JP2006217731A - Non-contact power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact power supply system that is simple and high in reliability, and can control a voltage fed to a load. <P>SOLUTION: The non-contact power supply system comprises a power supply which generates a supply-side current and a supply-side voltage for feeding power to the load; a primary coil which inputs power from the power supply; a secondary coil which is electrically connected to the primary coil, whose position to the primary coil is movable, and which feeds power to the load; a first resonance capacitor connected to the primary coil; and a secondary resonance capacitor connected to the secondary coil. The power supply comprises a current detector which detects the supply-side current; an operation part which operates the value of the supply-side current for setting a load-side voltage fed to the load as a prescribed target value, on the basis of the detection result of the current detector; and a voltage control unit which controls the supply-side voltage according to the operation result of the operation part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a non-contact power supply system for supplying power without directly contacting a load, and particularly, it is impossible or difficult to make direct contact such as a fully implantable artificial heart or a micromachine. It is suitable for transmitting energy to a certain object.

  Conventionally, a method using electromagnetic induction has been widely used as a system for supplying electric energy without directly contacting a load. At that time, as a means for controlling the voltage of a circuit on the load side to a predetermined target value, the following method is used. Things have been proposed.

  For example, in Non-Patent Document 1 below, output voltage information is obtained using infrared light or the like as means for stabilizing the load input voltage when power is transmitted in a contactless manner using electromagnetic induction to a device inside the human body. A system for transmitting information from the body to the outside has been proposed.

  Further, in Patent Document 1 below, an insulated power supply circuit is proposed that feedback-controls load input voltage information to the primary side using a pulse transformer.

  Moreover, in the following patent document 2, when the primary coil and the secondary coil are arranged in front, the distance in the vertical direction of the secondary coil with respect to the primary coil surface is calculated using the primary coil current. There has been proposed a wireless transmission device including means for obtaining a secondary coil induced voltage from a distance.

Further, in Patent Document 3 below, the distance between the primary coil current and the secondary coil is measured using the primary coil current, and the inverter oscillation is intermittently stopped so that the load input voltage does not exceed the rated voltage value. There has been proposed a mobile phone charging apparatus provided with means.
Y. Inoue et al .: Percutaneous optical telemetry system using laser diode, Journal of the Japanese Society for Artificial Organs, Artificial Heart, Vol. 27, No. 2, P363-367, April 1998 JP-A-5-260742 Japanese Patent Laid-Open No. 10-322247 Noto 3067306

  The systems or circuits of Non-Patent Document 1 and Patent Document 1 can be applied when the distance between the primary coil and the secondary coil is a short distance. In this system or circuit, one of the elements for transmitting information needs to be arranged so as to face each other through the skin and embedded in the body, which complicates the device and reduces reliability. In addition, if the element for information transmission moves away more than the distance that the infrared rays reach (about 10 to 20 mm), or the position is shifted and the transmitted signal cannot be received (about 10 mm), communication cannot be performed and control is performed. There is also the disadvantage of being unable to do so.

  In addition, the device of Patent Document 2 can be used only when two coils are arranged facing each other (when the orientation and position are not specified), and it is not known where the secondary coil is in the body. It cannot be used when the primary and secondary coils are not facing each other (when they are displaced laterally).

  Moreover, the apparatus of the said patent document 3 is effective only when not taking series resonance with a capacitor | condenser. For example, when the primary coil and the capacitor C1, and the secondary coil and the capacitor C2 are resonated, the characteristics are completely different. “The output voltage decreases as the distance between the coils increases, and the primary (coil) The theory that “current also decreases” simply does not hold.

  Furthermore, in general, when power is supplied to the implantable artificial heart, the secondary coil is implanted under the skin, but if it is implanted as it is, it is difficult to grasp the exact position of implantation. Therefore, in order to make the position of the secondary coil easy to understand and at the same time to prevent displacement of the positions of the coils, there are many cases where the secondary coil has an umbrella shape with a thickness of about 5 to 20 mm. However, this has a demerit that a burden on the living tissue is increased and a psychological burden is generated on the patient because the coil-embedded portion is conspicuous.

  Even when the position and orientation of the secondary coil with respect to the primary coil fluctuate or when the exact position of the secondary coil is not known, the present invention is output to the secondary coil without embedding a special control device. It is an object of the present invention to provide a simple and reliable device that can control a constant voltage.

  In order to solve the above problems, the present invention provides the following.

  (1) A power supply unit that generates a supply-side current and a supply-side voltage to supply power to a load, a primary coil that inputs power from the power supply unit, and a magnetic coupling with the primary coil A secondary coil for supplying power to the load, a first resonance capacitor connected to the primary coil, and a secondary coil that is movable relative to the primary coil. A second resonance capacitor, wherein the power supply unit is a current detection unit for detecting the supply side current, and a supply side for setting a load side voltage supplied to the load to a predetermined target value. A non-contact power supply system comprising: a calculation unit that calculates a current value based on a detection result of the current detection unit; and a voltage control unit that controls the supply-side voltage according to the calculation result of the calculation unit.

  According to (1), the non-contact power supply system detects a supply-side current of the power supply unit and performs a calculation based on the detected current, thereby controlling the power supply unit and setting the load-side voltage to a predetermined target value. Can be controlled. This makes it possible to control the load side voltage to a predetermined target value even when a relative position change such as the distance, direction, and deviation between the primary coil and the secondary coil occurs with a simple and reliable configuration. can do.

  (2) The calculation unit sets a value of a supply side current for setting a load side voltage supplied to the load as a predetermined target value, a detection result of the current detection unit, a primary coil current, and a primary coil voltage. The contactless power supply system according to (1), wherein calculation is performed using constants of load impedance, primary coil winding resistance, and secondary coil winding resistance.

  According to (2), when the non-contact power supply system detects the supply-side current of the power supply unit and determines the primary coil current, the primary coil voltage to be input, and the system circuit based on the detection result Controls the power supply unit to control the load side voltage to a predetermined target value by performing calculations based on predetermined load impedance, primary coil winding resistance, and secondary coil winding resistance constants. can do. As a result, even when a relative position change such as the distance, orientation, and deviation between the primary coil and the secondary coil occurs, the constants that can be obtained in advance and the parameters obtained on the primary coil side are: The load side voltage can be controlled to a predetermined target value.

  (3) Based on the detection result of the current detection unit, the calculation unit sets a supply-side current value for setting a load-side voltage supplied to the load as a predetermined target value, the power supply unit, Calculation is performed based on a relationship obtained by a closed circuit equation of an electrical equivalent circuit including a primary coil, the first resonance capacitor, the secondary coil, the second resonance capacitor, and the load. (2) The contactless power supply system according to (1).

  According to (3), it is possible to control the power supply unit to control the load side voltage to a predetermined target value by performing an operation based on the relationship obtained from the closed circuit equation obtained from the equivalent circuit of the system. . Accordingly, it is possible to easily cope with a change in the system configuration by using an equivalent circuit in which the model can be easily understood.

  (4) A medical system comprising the non-contact power supply system according to any one of (1) to (3) and an implantable medical device that receives power from the system.

  According to (4), by using the non-contact power supply system for an implantable medical device such as a fully implantable artificial heart, energy can be supplied without contacting the medical device. it can. At this time, the relative positions of the primary coil and the secondary coil are shifted when the exact positions of the primary coil and the secondary coil are not known or when the patient who has implanted the medical device changes posture. Even in this case, the load side voltage can be controlled to a predetermined target value by the system. Accordingly, a stable voltage can be supplied for the operation or charging of the medical device, and at the same time, the burden on the patient who uses the medical device can be reduced.

  (5) A medical system comprising: the non-contact power supply system according to any one of (1) to (3); and a medical device that is supplied with power from the system and that is supplied into the body.

  According to (5), the non-contact power supply system described above is applied to a medical device that is temporarily introduced into the body, such as a capsule-type gastro camera that captures the inside of a digestive organ such as the stomach by being swallowed from a patient's mouth. By using, energy can be continuously supplied to the medical device from outside the body. At that time, when the patient using the medical device or the medical device itself moves, the relative position between the primary coil and the secondary coil is shifted, or the exact position is not known when the medical device moves. Even in this case, the load side voltage can be controlled to a predetermined target value by the system. As a result, a stable voltage can be supplied for the operation of the medical device or for charging, the medical device can be miniaturized from a simple configuration of the system, and the burden on the patient can be reduced. I can do it.

  (6) A micromachine drive system comprising: the non-contact power supply system according to any one of (1) to (3); and a micromachine that receives supply of power from the system.

  According to (6), when energy is supplied to the micromachine in a non-contact manner, the above-described contactless power supply system can be used to change the position of the micromachine or to know the precise position of the micromachine. However, stable voltage power can be supplied to the micromachine.

  (7) A power supply unit that generates a supply-side current and a supply-side voltage to supply power to the load, a primary coil that inputs power from the power supply unit, and a magnetic coupling with the primary coil A secondary coil for supplying power to the load, a first resonance capacitor connected to the primary coil, and a secondary coil connected to the primary coil, the position of the primary coil being movable A method of controlling a non-contact power supply system including a second resonance capacitor, wherein the supply side current is detected, and a load side voltage supplied to a load is determined based on a result of the detection. A control method comprising a step of calculating a value of a supply-side current for obtaining a target value, and a step of controlling the supply-side voltage according to a result of the calculation.

  According to (7), an effect equivalent to that of the invention described in (1) can be expected.

  According to the present invention, the orientation of the surface of the primary coil and the orientation of the surface of the secondary coil do not have to face each other, and wherever the coils are located, particularly without complicating the secondary coil side. The load side voltage can be controlled with a simple configuration. As a result, even when the position and orientation of the secondary coil are not fixed, the load side voltage can be reduced while improving the reliability of the load side device and the like and reducing the burden on the patient when applied to a medical device. Stabilization is possible.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. This is merely an example, and the technical scope of the present invention is not limited to this.

[Non-contact power supply system]
FIG. 1 is a block diagram showing a configuration of a non-contact power supply system 100 according to the present invention. The non-contact power supply system 100 includes a supply side system 110 and a load side system 160.

[Supply system]
The supply-side system 110 includes a power supply unit 111, a primary coil 152, and a primary coil resonance capacitor 156 as main components.

  The power supply unit 111 supplies power to the primary coil 152 from commercial power or an AC power source obtained from a DC power source through a converter or the like. The power supply unit 111 includes a current detection unit 120, a calculation unit 130, and a voltage control unit 113.

  The current detection unit 120 detects an output current as a supply-side current using a high-frequency current detector. The calculation unit 130 calculates a voltage to be output based on the output voltage of the power supply unit and the detection result of the current detection unit 120. The voltage control unit 113 includes an oscillator 112 and a high-speed isolation amplifier 114 that can control the output voltage by changing the oscillation amplitude based on the calculation result of the calculation unit 130. The primary coil 152 receives power input from the power supply unit. The primary coil resonance capacitor 156 is connected to the primary coil 152 to resonate the primary coil side circuit.

[Load side system]
The load-side system 160 includes a load 162, a secondary coil 154, and a secondary coil resonance capacitor 158 as main components.

  The load 162 is a power supply target. The secondary coil 154 is magnetically coupled to the primary coil 152 and inputs power to the load 162. The secondary coil resonance capacitor 158 is connected to the secondary coil 154 to resonate the secondary coil side circuit.

[Control method]
First, energy transmission conditions are set. The type, size, shape, and number of turns of the transmission angular frequency ω, the primary coil, and the secondary coil are determined, thereby adjusting the primary coil and the secondary coil. The inductance of the primary coil and the secondary coil is measured by the LCR meter at the angular frequency ω, respectively, and the capacitance value of the capacitor C ₁ capable of taking series resonance with the primary coil at the angular frequency ω, and 2 at the angular frequency ω. The value of the capacitance of the capacitor C ₂ that can take series resonance with the next coil is calculated from the equation (1).

  Here, if the primary coil, the primary coil capacitor, the secondary coil and the secondary coil capacitor are in series resonance, the primary coil voltage and the primary coil current are in phase and the secondary coil voltage. The phase of the secondary coil current is in phase, and the phase of the primary coil voltage and the secondary coil voltage is shifted by 90 degrees. In the present invention, there are no restrictions on the number of turns, size, shape, etc. of the primary coil. Similarly, the number of turns, dimensions, and shape of the secondary coil are not limited. Furthermore, for the purpose of increasing the magnetic coupling degree of the primary coil and the secondary coil, the coil is wound around a magnetic material such as ferrite, or a magnetic material sheet such as ferrite or amorphous magnetic wire is attached to the coil for the purpose of suppressing noise. May be.

Next, the control operation will be described. In the non-contact power supply system 100 of FIG. 1, the effective value of the primary coil input voltage is V ₁ , the effective value of the primary coil current is I ₁ , and the effective value of the secondary coil output voltage (= load input voltage) is V the effective value of _2, the secondary coil current and _{I 2.} Further, the winding resistance of the primary coil is r ₁ , and the winding resistance of the secondary coil is r ₂ . The effective value of the target secondary coil output voltage is V _2id . The effective value of the primary coil voltage for outputting V _2id is defined as V _1id .

In the non-contact power supply system 100 is adjusted to stabilize the secondary coil output voltage V ₂ of the primary coil input voltage V ₁ of the energy transmission power (see Fig. 1). Specifically, the positional relationship between the primary coil and the secondary coil is expressed only by the mutual inductance M. That is, by substituting M into the relational expression between V _1id and V _2id obtained from the closed circuit equation of the equivalent circuit of this system, M can be eliminated (Formula (2)).

Therefore, even when M changes, V _1id necessary for controlling the secondary coil output voltage V ₂ can be determined only by the parameters on the primary side (outside the body). The primary parameters necessary for this control are the effective value V ₁ of the primary coil voltage, the load impedance R, the winding resistance r _{1 of} the primary coil, the winding resistance r ₂ of the secondary coil, and the primary coil current. of the effective value _{I 1.}

The primary coil current measured by the current detection unit 120 is input to the calculation unit 130 via the rectifying / smoothing circuit 122 and the effective value conversion circuit 124. V ₁ , R, r ₁ , and r ₂ that are known in advance are input to the calculation unit 130. In the arithmetic processing circuit unit, the measurement result of the current detection unit 120 is converted into a digital signal by the A / D conversion circuit unit 132, and the calculation of Expression (2) is performed by the microcomputer 134 (or personal computer), and the D / A The signal is again converted into an analog signal in the conversion circuit unit. Information on the primary coil voltage V _1id for outputting the target secondary coil voltage (= load input voltage) V _2id is input to the oscillator 112, and the oscillator has the angular frequency ω and the amplitude effective value V _1id . A sine wave is output. Again, the new primary coil current value I ₁ changes according to the newly set V _1id and is measured by the current detector 120. It is possible to control the secondary coil output voltage to the target value by repeating this control processing loop.

[Example of control operation]
An example of the control operation will be described for the circular primary coil and secondary coil shown in FIG. For both primary and secondary, the outer diameter of the coil is 5.5 cm, the inner diameter of the coil is 2 cm, the thickness is 0.09 cm, and the number of turns is 20.
Control is performed to fix the secondary coil output voltage (= load input voltage) to a target value of 6 V, assuming that a voltage of 5 V is first applied to the primary coil. Here, r ₁ = 0.4485Ω, r ₂ = 0.3915Ω, R = 4.6Ω, and f = 150 kHz.

  When the primary coil and the secondary coil are shifted as shown in step 1 of FIG. 3, the secondary coil is moved in the x direction to overlap the two coils (step 2) and further shifted in the y direction (step 3). )think of. The displacement in the x direction is 0.6 cm, and the displacement in the y direction is 3.8 cm.

  First, when not controlled, the secondary coil output voltage was 1.87 V in Step 1, 7.62 V in Step 2, 3.87 V in Step 3, and changed to nearly 6 ± 4.1 V. On the other hand, when the control was performed, it was 5.94V in Step 1, 6.11V in Step 2, 6.19V in Step 3, and was within 6 ± 0.2V. Therefore, it turns out that it has stabilized.

  As for responsiveness, the higher the control speed, the better the control accuracy, but the speed of the secondary coil is caused by the movement of the body, so it is unlikely to be a high speed movement, and it is a slow movement of about 1 Hz at the earliest. Therefore, if the repetition period of the control processing loop is about 0.01 seconds, the output can be sufficiently voltage-stabilized by the control.

[Protection circuit]
The power supply unit 111 included in the supply-side system 110 includes a protection circuit 126. The protection circuit 126 sets the predetermined value as the calculation result when the calculation result from the calculation unit is equal to or greater than the predetermined value. FIG. 4 shows a block diagram of the protection circuit 126. Without the protection circuit, the mutual inductance M decreases as the distance between the primary coil 152 and the secondary coil 154 increases. Therefore, the primary for outputting the desired secondary coil output voltage (= load input voltage). The coil voltage is controlled to increase. Therefore, when the distance between the primary coil 152 and the secondary coil 154 is increased, a large voltage is output from the power supply unit. However, when a command is issued so that an excessive voltage is output, the supply side system and the load are output. When used in the side system and medical device, it is dangerous for the human body. The protection circuit 126 causes the effective value of the primary coil voltage to be the set value V _1max (maximum value) when a command is issued from the arithmetic unit 130 to output a primary coil voltage that is equal to or higher than the set voltage. To. This protects the system and other things. The protection circuit 126 has a hysteresis characteristic, and is set so that the control is resumed when the voltage drops several V below the set value (see FIG. 4).

[Implantable artificial heart device]
FIG. 5 shows a block diagram of an implantable artificial heart system 500 that is another embodiment of the present invention. The implantable artificial heart system 500 includes, as main components, an artificial heart drive unit 560 as an implantable drive unit, a power supply unit 520 for generating electric power for driving the artificial heart drive unit 560, and It has the energy transmission part 540 for transmitting the electric power for driving the artificial heart drive part 560. FIG.

[Artificial heart drive unit]
The artificial heart drive unit 560 is an artificial heart pump 566 that is an actuator, a rectifying / smoothing circuit 562 for rectifying and smoothing electric power from the outside and supplying it to the artificial heart pump 566, and a secondary battery 568 for temporarily storing electric power by charging and discharging. And a switching circuit 564 that switches a power supply source for the artificial heart pump 566 to either the rectifying / smoothing circuit 562 or the secondary battery 568. When power transmission by this system is interrupted, the artificial heart pump 566 is driven by a backup secondary battery 568 embedded in the body. In the drive unit, a drive unit side voltage is generated by electric power supplied to drive the artificial heart pump 566. In the present embodiment, this drive unit side voltage is the converted output voltage of the rectifying and smoothing circuit 562.

  The rectifying / smoothing circuit 562 is a circuit that converts alternating current into direct current. A typical rectifying / smoothing circuit 562 includes a center tap full-wave rectifier circuit and a bridge full-wave rectifier circuit. Both perform full-wave rectification. However, in the case of the center tap full-wave rectification method, two internal coils that are secondary coils are required. However, the diode that generates a large loss uses the center tap full-wave method because it is better to reduce the number of diodes when considering high system efficiency. The loss due to the forward voltage of the diode becomes heat generation, and considering not only the system efficiency but also placing it in the body, there is a possibility that it may adversely affect living tissue, so it can be said that it is better to use fewer diodes. In addition, the fact that there are few elements and the circuit is simple reduces the possibility of failure and can be said to be safer. The rectifying / smoothing circuit 562 incorporates a choke input type smoothing circuit. As the artificial heart pump 566, for example, a steady flow type type using a direct current actuator can be used.

[Power supply section]
The power supply unit 520 includes a power supply unit 524, a current detection unit 526, and a voltage control unit 522. The power supply unit 520 generates a supply-side current and a supply-side voltage in order to output power for driving the artificial heart drive unit.

  The power supply unit 524 supplies the primary coil 542 from commercial power or the like. The current detection unit 526 is connected to the power supply unit 524 and detects an output current as a supply-side current. The voltage control unit 522 controls the output voltage of the power supply unit 524 based on the detection result of the current detection unit 526 and the output voltage from the power supply unit 524.

  In the present embodiment, the supply side voltage is the output voltage of the power supply unit 524, and the supply side current is the output current of the power supply unit 524.

[Energy transmission section]
The energy transmission unit 540 includes a primary coil 542 and a secondary coil 544. The primary coil 542 is placed outside the body, is connected to the power supply unit 520, and receives power from the power supply unit 520. The secondary coil 544 can be implanted in the body, is connected to the artificial heart drive unit 560, and supplies power to the artificial heart drive unit 560 (see FIG. 2). In the present embodiment, an example of an artificial heart drive unit will be described as an implantable medical device. However, the present invention is, for example, a medical device that can be inserted into the body (for example, a capsule type device that is swallowed and used) It can also be applied to other medical devices such as endoscopes.

  In the implantable artificial heart device system 500 of the present embodiment, the detection result of the current detection unit 526 and the output voltage of the power supply unit 524 are obtained in advance, and the artificial heart drive unit side voltage supplied to the artificial heart drive unit 560 is obtained. Is used by substituting into the relational expression between the supply side voltage and the artificial heart drive side voltage. In the present embodiment, the supply-side voltage is the output voltage of the power supply unit 524, that is, the voltage applied to the primary coil 542, and the supply-side current is the output current of the power supply unit 524, that is, the current flowing through the primary coil 542. The part side voltage is an output voltage of the secondary coil 544.

  When the non-contact power supply system according to the present invention is used for an artificial heart, when the artificial heart pump 566 is an artificial heart actuator that operates with direct current, the load (power supply object) includes a rectifying and smoothing circuit and an artificial heart actuator. It can also be considered as a combination of a driver and an artificial heart actuator. In an artificial heart actuator that directly operates with an alternating current induced by electromagnetic induction, the artificial heart actuator itself corresponds to a load. A secondary coil enters the body, and energy of about 1-40 W necessary for driving is constantly transcutaneously transmitted from the primary coil outside the body, but there is no influence due to the interposition of the skin.

  Even if the position of the primary coil 152 is slightly shifted due to body movement, the load input voltage can be made constant by controlling the shift on the primary side (see FIG. 6). Since there is no need for a communication means for controlling the load input voltage as in the prior art, there is no burden on the patient. In addition, although the secondary coil is embedded under the skin, it is often difficult to grasp the exact position where the secondary coil is embedded, so that the secondary coil has a thickness of 5 in order to make the position of the secondary coil easy to understand and prevent displacement. There were many things made into the umbrella shape made into about -20 mm. In the present invention, since the load input voltage can be stabilized by the control circuit even if the position of the primary coil 152 with respect to the secondary coil 154 is slightly deviated, the position of the secondary coil may be slightly deviated or moved. There is no need to make the coil umbrella-shaped. The ability to make the secondary coil planar has advantages that the burden on the living tissue is reduced and that the patient is not worried because the coil-embedded portion is inconspicuous.

  In the artificial heart, the flow rate may be changed by a command from the primary side. However, when the artificial heart pump 566 using an artificial heart actuator that operates with a direct current is used as in this embodiment, the load value changes. It will be done. However, since the content of the flow rate change command is known on the primary side, the load can be estimated on the primary side by obtaining the relationship between the flow rate and the load value in advance. FIG. 7 shows an example of a flow rate-load value table.

[Micromachine]
Another embodiment in which the non-contact power supply system according to the present invention is used to supply power to a micromachine will be described. The main components of this embodiment are a non-contact power supply system and a micromachine that receives power supply as a load.

  A micromachine (MEMS: Micro Electro Mechanical Systems) is a microfabrication technology that is one of the semiconductor integrated circuit manufacturing technologies. This is a technique for forming a minute motor having a size of, for example, several tens of microns. This technology uses a pattern formed by lithography technology on a single crystal silicon substrate having excellent characteristics as a mechanical material as a mask, and utilizes the property that the etching rate depends on the crystal axis direction, impurity concentration, etc. A structure is manufactured and has already been put into practical use in the field of microsensors typified by silicon diaphragm pressure sensors.

  A micromachine that receives power from a non-contact power supply system as a load includes not only elements such as actuators, sensors, and microprocessors for achieving the original purpose of the micromachine, but also secondary coils and 2 constituting the system. A secondary coil resonance capacitor connected to the secondary coil is mounted. The secondary coil is connected to each element of the micromachine. Thereby, the electric power from the secondary coil is supplied to each element.

  In some cases, the position of the secondary coil mounted may vary due to movement of the micromachine, or the precise position may be unknown. In this case as well, the power necessary for the operation and control of the micromachine can be supplied with a stable voltage by the operation and effect of the present invention.

  In the embodiment, the primary coil resonance capacitor is described as being arranged outside the power supply unit. However, the present invention is not limited to this, and the capacitor is integrated with the power supply unit to supply power. It may be arranged inside the housing of the part. Also, the secondary coil resonance capacitor may be configured integrally with the load unit, or may be configured outside the load unit.

It is a block diagram which shows the structure of the non-contact electric power supply system which concerns on this invention. It is a figure which shows the example of a primary coil and a secondary coil. It is a figure which shows the position shift of a primary coil, and a secondary coil, and the change of distance. It is a block diagram which shows the protection circuit of a supply side system. It is a block diagram which shows the structural example of the implantable artificial heart system using this invention. It is a figure which shows the shift | offset | difference of the position of a primary coil and a secondary coil of the implantable artificial heart system using this invention. It is the table | surface which showed the example of the relationship between the flow volume and the load of the artificial heart actuator which operate | moves by direct current | flow.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Non-contact power supply system 110 Supply side system 111 Power supply part 112 Oscillator 113 Voltage control part 114 High-speed insulation amplifier 116 Primary coil winding resistance 120 Current detection part 122 Rectification smoothing circuit 124 Effective value conversion circuit 126 Protection circuit 130 Operation part 132 A / D conversion circuit unit 134 Microcomputer 136 D / A conversion circuit unit 140 Ground terminal 150 Energy transmission unit 152 Primary coil 154 Secondary coil 156 Primary coil resonance capacitor 158 Secondary coil resonance capacitor 160 Load side system 162 Load (Power supply target)
164 Secondary coil winding resistance 400 Supply side system 420 Hysteresis comparator 440 Power supply for setting maximum reference voltage (V1max) 460 Switch 500 Implantable artificial heart system 520 Power supply unit 522 Voltage control unit 524 Power supply unit 526 Current detection unit 528 Calculation Unit 530 primary coil resonance capacitor 540 energy transmission unit 542 primary coil 544 secondary coil 560 artificial heart drive unit 562 rectification smoothing circuit 564 switching circuit 566 artificial heart pump 568 secondary battery 570 secondary coil resonance capacitor 600 embedded Type artificial heart power supply system 620 Rectifier smoothing circuit + artificial heart actuator driver + artificial heart actuator

Claims (7)

A power supply that generates a supply-side current and a supply-side voltage to supply power to the load;
A primary coil for inputting power from the power supply unit;
A secondary coil for supplying power to the load, wherein the secondary coil is magnetically coupled to the primary coil and movable relative to the primary coil;
A first resonance capacitor connected to the primary coil;
A second resonance capacitor connected to the secondary coil,
The power supply unit includes a current detection unit that detects the supply-side current;
A calculation unit that calculates a value of a supply-side current for setting a load-side voltage supplied to the load as a predetermined target value based on a detection result of the current detection unit;
A non-contact power supply system comprising: a voltage control unit that controls the supply-side voltage according to a calculation result of the calculation unit.   The calculation unit determines a value of a supply side current for setting a load side voltage supplied to the load as a predetermined target value, a detection result of the current detection unit, a primary coil current, a primary coil voltage, a load 2. The non-contact power supply system according to claim 1, wherein calculation is performed by using constants of impedance, primary coil winding resistance, and secondary coil winding resistance.   Based on the detection result of the current detection unit, the calculation unit sets a supply-side current value for setting a load-side voltage supplied to the load as a predetermined target value, the power supply unit, and the primary coil. And a calculation based on a relationship obtained by a closed circuit equation of an electrical equivalent circuit including the first resonance capacitor, the secondary coil, the second resonance capacitor, and the load. The contactless power supply system according to claim 1. A contactless power supply system according to any one of claims 1 to 3,
A medical system comprising: an implantable medical device that receives supply of electric power from the system. A contactless power supply system according to any one of claims 1 to 3,
And a medical device for receiving the power from the system and for injecting into the body. A contactless power supply system according to any one of claims 1 to 3,
A micromachine driving system comprising: a micromachine that receives supply of electric power from the system. A power supply unit that generates a supply-side current and a supply-side voltage to supply power to the load, a primary coil that inputs power from the power supply unit, and a magnetic coupling with the primary coil A secondary coil for supplying power to the load, a position relative to the primary coil being movable, a first resonance capacitor connected to the primary coil, and a second coil connected to the secondary coil A method for controlling a non-contact power supply system including a resonance capacitor,
Detecting the supply-side current;
Based on the result of the detection, calculating a value of a supply-side current for setting a load-side voltage supplied to a load as a predetermined target value;
Controlling the supply-side voltage in accordance with a result of the calculation.

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