JP5962550B2 - Power receiving device - Google Patents

Description

  The present invention relates to a power receiving device used for electric field coupling type non-contact power feeding.

  2. Description of the Related Art Conventionally, an electric field coupling type non-contact power feeding system that feeds power between a power transmitting electrode and a power receiving electrode arranged in an electrically non-contact state is known. In this type of system, a power transmission electrode connected to one pole of an AC power source provided in the power transmission apparatus is a first power transmission electrode, and a power transmission electrode connected to the other pole is a second power transmission electrode. A plurality of power receiving electrodes are provided, and the power receiving electrodes facing the first power transmitting electrode (first power receiving electrode group) and the power receiving electrodes facing the second power transmitting electrode (second power receiving electrode group) are connected. Then, the output obtained from the first power receiving electrode group and the second power receiving electrode group is rectified to generate a DC power source, and the load of the power receiving side device is driven.

  By the way, in order to efficiently supply power from the power transmission device to the power reception device, the connection state of the power reception electrodes constituting the first power reception electrode group and the second power reception electrode group according to the positional relationship between the power transmission electrode and the power reception electrode. Must be switched appropriately.

  As one of the methods, in the power transmission device, either the first power transmission electrode or the second power transmission electrode is formed of a ferromagnetic material, and the other is formed of a non-magnetic material. What is provided with a switch for switching which component of the first receiving electrode group or the second receiving electrode group the receiving electrode is based on the magnetic force acting between the transmitting electrode facing the receiving electrode and the permanent magnet. It is known (see, for example, Patent Document 1).

JP 2010-148287 A

  However, in the above-described conventional device, in order to determine whether each power receiving electrode is opposed to the first power transmitting electrode or the second power transmitting electrode, the material of the power transmitting electrode is limited or the power receiving electrode is mechanically operated. There is a problem that it is necessary to install new parts.

  In particular, the power receiving device needs to be directly attached to the power receiving electrode with a permanent magnet serving as a sensor and a magnetic switch operated by the magnetic force of the permanent magnet. There was a problem that it was difficult to reduce the size.

  Furthermore, since the power transmission characteristics between the power transmission electrode and the power reception electrode do not necessarily match the sensor detection characteristics (and thus the switch operation characteristics), the power transmission apparatus and the power reception apparatus are in a positional relationship that allows power transmission. Nevertheless, the problem is that power cannot be transmitted because the switch does not operate, or efficient power transmission cannot be performed because the receiving electrodes are not properly grouped. was there.

  In order to solve the above-described problems, an object of the present invention is to provide a power receiving device that realizes efficient power reception with a simple configuration.

The power receiving device of the present invention includes a power receiving electrode unit, a switch unit, a power supply unit, a polarity determination unit, and a switch control unit.
The power receiving electrode portion is composed of a plurality of power receiving electrodes. The switch unit individually connects each of the power receiving electrodes to the first output terminal or the second output terminal. A power supply part produces | generates the power supply output supplied to load based on the received power output which is the output obtained from the 1st output terminal and the 2nd output terminal. The polarity determination unit determines the polarity of the power transmission electrode disposed opposite to the power reception electrode for each power reception electrode according to a determination signal generated from the potential of the power reception electrode. The switch control unit controls the switch unit to connect the power receiving electrodes having the same polarity of the power transmitting electrodes arranged opposite to each other to the same output terminal according to the determination result in the polarity determining unit.

  According to the power receiving device of the present invention configured as described above, the determination signal generated from the potential of the power receiving electrode is used to determine the polarity of the power transmitting electrode arranged opposite to the power receiving electrode. There is no need to provide a sensor, a mechanical switch, or the like, which can be realized with a simple configuration, and the apparatus can be downsized. Further, according to the present invention, switching of the switch is performed according to the actual power reception state, so that the switch unit can be set to a state where efficient power reception is possible.

Here, as shown in FIG. 21, the power receiving electrode n is opposed to two power transmitting electrodes A and B having different polarities, the power transmitting electrodes A and B are connected to an appropriate power source, and the power receiving electrode n is connected to any other power source. Consider a state in which no objects are connected and no current flows. In this case, the potential of the power receiving electrode is Vn, the potentials of the power transmitting electrodes A and B are V _A and V _B , and the capacitance between the power receiving electrode n and the power transmitting electrodes A and B is C _An , C _Bn , and the power receiving electrode n. a transmission electrode a, the charge Q _an accumulated between the B, and the the Q _Bn, from the relationship of the charge stored in the potential difference between the power receiving electrode n between the electrodes (1) to (3) is established.

  Differentiating equation (1) yields equation (4), and substituting the result of differentiating equation (3) for the result of differentiating equation (2) yields equation (5).

  (4) Equation (6) is obtained from Equation (5), and Equation (7) is obtained from Equations (1) to (3).

That is, from the equation (6), when it can be considered that V _A = −V _B , the sign of the differential value (potential change rate) of the power receiving electrode n is the potential change rate of the power transmitting electrode that is more strongly coupled. From the equation (7), when it can be considered that V _A = −V _B and Q _An = −Q _Bn , the sign of the potential Vn of the receiving electrode n is more strongly coupled. It can be seen that it matches the sign of the potential of the power transmission electrode. Therefore, it is possible to determine which power transmission electrode A, B is more coupled by using a determination signal (potential change rate or potential itself) generated from the potential Vn of the power receiving electrode n.

  In addition to the power receiving device described above, the present invention is realized in a form in which a load driven by received power is incorporated in the power receiving device described above, or in a form of a non-contact power feeding system including the power receiving device as a component. Also good.

It is a whole lineblock diagram of a non-contact electric supply system. It is explanatory drawing which shows the installation state of a non-contact electric power feeding system, arrangement | positioning of an electrode, etc. It is an external view of a power receiving apparatus, (a) is a front view, (b) is a side view, and (c) is a rear view. (A) is a block diagram showing a configuration of a switch unit in the first embodiment, (b) is a circuit diagram showing a configuration of a unit switch shown in (a). It is a block diagram which shows the structure of the setting switching part in 1st Embodiment. (A) is a circuit diagram showing the configuration of the control block shown in FIG. 5, (b) is a truth table showing the operation of the switch control unit (relationship between input signal and output signal). It is a block diagram which shows the structure of the update instruction | indication part in 1st Embodiment. It is a flowchart which shows operation | movement of the state maintenance signal generator in 1st Embodiment. It is a wave form diagram which illustrates the relation between a state maintenance signal, a power reception output, and a power reception signal. It is explanatory drawing which shows the relationship between the positional relationship of a power transmission electrode part and a receiving electrode part, and the signal waveform of each part. (A) is a block diagram which shows the structure of the connection part in 2nd Embodiment, (b) is a wave form diagram which shows the state maintenance signal produced | generated by the update instruction | indication part. It is a block diagram which shows the structure of the connection part in 3rd Embodiment. It is a block diagram which shows the structure of the switch part in 3rd Embodiment. It is a block diagram which shows the structure of the setting switching part in 3rd Embodiment. (A) is a circuit diagram showing the configuration of the control block, mask block, and mask control unit shown in FIG. 14, and (b) is a truth table showing the operation of the setting switching unit (relationship between input signal and output signal). . It is a block diagram which shows the structure of the update instruction | indication part in 3rd Embodiment. It is a flowchart which shows operation | movement of the state maintenance signal generator in 3rd Embodiment. It is a wave form diagram which illustrates the relation between a state maintenance signal and a shutter signal, and a power reception output and a power reception signal. It is a block diagram which shows the structure of the connection part in 4th Embodiment. FIG. 20 is a waveform diagram showing a state maintenance signal and a shutter signal generated by the update instruction unit shown in FIG. 19. It is a schematic diagram which shows the state in which the receiving electrode is facing 2 power transmission electrodes from which polarity differs.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
<Overall configuration>
A contactless power supply system 1 to which the present invention is applied includes a power transmission device 2 and a power reception device 3 as shown in FIGS. 1 and 2. The power transmission device 2 is installed inside the bumper of the vehicle, and the power reception device 3 is used by being attached to the surface of the bumper. The power transmission device 2 receives power from the power transmission device 2 in a non-contact manner and drives a predetermined load (here, an imaging device). To do.

<Power transmission device>
The power transmission device 2 is set so as to resonate at a frequency of the DC power (for example, onboard battery) 21, the inverter 22 that converts DC power supplied from the DC power supply 21 into AC power, and the AC power output by the inverter 22. And a power transmission electrode unit 24 to which AC power is applied. Since the DC power source 21, the inverter 22, and the resonance unit 23 are well known, description thereof is omitted here.

  The power transmission electrode portion 24 is composed of a plurality of power transmission electrodes SDj (j = 1, 2) formed in a rectangular shape, and is formed in a sheet shape by regularly arranging the power transmission electrodes SDj vertically and horizontally (in FIG. 2). (Refer to the enlarged view of the part surrounded by the dashed line.) The power transmission electrode SDj connected to one pole of AC power is referred to as the first power transmission electrode SD1 and the electrode connected to the other pole is referred to as the second power transmission electrode SD2. The first power transmission electrode SD1 and the second power transmission electrode SD2 are alternately arranged in the longitudinal direction (left and right direction in the figure) of the sheet, and the same kind of power transmission is performed in the short direction (up and down direction in the figure) of the sheet. An electrode SDj is disposed.

  The power transmission electrode portion 24 formed in a sheet shape covers the entire front end portion of the bumper from the inside of the bumper as shown by a dotted line in FIG. 2, and the longitudinal direction of the seat coincides with the vehicle width direction, The seat is arranged so that the lateral direction of the seat coincides with the vehicle height direction.

<Power receiving device>
As shown in FIG. 1, the power receiving device 3 includes a power receiving electrode unit 31 that is disposed to face the power transmitting electrode unit 24 and receives power supply by electric field coupling, a connection unit 32 that extracts a power reception output V from the power receiving electrode unit 31, and a connection unit 32. A rectifying unit 34 that rectifies and smoothes the received power output V extracted by the above and converts it to DC power, a resonance circuit that efficiently supplies the received power output V to the rectifying unit 34, and a resonance that includes an impedance matching circuit. / A matching unit 33 and a load (imaging device) 35 driven by the DC power converted by the rectifying unit 34 are provided. Since the resonance / matching unit 33, the rectifying unit 34, and the load 35 are well known, the description thereof is omitted here.

  As shown in FIG. 3, the power receiving device 3 includes a cylindrical portion 3a and a hemispherical portion 3b formed so as to cover one end of the cylindrical portion 3a. In the cylindrical portion 3a, a power receiving electrode portion 31 is installed on a circular end surface (hereinafter referred to as “mounting surface”) 3d which is an end portion on the opposite side to the end where the hemispherical portion 3b is formed. A translucent window 3c that allows light to pass is provided at the tip of the hemispherical portion 3b, and an imaging element that is a load 35 and that constitutes the imaging apparatus is arranged to receive external light through the translucent window 3c. ing. On the peripheral surface of the cylindrical portion 3a, a protrusion 3e and a protrusion 3f representing the arrangement direction of the power receiving electrodes RDi are provided so as to protrude in directions orthogonal to each other when viewed from the central axis of the cylindrical portion 3a. Yes.

<< Receiving electrode >>
As shown in FIG. 1 to FIG. 3, the power receiving electrode portion 31 includes n (n = 9 in the figure) power receiving electrodes RDi (i = 1, 2,... N) formed in a square shape. RDi is regularly arranged vertically and horizontally on the mounting surface 3d.

  Note that the power receiving electrode RDi and the power transmitting electrode SDj have a size satisfying the condition shown in the equation (8), for example, Wr = About 2/3 Ws).

Ws <Wr <2Ws (8)
The power receiving electrodes RDi are arranged such that the vertical and horizontal arrangement directions coincide with the protruding directions of the protrusions 3e and 3f.

  That is, by attaching the power receiving device 3 so that the mounting surface 3d is in contact with the bumper surface of the vehicle, the power receiving electrode portion 31 and the power transmitting electrode portion 24 are arranged to face each other. At this time, by positioning so that one of the protrusion 3e and the protrusion 3f faces the vehicle width direction and the other faces the vehicle height direction, the direction of the side of the power reception electrode RDi is changed to the power transmission electrode as shown in FIG. The direction of the side of SDj can be matched.

<< Connection part >>
As shown in FIG. 1, the connection unit 32 includes a switch unit 321 that individually connects each of the power reception electrodes RDi to the first output terminal T1 or the second output terminal T2, and a power reception signal supplied from the power reception electrode RDi. The setting switching unit 322 for switching the setting of the switch unit 321 according to the state of Ei and the amplitude A of the power reception output V output from the output terminals T1 and T2 are monitored, and the setting state of the switch unit 321 is set to the setting switching unit 322. An update instruction unit 323 that outputs a state maintenance signal KP that instructs maintenance or update, and a standby power source 324 that supplies power to the setting switching unit 322 and the update instruction unit 323 are provided.

The standby power source 324 is composed of a secondary battery or a capacitor, and although not shown in the figure, the standby power source 324 is configured to be charged by the output when there is an output from the rectifying unit 34.
As shown in FIG. 4A, the switch unit 321 sends the power reception electrode RDi (power reception signal Ei) to the output terminal T1 (output LA) or the output terminal T2 in accordance with the control signals Si1 and Si2 supplied from the setting switching unit 322. It is composed of n unit switches SW1 to SWn connected to any one of (output LB). Note that the unit switches SW1 to SWn all have the same configuration, and therefore are also referred to as a unit switch 40 unless otherwise distinguished.

  As shown in FIG. 4B, the unit switch 40 (SWi) includes an analog switch 41 that conducts and cuts off the power receiving electrode RDi and the output terminal T1 according to the control signal Si1, and a power receiving electrode RDi and the output terminal according to the control signal Si2. It comprises an analog switch 42 that conducts and shuts off T2. Each of the analog switches 41 and 42 includes two insulated gate bipolar transistors (IGBTs) and two diodes, and is turned on (conductive) when the control signals Si1 and Si2 are at a high level. It is a well-known device configured to be turned off (blocked) at a low level.

  Hereinafter, the power receiving electrode RDi connected to the output terminal T1 via the unit switch 40 is also referred to as a first power receiving electrode group, and the power receiving electrode RDi connected to the output terminal T2 is also referred to as a second power receiving electrode group. Further, the output of the output terminal T1, that is, the combined output of the power receiving electrodes RDi constituting the first power receiving electrode group is represented by an output LA, and the output of the output terminal T2, ie, the power receiving electrode RDi constituting the second power receiving electrode group. The combined output is represented by output LB.

  As shown in FIG. 5, the setting switching unit 322 generates n control signals Si1 and Si2 according to the power reception signal Ei supplied from the power reception electrode RDi and the state maintenance signal KP supplied from the update instruction unit 323. It is configured by control blocks CB1 to CBn. Note that since the control blocks CB1 to CBn all have the same configuration, they are also expressed as a control block 50 unless otherwise distinguished.

  As shown in FIG. 6A, the control block 50 (CBi) uses a differentiation circuit for differentiating the received signal Ei, and a signal output from the differentiation circuit (here, -dEi / dt) as a determination signal. The polarity determination unit 51 including a comparison circuit that outputs a determination value Hi that is low level when the sign of the signal is positive and high when the sign is negative, and the control signals Si1 and Si2 according to the state maintaining signal KP and the determination value Hi. And a switch control unit 52 for determining the signal level of Si2. Note that the differential value of the power reception signal Ei appearing at the power reception electrode RDi, that is, the potential change rate, changes in opposite polarities depending on whether it is facing the first power transmission electrode SD1 or the second power transmission electrode SD2. Therefore, by examining the sign of the differential value of the power reception signal Ei, the polarity of the power transmission electrode SDj facing the power reception electrode RDi can be specified.

  The switch control unit 52 is configured by combining logic circuits so as to operate according to the truth table shown in FIG. Specifically, when the state maintaining signal KP is switched from the high level to the low level, the control signals Si1 and Si2 after the switching are both at the low level regardless of the control signals Si1 and Si2 and the determination value Hi before the switching.

  On the other hand, when the state maintaining signal KP is switched from the low level to the high level, when the control signals Si1 and Si2 before switching are both low level, according to the determination value Hi (the potential change rate dEi / dt of the power reception signal Ei), If the determination value Hi is high level (dEi / dt> 0), the control signal Si1 after switching is high level, the control signal Si2 is low level, and if the determination value Hi is low level (dEi / dt <0). Then, the control signal Si1 after switching becomes low level and the control signal Si2 becomes high level. Further, when at least one of the control signals Si1 and Si2 before switching is at a high level (that is, except when both are at a low level), the control signals Si1 and Si2 after switching are switched regardless of the determination value Hi. The signal level is the same as before. The signal levels of the control signals Si1 and Si2 after switching are maintained while the state maintaining signal KP is at a high level, that is, until both the control signals Si1 and Si2 are switched to a low level.

  As shown in FIG. 7, the update instruction unit 323 receives the power reception output V (= LA−LB = Asin θ) that appears between the terminals of the output terminals T1 and T2 based on the output LA of the output terminal T1 and the output LB of the output terminal T2. The amplitude extractor 61 for extracting the amplitude A of the power, the phase extractor 62 for extracting the phase θ of the received power output V based on the received power output V, and the memory for storing the amplitude A of the received power output V as the switched amplitude Ahold. A state in which the state maintaining signal KP is generated based on the amplitude 63 extracted by the detector 63, the amplitude extractor 61, the phase θ extracted by the phase extractor 62, and the switched amplitude Ahold stored in the amplitude saver 63 A maintenance signal generator 64 is provided. The amplitude extractor 61, the phase extractor 62, and the amplitude preserving unit 63 are well known and will not be described.

  Here, the operation of the state maintaining signal generator 64 will be described with reference to the flowchart of FIG. The state maintaining signal generator 64 first acquires the amplitude A of the power reception output V from the amplitude extractor 61 (S110), and determines whether or not the amplitude A is equal to or greater than a preset amplitude lower limit value Amin ( S120). The amplitude lower limit value Amin is set to a value obtained by adding a certain margin to a minimum level at which, for example, power necessary for driving the load 35 can be secured.

  If the amplitude A is greater than or equal to the lower limit value Amin, a deviation ΔA (= | A−Ahold |) of the amplitude A with respect to the post-switching amplitude Ahold stored in the amplitude storage 63 is calculated (S130), and the deviation ΔA is calculated in advance. It is determined whether or not the deviation upper limit value ΔAmax is less than or equal to the set upper limit value ΔAmax (S140). If the deviation ΔA is equal to or less than the deviation upper limit value ΔAmax, it is assumed that there is no need to reset the switch unit 321 and the process described below is skipped and the process returns to S110.

  When it is determined in the previous S120 that the amplitude A is smaller than the amplitude lower limit value Amin, or in the previous S140, when it is determined that the deviation ΔA is larger than the deviation upper limit value ΔAmax, the phase extracted by the phase extractor 62 Wait until θ reaches a desired phase at which the maximum value of the absolute value | dV / dt | of the potential change rate (differential value) of the power reception output V is obtained (S150). Specifically, when the power reception output is represented by V = Asin θ, it is determined that θ = 0 [rad] or θ = π [rad] is the desired phase. That is, the determination is made in the vicinity where the difference in the differential value dEi / dt of the power reception signal Ei between the power reception electrode RDi facing the first power transmission electrode SD1 and the power reception electrode RDi facing the second power transmission electrode SD2 is maximized. The vicinity mentioned here is a predetermined angle range, and may be set to a maximum point ± π / 6 [rad], for example.

If it is determined in S150 that the desired phase has been reached, the following processing (S160 to S210) is executed in order to switch the setting of the switch unit 321.
First, the state maintaining signal KP is set to a low level (KP ← L) (S160), and in this state, a certain time is waited (S170). Thereby, all the control signals Sij output from the setting switching unit 322 are changed to the low level. As a result, all the power receiving electrodes RD1 to RDn are disconnected from any of the output terminals T1 and T2 by the switch unit 321. However, the standby time in S170 is a sufficiently short time (for example, several tens of cycles of the power reception output V so that the potential change rate dEi / dt of the power reception signal Ei does not change greatly during the standby time. 1).

  Next, the state maintaining signal KP is set to a high level (KP ← H) (S180). As a result, the control signals Si1 and Si2 output from the setting switching unit 322 are one of the high level according to the polarity of the potential change rate dEi / dt of the power reception signal Ei at that time (and the signal level of the determination value Hi), and the other is The low level is set, and the setting is held while the state maintaining signal KP is at the high level. As a result, each of the power receiving electrodes RD1 to RDn is connected to any one of the output terminals T1 and T2 by the switch unit 321.

  In this state, after waiting for a predetermined time (S190), the amplitude A of the power reception output V is acquired from the amplitude extractor 61 (S200), and the post-switching amplitude Ahold stored in the amplitude storage 63 is stored by the acquired amplitude A. Is updated (Ahold ← A), and the process returns to S110. However, the standby time in S190 is set to a sufficiently long time (for example, about twice the cycle of the power reception output V) so that the waveform of the power reception output V is stabilized.

  The update instruction unit 323 that executes such processing may be realized by a combination of logic circuits, or may be realized by a microcomputer (that is, processing executed by a CPU constituting the microcomputer according to a program).

  In the connection section 32 configured as described above, as shown in FIG. 9, the power reception output V is obtained from the output terminals T1 and T2 when the state maintaining signal KP is ON (KP = H). Further, the amplitude A of the power reception output V is less than the amplitude lower limit value Amin, or the deviation ΔA exceeds the deviation upper limit value ΔAmax (that is, the value obtained by subtracting the deviation upper limit value ΔAmax from the switched amplitude Ahold (Ahold−ΔAmax)). The state maintenance signal KP is switched off (KP = L) (time t1). At this time, the state maintaining signal KP has a timing at which the absolute value | dV / dt | of the potential change rate of the power reception output V becomes maximum (the phase θ of the power reception output V is 0 [rad] or π [rad]), that is, Switching is made at a timing when the power reception output V crosses the reference level (amplitude center potential).

  While the state maintaining signal KP is off, the power receiving electrodes RD1 to RDn and the output terminals T1 and T2 are electrically disconnected, so the amplitude A of the power receiving output V is 0 and the output terminals T1 and T2 The supply of the power reception output V to the subsequent stage via the is stopped.

  After that, when a certain standby time has elapsed and the state maintaining signal KP changes to the on state (time t2), the state of the unit switches SW1 to SWn constituting the switch unit 321, that is, the first power receiving electrode group and the first receiving electrode group The grouping of the power receiving electrodes RDi constituting the two power receiving electrode groups is reset, and the supply of the power receiving output V to the subsequent stage via the output terminals T1 and T2 is resumed. When the sign of the differential value (potential change rate) of the power reception signal Ei is positive (determination value Hi = H) at time t2, the power reception electrode RDi is output as constituting the first power reception electrode group. Connected to the end T1. On the other hand, when the sign of the differential value of the power reception signal Ei is negative (determination value Hi = L), the power reception electrode RDi is connected to the output terminal T2 as constituting the second power reception electrode group.

  The graph shown in the lower part of FIG. 9 shows the power reception signal Ei detected by the power reception electrode RDi when the connection destination (output terminal T1 or T2) of the power reception electrode RDi is switched between time t1 and before time t2. The waveform is shown. That is, while the state maintaining signal KP is on, the waveform is a combination of all the power reception signals Ei obtained from the power reception electrodes RDi connected to the same output terminal. Thereby, before the time t1, that is, in a state where the setting of the switch unit 321 is inappropriate, the power reception signals Ei supplied from the power reception electrodes RDi connected to the same output terminal are not always in the same polarity. As a result, the received signals Ei having different polarities cancel each other, so that the amplitude A of the received power V becomes small. On the other hand, after time t2 when the switch unit 321 is appropriately reset, the power reception signals Ei supplied from the power reception electrodes RDi connected to the same output terminal all have the same polarity, so the amplitude of the power reception output V A is not suppressed. Further, while the state maintaining signal KP is off, each power receiving electrode RDi is disconnected from the output terminals T1 and T2, so that a single waveform for each power receiving signal Ei is obtained instead of a synthesized waveform. Based on this single waveform, particularly, here, the sign of the differential value of the power reception signal Ei is determined, and the setting of the unit switch SWi is switched according to the determination result.

<Operation example>
FIG. 10 is an explanatory diagram schematically showing waveforms obtained from each electrode when the number of power receiving electrodes RDi is five. FIG. 10A shows a state in which the state maintaining signal KP is off immediately after the power receiving device 3 is attached near the power transmitting device 2. In this state, each power receiving electrode RDi obtains a single power receiving signal E1 to E5. Here, the power receiving electrodes RD1 and RD2 are opposed to the power transmitting electrode SD1, the power receiving electrodes RD4 and RD5 are opposed to the power transmitting electrode SD2, and the power receiving electrode RD3 is opposed to the two power transmitting electrodes SD1 and SD2 by almost the same area. . For this reason, the sign of the differential value of the power reception signals E1 and E2 is opposite to the sign of the differential value of the power reception signals E4 and E5, and the differential value of the power reception signal E3 becomes zero.

  FIG. 10B shows a state after the state maintaining signal KP is switched on from the state of FIG. Here, the power receiving electrodes RD1 to RD3 are connected to the output terminal T1 to form a first power receiving electrode group, and the power receiving electrodes RD4 and RD5 are connected to the output terminal T2 to form a second power receiving electrode group. In this case, the power receiving electrode RD3 having a differential value of zero may be connected to either of the output terminals T1 and T2. As a result, a composite signal LA having the same polarity as the signal applied to the power transmission electrode SD1 is output from the output terminal T1, and a composite signal LB having the same polarity as the signal applied to the power transmission electrode SD2 is output from the output terminal T2. Will be.

  In FIG. 10C, the positional relationship between the power transmission electrode unit 24 and the power reception electrode unit 31 is changed while the setting of the switch unit 321 remains (b). Specifically, the power reception electrode unit 31 is entirely configured as the power transmission electrode. The state shifted to the SD2 side is shown. Here, the power reception electrode RD1 faces the power transmission electrode SD1, the power reception electrodes RD2 to RD4 face the power transmission electrode SD2, and the power reception electrode RD5 does not face any power transmission electrode SD1, SD2 (however, the power transmission electrode SD2 It is a state closer to. As a result, the power receiving electrodes RD1 to RD3 have a larger facing area with the power transmission electrode SD2 than the power transmission electrode SD1, so the combined signal LA output from the output terminal T1 is the same as the signal applied to the power transmission electrode SD2. It changes to a polar one. In addition, since the power receiving electrodes RD4 and RD5 have a small area facing the power transmission electrode SD2, the amplitude of the combined signal LB output from the output terminal T2 is reduced. As a result, the amplitude A of the power reception output V expressed by the difference between both signals LA and LB decreases.

  FIG. 10D shows a state in which the state maintaining signal KP is switched off while the positional relationship between the power transmission electrode unit 24 and the power reception electrode unit 31 remains (c). That is, the power receiving electrodes RD1 to RD5 are disconnected from the output terminals T1 and T2. As a result, the power reception electrode RD1 obtains the power reception signal E1 having the same polarity as the power transmission signal applied to the power transmission electrode SD1. In the power reception electrodes RD2 to RD5, power reception signals E2 to E5 having the same polarity as the power transmission signal applied to the power transmission electrode SD2 are obtained. Thereafter, when the state maintaining signal KP is switched on, the power receiving electrode RD1 is connected to the output terminal T1, the power receiving electrodes RD2 to RD5 are connected to the output terminal T2, and the connection state of the switch unit 321 is shown in (b). The state is switched to a state suitable for the current positional relationship between the power transmission electrode unit 24 and the power reception electrode unit 31.

<Effect>
As described above, the power receiving device 3 determines the sign of the differential value (potential change rate) dEi / dt of the power reception signal Ei in a state where the power reception electrode RDi is disconnected from the output terminals T1 and T2. According to the determination value Hi, the switch unit 321 is set so that the power receiving electrodes RDi having the same signal level of the determination value Hi are connected to the same output terminal T1 or T2.

  As described above, according to the power receiving device 3, the differential value dEi / dt of the power reception signal Ei obtained from the power reception electrode RDi is used to determine the polarities of the power transmission electrodes SD <b> 1 and SD <b> 2 that are arranged to face each other. Therefore, it is not necessary to provide a new sensor or a mechanical switch. For this reason, according to the power receiving device 3, it is possible to simplify the device configuration, and to downsize the device.

Moreover, in the power receiving device 3, since the setting of the switch unit 321 is performed according to the actual power receiving state at each power receiving electrode RDi, efficient power reception can be realized.
Further, in the power receiving device 3, when the amplitude A of the power receiving output V is smaller than the amplitude lower limit value Amin or the deviation ΔA with respect to the switched amplitude Ahold is larger than the deviation upper limit value ΔAmax, the switch unit 321 is reset. . Therefore, even if the positional relationship between the power transmitting electrode unit 24 and the power receiving electrode unit 31 changes during use and the setting of the switch unit 321 becomes inappropriate, the setting of the switch unit 321 is automatically set appropriately. Therefore, efficient power supply can be maintained regardless of a change in state.

[Second Embodiment]
A second embodiment will be described.
<Configuration>
In this embodiment, since it has the same configuration as that of the first embodiment except that the connection portion 32a is used instead of the connection portion 32, this difference will be mainly described.

  In the present embodiment, as shown in FIG. 11A, the connection unit 32a has a configuration other than the update instruction unit 325, that is, the switch unit 321, the setting switching unit 322, and the standby power source 324 are the same as those in the first embodiment. It is configured.

And the update instruction | indication part 325 repeatedly performs the process of S160-S180 shown to the flowchart of FIG. 8 for every fixed period.
That is, the signal level of the state maintaining signal KP generated by the update instructing unit 325 is first held at a low level for a certain waiting time Tw, as shown in FIG. It is held at the high level for a while, and the same is repeated thereafter.

<Effect>
According to this embodiment, even if the positional relationship between the power transmission electrode unit 24 and the power reception electrode unit 31 changes during use, the switch unit 321 is reset to an appropriate state at a constant cycle (Tw + Tcycl). The same effect as in the embodiment can be obtained. Further, according to the present embodiment, the device configuration (particularly, the update instruction unit 325) can be simplified.

[Third Embodiment]
A third embodiment will be described.
<Configuration>
In this embodiment, since it has the same configuration as that of the first embodiment except that the connection portion 36 is used instead of the connection portion 32, this difference will be mainly described.

  In the present embodiment, as shown in FIG. 12, the connection unit 36 includes a switch unit 361 that individually connects each of the power reception electrodes RDi to the first output terminal T1 or the second output terminal T2, and the power reception electrode RDi. A setting switching unit 362 for switching the setting of the switch unit 361 according to the state of the supplied power reception signal Ei, and the state A for monitoring the amplitude A of the power reception output V output from the output terminals T1 and T2 and controlling the setting switching unit 362. An update instruction unit 363 that generates a signal KP, shutter signals SH1 and SH2, and a shutter signal SH3 that controls the switch unit 361, and a standby power source 364 that supplies power to the setting switching unit 362 and the update instruction unit 363 are provided. Yes. Note that the standby power source 364 is the same as the standby power source 324 in the first embodiment, and thus description thereof is omitted.

<< Switch part >>
As shown in FIG. 13, the switch unit 361 conducts between the path from the unit switches SW1 to SWn to the output terminal T2 and the reference potential in accordance with the shutter signal SH3, as compared with the switch unit 321 (see FIG. 4). The configuration is the same as that of the switch unit 321 except that an analog switch 43 to be shut off is added. The analog switch 43 is formed of two IGBTs and two diodes, and is a well-known switch configured to turn on (conduct) when the shutter signal SH3 is at a high level and to turn off (cut off) when the shutter signal SH3 is at a low level. .

<< Setting switching section >>
As shown in FIG. 14, the setting switching unit 362 is provided with a mask block MSi for each control block CBi as compared to the setting switching unit 322 (see FIG. 5), according to the state maintenance signal KP and the shutter signals SH1 and SH2. The difference is that a mask control unit 53 for controlling the operation of the mask block MSi is provided, and the configuration of the control block CBi is partially different.

  Since the control blocks CB1 to CBn all have the same configuration, they are also referred to as the control block 50a unless otherwise distinguished, and since the mask blocks MS1 to MSn all have the same configuration, they are masked unless otherwise distinguished. Also referred to as block 54.

  Specifically, as shown in FIG. 15A, the control block 50a (CBi) uses the control block 50 (FIG. 6A) except that the polarity determination unit 51a is used instead of the polarity determination unit 51. )). The polarity determination unit 51a uses the potential Ei with respect to the reference potential of the power receiving electrode RDi as a determination signal, and generates a determination value Hi that is a high level when the sign of the determination signal is positive and a low level when the sign is negative. Comparing circuit. That is, the potential with respect to the reference potential of the power receiving electrode RDi, that is, the power receiving signal Ei changes in opposite polarity depending on whether it is facing the first power transmitting electrode SD1 or the second power transmitting electrode SD2. Therefore, by checking the sign of the power reception signal Ei, the polarity of the power transmission electrode SDj that is opposed to the power reception electrode RDi can be specified.

The mask control unit 53 and the mask block 54 are both realized by a combination of logic circuits, and operate as follows.
That is, the mask controller 53 is low when the state maintaining signal KP is high, and when the state maintaining signal KP is low, the mask signal 53 is high when the enable signal EN1 and the state maintaining signal KP are the same as the shutter signal SH1. When the level is low, the enable signal EN2 is generated. When the state maintaining signal KP is low, the enable signal EN2 having the same signal level as the shutter signal SH2 is generated.

  The mask block 54 (MBi) assumes that the control signals Si1, Si2 in the first embodiment are represented by the control signals Qi1, Qi2, and the logical sum of the permission signal EN1 and the control signal Qi1 is the control signal Si1, the permission signal EN2, and the control signal. The logical sum of Qi2 is output as a control signal Si2.

  The setting switching unit 362 configured as described above operates according to the truth table shown in FIG. That is, when the state maintaining signal KP switches from the high level to the low level, the control signal Si1 after switching is the signal level of the shutter signal SH1, the control signal after switching, regardless of the control signals Si1, Si2 and the determination value Hi before switching. Si2 is the signal level of the shutter signal SH2.

  On the other hand, when the state maintaining signal KP switches from the low level to the high level, as in the case of the first embodiment, when both the control signals Si1 and Si2 before switching are at the low level, the determination value Hi (the sign of the power reception signal Ei) ), When the determination value Hi is at a high level (Ei> 0), the control signal Si1 after switching is at a high level, the control signal Si2 is at a low level, and the determination value Hi is at a low level (Ei <0). In this case, the control signal Si1 after switching becomes low level and the control signal Si2 becomes high level. Further, when at least one of the control signals Si1 and Si2 before switching is at a high level (that is, except when both are at a low level), the control signals Si1 and Si2 after switching are switched regardless of the determination value Hi. The signal level is the same as before. Then, the signal levels of the control signals Si1 and Si2 after switching are maintained while the state maintaining signal KP is at a high level, that is, until both of the control signals Qi1 and Qi2 are switched to a low level.

<< Update instruction section >>
As shown in FIG. 16, the update instruction unit 363 uses the state maintenance signal KP instead of the state maintenance signal generator 64 that generates only the state maintenance signal KP, as compared with the update instruction unit 323 (see FIG. 7). In addition, the update instruction unit 323 is different from the update instruction unit 323 in that it includes a state maintaining signal generator 65 that generates the shutter signals SH1 to SH3.

  Here, the operation of the state maintaining signal generator 65 will be described with reference to the flowchart of FIG. However, as compared with the flowchart shown in FIG. 8, the only difference is that the judgment conditions in S150 are different and that S162, S164, and S166 are added between S160 and S170. The explanation is centered. Note that the shutter signals SH1 to SH3 are all set to OFF in the initial state.

S110 to S140 are the same as those in the first embodiment.
In S150, the process waits until the phase extracted by the phase extractor 62 becomes a desired phase at which the maximum value of the absolute value | dV / dt | of the potential change rate (differential value) of the power reception output V is obtained. That is, the switch unit 361 is updated at a timing when the power reception signal (potential with respect to the reference voltage of the power reception electrode RDi) Ei becomes sufficiently large.

  If it is determined in S150 that the desired phase has been reached, the state maintaining signal KP is set to off (KP = L) (S160), and the shutter signals SH2 and SH3 are both on (SH2 = SH3 =). H) (S162), and waits for a certain time in this state (S164). Accordingly, since the control signal Si1 is turned off (Si1 = L) and the control signal Si2 is turned on (Si2 = H), all the power receiving electrodes RDi are connected to the output terminal T2, and the analog switch 43 is used by the shutter signal SH3. Is turned on, the potentials of all the power receiving electrodes RDi are initialized to the reference potential.

Next, both the shutter signals SH2 and SH3 are set to OFF (SH2 = SH3 = L) (S166), and the system waits for a certain time in this state (S170).
As a result, since the control signals Si1 and Si2 are both turned off (Si1 = Si2 = L), all the power receiving electrodes RD1 to RDn are disconnected from any of the output terminals T1 and T2 and are analog. The switch 43 is turned off.

  Note that the standby time in S164 and S170 is sufficiently short so that the power reception signal Ei does not change greatly during the standby time (for example, approximately one-tenth of the period of the power reception output V). And

The processes in S180 to S210 are the same as those in the first embodiment.
In other words, when resetting the switch unit 361, the potentials of all the power receiving electrodes RD1 to RDn are initialized and then the sign of the power receiving signal Ei is determined.

In the connection section 32a configured as described above, as shown in FIG. 18, the operation when the state maintaining signal KP is on (KP = H) is the same as that in the first embodiment (see FIG. 9). .
Then, at the timing (time t11) when the state maintaining signal KP is turned off (KP = L), the shutter signals SH2 and SH3 are simultaneously turned on (SH2 = SH3 = H). At this time, the potentials of all the power receiving electrodes RDi (that is, the power receiving signal Ei) are initialized to the reference voltage level.

  After that, when a certain waiting time elapses and the shutter signals SH2 and SH3 are turned off (time t12), the power receiving electrodes RD1 to RDn and the output terminals T1 and T2 are both electrically disconnected. The amplitude A of the power reception output V becomes 0, and the supply of the power reception output V to the subsequent stage via the output terminals T1 and T2 is stopped. At this time, the power reception signal Ei supplied from the power reception electrode RDi is not a synthesized waveform but a single waveform for each power reception signal Ei. Based on this single waveform, in particular, the sign (polarity with respect to the reference potential) of the power reception signal Ei is determined here, and the setting of the unit switch SWi is switched according to the determination result.

  Thereafter, when a certain standby time has elapsed and the state maintaining signal KP is turned on (time t13), the states of the unit switches SW1 to SWn constituting the switch unit 361, that is, the first power receiving electrode group and the second power receiving power. The grouping of the power receiving electrodes RDi constituting the electrode group is reset, and the supply of the power receiving output V to the subsequent stage via the output terminals T1 and T2 is resumed. When the sign of the power reception signal Ei is positive at time t13, the power reception electrode RDi is connected to the output terminal T1, while when the sign of the power reception signal Ei is negative, the power reception electrode RDi is connected to the output terminal T1. Connected to T2.

<Effect>
As described above, the present embodiment differs from the first embodiment only in that the determination value Hi is generated using the sign of the power reception signal Ei instead of the sign of the differential value of the power reception signal Ei. The same effect as in the case of can be obtained.

In the present embodiment, since the polarity of the power reception signal Ei is determined after the potential of the power reception electrode RDi is initialized to the reference potential, the reliability of the determination can be improved.
[Fourth Embodiment]
A fourth embodiment will be described.

<Configuration>
In the present embodiment, the configuration is the same as that of the third embodiment except that the connection portion 36a is used instead of the connection portion 36. Therefore, this different portion will be mainly described.

  In the present embodiment, as shown in FIG. 19, the connection unit 36a has a configuration other than the update instruction unit 365, that is, the switch unit 361, the setting switching unit 362, and the standby power supply 364 are configured in the same manner as in the third embodiment. ing.

And the update instruction | indication part 365 repeatedly performs the process of S160-S180 shown to the flowchart of FIG. 17 for every fixed period.
That is, as shown in FIG. 20, the signal level of the state maintaining signal KP generated by the update instructing unit 365 is first maintained at a low level for a certain waiting time Tw1 + Tw2 and then a certain level. It is kept at a high level during the operation period Tcycl, and the same is repeated thereafter.

  Further, the shutter signal SH1 is held at the low level, and the shutter signals SH2 and SH3 are changed to the high level at the same time as the state maintaining signal KP is changed to the low level, and are held at the high level for a certain waiting time Tw1. After that, it is held at the low level, and the same is repeated thereafter.

<Effect>
According to this embodiment, the same effect as that of the second embodiment and the third embodiment can be obtained.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention can take a various form, without being limited to the said embodiment. For example, the functions of one component may be distributed to a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function.

  In the above embodiment, the power receiving device 3 is provided with the protrusion 3e and the protrusion 3f, but these may be omitted. Further, the protruding directions of the protrusions 3e and the protrusions 3f are not necessarily related to the arrangement direction of the power receiving electrodes RDi, and these protruding directions are not necessarily orthogonal to each other.

  DESCRIPTION OF SYMBOLS 1 ... Non-contact electric power feeding system 2 ... Power transmission apparatus 3 ... Power reception apparatus 21 ... DC power supply 22 ... Inverter 23 ... Resonance part 24 ... Power transmission electrode part 31 ... Power reception electrode part 32, 32a, 36, 36a ... Connection part 33 ... Resonance / matching Unit 34 ... Rectification unit 35 ... Load 40 (SWi) ... Unit switch 41, 42, 43 ... Analog switch 50, 50a (CBi) ... Control block 51, 51a ... Polarity determination unit 52 ... Switch control unit 53 ... Mask control unit 54 (MSi) ... Mask block 61 ... Amplitude extractor 62 ... Phase extractor 63 ... Amplitude preserving device 64, 65 ... State maintenance signal generator 321, 361 ... Switch unit 322, 362 ... Setting switching unit 323, 325, 363, 365 ... Update instruction section 324, 364 ... Standby power supply

Claims (9)

A power receiving electrode part (31) composed of a plurality of power receiving electrodes (RD1 to RDn);
A switch unit (321) for individually connecting each of the power receiving electrodes to the first output terminal (T1) or the second output terminal (T2);
A power supply unit (33, 34) for generating a power output to be supplied to a load based on a power receiving output which is an output obtained from the first output terminal and the second output terminal;
A polarity determining unit (51, 51a) for determining the polarity of the power transmitting electrode (SD1, SD2) disposed opposite to the power receiving electrode according to a determination signal generated from the potential of the power receiving electrode for each power receiving electrode;
According to the determination result in the polarity determination unit, a switch control unit (52) for controlling the switch unit to connect the power receiving electrodes having the same polarity of the power transmitting electrodes arranged opposite to each other to the same output terminal,
An update instruction unit (323, 325, 363, 365) for operating the switch control unit when a predetermined activation condition is satisfied;
A power receiving device comprising:   The said polarity determination part (51) uses the electric potential change rate in the said receiving electrode as said determination signal, and determines the polarity of the said power transmission electrode by the code | symbol of this electric potential change rate. Power receiving device.   The said polarity determination part (51a) uses the electric potential in the said receiving electrode with respect to the preset reference electric potential as said determination signal, and determines the polarity of the said power transmission electrode by the code | symbol of this electric potential. The power receiving device according to 1. An initialization circuit (40, 43) for initializing the potentials of all the receiving electrodes constituting the receiving electrode unit to the reference potential;
The power receiving device according to claim 3, wherein the switch control unit operates the initialization circuit before switching the setting of the switch unit. 5. The update instruction unit (323, 363) sets the timing at which the absolute value of the determination signal is maximized as the operation timing of the switch control unit (S <b> 150) . The power receiving device according to item 1 . The said update instruction | indication part (323,363) uses that the amplitude of the said receiving power output becomes smaller than the preset amplitude lower limit as said starting condition (S120), The Claim 1 thru | or 5 characterized by the above-mentioned . The power receiving device according to any one of claims. The update instruction unit (323, 363) includes an amplitude storage unit (63) that stores an amplitude of the power reception output detected within a certain period after the switch unit is switched by the switch control unit, and the power reception output amplitude and any of the claims 1 to 6 the deviation between the stored value of the amplitude storing part is characterized in that (S130) to be used as the starting condition that is larger than the preset upper limit value of the deviation of 1 The power receiving device according to the item. 6. The power receiving device according to claim 1, wherein the update instruction unit (325, 365) uses, as the activation condition, that a predetermined time elapses. Said switch controller (52), the polarity setting of the switch unit is switched in accordance with the determination result of the determination unit, wherein the update instruction unit, characterized in that holding until it is restarted claims 1 to The power receiving device according to claim 5 .