JP2014220940A - Non-contact charging system and non-contact charging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact charging method and non-contact charging system capable of saving weight and space, and supplying voltage and current most suitable for performing charging from a transmission unit to a reception unit.SOLUTION: A non-contact charging system comprises a power transmission unit 20 and a power reception unit 40. The power transmission unit 20 includes a current voltage variable unit 21 and a power transmission coil 22. The power reception unit 40 includes: a power reception coil 41; a rectification unit 44; a battery 42; a switch 45 for controlling conduction between the power reception coil 41 and the battery 42; and a switch control unit 46 for controlling the switch. The switch control unit 46 makes the switch 45 block the conduction when a value of voltage or current supplied to the battery 42 becomes a predetermined value. The current voltage variable unit 21 detects reduction in the value of current of the power transmission coil 22 caused by the switch 45 blocking the conduction; stores the value of voltage or current of the power transmission coil 22 immediately before the detection; and, after that, inputs voltage and current to the power transmission coil 22 on the basis of the stored value when the switch 45 connects the power reception coil 41 and the battery 42.

Description

Embodiments described herein relate generally to a contactless charging system and a contactless charging method.

Many mobile devices such as automatic guided vehicles and transport robots use a motor as a power source and a battery as a power source, and the battery needs to be charged. Until now, the battery has been charged by a method of removing the battery from the device body and connecting it to the charger, or a method of connecting a charger cable to the device body storing the battery.

In recent years, a non-contact power feeding technique has been put into practical use, and it is considered that charging to a battery is performed by non-contact charging even in the mobile device as described above. The non-contact charging apparatus includes a power transmission unit having a power source and a power reception unit having a battery. The non-contact charging means that power is transferred between the power transmission unit and the power reception unit without using a terminal.

A mobile device that is charged by non-contact charging includes a power receiving unit in the non-contact charging device, and operates using a battery incorporated in the power receiving unit as a power source. When the battery needs to be charged, the mobile device moves to the vicinity of the power transmission unit, and performs non-contact charging by bringing the power reception unit closer to the power transmission unit.

JP 2011-45195 A

A mobile device that operates using a battery as a power source has limited power that can be used, and it is necessary to reduce the weight as much as possible in order to extend the operation time. Therefore, it is necessary to reduce the weight of the power reception unit mounted on the mobile device. Also in the power transmission unit, it is necessary to reduce the installation space of the power transmission unit and reduce the weight in order to reduce restrictions on the installation location.

In addition, when performing non-contact charging, the positional relationship between the power reception unit and the power transmission unit is shifted every time, and the relative relationship between the power supplied to the power reception unit by the power transmission unit and the power received by the power transmission unit changes with each charge. To do. Therefore, the power supplied from the power transmission side to the power reception side is different every time in order to supply the battery with the optimum power for charging.

Therefore, the present invention provides a non-contact charging method and a non-contact charging system that can be reduced in weight and space and that can supply electric power optimal for charging from a power transmitting unit to a power receiving unit. With the goal.

In order to achieve the above object, a contactless charging system according to an embodiment is a contactless charging system including a power transmission unit and a power reception unit, and the power transmission unit is a current that is connected to a power source and outputs an arbitrary current value or voltage value. The power receiving unit includes a voltage variable unit, a power transmission coil electrically connected to the current voltage variable unit, and the power receiving unit includes a power receiving coil through which current flows by electromagnetic induction caused by a magnetic field generated by the power transmitting coil, and a rectifying unit connected to the power receiving coil And a battery connected to the power receiving coil via a rectifying unit, a switch for controlling conduction between the power receiving coil and the battery, and a switch control unit for controlling the operation of the switch. When it is detected that at least one of the voltage value and the current value has reached a predetermined value set in advance in the switch control unit, the switch is controlled so as to cut off the continuity between the power receiving coil and the battery. After the variable unit stores at least one of the voltage value and the current value input to the power transmission coil, the switch is controlled so that the power receiving coil and the battery are electrically connected. The current voltage variable unit gradually increases the voltage. And the switch detects the decrease in the current value of the power transmission coil due to the disconnection of the continuity between the power receiving coil and the battery, and is input to the power transmission coil before the current value of the power transmission coil decreases in response to the detection. It is assumed that at least one of the measured voltage value or current value is stored, and the current value or voltage value based on the storage is input to the power transmission coil.

In order to achieve the above object, the contactless charging method of the embodiment includes a power transmission unit and a power reception unit, and the power transmission unit is connected to a power source and outputs an arbitrary voltage value or current value; and A power receiving coil connected to the current voltage variable unit; the power receiving unit includes a power receiving unit side coil through which a current flows by electromagnetic induction caused by a magnetic field generated by the power transmitting coil; a rectifying unit connected to the power receiving coil; A non-contact charging method in a non-contact charging apparatus having a battery connected to a coil via a rectifying unit, a switch for controlling conduction between the power receiving coil and the battery, and a switch control unit for controlling the operation of the switch. The current voltage variable unit gradually increases the voltage and outputs the voltage, and the switch control unit detects that the current value of the battery has reached a predetermined charge current value preset in the switch control unit and With battery The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting the conduction between the power receiving coil and the battery, and the current of the power transmission coil is detected in response to the detection. After the charge default current value detection step for storing the current value flowing in the power transmission coil before the value decreases and stopping the input of the current to the power transmission coil, and the charge default current value detection step, the switch control unit receives the power reception coil A constant current charging step in which the switch is controlled so that the battery and the battery are electrically connected, the constant voltage charging unit inputs a constant current value determined based on the maximum transmission current value to the transmission coil, and the switch control unit is the battery current The switch controls the switch so as to cut off the conduction between the power receiving coil and the battery by detecting that the value has reached a predetermined charge voltage value preset in the switch control unit, The switch detects the decrease in the current value of the power transmission coil due to the disconnection between the power receiving coil and the battery, and the voltage value input to the power transmission coil before the current value of the power transmission coil decreases according to the detection is detected. After the charge default voltage value detection step for storing and stopping the input of the voltage to the power transmission coil, and the charge default voltage value detection step, the switch control unit controls the switch to make the power reception coil and the battery conductive, and the current voltage is variable. After the constant voltage charging step for inputting a constant current value determined based on the maximum power transmission voltage value to the power transmission coil and the predetermined charging voltage value detecting step, the switch control unit previously sets the battery current value to the switch control unit. Is detected and the switch is controlled to shut off the power receiving coil and the battery, and the current / voltage variable part is connected to the power receiving coil and the battery. And a charging completion step of detecting a decrease in the current value of the power transmission coil due to the interruption of the conduction of the power and stopping the input of the current to the power transmission coil.

The block diagram of the non-contact charge system of a 1st embodiment. The timing chart of the non-contact charge method of a 1st embodiment. The flowchart of the non-contact charge method of 1st Embodiment. The timing chart of the non-contact charge method of 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
Hereinafter, a first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a block diagram of a contactless charging system according to the first embodiment. FIG. 2 is a timing chart of the contactless charging method according to the first embodiment. FIG. 3 is a flowchart of the contactless charging method according to the first embodiment.

(Constitution)
The configuration of the present embodiment will be described below with reference to FIG. The contactless charging apparatus 10 according to the present embodiment includes a power transmission unit 20 connected to a commercial power source and a power reception unit 40 mounted on a mobile device such as an automatic guided vehicle or a transport robot.

First, the power transmission unit 20 will be described. The power transmission unit 20 includes a current-voltage variable unit 21 that converts the electric power of the commercial power source into an arbitrary current value or voltage value and outputs the current value, and a power transmission coil 22 that is electrically connected to the current-voltage variable unit 21. An inverter control unit 23 is provided between the current / voltage variable unit 21 and the power transmission coil 22. The inverter control unit 23 converts the DC voltage input from the current / voltage variable unit 21 into an AC voltage having an arbitrary frequency and inputs the AC voltage to the power transmission coil 22.

Next, the current / voltage variable unit 21 will be described. The current / voltage variable unit 21 is a power transmission side rectifying unit 24.
And a chopper controller 25 and a current / voltage controller 26. The power transmission side rectification unit 24 converts an AC voltage supplied from a commercial power source into a DC voltage. A DC voltage converted by the power transmission side rectification unit 24 is input to the chopper control unit 25. The chopper controller 25 is controlled by the current / voltage controller 26 and outputs an arbitrary voltage value or current value to the inverter controller 23. The operation of the inverter control unit 23 is also controlled by the current / voltage control unit 26.

The power transmission unit 20 includes a power transmission side current detection unit 28 that measures a current value input from the chopper control unit 25 to the inverter control unit 23, and a power transmission side voltage detection unit 27 that measures a voltage value applied to the inverter control unit 23. Have. The current value measured by the power transmission side current detection unit 28 is referred to as it,
The voltage value measured by the power transmission side voltage detection unit 27 is referred to as vt. It corresponds to a current value flowing through the power transmission coil 22, and vt corresponds to a voltage value applied to the power transmission coil 22.

The current / voltage control unit 26 detects that the power transmission side current detection unit 28 and the power transmission side voltage detection unit 27 detect.
And vt are monitored. Then, the current / voltage control unit 26 controls the chopper control unit 25 and the inverter control unit 23 based on it and vt.

Next, the power receiving unit 40 will be described. The power receiving unit 40 includes a power receiving coil 41 and a power receiving coil 41.
And the switch unit 4 that controls the conduction between the power receiving coil 41 and the battery 42.
3. The switch unit 43 includes a switch 45 and a switch control unit 46 that controls the switch 45. Further, when a current flows through the power transmission coil 22, a magnetic field is formed around the power transmission coil 22, and a current flows through the power reception coil 41 by electromagnetic induction around the power transmission coil 22.

A power receiving side rectifying unit 44 is provided between the power receiving coil 41 and the switch unit 43. The power receiving side rectifying unit 44 converts the AC voltage input from the power receiving coil 41 into a DC voltage and supplies it to the battery 42 via the switch unit 43.

The power receiving unit 40 includes a power receiving side AC voltage detecting unit 4 that detects a voltage applied to the power receiving coil 41.
7, a power-receiving-side charging current detector 48 that measures the current value of the battery 42, and a power-receiving-side charging current detector 49 that detects the voltage of the battery 42 are provided. The voltage value measured by the power receiving side AC voltage detecting unit 47 is referred to as vra, the current value detected by the power receiving side charging current detecting unit 48 is referred to as irb, and the voltage value detected by the power receiving side charging current detecting unit 49 is referred to as vrb.

The switch control unit 46 monitors vra, irb, and vrb detected by the power receiving side AC voltage detecting unit 47, the power receiving side charging current detecting unit 48, and the power receiving side charging current detecting unit 49. The switch control unit 46 controls the switch 45 based on vra, irb, and vrb. In addition,
It is assumed that when the switch 45 is in the ON state, the power receiving coil 41 and the battery 42 are in conduction, and when the switch 45 is in the OFF state, the conduction between the power receiving coil 41 and the battery 42 is interrupted.

Here, the relationship between the power transmission coil 22 and the power reception coil 41 will be described. The power transmission coil 22 and the power reception coil 41 are correlated with the voltage value and the current value of the power reception coil by the electromagnetic induction and the mutual induction, respectively. That is, vt and vra are values corresponding to each other, and it and irb are also values corresponding to each other.

Therefore, it is possible for the power receiving unit 40 to detect changes in the current value and voltage value of the battery as changes in the current value and voltage value in the power transmission unit 20.

(Non-contact charging method)
Next, the non-contact charging method will be described with reference to FIGS. In FIG. 2, the horizontal axis indicates time, and the vertical axis indicates the state of each part (voltage, current, switch state, etc.).

Charging in this embodiment is constant current constant voltage charging. In constant current / constant voltage charging, first, constant current charging is performed to supply a battery with a constant current value. When the voltage of the battery rises due to constant current charging and reaches a predetermined voltage, constant voltage charging is performed to supply the battery with a constant voltage value. Then, when the current value of the battery decreases and reaches the charging completion current value, the charging is completed.

The non-contact charging method in this embodiment will be described below. When starting charging, the power receiving unit 40
Is close to the power transmission unit 20, and the power receiving coil 41 and the power transmitting coil 22 are close to each other as shown in FIG.
The switch 45 is in an ON state.

First, the charging start step S1 will be described. Let charging start time be time t0. At time t0, a charging command for starting charging is input to the current voltage control unit 26, the current voltage control unit 26 outputs a duty signal (D *) to the chopper control unit 25, and an operation signal to the inverter control unit 23. Enter. The chopper controller 25 outputs a DC voltage based on the intensity of D *, and inputs the AC voltage to the power transmission coil 22 via the inverter controller 23. The power transmission side voltage detection unit 27 detects vt corresponding to D *, the power transmission coil 22 receives a voltage corresponding to vt, and the power reception side AC voltage detection unit 47 detects vra.

The charging command is output when the power receiving unit 40 and the power transmitting unit 20 are in a chargeable relationship. For example, the worker may visually determine that the power receiving unit 40 and the power transmission unit 20 are in a chargeable position, and output a charging command to the power transmission unit 20. In addition, power transmission unit 2
A sensor for grasping the positional relationship with the power receiving unit 40 is attached to 0, the sensor detects that the power receiving unit 40 and the power transmitting unit 20 are in a chargeable position, and outputs a charging command to the power transmitting unit 20 It may be a thing.

After time t0, the current / voltage control unit 26 outputs D * so as to gradually increase from zero. D
As * increases, so does vt and vra. However, from time t0 to t1
In this period, since vra is lower than vrb, no current flows through the battery, and irb is not detected by the power receiving side charging current detector 48.

At time t1, vra becomes equal to vrb, and after time t1, current starts to flow from the power receiving coil 41 to the battery 42, and the power receiving side charging current detection unit 48 detects irb. The power transmission side current detection unit 28 detects it corresponding to irb. In the current voltage control unit 26, i
When it is detected that t is detected, the intensity of D * is gradually increased so that it gradually increases, and D * is input to the chopper controller 25. As a result, the voltage output from the chopper controller 25 continues to gradually increase after time t1, and it also gradually increases and irb increases.

Next, the charging predetermined current detection step S2 will be described. Since it is not preferable to flow an excessive current value to the battery at the time of charging, a predetermined charging current value is uniquely determined as a current value that can flow safely during charging. The predetermined charging current detection step S2 is a step for obtaining the value of it when irb is the predetermined charging current value.

At time t2, irb reaches the predetermined charge current value. A predetermined charging current value is set in advance in the switch control unit 46. When the switch control unit 46 detects that irb has reached the predetermined charging current value, the command S * to the switch 45 is turned OFF, and the switch 45 is turned on. OFF
Let it be in a state. Then, the circuit is cut off and irb becomes 0, and it also becomes 0 corresponding to irb. In FIG. 2, at time t2, a weak excitation current actually continues to flow in it, but in the present embodiment, it will be described as 0.

When it becomes 0, the current-voltage control unit 26 stores it immediately before it becomes 0 as the maximum transmission current value. The maximum power transmission current value corresponds to when it is the charging default current value.
Is almost equal to Actually, the current / voltage control unit 26 detects that it has suddenly decreased, not when it has become 0, and stores it immediately before it suddenly decreases as the maximum transmission current value. Shall. Alternatively, a threshold value is set in advance in the current / voltage control unit 26, and
It is detected that it is less than or equal to the threshold, and it is stored as the maximum transmission current value immediately before it becomes less than or equal to the threshold.

Then, at time t3 after storing the maximum power transmission current value, the voltage / current control unit 26 performs D *
And a stop signal is output to the inverter control unit 23. Since D * becomes 0, vt becomes 0, and the voltage applied to the power transmission coil 21 also becomes 0. Since the voltage applied to the power transmission coil 21 is 0, vra is also 0.

Next, the constant current charging step S3 will be described. The switch control unit 46 detects that vra becomes 0 at time t3 and outputs an ON command S * to the switch 45. At time t4, the switch 45 is turned on. The current / voltage control unit 26
3, the time is measured with a timer etc. from the moment D * is set to 0, and at time t5, it
D * is output so as to be 95% of the maximum power transmission current value, an operation signal is output to the inverter control unit 23, and constant current charging is started. The battery 42 is supplied with a current value corresponding to 95% of the predetermined charge current value due to the correspondence between it and irb. Since the voltage of the battery 42 increases as charging by constant current charging proceeds, vrb and vra rise, and vt also rises corresponding to vrb. It should be noted that it may be determined based on the maximum power transmission current value during constant current charging and is not limited to 95% of the maximum power transmission current value.

At time t6, vrb reaches a predetermined charge voltage value preset in the switch control unit 46, and the switch control unit 46 detects that vrb has reached the predetermined charge voltage value. The switch controller 46 turns off the command S * to the switch 45, and the switch 45 is turned off. Then, the circuit is cut off, irb becomes 0, it also becomes 0 corresponding to irb, and constant current charging is completed.

Next, the charge predetermined voltage detection step S4 will be described. Since it is not preferable to apply an excessive voltage to the battery at the time of charging, a predetermined charging voltage value is determined as a voltage value that can be safely applied during charging. In the predetermined charging voltage detection step S2, vrb
Is a step of obtaining a value of vt when is a predetermined charge voltage value.

When it becomes 0 at time t6, the current-voltage control unit 26 determines that vt immediately before it becomes 0.
Is stored as the maximum power transmission voltage value. The maximum power transmission voltage value is substantially equal to the corresponding value of vt when vrb is the predetermined charging current value. It is assumed that the current / voltage control unit 26 detects that it has become 0 by the same means as in the predetermined charge current detection step S2.

Further, vrb detected by the power receiving side charging voltage detector 49 is the sum of the voltage of the battery 42 and the voltage value applied to the internal resistance of the battery 42. At time t6, the switch is turned off and irb becomes 0, so that the battery current value becomes 0 and the voltage applied to the internal resistance of the battery becomes 0. Therefore, at time t6, vrb decreases from the predetermined charge voltage value by the amount of voltage applied to the internal resistance.

At time t7 when the current voltage control unit 26 stores the maximum power transmission voltage value, the current voltage control unit 26 sets D * to 0, outputs a stop signal to the inverter control unit 23, and inputs the voltage to the power transmission coil 22. Stop. Therefore, the voltage applied to the power transmission coil 21 is 0, and vra
Is also 0.

Next, a constant voltage charging step S5 is performed. The switch control unit 46 performs v at time t7.
It is detected that ra has become 0, and an ON command S * is output to the switch 45. At time t8, the switch 45 is turned ON. The current voltage control unit 26 measures the time from the moment when D * is set to 0 at time t7 by a timer or the like, and at time t9, vt is 98 of the maximum power transmission voltage value.
D * is output so as to be a value of%, an operation signal is output to the inverter control unit 23, and constant voltage charging is started.

Since vt, which is the voltage supplied to the battery 42 via the power transmission coil 41, is 98% of the maximum charging voltage value, the current value irb of the battery 42 is also greater than when vrb is the predetermined charging voltage value. Is about 2% lower. Therefore, the voltage value applied to the internal resistance of the battery 42 at time t9 is smaller than the predetermined charging voltage value, and vrb at time t9 is smaller than the predetermined charging voltage value. Further, as charging by constant voltage charging proceeds, irb decreases and the voltage applied to the internal resistance also decreases. Therefore, in a series of non-contact charging steps, vrb never exceeds the predetermined charging voltage after time t6.

In addition, vt at the time of constant current charge should just be determined based on the power transmission maximum voltage value, and is not restricted to the value of 98% of the power transmission maximum voltage value.

At time t10, the switch control unit 46 has irb in advance.
Detects that the charge completion current value set in is reached and turns off the command S * to the switch 45
Then, the switch unit 45 is turned off. When the circuit is cut off, irb becomes 0, and it also becomes 0 corresponding to irb. When the current voltage control unit 26 detects that it has become 0 at time t10, D * is set to 0 at time t11, and the inverter control unit 23
A stop signal is output to stop the input of the voltage to the power transmission coil 22. Therefore, the voltage applied to the power transmission coil 21 is 0, the voltage applied to the power transmission coil 42 is also 0, and vra is also 0, and constant voltage charging is completed.

Next, charging completion step S6 is performed. The switch control unit 46 performs v at time t11.
It is detected that ra has become 0, and at time t12, an ON command S * is output to the switch 45, and the switch 45 is turned on. And it prepares for the next charge.

Note that the switch control unit 46 can grasp which step of a series of constant voltage and constant current charging is being performed, and sets a preset charge default current value, charge default voltage value, and charge. It is possible to determine which of the completed current values should be detected. For example, when charging is started, the switch control unit 46 first monitors irb to detect a predetermined charging current value. Then, it is determined that the next step is a constant current charging step, and vrb is monitored to detect a predetermined charging voltage value. Then, when detecting the predetermined charge current value, the switch control unit 46 determines that the next step is the charge completion step, monitors irb, and detects the charge completion current value.

(effect)
Hereinafter, effects of the non-contact charging method and the non-contact charging system of the present embodiment will be described. In the non-contact charging method and the non-contact charging system of the present embodiment, since it becomes 0 by turning off the switch 46 when irb or vrb reaches a predetermined value, the power transmission unit 2
0 can detect that the battery current has reached a predetermined value. Also, the power transmission unit 20 is i
By obtaining the value of vt or it when t becomes 0, the value of vt or it when irb or vrb becomes a predetermined value can be obtained.

Therefore, even if the power transmission unit 20 and the power reception unit 40 do not have a configuration such as a communication device for transmitting and receiving the voltage and current values of the battery, the optimum voltage and current for charging are supplied from the power transmission unit to the power reception unit. Is possible. And since the communication apparatus etc. are not mounted, the structure of the power receiving part 40 can be simplified compared with the past, and it can reduce in weight.

Moreover, since the power transmission unit 20 detects it or vt when irb or vrb becomes a predetermined value, it is not necessary to calculate the correspondence between irb and it and the correspondence between vrb and vt by calculation. Therefore, the power transmission unit 20 includes a correspondence relationship between irb and it and vrb and vt.
The configuration of a computer or the like for calculating the correspondence relationship is not necessary. Therefore, the configuration of the power transmission unit 20 can be simplified, the installation space can be reduced, and the weight can be reduced.

Further, in the present embodiment, since it is not necessary to obtain the correspondence between irb and it and the correspondence between vrb and vt by calculation, it is possible to reduce the time required for charging by the time required for calculation.

Moreover, in this embodiment, after the current voltage control part 26 memorize | stores the power transmission maximum current value, after the switch control part 46 detects that vra became 0, constant current charge is started. Therefore, constant current charging is always started after the current-voltage control unit 26 stores the maximum power transmission current value. Therefore, current exceeding a predetermined charging current does not flow through the battery, and safety during charging can be maintained. Similarly, in the case of constant voltage charging, since the constant voltage charging is started after the current voltage control unit 26 stores the maximum power transmission voltage value, the battery is not charged with a voltage higher than the predetermined charging voltage value. It is possible to keep time safety.

(Second Embodiment)
Hereinafter, a second embodiment will be described with reference to FIG. FIG. 4 is a timing chart of the contactless charging method of the present embodiment. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted. In addition, the configuration of the contactless charging system in the present embodiment is as follows.
Although it is the same as that of the non-contact charge system in 1st Embodiment, the switch control part 46 in this embodiment shall have the structure which can measure time, such as a timer.

(Non-contact charging method)
The non-contact charging method in this embodiment will be described with reference to FIG. The non-contact charging method in this embodiment includes the same steps as those in the first embodiment. Charging start step S1 is the same as in the first embodiment.

The predetermined charging current detection step S2 will be described. At time t2, when irb reaches the predetermined charge current value, the switch control unit 46 turns off the command S * to the switch 45, and it
And irb are 0. The current / voltage control unit 26 detects that it has become 0, and
It is stored immediately before it becomes 0 as the maximum transmission current value. The current / voltage control unit 26 stores the maximum power transmission current value and then inputs D * to the chopper control unit 25 so as to input a current equal to or lower than the maximum power transmission current value to the power transmission coil 22. Note that the switch control unit 46 starts the timer and measures the time from the moment when it is detected that irb has reached the predetermined charge current value.

Next, the constant current charging step S3 will be described. The switch control unit 46 measures time, and outputs an ON command S * to the switch 45 at time t4 after a sufficient time has elapsed for the current / voltage control unit 26 to store the maximum transmission power value. To do. Switch 45 is ON
The state is reached, and irb and it are detected at time t5. The current voltage control unit 26 is
When t is detected, D * is output to the chopper control unit 25 so that it is 95% of the maximum power transmission current value, an operation signal is output to the inverter control unit 23, and constant current charging is started. .

At time t6, the switch control unit 46 detects that vrb has reached the predetermined charging voltage, turns off the switch 45, and irb and it become 0. In addition, the switch control unit 46 measures time from the moment when it is detected that irb has reached the predetermined charge current value.

Next, the charge predetermined voltage detection step S4 will be described. The current-voltage control unit 26 detects that it has become 0 at time t6, and stores vt immediately before it has become 0 as the maximum transmission voltage value. Then, the current voltage control unit 26 stores the maximum transmission voltage value, and then inputs D * to the chopper control unit 25 so as to input a voltage equal to or lower than the maximum transmission voltage value to the transmission coil 22.

Next, the constant voltage charging step S5 will be described. The switch control unit 46 measures time, and outputs an ON command S * to the switch 45 at time t8 after a sufficient time has elapsed for the current / voltage control unit 26 to store the maximum transmission voltage value. To do. Switch 45 is ON
The state is reached, and irb and it are detected at time t9. The current voltage control unit 26 is
When t is detected, D * is output to the chopper control unit 25 so that it becomes 98% of the maximum charging voltage value, an operation signal is output to the inverter control unit 23, and constant voltage charging is started. .

At time t10, the switch control unit 46 detects that irb has reached the charge completion current value, turns off the switch 45, and irb and it become 0. Also,
The switch control unit 46 measures time from the moment when it is detected that irb has reached the charge completion current value.

Next, the charging completion step S6 will be described. The current voltage control unit 26 detects that it has become 0, and stops the input of current to the power transmission coil 22 at time t11.
* Is set to 0, and a stop signal is transmitted to the inverter control unit 23. Then, the switch control unit 46
Outputs a command S * of ON to the switch 45 at the time t12 after a sufficient time has elapsed for the current / voltage control unit 26 to stop the input of the current to the power transmission coil 22 for the next charging. Prepare.

In the first embodiment, the switch control unit 46 outputs the ON command S * to the switch 45 by detecting that vra becomes zero. On the other hand, in this embodiment, the switch 45 outputs an ON command S * after a predetermined time from when the switch controller 46 detects a value preset in the switch controller 46. In this embodiment, vra
Therefore, the power receiving side AC voltage detector is not necessary.

In addition, the switch control unit 46 outputs the ON command S * to the switch 45 after a predetermined time from when the switch control unit 46 detects a preset value. It may be a certain time after the control unit 46 detects and outputs the ON command S * to the switch 45.

(effect)
Hereinafter, effects of the non-contact charging method and the non-contact charging system of the present embodiment will be described.

In this embodiment, since it is not necessary to detect vra, it is not necessary to mount a power receiving side AC voltage detection unit. Accordingly, the configuration of the power receiving unit 40 can be simplified and reduced in weight.

Further, in the present embodiment, similarly to the first embodiment, even if the power transmitting unit 20 and the power receiving unit 40 do not have a configuration of a communication device or the like, the optimum voltage and current for charging are supplied from the power transmitting unit to the power receiving unit. Therefore, the configuration of the power receiving unit 40 can be simplified and reduced in weight compared to the conventional case.

Similarly to the first embodiment, the power transmission unit 20 includes the correspondence between irb and it and vr.
Since the configuration of a computer or the like for calculating the correspondence relationship between b and vt is not necessary, the configuration of the power transmission unit 20 can be simplified, the installation space can be reduced, and the weight can be reduced. Further, it is possible to shorten the time required for charging by the time required for the calculation.

As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

For example, although the charging method of the first embodiment and the second embodiment is constant current constant voltage charging, only the constant current charging method or the constant voltage charging method may be performed.

Further, the power source connected to the power transmission unit 20 is not limited to a commercial power source. For example, it may be a power source by private power generation.

Further, the switch control unit 46 detects that either irb or vrb has become a preset value and controls the switch 45, but irb and vrb have become preset values. May be detected to control the switch 45.

In addition, the current voltage control unit 26 stores the value of vt or it.
Both t and it may be stored.

DESCRIPTION OF SYMBOLS 10 ... Non-contact charging device 20 ... Power transmission part 21 ... Current-voltage variable part 22 ... Power transmission coil 23 ... Inverter control part 24 ... Power transmission side rectification unit 25 ... chopper control unit 26 ... current / voltage control unit 27 ... power transmission side voltage detection unit 28 ... power transmission side current detection unit 40 ...・ ・ Receiving unit 41 ・ Receiving coil 42 ・ Battery 43 ・ Switching unit 44 ・ Receiving side rectifying unit 43 ・ Switching unit 45 ・ ・ ・ ・・ Switch 46... Switch control unit 47... Power receiving side AC voltage detecting unit 48... Power receiving side charging current detecting unit 49... Power receiving side charging current detecting unit S 1. ... Charge start step S2 ... Charge predetermined current detection step S3 ... Constant current charge step S4・ ・ ・ Charge predetermined voltage detection step S5 ・ ・ ・ ・ ・ Constant voltage charge step S6 ・ ・ ・ ・ ・ Charge completion step vt ・ ・ ・ ・ ・ Voltage value it detected by the power transmission side voltage detection unit Current value irb detected by the side current detector ... Current value vrb detected by the charge side current detector ... Voltage value D * detected by the charge side voltage detector ... Duty signal S * ... Command to switch

Claims (8)

A non-contact charging system including a power transmission unit and a power reception unit,
The power transmission unit is connected to a power supply and outputs an arbitrary current value or voltage value.
A power transmission coil that is electrically connected to the current-voltage variable unit;
The power receiving unit includes a power receiving coil through which a current flows by electromagnetic induction caused by a magnetic field generated by the power transmitting coil,
A rectifying unit connected to the power receiving coil;
A battery connected to the power receiving coil via the rectifying unit;
A switch for controlling conduction between the power receiving coil and the battery;
A switch control unit for controlling the operation of the switch;
When the switch control unit detects that at least one of the voltage value and the current value of the battery has reached a predetermined value set in the switch control unit in advance, the switch control unit establishes continuity between the power receiving coil and the battery. The switch is controlled so as to be cut off, and the current / voltage variable unit stores at least one of the voltage value and the current value input to the power transmission coil, and then the power reception coil and the battery are made conductive. Control
The current-voltage variable unit gradually increases the voltage to output, detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and according to the detection Non-contact that stores at least one of the voltage value or the current value input to the power transmission coil before the current value of the power transmission coil decreases, and inputs the current value or the voltage value based on the storage to the power transmission coil Charging system. When the switch control unit detects that the current value of the battery has reached a predetermined charge current value preset in the switch control unit, the switch control unit switches the switch to cut off the conduction between the power receiving coil and the battery. Control
The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and the current value of the power transmission coil decreases in response to the detection. The non-contact charging system according to claim 1, wherein a current value of the previous power transmission coil is stored as a power transmission maximum current value, and a constant current value determined based on the power transmission maximum current value is input to the power transmission coil. When the switch control unit detects that the voltage value of the battery has reached a predetermined charge voltage value set in the switch control unit in advance, the switch control unit switches the switch to cut off the conduction between the power receiving coil and the battery. Control
The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and the current value of the power transmission coil decreases in response to the detection. The voltage value of the said power transmission coil before is memorize | stored as a power transmission maximum voltage value, and the fixed voltage value determined based on the said power transmission maximum voltage value is input into the said power transmission coil. Contact charging system. After the input of a constant voltage value based on the maximum power transmission voltage value is started for the power transmission coil,
When the switch control unit detects that the current value of the battery has reached a charge completion current value set in the switch control unit in advance, the switch control unit switches the switch so as to cut off conduction between the power receiving coil and the battery. Control
The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and inputs a voltage to the power transmission coil in response to the detection. The non-contact charging system according to claim 3 which stops. The current voltage variable unit stops the input of the voltage to the power transmission coil after the storage,
The switch control unit, when detecting a decrease in the voltage value of the power receiving coil due to the stop of voltage input to the power transmitting coil, controls the switch so that the power receiving coil and the battery are electrically connected. The non-contact charging system according to claim 4. The switch control unit has a configuration capable of measuring time,
From the time when at least one of the voltage value and the current value of the battery becomes a predetermined value set in the switch control unit in advance, after the time necessary for the storage of the current voltage variable unit, The non-contact charging system according to claim 1, wherein the switch is controlled so that the power receiving coil and the battery are electrically connected. A power transmission unit and a power reception unit,
The power transmission unit is connected to a power supply and outputs an arbitrary voltage value or current value.
A power transmission coil that is electrically connected to the current-voltage variable unit;
The power receiving unit includes a power receiving unit side coil through which a current flows by electromagnetic induction caused by a magnetic field generated by the power transmitting coil,
A rectifying unit connected to the power receiving coil;
A battery connected to the power receiving coil via the rectifying unit;
A switch for controlling conduction between the power receiving coil and the battery;
A non-contact charging method in a non-contact charging device having a switch control unit for controlling the operation of the switch,
The current-voltage variable unit gradually increases the voltage and outputs it,
The switch control unit detects the current value of the battery reaching a predetermined charge current value set in the switch control unit in advance, and controls the switch to cut off conduction between the power receiving coil and the battery. ,
The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and the current value of the power transmission coil decreases in response to the detection. A charge default current value detection step for storing a current value flowing in the previous power transmission coil and stopping input of a current to the power transmission coil;
After the predetermined charging current value detecting step, the switch control unit controls the switch to make the power receiving coil and the battery conductive, and the current voltage variable unit is determined based on the maximum power transmission current value. A constant current charging step for inputting a current value of
The switch control unit detects the current value of the battery reaching a predetermined charge voltage value set in the switch control unit in advance, and controls the switch to cut off conduction between the power receiving coil and the battery. ,
The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and the current value of the power transmission coil decreases in response to the detection. A charging default voltage value detecting step for storing the voltage value input to the previous power transmission coil and stopping the input of the voltage to the power transmission coil;
After the predetermined charging voltage value detecting step, the switch control unit controls the switch so that the power receiving coil and the battery are brought into conduction, and the current voltage variable unit is determined based on the maximum power transmission voltage value. A constant voltage charging step of inputting a current value of
After the predetermined charging voltage value detecting step, the switch control unit detects that the current value of the battery has reached a predetermined charging current value set in the switch control unit in advance, and connects the power receiving coil and the battery. Control the switch to shut off,
The current voltage variable unit detects a decrease in the current value of the power transmission coil due to the switch interrupting conduction between the power receiving coil and the battery, and completes a charging completion step of stopping the input of current to the power transmission coil When,
A contactless charging method. In the constant current charging step and the constant voltage charging step, the switch control unit,
8. The switch is controlled to detect a decrease in the voltage value of the power receiving coil due to the current voltage variable unit stopping the input of voltage to the power transmitting coil, and to connect the power receiving coil to the battery. The non-contact charge method as described in.

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