged at intervals along the vertical direction. The laminating units are detachably mounted on the flexible connector. Each laminating unit is capable of carrying photovoltaic modules and transporting the photovoltaic modules along the first horizontal direction. Two adjacent laminating units can both perform lamination of photovoltaic modules.

[0101] The lifting drive device is used to vertically drive the flexible connector to produce deformation, so as to drive adjacent lamination units to move closer or farther away. When two adjacent lamination units approach each other, the photovoltaic modules between them are laminated.

[0102] The feeding mechanism includes a second frame and a plurality of feeding and conveying units, wherein:

[0103] A plurality of feeding and conveying units are vertically spaced apart and arranged on the second frame, and the feeding and conveying units are used to convey the photovoltaic modules to be processed to the corresponding laminating units along the first horizontal direction;

[0104] The discharging mechanism includes a third frame and several discharging conveying units, among which:

[0105] A plurality of discharge conveying units are vertically spaced apart and arranged on the third frame, the discharge conveying units being used to receive the laminated photovoltaic modules outputted by the corresponding laminating units and to output the laminated photovoltaic modules along the first horizontal direction;

[0106] The hot pressing plate and coil in the electromagnetic heating system are arranged in the laminating unit.

[0107] In one implementation, the flexible connector is a belt or strip capable of flexible deformation, such as a chain or a steel wire rope. The lifting device can be a cylinder, a hydraulic cylinder or a motor.

[0108] In one implementation, the feed conveying unit and the discharge conveying unit each include a bracket and a conveyor belt.

[0109] In one implementation, the lamination unit includes a sleeved high-temperature cloth and a drive motor for driving the high-temperature cloth to rotate, and the photovoltaic components are transported by the rotation of the high-temperature cloth.

[0110] The laminator provided in this application can effectively achieve compatibility with different heating coils and heating plates by setting up an electromagnetic heating system, thereby improving the versatility of the equipment.

[0111] All of the above optional technical solutions can be combined in any way to form optional embodiments of the present invention, that is, any multiple embodiments can be combined to meet the needs of different application scenarios. They are all within the scope of protection of this application and will not be described in detail here.

[0112] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electromagnetic heating system, characterized in that: The electromagnetic heating system comprises: A hot pressing plate, on which a heating coil is laid; a rectifier bridge, wherein an input end of the rectifier bridge is connected to an external AC power source to convert the AC power input by the external AC power source into DC power; A main control chip obtains the working current of the heating coil in real time; a step-down digitally controlled power supply, wherein a first input terminal of the step-down digitally controlled power supply is coupled to the output terminal of the rectifier bridge, a second input terminal of the step-down digitally controlled power supply is coupled to the main control chip, and the step-down digitally controlled power supply adjusts the direct current input from the rectifier bridge under the control of the main control chip to output a target voltage; An inverter unit, wherein the input end of the inverter unit is coupled to the output end of the step-down CNC power supply, and the output end of the inverter unit is coupled to the heating coil. After the inverter unit converts the target voltage into high-frequency alternating current, the high-frequency alternating current is provided to the heating coil so that the actual power of the heating coil reaches the predetermined rated power.

2. The electromagnetic heating system according to claim 1, wherein: The step-down digital control power supply includes a BUCK circuit. The main control chip is coupled to a first switch tube in the BUCK circuit to control a switching frequency and a duty cycle of the first switch tube.

3. The electromagnetic heating system according to claim 2, wherein: The electromagnetic heating system further includes a current transformer, which is coupled between the inverter unit and the heating coil to obtain the working current of the heating coil in real time; The main control chip is coupled to the current transformer to obtain the working current of the heating coil in real time.

4. The electromagnetic heating system according to claim 3, characterized in that The main control chip is used to determine the real-time power of the heating coil based on the working current. When the real-time power is less than the rated power of the heating coil, the switching frequency and / or duty cycle of the first switching tube is increased to increase the output voltage of the step-down CNC power supply.

5. The electromagnetic heating system according to claim 4, characterized in that The inverter unit includes an H-bridge circuit and a corresponding driver stage; The main control chip is also used to calculate and obtain the angle value of the phase difference between the voltage output by the step-down CNC power supply and the working current at the same time; determine whether the angle value of the phase difference is greater than 0°; and adjust the driving frequency of any driving level based on the judgment result so that the angle value of the phase difference is greater than 0°.

6. The electromagnetic heating system according to claim 5, characterized in that The electromagnetic heating system further includes a first comparator and a second comparator; The positive input terminal of the first comparator is connected to a pin of the main control chip, and the signal output by the pin of the main control chip is related to the output voltage of the step-down digital control power supply; The positive input terminal of the second comparator is connected to the output terminal of the current transformer, and the signal output by the output terminal of the current transformer is related to the current of the heating coil; The main control chip calculates the angle value according to the output signal of the first comparator and the output signal of the second comparator.

7. The electromagnetic heating system according to claim 4, characterized in that The electromagnetic heating system further includes an impedance matching unit, which includes a transformer. The primary coil included in the transformer is coupled to the output end of the inverter unit, and the secondary coil included in the transformer is connected to the heating coil.

8. The electromagnetic heating system according to claim 1, wherein: The heating coils are arranged in a serpentine structure along the length of the hot pressing plate; or, The heating coils are arranged in a serpentine structure along the width direction of the hot pressing plate.

9. The electromagnetic heating system according to claim 8, characterized in that The heating coil further includes a compensation coil wound around the lengthwise side and / or widthwise side of the heating plate.

10. The electromagnetic heating system according to claim 1, wherein: The heating plate is provided with multiple rows or columns of grooves, and the heating coil is arranged in the grooves on the heating plate, or the heating plate is provided with winding posts, and the heating coil is wound on the heating plate through the winding posts.

11. An electromagnetic heating method, characterized in that: The electromagnetic heating method is used to control the heating coil to heat the heating plate, and the electromagnetic heating method includes: The rectifier bridge is used to convert the AC power input from the external AC power supply into DC power; obtaining the operating current of the heating coil in real time; Calculating a target voltage to be provided to the heating coil according to the operating current and the rated power of the heating coil; regulating the DC power to obtain the target voltage; After the target voltage is converted into high-frequency alternating current by an inverter unit, the high-frequency alternating current is provided to the heating coil so that the actual power of the heating coil reaches the rated power of the heating coil.

12. A laminating machine, characterized in that: The laminator comprises the electromagnetic heating system according to any one of claims 1 to 10.

13. The laminating machine according to claim 12, characterized in that The laminator further comprises a temperature sensor and a controller, wherein the temperature sensor is installed at the heating plate to sense the real-time temperature of the heating plate; The controller is electrically connected to the temperature sensor to obtain the real-time temperature of the heating plate sensed by the temperature sensor; The controller is also electrically connected to the electromagnetic heating system. When the real-time temperature of the heating plate exceeds a predetermined temperature, the controller controls the electromagnetic heating system to stop supplying power to the heating coil.

14. The laminating machine according to claim 12, characterized in that The laminator comprises a feeding mechanism, at least one laminating mechanism and a discharging mechanism arranged in sequence along a first horizontal direction, wherein: The laminating mechanism includes a first frame, a lifting drive device, a flexible connector and a plurality of laminating units, wherein: The first end of the flexible connector is arranged on the frame, and the second end of the flexible connector is transmission-connected to the lifting drive device; A plurality of laminating units are arranged vertically at intervals, and the laminating units are detachably mounted on the flexible connector. Each laminating unit is capable of carrying a photovoltaic module and transporting the photovoltaic module along the first horizontal direction. Two adjacent laminating units can both laminate photovoltaic modules. The lifting drive device is used to vertically drive the flexible connector to deform, so as to drive the adjacent lamination units to move closer or farther away. When two adjacent lamination units move closer to each other, the photovoltaic modules between them are laminated. The feeding mechanism includes a second frame and a plurality of feeding and conveying units, wherein: A plurality of the feeding and conveying units are vertically spaced apart and arranged on the second frame, and the feeding and conveying units are used to convey the photovoltaic components to be processed to the corresponding laminating units along the first horizontal direction; The discharging mechanism includes a third frame and a plurality of discharging conveying units, wherein: A plurality of discharge conveying units are vertically spaced apart and arranged on the third frame, wherein the discharge conveying units are used to receive the laminated photovoltaic modules outputted by the corresponding laminating units and output the laminated photovoltaic modules along the first horizontal direction; The hot press plate and the heating coil in the electromagnetic heating system are disposed within the laminating unit.

Images