A low-power continuous heating method for IH heating pot

Abstract

The present invention provides a low-power continuous heating method for an IH heating pot, which specifically includes the following steps: S1, finding out the factors that cause large deviations in the IH heating pot product, adjusting a suitable power, which is 100-200W or higher than the rated power, and ensuring that in all extreme error conditions, the power is fully turned on without causing hard conduction, and fixing the target power parameter; S2, using the target power parameter obtained in step S1 to drive the IGBT, detecting zero crossing, and using the zero crossing signal to perform wave loss adjustment to reduce the power to the rated power required by the IH heating pot product. The low-power continuous heating method for the IH heating pot not only meets the product rated power requirements, but also avoids the IGBT hard conduction situation, and solves the problem of universalization of the structural platform.

Description

Technical Field

[0001] The invention relates to the technical field of production of rice cookers, electric pressure cookers and other cooker products, and in particular to a low-power continuous heating method applied to an IH heating cooker. Background Art

[0002] IH heating cookers include rice cookers, electric pressure cookers and other IH heating cooker products. At present, when IH heating cooker products on the market replace different process inner pots on a general structural platform, with the same power output, the same specifications of resonant capacitors and wire reels, the equivalent inductance and resistance during oscillation are different due to factors such as different materials and metal coatings of the inner pots, wire reel parameters, and differences in pot distances. The IGBT is prone to hard conduction. Severe IGBT hard conduction amplitude will cause rapid overtemperature damage to the IGBT. Although low amplitudes will not damage the IGBT in the short term, long-term use will easily cause IGBT fatigue damage and affect the life of the IGBT. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention proposes a low-power continuous heating method applied to an IH heating pot, which not only meets the product rated power requirements, but also avoids the IGBT hard conduction situation, and solves the problem of universalization of the structural platform.

[0004] To achieve the above technical solution, the present invention provides a low-power continuous heating method applied to an IH heating pot, which specifically comprises the following steps:

[0005] S1. Find out the factors that cause large deviations in the IH heating pot product, and adjust a suitable power, which should be 100-200W or higher than the rated power. Ensure that under all extreme error conditions, the power is fully turned on without causing hard conduction, and fix the target power parameter.

[0006] S2. Use the target power parameter obtained in step S1 to drive the IGBT, detect zero crossing, and use the zero crossing signal to perform wave loss regulation to reduce the power to the rated power required by the IH heating pot product.

[0007] Preferably, in step S2, the zero-crossing cycle information of the power grid is obtained through a zero-crossing detection circuit, and a certain number of PPG signals are discarded within a power grid cycle, thereby discarding part of the power, so that the average power reaches the rated power value of the IH heating cooker product.

[0008] Preferably, the zero-crossing detection circuit includes a transistor Q10, a diode D11, capacitors C23 and C26, and resistors R55, R56, R57, R65 and R67, wherein the collector of the transistor Q10 is connected to one end of the resistor R55, and the other end of the resistor R55 is connected to a 5V power supply, the emitter of the transistor Q10 is grounded, the base of the transistor Q10 is connected to the resistor R67, and the other end of the resistor R67 is grounded, the capacitor C26 is connected in parallel to the resistor R67, and the diode One end of the diode D11 is connected to the power grid, the other end of the diode D11 is connected to one end of the resistor R56, the other end of the resistor R56 is connected to one end of the resistor R57, the other end of the resistor R57 is connected to the resistor R67, one end of the resistor R65 is connected to the collector of the transistor Q10, the other end of the resistor R65 is connected to the electromagnetic flowmeter, one end of the capacitor C23 is connected to the collector of the transistor Q10, and the other end of the capacitor C23 is connected to the emitter of the transistor Q10.

[0009] Preferably, the factors causing large deviations in step S1 include the inner pot, the wire reel, the pot distance, and the circuit board.

[0010] The beneficial effect of a low-power continuous heating method applied to an IH heating pot provided by the present invention is that: under the driving mode of maintaining the original PPG width of the power that will not generate hard conduction unchanged, the present invention uses a wave dropping method to drive the IGBT, reduces the power to the rated power, meets the rated power requirement, and avoids the IGBT hard conduction situation, perfectly solves the universal problem of the structural platform, accommodates the errors caused by the wire reel, inner pot, and pot distance, eliminates the influence of various error factors, saves time and effort in product development, shortens the development cycle, and improves the development efficiency and the universality of the platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a flow chart of the present invention.

[0012] Figure 2 This is a waveform diagram showing the hard conduction condition.

[0013] Figure 3 Schematic diagram of the driving waveform with maximum power without hard conduction.

[0014] Figure 4 This is the zero-crossing detection circuit diagram.

[0015] Figure 5 Schematic diagram of zero-crossing signal.

[0016] Figure 6 It is a waveform diagram of the driving mode of continuous low-power heating, wave dropping and power reduction obtained by the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. All other embodiments obtained by ordinary persons in the art without creative work are within the scope of protection of the present invention.

[0018] Embodiment: A low-power continuous heating method applied to an IH heating pot.

[0019] In the general structure platform of IH heating pot products, when there is an error in the coordination of the reel, inner pot and circuit board with the resonant circuit, the IGBT is prone to hard conduction. The waveform diagram of hard conduction is as follows Figure 2 To solve the above situation, the present invention provides a low-power continuous heating method applied to an IH heating pot, which can solve the problem of IGBT hard conduction, meet the rated power output, and eliminate the influence of various error factors.

[0020] Reference Figures 1 to 6 As shown, a low-power continuous heating method applied to an IH heating pot specifically comprises the following steps:

[0021] S1. Find out the inner pot, wire coil, pot distance, circuit board and other physical objects of the IH heating pot product with large deviations, and adjust a suitable power, which should be 100-200W or higher than the rated power, and ensure that under all extreme error conditions, the power is fully turned on without hard conduction. Figure 3 The driving waveform diagram of the maximum power without hard conduction is shown, and the target power parameter of the power is fixed;

[0022] S2. Use the target power parameters obtained in the first step to drive the IGBT. By detecting the zero crossing, the zero crossing signal is used for wave loss regulation, i.e. continuous low-power heating technology, to reduce the power to the rated power required by the product. This meets the rated power requirement and avoids the hard conduction situation of the IGBT.

[0023] Reference Figure 4 and Figure 5As shown, the zero-crossing detection circuit includes a transistor Q10, a diode D11, capacitors C23, C26, resistors R55, R56, R57, R65, and R67, wherein the collector of the transistor Q10 is connected to one end of the resistor R55, and the other end of the resistor R55 is connected to a 5V power supply, the emitter of the transistor Q10 is grounded, the base of the transistor Q10 is connected to the resistor R67, and the other end of the resistor R67 is grounded, the capacitor C26 is connected in parallel to the resistor R67, and the diode One end of D11 is connected to the power grid, the other end of the diode D11 is connected to one end of the resistor R56, the other end of the resistor R56 is connected to one end of the resistor R57, the other end of the resistor R57 is connected to the resistor R67, one end of the resistor R65 is connected to the collector of the transistor Q10, the other end of the resistor R65 is connected to the electromagnetic flowmeter, one end of the capacitor C23 is connected to the collector of the transistor Q10, and the other end of the capacitor C23 is connected to the emitter of the transistor Q10. The zero-crossing cycle information of the power grid is obtained through this zero-crossing detection circuit, and a certain number of PPG signals are discarded in one power grid cycle, thereby discarding part of the power, so that the average power reaches the rated power value of the IH heating pot product.

[0024] Reference Figure 6 As shown, the driving mode waveform diagram of continuous low-power heating wave dropping and power reduction obtained by the present invention shows that through the driving mode waveform diagram of continuous low-power heating wave dropping and power reduction (no hard conduction, △V=28V), the relevant parameters of the target power are driven in a maximum power manner, combined with the wave dropping processing method, which not only meets the power requirements, but also does not cause hard conduction of the IGBT.

[0025] The present invention drives the IGBT in a wave dropping manner while maintaining the original driving mode of the target power that will not produce hard conduction, thereby reducing the power to the rated power, thereby meeting the rated power requirement and avoiding the hard conduction of the IGBT, perfectly solving the universalization problem of the structural platform, accommodating the errors caused by the wire reel, inner pot, and pot distance, and eliminating the influence of various error factors, saving time and effort in product development, shortening the development cycle, and improving development efficiency and the universalization of the platform.

[0026] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the contents disclosed in the embodiment and the drawings, so any equivalent or modification completed without departing from the spirit disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A low-power continuous heating method for an IH heating pot, Features The specific steps include: S1. Find out the factors that cause large deviations in the IH heating pot product, including the inner pot, wire coil, pot distance, and circuit board, and adjust a suitable target power. The target power should be 100-200W or higher than the rated power, and ensure that under all extreme error conditions, the power is fully turned on without hard conduction, and fix the target power parameter; S2. Use the target power parameter obtained in step S1 to drive the IGBT, detect zero crossing, and use the zero crossing signal to perform wave drop adjustment to reduce the power to the rated power required by the IH heating pot product. Specifically, obtain the zero crossing cycle information of the power grid through the zero crossing detection circuit, discard a certain number of PPG signals within a power grid cycle, thereby discarding part of the power, so that the average power reaches the rated power value of the IH heating pot product.

2. The low-power continuous heating method for an IH heating pot as claimed in claim 1, Features: The zero-crossing detection circuit includes a transistor Q10, a diode D11, capacitors C23 and C26, and resistors R55, R56, R57, R65 and R67, wherein the collector of the transistor Q10 is connected to one end of the resistor R55, and the other end of the resistor R55 is connected to a 5V power supply, the emitter of the transistor Q10 is grounded, the base of the transistor Q10 is connected to the resistor R67, and the other end of the resistor R67 is grounded, the capacitor C26 is connected in parallel to the resistor R67, and the diode D One end of diode D11 is connected to the power grid, the other end of diode D11 is connected to one end of resistor R56, the other end of resistor R56 is connected to one end of resistor R57, the other end of resistor R57 is connected to resistor R67, one end of resistor R65 is connected to the collector of transistor Q10, the other end of resistor R65 is connected to the electromagnetic flowmeter, one end of capacitor C23 is connected to the collector of transistor Q10, and the other end of capacitor C23 is connected to the emitter of transistor Q10.

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