CN117929864A

CN117929864A - Load detection method and device

Info

Publication number: CN117929864A
Application number: CN202211254797.9A
Authority: CN
Inventors: 朱成彬; 江德勇; 雷俊; 刘锦泉; 卞在银; 周云
Original assignee: Foshan Shunde Midea Electrical Heating Appliances Manufacturing Co Ltd
Current assignee: Foshan Shunde Midea Electrical Heating Appliances Manufacturing Co Ltd
Priority date: 2022-10-13
Filing date: 2022-10-13
Publication date: 2024-04-26

Abstract

The embodiment of the application provides a load detection method and device. The method is applied to electrical equipment provided with a wireless power supply and heating multiplexing circuit, wherein the wireless power supply and heating multiplexing circuit comprises a switch module and a resonance module, the switch module and the resonance module are electrically connected, and the method comprises the following steps: driving the switch module to be conducted based on a preset frequency sequence, wherein the preset frequency sequence comprises a plurality of frequencies arranged according to a specified sequence; respectively acquiring first working parameters of the resonance module at a plurality of frequencies; determining a first load type of a load arranged on the electrical equipment based on first working parameters of the resonance module at a plurality of frequencies; wherein the first load type includes a passive load and a non-passive load. The technical scheme provided by the embodiment of the application can accurately detect the first load type of the load arranged on the electrical equipment, thereby improving the use efficiency of the wireless power supply and heating multiplexing circuit.

Description

Load detection method and device

Technical Field

The present application relates to the field of circuit technologies, and in particular, to a load detection method and apparatus.

Background

Currently, there is a heating coil commonly existing on an electrical device (such as an induction cooker), and in order to improve the hardware utilization rate of the heating coil, the heating coil has a wireless power supply function in addition to a heating function.

In the related art, a function panel of the electrical equipment comprises a heating function button and a wireless power supply function button, and a user can trigger the electrical equipment to realize the heating function or the wireless power supply function according to the use requirement of the user. For example, the user may press the heating function button when he or she wants to cook a dish.

In order to improve the use efficiency of the electrical equipment, an automatic control scheme can be designed for the electrical equipment, wherein the use premise of the automatic control method is that the load arranged on the electrical equipment can be accurately identified.

Disclosure of Invention

The embodiment of the application provides a load detection method and device.

In a first aspect, an embodiment of the present application provides a load detection method applied to an electrical apparatus provided with a wireless power supply and heating multiplexing circuit, where the wireless power supply and heating multiplexing circuit includes a switch module and a resonance module, and the switch module and the resonance module are electrically connected, the method includes: driving the switch module to be conducted based on a preset frequency sequence, wherein the preset frequency sequence comprises a plurality of frequencies arranged according to a specified sequence; respectively acquiring first working parameters of the resonance module at a plurality of frequencies; determining a first load type of a load arranged on the electrical equipment based on first working parameters of the resonance module at a plurality of frequencies; the first load type comprises a passive load and a non-passive load, wherein the passive load refers to a load which passively absorbs the transmitting power of the resonance module, and the non-passive load refers to a load which does not passively absorb the transmitting power of the resonance module.

In a second aspect, an embodiment of the present application provides a load detection device applied to an electrical apparatus provided with a wireless power supply and heating multiplexing circuit, the wireless power supply and heating multiplexing circuit including a switch module and a resonance module, the switch module and the resonance module being electrically connected, the device including: the driving module is used for driving the switching module to be conducted based on a preset frequency sequence, wherein the preset frequency sequence comprises a plurality of frequencies arranged according to a specified sequence; the first parameter acquisition module is used for respectively acquiring first working parameters of the resonance module under a plurality of frequencies; the load detection module is used for determining a first load type of a load arranged on the electrical equipment based on first working parameters of the resonance module at a plurality of frequencies; the first load type comprises a passive load and a non-passive load, wherein the passive load refers to a load which passively absorbs the transmitting power of the resonance module, and the non-passive load refers to a load which does not passively absorb the transmitting power of the resonance module.

In a third aspect, an embodiment of the present application provides an electrical apparatus, including: one or more processors; a memory, wherein the memory stores one or more application programs configured for execution by the one or more processors, the one or more application programs configured for performing a method as in the first aspect.

In a fourth aspect, embodiments of the present application provide a computer readable storage medium having program code stored therein, the program code being executable by a processor to perform a method as in the first aspect.

The embodiment of the application provides a load detection method, which sequentially drives a switch module to be conducted under a plurality of frequencies included in a preset frequency sequence, then obtains a first working parameter of a resonance module under each frequency, and finally determines whether a load arranged on electrical equipment is a passive load or a non-passive load based on the first working parameter of the resonance module under each frequency. Subsequently, under the condition that the load type is accurately determined, the electrical equipment can further control the wireless power supply and heating protection circuit to realize a wireless power supply function or a heating function, and the service efficiency of the wireless power supply and heating multiplexing circuit is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of an electrical device according to an embodiment of the present application.

Fig. 2 is a circuit diagram of a wireless power and heat multiplexing circuit according to an embodiment of the application.

Fig. 3 is a circuit diagram of a pulse acquisition module according to an embodiment of the present application.

Fig. 4 is a flowchart of a load detection method according to an embodiment of the present application.

Fig. 5 is a schematic diagram of a driving pulse signal according to an embodiment of the present application.

Fig. 6 is a flowchart of a load detection method according to another embodiment of the present application.

Fig. 7 is a schematic diagram showing the absorption probability of the load and the transmission power of the resonance module according to an embodiment of the present application.

Fig. 8 is a flowchart of a load detection method according to another embodiment of the present application.

Fig. 9 is a schematic diagram showing a comparison result of a phase of a first resonant current and an on phase of a switch module according to an embodiment of the present application.

Fig. 10 is a schematic diagram showing a comparison result of a phase of a first resonant current and an on phase of a switch module according to another embodiment of the present application.

Fig. 11 is a flowchart of a load detection method according to another embodiment of the present application.

Fig. 12 is a schematic diagram of a driving pulse signal and a current waveform diagram of different load information in a load detection stage according to an embodiment of the present application.

Fig. 13 is a block diagram of a load detection apparatus according to an embodiment of the present application.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present application and are not to be construed as limiting the present application.

In order to enable those skilled in the art to better understand the solution of the present application, the following description will make clear and complete descriptions of the technical solution of the present application in the embodiments of the present application with reference to the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Referring to fig. 1, an embodiment of the present application provides a wireless power supply and heating multiplexing circuit 100 and an electrical device 200 configured with the wireless power supply and heating multiplexing circuit 100. The appliance 200 may be an induction cooker, a wireless charger, a wireless juice glass, a wireless vacuum cleaner, etc.

The electrical device 200 includes a housing 210 and the wireless power and heat multiplexing circuit 100 described above. In the present embodiment, the housing 210 includes a first housing 212 and a second housing 214, and the first housing 212 and the second housing 214 are covered with each other to form a housing space for the wireless power supply and heating multiplexing circuit 100, that is, the housing 210 plays a role in protecting and housing the components in the wireless power supply and heating multiplexing circuit 100.

A fixing structure is disposed in the first housing 212, and the fixing structure is used for fixing a part of the structure (for example, a circuit board) of the wireless power supply and heating multiplexing circuit 100. Specifically, the securing structure includes, but is not limited to, a securing slot, a clip (e.g., a resilient clip), and the like.

The outer surface of the second housing 120 is used for placing a load, which may be a passive load, without a control circuit, and only can passively absorb the load of the emission power (i.e., the emission frequency of the resonance module) of the wireless power supply and heating multiplexing current 100, such as a metal pot, a metal knife, a metal spoon, a metal bottle cap, etc. In addition, the load may be a non-passive load, i.e. a load provided with a control circuit, which does not passively receive the transmission power of the wireless power and heat multiplexing circuit 100, such as a smart phone, a tablet computer, a wireless vacuum cleaner, a wireless juice glass, etc.

In the embodiment of the present application, the electrical apparatus 200 further includes a control module 220, where the control module 220 is configured to control the wireless power supply and heating multiplexing circuit 100 to be turned on or off, and determine whether the passive load or the non-passive load is placed on the outer surface of the second housing 120 according to the working parameter when the wireless power supply and heating multiplexing circuit 100 is in the on state. Then, the control module 220 can determine the functions implemented by the wireless power supply and heating multiplexing circuit 100 according to the control detection result, without manual selection by a user, so that the use efficiency of the wireless power supply and heating multiplexing circuit 100 can be improved. For example, in the case that a passive load is placed on the outer surface of the second housing 120, the control module 220 controls the wireless power supply and heating multiplexing circuit 100 to implement a heating function; for another example, in the case that a non-passive load is placed on the outer surface of the second housing 120, the control module 220 controls the wireless power supply and heating multiplexing circuit 100 to implement a wireless power supply function.

Referring to fig. 2, a schematic diagram of a wireless power and heat multiplexing circuit 100 according to an embodiment of the application is shown. The wireless power supply and heating multiplexing circuit comprises a power module 10, a switch module 20 and a resonance module 30. The switch module 20 is connected between both ends of the power module 10, and the switch module 20 is electrically connected with the resonance module 30.

The power module 10 is used to power the various modules in the wireless power and heat multiplexing circuit 100. In some embodiments, the power module 10 includes an ac power sub-module, a filter circuit sub-module, a rectifier circuit sub-module, a choke, and a smoothing filter capacitor. The filter circuit submodule is connected between the alternating current power supply submodule and the rectifying circuit submodule. After the choke coil and the smoothing filter capacitor are connected in series, one end far away from the smoothing filter capacitor is connected to the voltage output end of the rectifying circuit submodule, and the other end close to the smoothing filter capacitor is grounded. The common terminal of the choke and the smoothing filter capacitor is connected to the switching module 20.

The alternating current power supply sub-module is used for outputting alternating current. The filtering circuit submodule is connected with the alternating current power supply submodule and used for filtering alternating current output by the alternating current power supply submodule, and noise interference in the alternating current is restrained. The rectifying circuit submodule is connected between the filtering circuit submodule and the switch module 20 and is used for rectifying the alternating current filtered by the filtering circuit submodule, namely, converting the alternating current into direct current. The choke is used for preventing the passage of alternating current components, so that the direct current power supply is purer. The smoothing filter capacitor can further smooth the direct-current voltage output by the rectifying sub-module, so that the wireless power supply and heating multiplexing circuit 100 is more stable in working.

In some embodiments, the power module 10 is a variable power supply, i.e., it can output different voltages. Alternatively, the power module 10 includes a voltage-reducing sub-module through which different voltages are output. In a specific example, the power module 10 includes a first power output terminal, a second power output terminal, a third power output terminal, a first voltage reduction sub-module, and a second voltage reduction sub-module; the first power supply output end is connected to the tail end of the first voltage reduction submodule and is used for outputting the original voltage reduced by the first voltage reduction submodule, for example, the original voltage is Vcc, and the first power supply output end outputs 1/2Vcc; the second power output end is connected to the tail end of the second voltage reduction submodule and is used for outputting the original voltage reduced by the second voltage reduction submodule, for example, the original voltage is Vcc, and the second power output end outputs 1/3Vcc; the third power supply output end outputs the original voltage.

The switch module 20 is used for controlling the on or off of the branch where the resonance module 30 is located. In the embodiment of the present application, the switch module 20 includes a first switch 21, a second switch 22, a third switch 23, and a fourth switch 24. The first switch 21 and the third switch 23 are connected in series with each other between both ends of the power module 10, and the second switch 22 and the fourth switch 24 are connected in series with each other between both ends of the power module 10. In fig. 2, the first switch 21, the second switch 22, the third switch 23 and the fourth switch 24 are all power switch tubes (Insulated Gate Bipolar Transistor, IGBTs), and the specific model of the power switch tubes is not limited in the present application.

The resonance module 30 is used to implement a wireless power supply function and a heating function. In an embodiment of the present application, the resonance module 30 includes a resonance capacitor 31 and a resonance inductor 32. After the resonance capacitor 31 and the resonance inductor 32 are connected in series, one end close to the resonance capacitor 31 is connected to the common terminal of the first switch 21 and the third switch 23, and one end far from the resonance capacitor 31 is connected to the common terminal of the second switch 22 and the fourth switch 24. The resonant inductor 32 is a coil disk, which can generate an alternating magnetic field, and generates electric energy or heat energy by means of the alternating magnetic field, thereby realizing a wireless power supply function and a heating function.

In some embodiments, the wireless power and heat multiplexing circuit 100 includes a current detection module 40, where the current detection module 40 is connected between the resonant capacitor 31 and the resonant inductor 32, and is configured to detect parameters related to the resonant current of the resonant module 30, including, but not limited to, the magnitude, phase, etc. of the resonant current. In the embodiment of fig. 2, the current detection module 40 includes a current transformer, which is an instrument for converting a primary side large current into a secondary side small current according to the electromagnetic induction principle to measure, and is composed of a closed core and a winding.

In some embodiments, the wireless power and heat multiplexing circuit 100 further includes a pulse output module 50, the pulse output module 50 being configured to output the resonant pulse of the resonant module 30.

Referring in conjunction with fig. 3, a circuit diagram of a pulse output module 50 provided in one embodiment of the present application is shown. The pulse output module 50 includes a first resistor 510, a second resistor 520, a third resistor 530, a fourth resistor 540, a fifth resistor 550, a first diode 560, a second diode 570, and a comparator 580. The first resistor 510, the first diode 560 and the second diode 570 are sequentially connected in parallel to two ends of the comparator 580. The second resistor 520 is connected between the first diode 560 and the first resistor 510, and is connected to the positive input terminal of the comparator 580. The third resistor 530 is connected between the power module 10, the first diode 560 and a first common terminal of the first diode 570, which is a common terminal far from the negative input terminal of the comparator 580. A fourth resistor 540 is connected between the current transformer and the first common terminal. One end of the fifth resistor 550 is grounded, and the other end is connected to a common terminal of the current transformer and the fourth resistor 540.

Comparator 580 is a circuit that compares an analog voltage signal with a reference voltage. In the embodiment of the present application, the negative input terminal of the comparator 580 is the reference voltage. When the output voltage of the resonance module 30 is greater than the reference voltage, the comparator 580 outputs a high level; when the output voltage of the resonance module 30 is smaller than the reference voltage, the comparator 580 outputs a low level, so that the number of oscillations can be counted by the number of inversions of the comparator 580, thereby identifying the load.

In some embodiments, the wireless power and heat multiplexing circuit 100 includes a power detection module 60, where the power detection module 60 is connected between the negative output terminal of the power module 10 and the third switch 23, for detecting the transmission power of the resonance module 30. In the embodiment of fig. 2, the power detection module 60 includes a sampling resistor R00. The detection principle of the power detection module 60 is as follows: under the condition that the resonance module 30 transmits power, the control module obtains the voltage difference between two ends of the sampling resistor R00, determines the ratio between the voltage difference and the resistance value of the sampling resistor R00 as a first current, under the condition that the resonance module does not transmit power, the control module also obtains the voltage difference between two ends of the sampling resistor R00, determines the ratio between the voltage difference and the resistance value of the sampling resistor R00 as a second current, and finally determines the product of the difference between the second current and the first current and the output voltage of the power module 10 as the transmission power of the resonance module 30.

In the embodiment of the present application, the main control chip (i.e. the control module) generates the driving pulse signal waveform through the timer to drive the switch module 20 to be turned on. However, the output voltage of the control module is low (typically 5 v), which typically does not reach the threshold voltage of the switching module 20, and the output voltage of the control module needs to be amplified. In some embodiments, a driving module (not shown) may be disposed in the wireless power and heating multiplexing circuit 100, where the driving module is connected between the control module and the switch module 20, and after the control module inputs a driving waveform to the driving module, the driving module may generate a driving waveform with the same frequency and amplified voltage. In other possible implementations, a boost circuit may also be provided between the control module and the switch module 20 to effect voltage amplification.

Referring to fig. 4, a flowchart of a load detection method according to an embodiment of the application is shown. The method comprises the following steps S401-S403.

Step S401, driving the switch module to be turned on based on a preset frequency sequence.

The preset frequency sequence includes a plurality of frequencies arranged in a specified order. The order of designation may be from large to small or from small to large. In the embodiment of the present application, the explanation is made only with the preset frequency sequence including the plurality of frequencies arranged in order from large to small.

The number of frequencies included in the preset frequency sequence can be set according to actual requirements. The frequencies included in the preset frequency sequence may be set according to a designated frequency, where the designated frequency refers to a frequency corresponding to a standby power of the non-passive load, and the standby power refers to a power of the non-passive load in a standby state, which is usually the minimum power of the non-passive load that can normally work. In a specific example, if the standby power of the passive load is Pmin, the designated power is fmax, and the frequencies of the preset frequency sequence from large to small are sequentially 2fmax, 1.9fmax, 1.8fmax, 1.7fmax,1.6fmax, 1.5fmax, 1.4fmax, 1.3fmax, 1.2fmax, 1.1fmax, 0.9fmax, and 0.8fmax.

The control module drives the switch module to be conducted based on a preset frequency sequence, which means that the control module controls the drive module to sequentially send driving pulse signals to the switch module according to a plurality of frequencies included in the preset frequency sequence. The time for the driving module to send the driving pulse signal to the switching module at each frequency may be the same or different.

In some embodiments, the control module controls the driving module to drive the switch module to conduct according to a full-bridge driving mode. Specifically, in each signal transmission period, the driving module firstly transmits driving pulse signals to the first switch and the fourth switch at the same time, and then transmits driving pulse signals to the second switch and the third switch at the same time after a first dead time is spaced; or the driving module firstly transmits driving pulse signals to the second switch and the third switch at the same time in each signal transmission period, and then transmits driving pulse signals to the first switch and the fourth switch at the same time after a second dead time is separated. The first dead time and the second dead time may be set experimentally or empirically, and the embodiment of the present application is not limited thereto. The first dead time and the second dead time may be the same or different.

In other embodiments, the control module controls the driving module to drive the switch module to conduct according to the half-bridge driving mode. Specifically, the driving module always sends a low level to the second switch to enable the second switch to be always in an off state, and always sends a high level to the fourth switch to enable the fourth switch to be always in an on state, and in each signal sending period, a driving pulse signal is sent to the first switch first, and after a third dead time is separated, then a driving pulse signal is sent to the third switch. Or the driving module always sends low level to the first switch to enable the first switch to be always in an off state, and always sends high level to the third switch to enable the third switch to be always in an on state, in each signal sending period, a driving pulse signal is sent to the second switch first, and after a fourth dead time is separated, then the driving pulse signal is sent to the fourth switch. The third dead time and the fourth dead time may be set experimentally or empirically, and the embodiment of the present application is not limited thereto. The third dead time and the fourth dead time may be the same or different.

Referring in conjunction to fig. 5, a schematic diagram of transmitting a driving pulse signal is shown in accordance with one embodiment of the present application. In each signal transmission period, a driving pulse signal is transmitted to the first switch first, and after a third dead time is spaced, the driving pulse signal is transmitted to the third switch.

Step S402, first working parameters of the resonance module under a plurality of frequencies are respectively obtained.

The first operating parameter comprises the transmit power of the resonant module and/or the phase of the first resonant current. The transmission power of the resonance module at a specified frequency refers to the transmission power of the resonance module in the case of driving the switching module at the specified frequency. Likewise, the phase of the first resonant current of the resonant module at the specified frequency refers to the phase of the first resonant current of the resonant module in the case of driving the switching module at the specified frequency. Specific implementation details for obtaining the first operating parameter will be described in the following examples.

When the driving module controls the switching module to be conducted one by one according to a plurality of frequencies in a preset frequency sequence, the control module obtains working parameters of the resonance module under each frequency, and whether the passive load or the passive load is arranged on the electrical equipment can be determined subsequently according to the change condition of the first working parameters of the resonance module under different frequencies.

Step S403, determining a first load type of a load set on the electrical device based on the first operating parameters of the resonance module at the plurality of frequencies.

The first load type includes passive loads and non-passive loads. Passive load refers to a load that passively absorbs the transmit power of the resonant module, which is typically not provided with a control circuit. The non-passive load refers to a load that does not passively absorb the transmission power of the wireless power supply and heating multiplexing circuit, and is typically provided with a control circuit.

In the embodiment of the application, the control module can determine whether the electric equipment is provided with the passive load or the non-passive load according to the change condition of the first working parameters of the resonance module under different frequencies.

In some embodiments, when the load set on the electrical device is a passive load, and when the frequency at which the driving module sends the driving pulse signal is continuously reduced, the passive load passively absorbs the emission power of the resonant module, so that the emission power of the resonant module is continuously increased, however, when the load set on the electrical device is a non-passive load, the emission power of the resonant module is continuously increased before the non-passive load enters the standby state, and after the non-passive load enters the standby state, the emission power of the resonant module approaches to the standby power of the non-passive load and does not continuously increase. Based on the above principle, it is possible to determine whether the first load of the load provided to the electrical device is a passive load or a non-passive load based on the transmission power of the resonance module at a plurality of frequencies.

In other embodiments, in the case that the load provided to the electrical device is a passive load, the load is usually in a capacitive region, that is, the current phase leads the on phase of the switching module (that is, the switching module is hard-turned on) when the frequency of the driving pulse signal transmitted by the driving module is continuously reduced, and in the case that the load provided to the electrical device is a non-passive load, the load is usually in an inductive region, that is, the current phase lags the on phase of the switching module when the frequency of the driving pulse signal transmitted by the driving module is continuously reduced. Based on the above principle, it is possible to determine whether the first load type of the load provided to the electrical device is a passive load or a non-passive load based on the phase of the first resonant current of the resonant module at a plurality of frequencies.

In summary, according to the technical scheme provided by the embodiment of the application, the switch module is driven to be turned on sequentially under a plurality of frequencies included in the preset frequency sequence, then the first working parameter of the resonance module under each frequency is obtained, finally the load set on the electrical equipment is determined to be a passive load or a non-passive load based on the first working parameter of the resonance module under each frequency, and as the change conditions of the first working parameters of the resonance module under the conditions of different frequencies and different load types are different, the first load type of the load set on the electrical equipment can be accurately detected. Then, under the condition that the first load type of the load is accurately determined, the electrical equipment can further control the wireless power supply and heating protection circuit to realize the wireless power supply function or the heating function, and the service efficiency of the wireless power supply and heating multiplexing circuit is improved.

Referring to fig. 6, a flowchart of a current detection method according to an embodiment of the application is shown. The method comprises the following steps S601-S605.

Step S601, the switch module is driven to be turned on based on a preset frequency sequence.

The preset frequency sequence includes a plurality of frequencies arranged in a specified order. In an embodiment of the present application, the plurality of frequencies includes m first frequencies and n second frequencies, m is an integer greater than 1, and n is an integer greater than or equal to 1. The first frequency is larger than or equal to the designated frequency, the second frequency is smaller than the designated frequency, and the designated frequency corresponds to the standby power of the non-passive load.

The value of m may be experimentally or empirically set, and may be an integer greater than 1 and less than or equal to 10, such as 10. Since the mapping relationship between the driving frequency and the absorption power of the load also depends on the characteristics of the load itself, such as when the load area is small (coin), the maximum absorption power is limited by the area, and is usually small, and if the passive load or the non-passive load is determined according to the emission frequency of the resonant module, misjudgment may occur. For example, if the maximum absorbed power of the coin is small and does not continue to increase after the emitted power of the resonant module reaches the maximum absorbed power of the coin, then the coin may be erroneously determined to be a non-passive load. Therefore, the value of m is reasonably set, and the detection efficiency can be improved on the premise of ensuring the accuracy of load detection.

The value of n can also be experimentally or empirically set, and can be an integer greater than or equal to 1 and less than 5, such as 2. The value of n is reasonably set, so that the detection efficiency can be improved.

In connection with the above example, where the specified frequency is fmax, then 2fmax, 1.9fmax, … …, fmax are the first frequency, and 0.9fmax and 0.8fmax are the second frequency.

The implementation manner in which the driving module drives the switch module to be turned on based on the m first frequencies and the n second frequencies may refer to step S401, which is not described herein.

Step S602, m first transmitting powers of the resonant module at m first frequencies and n second transmitting powers of the resonant module at n second frequencies are respectively obtained.

Under the condition that the resonance module transmits power, the control module obtains a first voltage difference between two ends of the sampling resistor, the ratio between the first voltage difference and the resistance value of the sampling resistor is determined to be a first current, under the condition that the resonance module does not transmit power, the control module also obtains a second voltage difference between two ends of the sampling resistor, the ratio between the second voltage difference and the resistance value of the sampling resistor is determined to be a second current, and finally the product between the difference between the second current and the first current and the output voltage of the power module is determined to be the first transmission power.

Under the condition that the resonance module transmits power, the control module obtains a third voltage difference between two ends of the sampling resistor, the ratio between the third voltage difference and the resistance value of the sampling resistor is determined to be third current, under the condition that the resonance module does not transmit power, the control module also obtains a fourth voltage difference between two ends of the sampling resistor, the ratio between the fourth voltage difference and the resistance value of the sampling resistor is determined to be fourth current, and finally the product between the difference between the fourth current and the third current and the output voltage of the power module is determined to be second transmitting power.

In step S603, the variation trends of the m first transmission powers are obtained.

In the embodiment of the present application, the variation trend of the m first transmission powers includes an increasing trend, that is, in the case where the variation trend of the first transmission power is an increasing trend, the ratio between the difference between any two adjacent first transmission powers and the smaller first transmission power in the any two adjacent first transmission powers is greater than or equal to a preset ratio. The preset ratio may be experimentally or empirically set, and may be any value greater than 10% and less than 50%, such as 20%.

In step S604, an absolute value of a difference between a first specified transmission power of the m first transmission powers and a second specified transmission power of the n second transmission powers is obtained.

The first designated transmission power is the largest first transmission power among the m first transmission powers, and the second designated transmission power is the smallest second transmission power among the n second transmission powers.

Since the driving frequency of the on driving switch module and the transmitting power are usually in a negative correlation, the first designated transmitting power is usually the transmitting power corresponding to the minimum first frequency, and the second designated transmitting power is usually the transmitting power corresponding to the maximum second frequency. In combination with the above example, the first specified transmission power is the transmission power corresponding to fmax, and the second specified transmission power is the transmission power corresponding to 0.9 fmax. The second specified transmit power is typically greater than the first specified transmit power.

Step S605 determines a first load type of the load based on the variation trend of the m first transmission powers and the absolute value of the difference.

In some embodiments, when the trend of the variation of the m first transmission powers is an increasing trend, and the ratio of the absolute value of the difference to the first designated transmission power is smaller than a preset ratio, the load type of the load is determined to be a non-passive load. The preset ratio may be set according to practical experience, for example, the preset ratio is 10%.

In the above embodiment, it is mentioned that the transmitting power of the resonant module is continuously increased before the passive load enters the standby state, however, after the passive load enters the standby state, the transmitting power of the resonant module approaches to the standby power of the passive load and does not continue to increase. Under the condition that the variation trend of the m first transmitting powers is an increasing trend, and the ratio of the absolute value of the difference to the first designated transmitting power is smaller than a preset ratio, the fact that the transmitting power of the resonance module approaches to a certain fixed value after continuously increasing for a period of time can be indicated, and the high probability of the load arranged on the electrical equipment is a non-passive load.

In other embodiments, when the trend of the variation of the m first transmission powers is an increasing trend, and the ratio of the absolute value of the difference to the first designated transmission power is greater than or equal to a preset ratio, the load type of the load is determined to be a passive load. In the above embodiment, it is mentioned that in the case where the frequency at which the driving module transmits the driving pulse signal is continuously reduced, the transmission power of the resonance module is continuously increased because the passive load passively absorbs the transmission power of the resonance module. When the variation trend of the m first transmitting powers is an increasing trend, and the ratio of the absolute value of the difference to the first designated transmitting power is greater than or equal to the preset ratio, it can be indicated that the transmitting power of the resonance module keeps continuously increasing, and the load set in the electrical equipment is a passive load with high probability.

Referring to fig. 7 in combination, a schematic diagram of the transmit power versus the absorption probability of a load of a resonant module according to one embodiment of the present application is shown. As can be seen from fig. 7, the absorption power of the passive load increases with the increase of the emission power of the resonant module, and the absorption power of the passive load approaches a fixed value after a period of time, that is, the standby power of the passive load.

It should be noted that the control module may control the power module to output different voltages, and execute the steps S501 to S505 under the different voltages. In one example, the control module may control the power module to output Vcc,1/2Vcc, 1/3Vcc, respectively, and then perform steps S501-S505 described above in the case where the output voltages are Vcc,1/2Vcc, 1/3Vcc, respectively.

Under the condition of sufficient energy (for example, the output voltage is Vcc), if the transmitting power of the resonant module approaches the upper limit value of the absorbing power of the load, the transmitting power of the resonant module will not continue to increase, and thus a misjudgment phenomenon may occur, for example, the load is a coin, and since the maximum absorbing power of the coin is smaller, the transmitting power of the resonant module will not continue to increase after approaching the maximum absorbing power of the coin, and at this time, the electrical equipment obtains an erroneous judgment result: coins are passively loaded. The power supply module is arranged to output different voltages, so that the phenomenon of misjudgment under the condition of sufficient energy can be avoided, and the success rate of load detection is increased.

In summary, according to the technical scheme provided by the embodiment of the application, the switch module is driven to be turned on sequentially under a plurality of frequencies included in the preset frequency sequence, then the transmitting power of the resonant module under each frequency is obtained, finally the load arranged on the electrical equipment is determined to be a passive load or a non-passive load based on the transmitting power of the resonant module under each frequency, and the first load type of the load arranged on the electrical equipment can be accurately detected because the transmitting power of the resonant module under the conditions of different frequencies and different load types is different.

Referring to fig. 8, a flowchart of a current detection method according to an embodiment of the application is shown. The method comprises the following steps S801-S803.

Step S801, the switch module is driven to be turned on based on a preset frequency sequence.

The implementation manner of step S801 may refer to step S401 and step S601, which are not described herein.

In step S802, a phase of a first resonant current of the resonant module at a plurality of frequencies is obtained.

The electrical device acquires the phase of the first resonance current through the current detection means 40 in fig. 2.

Step S803 determines a first load type of the load based on a comparison result of the phase of the first resonant current and the on phase of the switching module.

And determining the first load type of the load as a passive load under the condition that the phase of the first resonant current leads the opening phase of the switch module or the difference between the phase of the first resonant current and the opening phase of the switch module is smaller than a preset difference value. In the embodiment of the application, the on phase of the switch module refers to the on phase of the first switch. The preset difference may be set according to experiments or experience, which is not limited in the embodiment of the present application. And if the difference between the phase of the first resonant current and the on phase of the switch module is smaller than the preset difference, the free resonance of the resonant module is indicated.

In the above embodiment, it is mentioned that, in the case where the load provided to the electrical device is a passive load, in the case where the frequency at which the driving module transmits the driving pulse signal is continuously reduced, the load is generally in the capacitive region, that is, the current phase leads the on phase of the switching module (that is, the switching module is turned on hard), so that in the case where the phase of the first resonant current leads the on phase of the switching module, or in the case where the difference between the phase of the resonant current and the on phase of the switching module is smaller than the preset difference, it is indicated that the load is a passive load with a large probability.

Referring to fig. 9 in combination, a schematic diagram of a comparison result of a phase of a first resonant current and an on phase of a switch module according to an embodiment of the present application is shown. In fig. 9, the phase of the first resonant current leads the on phase of the switching module (i.e., the first switch).

And determining the load type of the load as a non-passive load under the condition that the phase of the first resonant current lags the opening phase of the switch module. In the above embodiments, it is mentioned that in the case where the load provided to the electrical device is a non-passive load, in the case where the frequency at which the driving module transmits the driving pulse signal is continuously reduced, the load is generally in an inductive region, that is, the current phase lags the on phase of the switching module. Therefore, when the phase of the first resonant current lags behind the on-phase of the switching module, the load is a non-passive load with a high probability.

Referring to fig. 10 in combination, a schematic diagram of a comparison result of a phase of a first resonant current and an on phase of a switch module according to another embodiment of the present application is shown. In fig. 10, the phase of the first resonant current lags the on phase of the switching module (i.e., the first switch).

In summary, according to the technical scheme provided by the embodiment of the application, the switch module is driven to be turned on sequentially under a plurality of frequencies included in the preset frequency sequence, then the phase of the first resonant current of the resonant module under each frequency is obtained, finally the load arranged on the electrical equipment is determined to be a passive load or a non-passive load based on the phase of the first resonant current of the resonant module under each frequency, and the comparison result of the phase of the first resonant current and the on phase of the switch module under the conditions of different frequencies and different load types of the resonant module is different, so that the first load type of the load arranged on the electrical equipment can be accurately detected.

Referring to fig. 11, a flowchart of a load detection method according to an embodiment of the application is shown. The method comprises the following steps S1101-S1103.

Step S1101, controlling the second switch to be in an off state within a first preset duration, controlling the fourth switch to be in an on state within the first preset duration, driving the first switch by a first pulse signal within the first preset duration, and driving the third switch by a second pulse signal after a preset dead time.

The first preset duration is actually determined according to the duration of load detection. In some embodiments, the first preset duration is equal to the duration of the load detection, i.e. the second switch is in an off state and the fourth switch is in an on state during the whole load detection phase, thus forming a half-bridge circuit.

The number of first pulse signals is typically one. The width of the first pulse signal may be any value smaller than 50us, for example 40us, and since the internal resistance of the resonant inductor is very small, a very small on pulse is set to avoid burning out devices in the wireless power supply and heating multiplexing circuit. The number of third pulse signals is typically one. The width of the third pulse signal may be any value smaller than 50us, for example 40us, and since the internal resistance of the resonant inductor is very small, a very small on pulse is set to avoid burning out the devices in the wireless power supply and heating multiplexing circuit. The preset dead time may be set experimentally or empirically, and the embodiment of the present application is not limited thereto.

Referring to fig. 12 in combination, a schematic diagram of a driving pulse signal and a current waveform diagram of different load information in a load detection stage according to an embodiment of the present application are shown. In the load detection stage, PWM1 outputs a first driving signal to the first switch, PWM2 continuously outputs a low level to enable the second switch to be always closed, PWM3 sends a second driving signal to the third switch after the preset dead time passes, and PWM4 continuously outputs a high level to enable the second switch to be always opened.

In other possible implementations, the electrical device may also perform load detection through a full bridge circuit. Specifically, the electrical equipment control driving module generates a third pulse signal to the first switch and the fourth switch, and after a preset dead time, the electrical equipment control driving module generates a fourth pulse signal to the second switch and the third switch.

Step S1102, obtaining a second operating parameter of the resonant module.

The second operating parameter of the resonant module comprises at least one of: the current value of the second resonance current, the oscillation duration, the oscillation number, the resonance frequency, and the like.

When a metal or other material with high magnetic permeability is placed around the resonance module, the inductance measurement of the resonance inductance will change, because the wire coil is mutually transformed with the metal or other material with high magnetic permeability, that is, the flux linkages of two closed loops adjacent to each other are mutually linked. The mutual inductance phenomenon can be expressed by the following expression.

Subscript 1 is the launch pad and subscript 2 is the load. M12 is the mutual inductance of the load to the resonant inductance, I2 is the induced current on the load, and ψ12 is the flux linkage of the magnetic flux generated on the load to the resonant inductance. Bi is the magnetic induction through the load end, si is the area through which the magnetic flux passes, μ0 is the vacuum permeability, μr is the relative permeability, and Hi is the magnetic field strength generated by the resonant module.

As can be seen from the above expression, the mutual inductance is related to parameters such as current at the load end, relative permeability, area through which magnetic flux passes, and load resistivity. Since the receiving end of the passive load is also a coil, the relative magnetic permeability and area of the magnetic core are known, while the passive load such as a key, a spoon, a knife or a coin is metal and generates mutual inductance with the resonance module, but the relative magnetic permeability is obviously different from that of the receiving coil with the magnetic core, so that the mutual inductances generated by the receiving end and the receiving end are different, and the current waveforms of the receiving end and the receiving end are obviously different. Based on the above principle, load information may be detected based on the second operating parameter of the resonance module.

In step S1103, load information of the electrical device is determined based on the second operating parameter of the resonance module.

The load information is used to indicate at least one of: whether the electrical device is placed with a load, a second load type of the load the electrical device is placed with. The second load type includes a light load and a heavy load, the light load having a weight less than a weight of the heavy load.

In some embodiments, the second operating parameter of the resonant module includes a current value of a second resonant current, the second resonant current being a current of the resonant module within a preset period of time. The preset time period is a current with the driving time of the first switch driven by the first pulse signal as a starting point and the duration time being a second preset time period. The second preset time period may be empirically set. In this embodiment, step S1103 is implemented as: under the condition that the current value of the second resonance current is larger than or equal to a first preset value, determining that the electrical equipment is placed with a load; and under the condition that the current value of the second resonant current is smaller than the first preset value, determining that the electrical equipment is not loaded or is abnormally loaded.

The first preset value is set experimentally or empirically. Abnormal loads include objects of relatively low permeability, such as non-metallic materials, including, but not limited to: plastic bowls, porcelain bowls, and the like. Under no load (i.e. under the condition that the electrical equipment is not loaded) or under the condition that the electrical equipment is loaded with abnormal load, as no device is mutually coupled with the coil disc of the resonant inductor, the inductance of the resonant inductor is self inductance L1 of the coil disc, under the condition that the electrical equipment is loaded with the load, the resonant inductor and the coil disc in the load are mutually inductive, the inductance of the resonant inductor is L2, when the load contains metal substances, L1> L2, and the inductance blocks the change of current, under no load (i.e. under the condition that the electrical equipment is not loaded) or under the condition that the electrical equipment is loaded with abnormal load, the current value of the second resonant current is smaller than that of the second resonant current, so that the load information of the electrical equipment can be detected through the current value of the second resonant current.

Referring again to fig. 12, when the electrical device is placed with a light load or a heavy load, the current value of the second resonant current is large. When the electrical equipment is not provided with a load or is provided with an abnormal load, the current value of the second resonance current is smaller.

In some embodiments, the second operating parameter further includes a resonant frequency, which refers to a frequency at which the resonant module freely resonates. After determining that the electrical equipment is not loaded or is loaded abnormally, the electrical equipment can be further judged to be not loaded or is loaded abnormally according to the resonant frequency. In this embodiment, in the case where the resonance frequency is greater than or equal to the preset frequency, it is determined that the load set to the electrical equipment is an abnormal load; and under the condition that the resonant frequency is smaller than the preset frequency, determining that the electrical equipment is not loaded.

For a first order LC tank, the expression of its resonant frequency is as follows:

The inductance of the resonant inductor is large when the electrical equipment is in idle load, so that the resonant frequency is small. Because of the relative permeability, magnetic energy passing area and resistivity of the abnormal load, the resonant frequency of the abnormal load should be greater than that of the electrical equipment when no load exists.

Referring again to fig. 12, the resonant frequency is small when the electrical device is empty. When the electrical equipment is placed with abnormal load, the resonance frequency is larger.

In some embodiments, the second operating parameter includes an oscillation duration, which refers to a duration for which the resonant module is free to resonate. The oscillation duration can be obtained by the pulse obtaining module in fig. 3, when the resonance module outputs different voltages, the comparator in the pulse obtaining module can overturn, and the oscillation duration can be determined by counting the overturn duration. In this embodiment, step S1103 is implemented as: under the condition that the oscillation time length is greater than or equal to a third preset time length, determining that a second load type of a load arranged on the electrical equipment is a light load; under the condition that the oscillation time length is smaller than a third preset time length, determining a second load type of a load arranged on the electrical equipment to be a heavy load; and under the condition that the oscillation time period is longer than the fourth preset time period, determining that the electrical equipment is not loaded or is abnormally loaded.

The third preset time period is set according to experiments or experience. The fourth preset time period is set according to experiments or experience. The fourth preset time period is longer than the third preset time period. The light load consumes less energy compared with the heavy load, so that after the switch module is conducted to generate instantaneous heavy current, the time for the heavy load to consume the energy is shorter than the time for the light load to consume the energy, and the oscillating time for the electric equipment to be placed with the heavy load is shorter than the oscillating time for the electric equipment to be placed with the light equipment. Based on the above principle, it is possible to determine whether the electrical device is placed with a light load or a heavy load based on the oscillation period. The electrical device consumes less energy in the case of no load or placed with an abnormal load, and thus the oscillation time is longer.

Referring to fig. 12 again, when the electrical equipment is placed with a heavy load, the oscillation duration is short; when the electrical equipment is placed with a light load, the oscillation time length is longer than that when the electrical equipment is placed with a heavy load; when the electrical equipment is in no-load or placed with abnormal load, the oscillation time is longest.

In some embodiments, the second operating parameter includes a number of oscillations, which refers to a number of resonances at which the resonant module is free to resonate. The oscillation times can be obtained by the pulse obtaining module in fig. 3, when the resonance module outputs different voltages, the comparator in the pulse obtaining module can overturn, and the oscillation times can be determined by counting the overturn times. In this embodiment, step S1103 is implemented as: under the condition that the oscillation frequency is greater than or equal to the first preset frequency, determining that a second load type of a load arranged on the electrical equipment is a light load; under the condition that the oscillation frequency is smaller than the first preset frequency, determining a second load type of a load arranged on the electrical equipment to be a heavy load; and under the condition that the oscillation frequency is larger than the second preset frequency, determining that the electrical equipment is not placed with a load or is placed with an abnormal load.

The first preset number of times is set according to experiments or experience. The second preset number of times is set according to experiments or experience. The second preset times are larger than the first preset times. The light load consumes less energy than the heavy load, so that after the switch module is conducted to generate instantaneous heavy current, the time for the heavy load to consume the energy is shorter than the time for the light load to consume the energy, and the oscillation frequency of the electric equipment with the heavy load is smaller than the oscillation frequency of the electric equipment with the light equipment. Based on the above principle, it is possible to determine whether the electrical device is placed with a light load or a heavy load based on the number of oscillations. The electrical equipment consumes less energy in the case of no load or an abnormal load placed, and thus the number of oscillations is greater.

Referring again to fig. 12, when the electrical equipment is placed with a heavy load, the number of oscillations is small; when the electrical equipment is placed with a light load, the oscillation frequency is larger than that when the electrical equipment is placed with a heavy load; when the electrical equipment is unloaded or placed with abnormal load, the oscillating frequency is the largest.

In summary, according to the technical scheme provided by the embodiment of the application, based on the free resonance of the half-bridge circuit driving resonance module, the second working parameter when the free resonance of the resonance module occurs is obtained, and the load information of the electrical equipment can be accurately detected.

Referring to fig. 13, a block diagram of a load detection device according to an embodiment of the application is shown. The load detection device is applied to electrical equipment provided with a wireless power supply and heating multiplexing circuit, the wireless power supply and heating multiplexing circuit comprises a switch module and a resonance module, the switch module and the resonance module are electrically connected, and the device comprises: a driving module 1210, a first parameter acquisition module 1220 and a load detection module 1230.

The driving module 1210 is configured to drive the switch module to conduct based on a preset frequency sequence, where the preset frequency sequence includes a plurality of frequencies arranged in a specified order.

The first parameter obtaining module 1220 is configured to obtain first operating parameters of the resonant module at a plurality of frequencies, respectively.

The load detection module 1230 is configured to determine a first load type of a load set on the electrical device based on a first operating parameter of the resonance module at a plurality of frequencies; the first load type comprises a passive load and a non-passive load, wherein the passive load refers to a load which passively absorbs the transmitting power of the resonance module, and the non-passive load refers to a load which does not passively absorb the transmitting power of the resonance module.

In some embodiments, the plurality of frequencies includes m first frequencies and n second frequencies, m is an integer greater than 1, n is an integer greater than or equal to 1; the first frequency is greater than or equal to the designated frequency, the second frequency is less than the designated frequency, and the designated frequency corresponds to the standby power of the non-passive load; the first operating parameter comprises the transmit power of the resonant module; the first parameter obtaining module 1220 is configured to obtain m first transmission powers of the resonant module at m first frequencies, and n second transmission powers of the resonant module at n second frequencies, respectively. The load detection module 1230 is configured to obtain a variation trend of the m first transmission powers; acquiring the absolute value of the difference between a first appointed transmitting power in m first transmitting powers and a second appointed transmitting power in n second transmitting powers, wherein the first appointed transmitting power is the largest first transmitting power in m first transmitting powers, and the second appointed transmitting power is the smallest second transmitting power in n second transmitting powers; and determining a first load type of the load based on the variation trend of the m first transmission powers and the absolute value of the difference.

In some embodiments, the load detection module 1230 is configured to determine that the first load type of the load is a non-passive load when the variation trend of the m first transmission powers is an increasing trend and the ratio of the absolute value of the difference to the first specified transmission power is smaller than a preset ratio; and determining the first load type of the load as a passive load under the condition that the variation trend of the m first transmitting powers is an increasing trend and the ratio of the absolute value of the difference to the first appointed transmitting power is larger than or equal to a preset ratio.

In some embodiments, the plurality of frequencies includes m first frequencies and n second frequencies, m is an integer greater than 1, n is an integer greater than or equal to 1; the first frequency is greater than or equal to the designated frequency, the second frequency is less than the designated frequency, and the designated frequency corresponds to the standby power of the non-passive load; the first operating parameter includes a phase of a first resonant current of the resonant module; the load detection module 1230 is configured to determine a first load type of the load based on a comparison result of the phase of the first resonant current and the on phase of the switching module.

In some embodiments, the load detection module 1230 is configured to determine that the first load type of the load is a passive load if the phase of the first resonant current leads the on phase of the switching module, or if the difference between the phase of the first resonant current and the on phase of the switching module is less than a preset difference; in the case of a phase lag switching module of the first resonant current, the first load type of the load is determined to be a non-passive load.

In some embodiments, the switch module includes a first switch, a second switch, a third switch, and a fourth switch, the first switch and the third switch being connected in series with each other between two ends of the power module, the second switch and the fourth switch being connected in series with each other between two ends of the power module; one end of the resonance module is connected with the common end of the first switch and the third switch, and the other end of the resonance module is connected with the common end of the second switch and the fourth switch; the driving module 1210 is further configured to control the second switch to be in an off state within a first preset duration, control the fourth switch to be in an on state within the first preset duration, drive the first switch through a first pulse signal within the first preset duration, and drive the third switch through a second pulse signal after a preset dead time. And the second parameter acquisition module is used for acquiring a second working parameter of the resonance module. The load detection module 1230 is further configured to determine load information of the electrical device based on the second operating parameter of the resonance module, where the load information is used to indicate at least one of: whether the electrical device is placed with a load, a second load type of the load the electrical device is placed with.

In some embodiments, the second operating parameter of the resonant module includes a current value of a second resonant current, where the second resonant current is a current of the resonant module in a preset period, and the preset period is a current with a driving time of the first switch driven by the first pulse signal as a starting point and a duration of the first switch being a second preset duration; the load detection module 1230 is configured to determine that the electrical device is loaded when the current value of the second resonant current is greater than or equal to the first preset value; and under the condition that the current value of the second resonant current is smaller than the first preset value, determining that the electrical equipment is not loaded or is abnormally loaded.

In some embodiments, the second operating parameter of the resonant module further includes a resonant frequency, and the load detection module 1230 is further configured to determine that the load set in the electrical device is an abnormal load when the resonant frequency is greater than or equal to a preset frequency; and under the condition that the resonant frequency is smaller than the preset frequency, determining that the electrical equipment is not loaded.

In some embodiments, the second operating parameter of the resonant module includes an oscillation time period, and the load detection module 1230 is configured to determine that the second load type of the load set on the electrical device is a light load when the oscillation time period is greater than or equal to a third preset time period; under the condition that the oscillation time length is smaller than a third preset time length, determining a second load type of a load arranged on the electrical equipment to be a heavy load; under the condition that the oscillation time length is greater than or equal to a fourth preset time length, determining that the electrical equipment is not loaded or is abnormally loaded; the mass of the light load is smaller than that of the heavy load, and the fourth preset time period is longer than the third preset time period.

In some embodiments, the second operating parameter of the resonant module includes a number of oscillations, and the load detection module 1230 is configured to determine that the second load type of the load provided to the electrical device is a light load if the number of oscillations is greater than or equal to the first preset number of oscillations; under the condition that the oscillation frequency is smaller than the first preset frequency, determining a second load type of a load arranged on the electrical equipment to be a heavy load; under the condition that the oscillation frequency is greater than or equal to a second preset frequency, determining that the electrical equipment is not loaded or is abnormally loaded; the weight of the light load is smaller than that of the heavy load, and the second preset times are larger than the first preset times.

In the description of the present application, certain terms are used throughout the description and claims to refer to particular components. Those of skill in the art will appreciate that a hardware manufacturer may refer to the same component by different names. The description and claims do not take the difference in name as a way of distinguishing between components, but rather take the difference in functionality of the components as a criterion for distinguishing. As used throughout the specification and claims, the word "comprise" and "comprises" are to be construed as "including, but not limited to"; by "substantially" is meant that a person skilled in the art can solve the technical problem within a certain error range, essentially achieving the technical effect.

In the description of the present application, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "inner," and the like indicate orientation or positional relationships based on those shown in the drawings, and are merely for convenience of description of the application, but do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the application.

In the present application, the terms "mounted," "connected," "secured," and the like are to be construed broadly, unless otherwise specifically indicated or defined. For example, the connection can be fixed connection, detachable connection or integral connection; can be mechanically or electrically connected; the connection may be direct, indirect via an intermediate medium, or communication between two elements, or only surface contact. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be appreciated by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not drive the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. The utility model provides a load detection method which characterized in that is applied to the electrical equipment that is equipped with wireless power supply and heating multiplex circuit, wireless power supply and heating multiplex circuit includes switch module and resonance module, switch module and resonance module electricity are connected, the method includes:

Driving the switch module to be conducted based on a preset frequency sequence, wherein the preset frequency sequence comprises a plurality of frequencies arranged according to a specified sequence;

respectively acquiring first working parameters of the resonance module under a plurality of frequencies;

Determining a first load type of a load arranged on the electrical equipment based on first working parameters of the resonance module at a plurality of frequencies; the first load type comprises a passive load and a non-passive load, wherein the passive load refers to a load which passively absorbs the transmitting power of the resonance module, and the non-passive load refers to a load which does not passively absorb the transmitting power of the resonance module.

2. The method of claim 1, wherein the plurality of frequencies comprises m first frequencies and n second frequencies, m being an integer greater than 1, n being an integer greater than or equal to 1; the first frequency is greater than or equal to a specified frequency, the second frequency is less than the specified frequency, and the specified frequency is a frequency corresponding to the standby power of the non-passive load; the first operating parameter comprises the transmit power of the resonant module;

the respectively obtaining the first working parameters of the resonance module under a plurality of frequencies includes:

Respectively acquiring m first transmitting powers of the resonance module at m first frequencies and n second transmitting powers of the resonance module at n second frequencies;

The determining, based on the first operating parameters of the resonant module at the plurality of frequencies, a first load type of a load disposed on the electrical device includes:

Acquiring variation trends of m first transmission powers;

Acquiring the absolute value of the difference between a first appointed transmitting power in m first transmitting powers and a second appointed transmitting power in n second transmitting powers, wherein the first appointed transmitting power is the largest first transmitting power in m first transmitting powers, and the second appointed transmitting power is the smallest second transmitting power in n second transmitting powers;

and determining a first load type of the load based on the variation trend of the m first transmission powers and the absolute value of the difference value.

3. The method of claim 2, wherein the determining a first load type of the load based on the m first transmit power trends and the absolute difference value comprises:

Determining that the first load type of the load is the non-passive load when the variation trend of the m first transmitting powers is an increasing trend and the ratio of the absolute value of the difference to the first designated transmitting power is smaller than a preset ratio;

And determining that the first load type of the load is the passive load under the condition that the variation trend of the m first transmitting powers is an increasing trend and the ratio of the absolute value of the difference to the first appointed transmitting power is larger than or equal to the preset ratio.

4. The method of claim 1, wherein the plurality of frequencies comprises m first frequencies and n second frequencies, m being an integer greater than 1, n being an integer greater than or equal to 1; the first frequency is greater than or equal to a specified frequency, the second frequency is less than the specified frequency, and the specified frequency is a frequency corresponding to the standby power of the non-passive load; the first operating parameter includes a phase of a first resonant current of the resonant module;

And determining a first load type of the load based on a comparison result of the phase of the first resonant current and the on phase of the switch module.

5. The method of claim 4, wherein determining the first load type of the load based on the comparison of the phase of the first resonant current and the on-phase of the switching module comprises:

determining a first load type of the load as the passive load under the condition that the phase of the first resonant current leads the opening phase of the switch module or the difference value between the phase of the first resonant current and the opening phase of the switch module is smaller than a preset difference value;

And determining a first load type of the load as the non-passive load under the condition that the phase of the first resonant current lags the opening phase of the switch module.

6. The method of any one of claims 1 to 5, wherein the switch module comprises a first switch, a second switch, a third switch, and a fourth switch, the first switch and the third switch being connected in series with each other between two ends of the power module, the second switch and the fourth switch being connected in series with each other between two ends of the power module; one end of the resonance module is connected with the common end of the first switch and the third switch, and the other end of the resonance module is connected with the common end of the second switch and the fourth switch;

before the switch module is driven to be conducted based on the preset frequency sequence, the method further comprises the following steps:

Controlling the second switch to be in a closed state within a first preset time period, controlling the fourth switch to be in an open state within the first preset time period, driving the first switch through a first pulse signal within the first preset time period, and driving the third switch through a second pulse signal after a preset dead time period;

Acquiring a second working parameter of the resonance module;

Based on a second operating parameter of the resonance module, load information of the electrical device is determined, the load information being used to indicate at least one of: whether the electrical equipment is placed with a load, and a second load type of the load placed with the electrical equipment.

7. The method of claim 6, wherein the second operating parameter of the resonant module includes a current value of a second resonant current, the second resonant current being a current of the resonant module during a preset period of time, the preset period of time being a current starting at a driving time when the first switch is driven by the first pulse signal and having a duration of a second preset duration;

The determining the load information of the electrical equipment based on the second working parameter of the resonance module includes:

Under the condition that the current value of the second resonance current is larger than or equal to a first preset value, determining that the electrical equipment is placed with a load;

And under the condition that the current value of the second resonant current is smaller than the first preset value, determining that the electrical equipment is not loaded or is abnormally loaded.

8. The method of claim 7, wherein the second operating parameter of the resonant module further comprises a resonant frequency, and wherein the determining that the electrical device is not loaded or is abnormally loaded if the second resonant current is less than the first preset value further comprises:

Under the condition that the resonance frequency is greater than or equal to a preset frequency, determining that the load arranged on the electrical equipment is an abnormal load;

And under the condition that the resonant frequency is smaller than the preset frequency, determining that the electrical equipment is not loaded.

9. The method of claim 6, wherein the second operating parameter of the resonant module comprises an oscillation duration, and wherein the determining load information of the electrical device based on the second operating parameter of the resonant module comprises:

determining that a second load type of the load arranged on the electrical equipment is a light load under the condition that the oscillation time length is greater than or equal to a third preset time length;

Determining a second load type of the load arranged on the electrical equipment to be a heavy load under the condition that the oscillation duration is smaller than the third preset duration;

Under the condition that the oscillation time length is greater than or equal to a fourth preset time length, determining that the electrical equipment is not loaded or is abnormally loaded;

the mass of the light load is smaller than that of the heavy load, and the fourth preset time period is longer than the third preset time period.

10. The method of claim 6, wherein the second operating parameter of the resonant module comprises a number of oscillations, and wherein determining the load information of the electrical device based on the second operating parameter of the resonant module comprises:

determining that a second load type of a load arranged on the electrical equipment is a light load under the condition that the oscillation frequency is greater than or equal to a first preset frequency;

determining a second load type of a load arranged on the electrical equipment to be a heavy load under the condition that the oscillation frequency is smaller than the first preset frequency;

Under the condition that the oscillation frequency is greater than or equal to a second preset frequency, determining that the electrical equipment is not loaded or is abnormally loaded;

Wherein the mass of the light load is smaller than the mass of the heavy load, and the second preset times are larger than the first preset times.

11. The utility model provides a load detection device, its characterized in that is applied to the electrical equipment that is equipped with wireless power supply and heating multiplex circuit, wireless power supply and heating multiplex circuit includes switch module and resonance module, switch module with resonance module electricity is connected, the device includes:

The driving module is used for driving the switch module to be conducted based on a preset frequency sequence, and the preset frequency sequence comprises a plurality of frequencies arranged according to a specified sequence;

The first parameter acquisition module is used for respectively acquiring first working parameters of the resonance module under a plurality of frequencies;

The load detection module is used for determining a first load type of a load arranged on the electrical equipment based on first working parameters of the resonance module at a plurality of frequencies; the first load type comprises a passive load and a non-passive load, wherein the passive load refers to a load which passively absorbs the transmitting power of the resonance module, and the non-passive load refers to a load which does not passively absorb the transmitting power of the resonance module.