TWI683498B - Method and supplying-end module for detecting receiving-end module - Google Patents

Abstract

A method of detecting a receiving-end module, for a supplying-end module of an induction type power supply system wherein the supplying-end module includes a supplying-end coil, includes detecting a resonant frequency of the supplying-end coil; determining a coil distance of the receiving-end module and the supplying-end module according to the resonant frequency; obtaining a maximum resonant voltage and a minimum resonant voltage corresponding to the coil distance; and determining whether there is a deviation between the supplying-end module and the receiving-end module according to the maximum resonant voltage and the minimum resonant voltage and an input current of the supplying-end coil.

Description

Method for detecting power receiving module and power supply module

The invention refers to a method for detecting a power receiving module and a power supply module, in particular to a method for detecting a deviation between a power supply module and a power receiving module and a power supply module thereof.

In the inductive power supply, for safe operation, it is necessary to confirm that the induction area on the power supply coil of the power supply coil is the correct power receiving device, and only transmit power when the power can be received. In order to enable the power supply terminal to recognize whether the power receiving terminal For the correct power receiving device, it needs to be identified by data code transmission. The transmission of the data code is driven by the power supply end to drive the power supply coil to generate resonance, send electromagnetic energy to the power receiving end for power transmission, and when the power receiving end receives power, the impedance state on the receiving coil can be changed by signal modulation technology, and then The feedback affects the change of the resonant carrier signal on the power supply coil to transmit the data code.

In the conventional technology, the position and distance between the power supply terminal and the power receiving terminal cannot be detected and calculated, so that the power adjustment is often limited to a predetermined maximum resonance voltage, and cannot be adjusted according to the distance . In this case, when the power supply and the power receiving terminal are close to each other, the power receiving terminal may be burned because the output power is too large; or when the power output is too small, the power receiving terminal may be insufficient and the operation may be interrupted. . In view of this, it is necessary to improve the conventional technology.

Therefore, the main purpose of the present invention is to provide a method for detecting a power receiving module, which can be used to detect the distance between the power receiving module and the power supply module, and to set the maximum resonance voltage and the minimum resonance voltage of the power supply coil according to the distance Then, according to the magnitude of the coil voltage and current, it is determined whether there is an offset between the power supply module and the power receiving module.

The invention discloses a method for detecting a power receiving module for a power supply module of an inductive power supply, the power supply module includes a power supply coil, and the method includes detecting a resonance frequency of the power supply coil; The resonant frequency, determine a coil distance between the power receiving module and the power supply module; obtain a maximum resonance voltage and a minimum resonance voltage corresponding to the coil distance; and according to the maximum resonance voltage and the minimum resonance voltage and the power supply Input current to one of the coils to determine whether there is an offset between the power supply module and the power receiving module.

The invention also discloses a power supply module for an inductive power supply. The power supply module includes a power supply coil, a current detector and a power supply microprocessor. The current detector can be used to detect an input current of the power supply coil. The power supply microprocessor is coupled to the power supply coil and can be used to perform the following steps: detect a resonant frequency of the power supply coil; determine the distance between the power receiving module and a coil of the power supply module according to the resonant frequency; obtain a correspondence A maximum resonance voltage and a minimum resonance voltage at the coil distance; and according to the maximum resonance voltage and the minimum resonance voltage and the input current, it is determined whether there is an offset between the power supply module and the power receiving module.

100‧‧‧Inductive power supply system

1‧‧‧Power supply module

10‧‧‧Power supply

11‧‧‧Power supply microprocessor

111‧‧‧Processing unit

112‧‧‧clock generator

115‧‧‧Memory unit

120‧‧‧Signal receiving module

121、122‧‧‧Power supply drive unit

130‧‧‧Voltage dividing circuit

131, 132‧‧‧Voltage resistor

141, 142‧‧‧Resonance capacitor

16‧‧‧Power supply coil

161,261‧‧‧Magnetic conductor

17‧‧‧Input unit

18‧‧‧current detector

C1‧‧‧coil signal

D1, D2 ‧‧‧ drive signal

2‧‧‧Power receiving module

21‧‧‧ Load unit

26‧‧‧Power receiving coil

FLC1, FLC2, FLC3, FLCX ‧‧‧ resonance frequency

VMAX2, VMAX3, VMAX‧‧‧ Maximum resonance voltage

VMIN2, VMIN3, VMIN‧‧‧minimum resonance voltage

X, Y, Z, W ‧‧‧ coil distance

V1, V2, V3 ‧‧‧ resonance voltage

Line L1, L2‧‧‧

I1‧‧‧Input current

IT‧‧‧critical current

IMAX‧‧‧full load current

VT‧‧‧critical resonance voltage

60‧‧‧Detection process

600~610‧‧‧Step

FIG. 1 is a schematic diagram of an inductive power supply according to an embodiment of the invention.

FIG. 2A is a schematic diagram of the power supply coil in an idle state.

Figure 2B is a schematic diagram of the furthest working distance between the power supply coil and the power receiving coil.

Figure 2C is a schematic diagram of the shortest working distance between the power supply coil and the power receiving coil.

Figure 2D is a schematic diagram of the horizontal deviation of the power supply coil and the power receiving coil.

FIG. 3 is a schematic diagram of the resonance frequency of the power supply coil and the corresponding resonance voltage according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of the coil operating voltage and corresponding input current according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of judging the coil offset according to the coil resonance voltage and the input current according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a detection process according to an embodiment of the present invention.

Please refer to FIG. 1, which is a schematic diagram of an inductive power supply 100 according to an embodiment of the present invention. As shown in FIG. 1, the inductive power supply 100 includes a power supply module 1 and a power receiving module 2. The power supply module 1 can receive power from a power supply 10 and output wireless power to the power receiving module 2. The power supply module 1 includes a power supply coil 16 and resonance capacitors 141 and 142, which are arranged in a C-L-C structure. The power supply coil 16 can be used to send electromagnetic energy to the power receiving module 2 for power supply. The resonance capacitors 141 and 142 are respectively coupled to the two ends of the power supply coil 16 and can be used to resonate with the power supply coil 16 during power supply. In addition, in the power supply module 1, a magnetic conductor 161 composed of a magnetic material can be selectively used to improve the electromagnetic induction capability of the power supply coil 16, while avoiding the influence of electromagnetic energy on objects in the direction of the non-inductive surface of the coil.

In order to control the operation of the power supply coil 16 and the resonance capacitors 141 and 142, the power supply module 1 further includes a power supply microprocessor 11, power supply drive units 121 and 122, and a voltage divider circuit 130. Power supply drive unit 121 and 122 are coupled to the power supply coil 16 and the resonance capacitors 141 and 142, and can send driving signals D1 and D2 to the power supply coil 16, respectively, which can receive the control of the power supply microprocessor 11 to drive the power supply coil 16 to generate and send energy . When both the power supply driving units 121 and 122 operate simultaneously, full-bridge driving can be performed. In some embodiments, only one of the power supply driving units 121 and 122 may be turned on, or only one power supply driving unit 121 or 122 may be configured for half-bridge driving. The power supply microprocessor 11 generally refers to a processing circuit for controlling inside the power supply module 1, which can be used to process and control various operations of the power supply module 1.

In detail, the power supply microprocessor 11 includes a processing unit 111, a clock generator 112, a memory unit 115, and a signal receiving module 120. The processing unit 111 can be used to process and control various operations of the power supply module 1. The clock generator 112 is coupled to the power supply driving units 121 and 122, and can be used to control the power supply driving units 121 and 122 to send driving signals D1 and D2. The clock generator 112 may be a pulse width modulation generator (Pulse Width Modulation generator, PWM generator) or other types of clock generators for outputting a clock signal to the power supply driving units 121 and 122. The processing unit 111 can control the power supply driving units 121 and 122 to adjust the output power and the coil resonance voltage according to the coil signal C1 on the power supply coil 16 received by the signal receiving module 120, and perform an operation to obtain the power supply module 1 required Various parameters. The processing unit 111 may be a central processing unit (Central Processing Unit, CPU), or may be implemented by other types of processing devices or computing devices. The memory unit 115 can be used to store information required for the operation of the processing unit 111, which can be implemented by various types of memory, such as read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), flash memory (Flash Memory), optical storage media (Optical Storage Media), other types of memory, or a combination of multiple memories. The signal receiving module 120 can receive the coil signal C1 and convert it into a message readable by the processing unit 111 and send it to the processing unit 111. The detailed structure and operation method of the signal receiving module 120 are described in the Republic of China Patent Publication No. TW 201742354 (ie, the comparator module), and are not repeated here. The voltage dividing circuit 130 includes a voltage dividing resistor 131 and 132, after attenuating the coil signal C1 on the power supply coil 16, it is output to the processing unit 111 and the signal receiving module 120. In some embodiments, if the circuits such as the processing unit 111 and the signal receiving module 120 have sufficient withstand voltage, the signal receiving module 120 may directly receive the coil signal C1 on the power supply coil 16 without using the voltage dividing circuit 130.

In addition, FIG. 1 also shows a power supply 10, an input unit 17 and a current detector 18. In detail, the power supply 10 may be a DC or AC power supply, which is used to provide the power that the inductive power supply 100 wants to output to the load and the power required inside. The input unit 17 provides a user interface for receiving settings to be input by the user. The current detector 18 can be used to detect the input current of the power supply module 1 or the power supply coil 16. In FIG. 1, the above-mentioned device/module is independent of the power supply module 1, but in other embodiments, the above-mentioned device/module may also be integrated within the power supply module 1, or realized by other means, and Not limited to this.

Please continue to refer to Figure 1. The power receiving module 2 includes a load unit 21 and a power receiving coil 26. In the power receiving module 2, a magnetic conductor 261 composed of a magnetic material may be selectively used to improve the electromagnetic induction capability of the power receiving coil 26 while avoiding the influence of electromagnetic energy on objects in the direction of the non-inductive surface of the coil. The power receiving coil 26 can be used to receive the power from the power supply coil 16, rectify it, and transmit it to the load unit 21. In the power receiving module 2, other possible components or modules, such as a rectifier circuit, a voltage stabilizing capacitor, a signal feedback circuit, a power receiving microprocessor, etc., may increase or decrease depending on system requirements, so it does not affect the Under the description, it is not shown.

The power supply microprocessor 11 of the inductive power supply 100 can determine the distance between the power supply coil 16 and the power receiving coil 26 by detecting the self-resonant frequency of the power supply coil 16, when the distance between the power receiving coil 26 and the power supply coil 16 is closer , The smaller the measured resonant frequency, when the distance between the power receiving coil 26 and the power supply coil 16 The farther away, the greater the measured resonant frequency. For the detailed operation mode, please refer to the description of Republic of China Patent Publication No. TW 201742354, which will not be repeated here. Generally speaking, when there is no power receiving module or other objects approaching, the power supply coil 16 is in an idle state, as shown in FIG. 2A. After the power is turned on, the power supply module 1 can first confirm the resonance frequency of the power supply coil 16 and determine whether it meets the predetermined resonance frequency in the idle state. If they are not equal, there may be other objects near the power supply coil 16 or the power supply coil 16 itself malfunctions. In this case, the power supply module 1 can turn off the operation of the output power until the resonance frequency enters the range of the predetermined resonance frequency, and then start the operation.

When the power receiving module 2 approaches the power supply module 1, the magnetic material of the magnetic conductor 261 causes the resonance frequency of the power supply coil 16 to start to drop. When the resonance frequency falls below the frequency value corresponding to the farthest working distance of the coil, the power supply module 1 to start power transmission. At this time, the power supply coil 16 and the power receiving coil 26 have the longest working distance, as shown in FIG. 2B. During power transmission, the power supply module 1 can continuously monitor the resonance frequency. If the resonance frequency exceeds the range of the frequency value corresponding to the farthest working distance of the coil, it means that the power receiving coil 26 may be away from the working distance. The power transmission can be stopped. If the power receiving coil 26 gradually approaches the power supply coil 16, the energy sent by the power supply end should be reduced so that the power receiving coil 26 receives appropriate power. However, when the two coils are too close, the power supply drive units 121 and 122 of the power supply module 1 have basic driving capabilities, which causes the power receiving end to receive excessive energy. Therefore, if the coil distance is less than a closest working distance, the power supply module Group 1 can forcibly stop power output. FIG. 2C is a schematic diagram showing the shortest working distance between the power supply coil 16 and the power receiving coil 26.

It can be seen from the above that different resonance frequencies can correspond to different distances between the power supply coil 16 and the power receiving coil 26. Therefore, the power supply microprocessor 11 can determine the coil distance according to the resonance frequency. Please refer to FIG. 3, which is a schematic diagram of the resonance frequency of the power supply coil 16 and the corresponding resonance voltage according to an embodiment of the present invention. As shown in Figure 3, the resonance frequency FLC1 is the self-resonance frequency when the power supply coil 16 is idle; resonance The frequency FLC2 is the self-resonant frequency of the power supply coil 16 when the distance between the power receiving coil 26 and the power supply coil 16 reaches the farthest working distance; the resonance frequency FLC3 is the power supply coil 16 when the power receiving coil 26 is closer to the nearest working distance Self-resonant frequency.

Furthermore, in order for the power supply microprocessor 11 to accurately set the upper and lower limits of the resonance voltage, it is necessary to accurately determine the distance between the power supply coil 16 and the power receiving coil 26. It should be noted that the distance is a continuous value. Traditionally, if you want to achieve accurate upper and lower limits of resonance voltage, you need to set multiple distance points between the closest working distance and the farthest working distance, and for each The distance sub-point sets a maximum value and a minimum value. However, when there are more distance points, more memory is often needed to store the setting values, and the setting method is very complicated.

供電線圈16之最小諧振電壓VMIN可由以下方式計算而得：

In one embodiment, the power supply microprocessor 11 can calculate the upper and lower limits of the resonance frequency under each distance by the resonance frequency setting values of the longest working distance and the nearest working distance. As shown in FIG. 3, the power supply microprocessor 11 can obtain a maximum resonance voltage VMAX2 and a minimum resonance voltage VMIN2 corresponding to the longest working distance and a maximum resonance voltage VMAX3 and a minimum resonance voltage VMIN3 corresponding to the shortest working distance . The maximum resonance voltage VMAX2, VMAX3 and the minimum resonance voltage VMIN2, VMIN3 can be preset in the power supply microprocessor 11 before the inductive power supply 100 is shipped from the factory, and/or set by the user or manufacturer through the input unit 17 and modify. Then, the power supply microprocessor 11 can determine the coil distance between the power supply coil 16 and the power receiving coil 26, to calculate the maximum resonance voltage corresponding to the coil distance according to the maximum resonance voltages VMAX2 and VMAX3, and to calculate according to the minimum resonance voltages VMIN2 and VMIN3 The minimum resonance voltage corresponding to the distance of the coil. As shown in FIG. 3, the power supply microprocessor 11 can obtain the coil resonance frequency of FLCX to determine the distance between the power supply coil 16 and the power receiving coil 26 as X, and the coil distance X is between the farthest working distance and the closest working distance ( When X leaves the above range, the power supply is stopped). Below the distance X, the maximum resonance voltage VMAX of the power supply coil 16 can be calculated as follows:

The minimum resonance voltage VMIN of the power supply coil 16 can be calculated as follows:

In other words, the maximum resonant voltage VMAX and the minimum resonant voltage VMIN have a linear relationship with the coil distance, so their values can be calculated in a proportional manner. That is, the four end points of the upper and lower limits of the resonance voltage can be defined on the boundary of the maximum and minimum working distance of the inductive power supply 100, that is, at any coil distance within the working distance range, according to these four ends Point to calculate the working voltage range corresponding to the coil distance.

In this case, the power supply microprocessor 11 can set the resonance voltage according to the maximum resonance voltage VMAX and the minimum resonance voltage VMIN, that is, set the output power. In one embodiment, the power supply microprocessor 11 can adjust the resonance voltage according to the information from the power receiving end, that is, after the power receiving module 2 receives the energy from the power supply module 1, it can measure the energy and Converted to data, and then transmitted to the power supply module 1 through data modulation technology, so that the power supply module 1 can be adjusted according to the content of the modulated data, and the above-mentioned maximum resonance voltage VMAX and minimum resonance voltage VMIN can be used as the upper limit of the resonance voltage adjustment and The lower limit value to avoid the problem that the output terminal is too large to cause the power receiving terminal to burn out or the output power is too small, which prevents the power receiving terminal from operating normally. As shown in FIG. 3, if the coil is far away, the power supply module 1 needs a higher output power, so the power supply microprocessor 11 can control the voltage of the power supply coil 16 to a higher maximum resonance voltage VMAX and minimum resonance Between the voltage VMIN; if the coil distance is close, the power supply module 1 does not need too high output power, so the power supply microprocessor 11 can control the voltage of the power supply coil 16 at a lower maximum resonance voltage VMAX and minimum resonance voltage Between VMIN.

In addition, the above-mentioned maximum resonance voltage VMAX and minimum resonance voltage VMIN have another meaning. When the power supply coil 16 outputs at the maximum resonance voltage VMAX, the output power reaches the maximum value within the operating range, and the input current at the power supply terminal also reaches the maximum value at this time. Therefore, the maximum resonance voltage VMAX is the output resonance voltage of the power supply module 1 when the power receiving end of the inductive power supply 100 is fully loaded to provide full load power to the power receiving end. Conversely, when the power supply coil 16 outputs at the minimum resonance voltage VMIN, the output power is the minimum value within the operating range, and the input current at the power supply terminal is also the minimum value at this time. Therefore, the minimum resonance voltage VMIN is the output resonance voltage of the power supply module 1 when the power receiving end of the inductive power supply 100 is idling. Under no-load, the power supply coil 16 does not need to output power to the load, and its current consumption is close to 0, and the input current of the power supply terminal is mostly used to power the internal circuit of the microprocessor 11, and the required current is much less than the general load. The current required by the power supply coil 16 can therefore be regarded as the input current of the power supply module 1 approaching zero under no load. Between the maximum resonance voltage VMAX and the minimum resonance voltage VMIN is the working voltage range of the power supply coil 16 below the coil distance X, as shown in FIG. 3.

As described in the foregoing FIGS. 2A to 2C, there are many different distance correspondences between the power supply coil 16 and the power receiving coil 26, and the power supply module 1 can determine the coil distance according to the self-resonant frequency of the power supply coil 16. However, in some cases, the power supply module 1 may not be able to correctly determine the coil distance, for example, the coil is offset. As shown in FIG. 2D, the power supply coil 16 and the power receiving coil 26 may be shifted or misaligned in the horizontal direction. In this case, the distance between the centers of the two coils is far, making the efficiency of receiving power at the power receiving end worse. At this time, The power receiving module 2 transmits modulation data to instruct the power supply module 1 to increase the output power so that the power receiving end can receive appropriate energy. However, since the magnetic conductors 161 and 261 tend to have a larger area than the coil, the resonance frequency of the power supply coil 16 is still affected by the magnetic conductor behind the power receiving coil 26 when the coil is offset in the horizontal direction but not far away The impact of 261. Therefore, according to the calculation of the resonance frequency, it is determined that the coil distance is short. In this case, the power supply module 1 easily underestimates the distance between the power supply coil 16 and the power receiving coil 26, and then calculates the underestimated maximum resonance voltage VMAX and minimum resonance voltage VMIN.

Please refer to FIG. 4, which is a schematic diagram of the coil operating voltage and the corresponding input current according to an embodiment of the present invention. Figure 4 shows the same operating voltage range as Figure 3 for ease of explanation. As described above, the maximum resonance voltage VMAX and the minimum resonance voltage VMIN correspond to the input currents of the power supply terminal under full load and no load when the coil distance is Y, respectively. Therefore, the power supply microprocessor 11 can estimate the position where the input current is one-half the full-load current, which is approximately at the midpoint between the maximum resonance voltage VMAX and the minimum resonance voltage VMIN, forming a broken line in FIG. 4. Therefore, in the case where the coil distance is Y and the input current is half the full-load current, the coil resonance voltage should fall at the position of V1.

As described above, when the power supply coil 16 and the power receiving coil 26 are horizontally shifted (as in the case of FIG. 2D), the power supply module 1 easily underestimates the distance between the power supply coil 16 and the power receiving coil 26, if the actual coil distance is Y , The coil distance calculated by the power supply module 1 is Z. In this case, the actual output resonance voltage of the power supply module 1 is V2 (equal to V1), which is higher than the resonance expected by the power supply module 1 when the input current is equal to half the full-load current and the coil distance is judged to be Z Voltage V3. In other words, based on the estimated resonant voltage value and its corresponding current, when the actual resonant voltage is too large, the power supply microprocessor 11 of the power supply module 1 can determine that the coil induction efficiency is poor, and then determine that the coil is too large. Offset.

所得到的諧振電壓V1為線圈未發生偏移的情況下供電線圈16應輸出的電壓。進一步地，根據最大諧振電壓VMAX、最小諧振電壓VMIN及輸入電流I1，供電微處理器11可計算臨界諧振電壓VT如下：

In this case, the power supply microprocessor 11 can determine whether there is an offset between the power supply coil 16 and the power receiving coil 26 according to the maximum resonance voltage VMAX and the minimum resonance voltage VMIN and the input current of the power supply coil 16, that is, the power supply module 1 Is there any deviation between the power receiving module 2 and the deviation is too large? Please refer to FIG. 5, which is a schematic diagram of judging the coil offset according to the coil resonance voltage and the input current according to an embodiment of the present invention. Assuming that the distance between the power supply coil 16 and the power receiving coil 26 is W, which corresponds to the maximum resonance voltage VMAX and the minimum resonance voltage VMIN, where the input current when the power supply terminal outputs the maximum resonance voltage VMAX is IMAX (that is, full load current), and the power supply terminal outputs The input current at the minimum resonance voltage VMIN is 0 (only the current required by the processing circuit is included, which is ignored here). In Figure 5, line segment L1 is the coil resonance voltage corresponding to the current input current I1 at the power supply end; line segment L2 is the critical resonance voltage VT corresponding to the current value after the current input current I1 plus a critical current IT. According to the ratio of input current I1 and full load current IMAX, the resonant voltage V1 can be calculated as:

The obtained resonance voltage V1 is the voltage that the power supply coil 16 should output when the coil is not shifted. Further, based on the maximum resonance voltage VMAX, the minimum resonance voltage VMIN and the input current I1, the power supply microprocessor 11 can calculate the critical resonance voltage VT as follows:

It can be seen from the above that the coil offset may cause the power supply end to judge that the resonance voltage of the coil abnormally rises. Therefore, when the power supply microprocessor 11 determines that the current resonance voltage of the power supply coil 16 is greater than the critical resonance voltage VT, it can be determined that the coil is too biased Move, you can further perform follow-up operations. In an embodiment, the power supply microprocessor 11 can control the power supply module 1 to stop outputting power when it is judged that there is an excessive deviation between the power supply coil 16 and the power receiving coil 26, or to avoid misjudgment caused by noise interference, the power supply mode Group 1 can stop outputting power when it is judged that the coil deviation is too large for several consecutive times. In an embodiment, the power supply module 1 may also perform other protection actions and/or issue warning signals (such as through a display, a light, or a buzzer, etc.) when the coil deviation is too large.

It is worth noting that the purpose of the present invention is to provide a method that can detect the distance between the power receiving module and the power supply module and set the upper and lower limits of the resonance voltage of the power supply coil, and then determine the power supply module according to the magnitude of the coil voltage and current Whether there is a deviation from the power receiving module. Those with ordinary knowledge in the art may modify or change accordingly, but not limited to this. For example, in the above embodiment, the power supply microprocessor 11 can determine the coil offset status by detecting the input current of the power supply module 1, which can be coupled to the power supply 10 and the power supply module 1. Current detector 18 to detect, as the first The picture shows. Since the current required to power the microprocessor 11 is extremely small, the current input to the power supply module 1 is approximately equal to the current consumed by the power supply coil 16 during operation. In other embodiments, in order to detect the current of the power supply coil 16 more accurately, the current detector may also be disposed on other current paths passing through the power supply coil 16, such as the front end of the clock generator 112. As long as the inductive power supply 100 has a module, device or function that can detect the coil current, its setting or operating method should not be a limitation of the present invention. In addition, in the embodiment of the present invention, determining the distance and offset between the power supply terminal and the power receiving terminal is one of the main technical features, where the power supply terminal may represent a power supply coil or a power supply module, and the power receiving terminal may represent a power receiving coil or a power receiving module . That is, the distance/offset determined by the present invention may be the distance/offset between the power supply module and the power receiving module, the distance/offset between the power supply coil and the power receiving coil, the distance/offset between the power supply coil and the power receiving module, Or the distance/offset between the power supply module and the power receiving coil. The above names are used interchangeably in this specification and can be replaced with each other. The above distances can correspond to the maximum resonance voltage and the minimum resonance voltage, which are used as the basis for setting the output power and determining the offset, and the above offsets can be used to determine whether The basis for stopping power output.

The above method for the power supply module to detect the power receiving module and determine the coil offset can be summarized as a detection process 60, as shown in FIG. 6. The detection process 60 can be used for the power supply end of an inductive power supply, such as the power supply module 1 in FIG. 1, which includes the following steps:

Step 600: Start.

Step 602: Detect one of the resonance frequencies of the power supply coil 16.

Step 604: Determine the coil distance between the power receiving module 2 and the power supply module 1 according to the resonance frequency.

Step 606: Obtain a maximum resonance voltage VMAX and a minimum resonance voltage VMIN corresponding to the coil distance.

Step 608: According to the maximum resonance voltage VMAX and the minimum resonance voltage VMIN and the supply One of the electric coils 16 inputs current to determine whether there is an offset between the power supply module 1 and the power receiving module 2.

Step 610: End.

For the detailed operation mode and changes of the detection process 60, please refer to the descriptions in the above paragraphs, which will not be repeated here.

In summary, the present invention provides a detection method that can detect the distance between the power receiving module and the power supply module, and set the upper and lower limits of the resonant voltage of the power supply coil according to the size of the coil voltage and the input current Determine whether there is an offset between the power supply module and the power receiving module. The power supply microprocessor can obtain the longest working distance and the shortest working distance according to the self-resonant frequency of the power supply coil, and obtain the maximum/minimum resonance voltage corresponding to the longest working distance and the shortest working distance, respectively, the maximum/minimum resonance voltage obtained The upper and lower limits of the resonance voltage at different coil distances can be obtained by calculation. Then, the offset judgment can be performed based on the resonance voltage of the coil under a certain distance and the input current of the power supply coil, that is, the power supply microprocessor can calculate a critical resonance voltage according to the input current and determine whether the current resonance voltage is Exceed the critical resonance voltage, and then determine whether the coil deviation or excessive deviation occurs. When the coil deviation is too large, it will cause the power supply terminal to fail to accurately determine the upper and lower limits of the resonance voltage. At this time, the power supply module can stop outputting power to avoid danger. The above are only the preferred embodiments of the present invention, and all changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

60‧‧‧Detection process

600~610‧‧‧Step

Claims (10)

A method for detecting a power receiving module, used for a power supply module of an inductive power supply, the power supply module includes a power supply coil, the method includes: detecting a resonance frequency of the power supply coil; according to the resonance Frequency, determine the distance between a coil of the power receiving module and the power supply module; obtain a maximum resonance voltage and a minimum resonance voltage corresponding to the coil distance; and according to the maximum resonance voltage and the minimum resonance voltage and the power supply coil An input current determines whether there is an offset between the power supply module and the power receiving module. The method according to claim 1, wherein the step of determining whether there is an offset between the power supply module and the power receiving module based on the maximum resonance voltage and the minimum resonance voltage and the input current of the power supply coil includes: Obtain one of the current resonance voltage of the power supply coil; calculate a critical resonance voltage based on the maximum resonance voltage and the minimum resonance voltage and the input current of the power supply coil; and determine when the current resonance voltage is greater than the critical resonance voltage There is an excessive offset between the power supply module and the power receiving module. The method of claim 1, wherein the step of obtaining the maximum resonant voltage and the minimum resonant voltage corresponding to the distance of the coil comprises: obtaining a maximum distance and a distance within an operating range of the inductive power supply The closest distance; setting a first maximum resonance voltage and a first minimum resonance voltage corresponding to the farthest distance, and setting a second maximum resonance voltage and a second minimum resonance voltage corresponding to the closest distance; and Calculate the maximum resonance voltage corresponding to the coil distance based on the first maximum resonance voltage and the second maximum resonance voltage, and calculate the distance corresponding to the coil distance based on the first minimum resonance voltage and the second minimum resonance voltage The minimum resonance voltage. The method according to claim 1, wherein the maximum resonance voltage is the output voltage of the power supply module when the inductive power supply is fully loaded, and the minimum resonance voltage is the power supply module when the inductive power supply is empty The output voltage. The method according to claim 1, wherein when it is determined that there is an excessive deviation between the power supply module and the power receiving module, the power supply module stops outputting power. A power supply module for an inductive power supply. The power supply module includes: a power supply coil; a current detector for detecting an input current of the power supply coil; and a power supply microprocessor, coupled Connected to the power supply coil to perform the following steps: detect a resonance frequency of the power supply coil; determine the coil distance between the power receiving module and the power supply module according to the resonance frequency; obtain one corresponding to the coil distance A maximum resonance voltage and a minimum resonance voltage; and according to the maximum resonance voltage and the minimum resonance voltage and the input current, determine whether there is an offset between the power supply module and the power receiving module. The power supply module according to claim 6, wherein the power supply microprocessor further performs the following steps to determine between the power supply module and the power receiving module based on the maximum resonance voltage and the minimum resonance voltage and the input current Is there an offset: Obtain one of the current resonance voltages of the power supply coil; calculate a critical resonance voltage based on the maximum resonance voltage and the minimum resonance voltage and the input current; and determine the power supply module when determining that the current resonance voltage is greater than the critical resonance voltage There is an excessive deviation from the power receiving module. The power supply module according to claim 6, wherein the power supply microprocessor further performs the following steps to obtain the maximum resonant voltage and the minimum resonant voltage corresponding to the coil distance: obtaining one of the operations of the inductive power supply One of the longest distance and the shortest distance within the range; set a first maximum resonance voltage and a first minimum resonance voltage corresponding to the longest distance, and set a second maximum resonance voltage and a corresponding to the closest distance A second minimum resonance voltage; and based on the first maximum resonance voltage and the second maximum resonance voltage, calculating the maximum resonance voltage corresponding to the coil distance, and based on the first minimum resonance voltage and the second minimum resonance voltage, Calculate the minimum resonance voltage corresponding to the coil distance. The power supply module according to claim 6, wherein the maximum resonance voltage is the output voltage of the power supply module when the inductive power supply is fully loaded, and the minimum resonance voltage is the power supply mode when the inductive power supply is empty The output voltage of the group. The power supply module according to claim 6, wherein when it is determined that there is an excessive deviation between the power supply module and the power receiving module, the power supply module stops outputting power.

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