JP3430120B2 - Energy transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy transfer device which is connected to a plurality of energy storage means and transfers energy between the energy storage means, and more specifically, a voltage across the plurality of energy storage means is uniform. The present invention relates to an energy transfer device suitable for converting into energy.

[0002]

2. Description of the Related Art Nowadays, electric vehicles are actively developed, and batteries for driving the electric vehicles are also actively developed. As a battery of this type, an electric double layer capacitor is currently regarded as promising. On the other hand, at this stage, it is difficult to charge the electric double layer capacitor to a high voltage. Therefore, in order to use as a battery for an electric vehicle capable of outputting a high voltage and having a large capacity, several to several tens of them are connected in series, and the voltage between terminals of each electric double layer capacitor is made equal. It is necessary to charge it efficiently. Therefore, the applicant has already proposed a transfer device as a device for homogenizing the electric energy stored in a plurality of electric double layer capacitors (Japanese Patent Application No. 11-113235).

Transfer device 3 already proposed by the applicant
Basically, as shown in FIG. 3, 1 is N capacitors C1 to CN (hereinafter, referred to as "capacitor C" when not distinguished) as electric energy storage means connected in series in a battery BT. ) It is configured to allow the transfer of energy between each other. Specifically, the transfer device 31 includes windings W1 to WN wound with the same number of turns.
(Hereinafter, when no distinction is made, it will be referred to as “winding W”)
The winding W (N +) wound by the number of times N times that of the winding W.
1) and a transformer 12 having in this case,
The windings W1 to W (N + 1) are magnetically coupled to each other by an iron core. Further, the transfer device 31 is configured so that each winding W
Of the winding S and the switches S1 to SN (hereinafter, referred to as "switch S" when no distinction is made) connected between the winding end side terminal and the negative side terminal of the capacitor C, respectively.
It has a diode D connected between the winding start side terminal of (N + 1) and the negative side terminal of the capacitor CN. In this case, each switch S is composed of, for example, an FET or a bipolar transistor, and is turned on / off in synchronization with each other by a switching control unit (not shown). Further, the transfer device 31 includes a connecting connector 3, and the connecting connector 3 is configured to be connectable to the connecting connector 21 on the battery BT side. On the other hand, each connection terminal of the connection connector 21 is connected to the battery B.
Each of the capacitors C1 to CN in T is connected to each terminal via a connection cable WC.

In the transfer device 31, the connection connector 3 is connected to the connection connector 21 on the battery BT side, and in this state, the switches S are controlled to be turned on in synchronization with each other. At this time, the capacitor C having a high terminal voltage among the capacitors C outputs a current through a current path composed of its plus terminal, the winding W, the switch S, and the minus terminal of the capacitor C. In this case, a voltage approximately equal to the terminal voltage of the capacitor C is induced at both ends of each winding W, and the transformer 12 is excited. At the same time, a current based on each induced voltage is applied to the winding start side terminal of each winding W, the capacitor C, the switch S, and each winding W.
The current continues to flow through the current path composed of the winding end side terminals, whereby the capacitors C other than the capacitor C having a high terminal voltage are charged. Next, as a result of the charging being sequentially stopped from the capacitor C in which the voltage between terminals has reached the voltage equal to the induced voltage, a part of the energy stored in the capacitor C having a high terminal voltage is distributively transferred to another capacitor C.

Next, when the switch S is controlled to the off state, the current based on the excitation energy of the transformer 12 becomes
Winding end terminal of winding W (N + 1), capacitor C1
~ CN series circuit, diode D, and winding W (N +
The current flows from the winding start side terminal of 1), whereby the excitation energy of the transformer 12 is dispersed and transferred to each capacitor C. Thus, by synchronously turning on / off each switch S, a part of the energy stored in the capacitor C having a high terminal voltage is dispersed and transferred to another capacitor C, resulting in a simple configuration. The voltage between the terminals of each capacitor C can be made uniform.

[0006]

However, the transfer device 31 proposed by the applicant has the following points to be improved. That is, in the transfer device 31, it is necessary to connect each terminal of the numerous capacitors C and each terminal of the connection connector 3 in the transfer device 31 with the connection cable WC. On the other hand, in each cable in the connection cable WC, a connection failure between each terminal of the connection connector 21 and each terminal of the capacitor C, and a connection abnormality such as disconnection may occur. In such a case, when the switch S is turned on, the capacitor C connected to the cable in which the connection abnormality has occurred cannot release the stored energy, but the switch S is turned off. When this is done, the excitation energy of the transformer 12 is forcibly accumulated. Therefore, the voltage across the terminals of only the capacitor C continues to rise. Therefore, contrary to the purpose of equalizing the terminal voltage of each capacitor C, there is a possibility that an abnormal increase in the terminal voltage occurs, and the transfer device 31 is desired to be improved in this respect.

The present invention has been made to solve the above points to be improved, and it is possible to avoid an abnormal rise in the voltage between terminals in the energy storage means due to an abnormal connection with the energy storage means. The main purpose is to provide an energy transfer device.

[0008]

In order to achieve the above object, an energy transfer device according to claim 1 is a transformer having a plurality of windings magnetically coupled to each other, and each of the windings is connected in series and is mutually connected. A plurality of switch means that are switched in synchronization with each other, and an energy transfer configured such that each of the first series circuits including at least the winding and the switch means can be connected in parallel to each of the plurality of energy storage means. A device, wherein
Connected between both ends of the plurality of first series circuits
A first photodiode and each of the first photodiodes
A plurality of first switches that are turned on each time the lamp emits light
And a phototransistor of each of the plurality of first series circuits for monitoring each voltage between both ends of each of the plurality of first series circuits .
1 is provided with a voltage monitoring means for outputting a monitoring result according to the operating state of the phototransistor .
In this case, the output of the monitoring result is the display of each voltage value itself between both ends of the first series circuit, the output of the voltage data corresponding to each voltage value, and each of the voltage values is almost 0 volt. The output of an alarm signal when the voltage drops is included.

Further, there is provided a control unit for stopping switching to the switch means when it is determined that at least one of the voltages is substantially 0 volt during the off state of the switch means based on the monitoring result of the voltage monitor means. Is preferred.

Further, it is more preferable to include a monitor control switch means for controlling the start and stop of the monitor operation by the voltage monitor means.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of an energy transfer device according to the present invention will be described below with reference to the accompanying drawings. The same components as those of the transfer device 31 are designated by the same reference numerals, and duplicated description will be omitted.

First, the operating principle of the energy transfer device according to the present invention will be described with reference to FIG.

As shown in FIG. 1, the transfer device 1 is capable of transferring energy between N electric double layer type capacitors C1 to CN as energy storage means connected in series in the battery BT. Is configured. Specifically, the transfer device 1 includes a transformer 2 having windings W1 to WN wound with the same number of turns. In this case, it is assumed that the transformer 2 functions as an ideal transformer in which the resistance component of each winding W is 0Ω, there is no leakage inductance, and there is no exciting current. The windings W1 to WN are magnetically coupled to each other by an iron core. Further, the transfer device 1 includes switches S1 to SN, which are respectively connected between the winding end side terminal of each winding W and the negative side terminal of each capacitor C, and the connector 3 for connection.
And N voltage detection circuits A1 to AN (hereinafter, referred to as "voltage detection circuit A" when no distinction is made) corresponding to the voltage monitoring means in the present invention.

The voltage detection circuit AM (in this specification, the symbol M is the M-th number of the voltage detection circuits A1 to AN,
Alternatively, it means the M-th number of each component corresponding to the voltage detection circuit AM) is connected to the pair of connection terminals TM1 and TM2 in the connection connector 3, respectively. On the other hand, the pair of connection terminals TM1 and TM2 are connected to the connection connector 21 on the battery BT side and the connection cable WC.
Through the capacitor CM corresponding to the voltage detection circuit AM
Are connected to both terminals. This voltage detection circuit AM
Monitors the voltage between both ends of the first series circuit composed of the winding W and the switch S, and when the voltage between both ends of the first series circuit is almost 0V during the period when the switch S is in the OFF state, Low level (earth potential) alarm signal S
Output A. In this case, when at least one voltage detection circuit A outputs the alarm signal SA, the transfer device 1 outputs the alarm signal SA to the outside of the device.

In this transfer device 1, the connecting connector 3 is connected to the connecting connector 21 on the battery BT side, and in this state, the switches S are controlled to be turned on synchronously.
At this time, the capacitor C having a high terminal voltage among the capacitors C outputs a current through a current path composed of its plus terminal, the winding W, the switch S, and the minus terminal of the capacitor C. In this case, a voltage approximately equal to the terminal voltage of the capacitor C is induced at both ends of each winding W, and the transformer 2 is excited. at the same time,
The current based on each induced voltage continues to flow through the current path formed by the winding start side terminal of each winding W, the capacitor C, the switch S, and the winding end side terminal of each winding W, whereby
The capacitors C other than the capacitor C having a high terminal voltage are charged. Next, as a result of the charging being sequentially stopped from the capacitor C in which the voltage between terminals has reached the voltage equal to the induced voltage, a part of the energy stored in the capacitor C having a high terminal voltage is distributively transferred to another capacitor C. Therefore, the voltage across the terminals of each capacitor C can be made uniform even with a simple configuration.

On the other hand, due to long-term use and the like, the connection cable WC is broken, the connection between the connection cable WC and the capacitor C is defective, and the switch SM and the winding WM are used.
A contact failure between the both ends of the series circuit and the pair of connection terminals TM1 and TM2 and a contact failure between the connection connector 21 and the connection connector 3 may occur. If such an abnormal connection state continues, only the voltage across the terminals of the specific capacitor C rises abnormally. Therefore, each voltage detection circuit A monitors the voltage between both ends of the first series circuit during the period in which each switch S is in the off state, and when the monitoring result is almost 0 V, the alarm signal is output. Output SA. At this time, the control device (not shown) controls each switch S to the off state when detecting the output from the transfer device 1 of the alarm signal SA. As a result, it is possible to avoid an abnormal voltage rise of the capacitor C due to a connection abnormality such as a disconnection of the connection cable WC.

Next, the specific structure and operation of the energy transfer device according to the present invention will be described with reference to FIG. The same components as those of the transfer devices 1 and 31 are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 1, the transfer device 11 includes a transformer 12, switches S1 to SN, a diode D, voltage detection circuits A1 to AN, a connector 3, a controller 13 for controlling switching of each switch, and A switch Sa corresponding to the monitor control switch means in the present invention is provided.

The voltage detection circuit AM is formed of a resistor RM, a photodiode PD2M corresponding to the first photodiode of the present invention, and a phototransistor PT1M corresponding to the second phototransistor of the present invention. A pair of connection terminals TM1,
It has a second series circuit connected between TM2. Further, the voltage detection circuit AM is a phototransistor PT2M corresponding to the first phototransistor in the present invention.
And a photodiode PD1M connected in series with the resistor Ra and corresponding to the second photodiode in the present invention. In this case, the photodiode PD2M and the phototransistor PT2M are housed in one integrated package, and the phototransistor P2M
The T2M enters light emitted when a current flows through the photodiode PD2M, and shifts from the off state to the on state. Further, the photodiodes PD11 to PD1N are connected to the connector 3 for connection via the resistor Ra and the switch Sa.
Are connected in series between the pair of power supply connection terminals Ta and Tb. Further, the photodiode PD1M and the phototransistor PT1M are housed in one integrated package, and
The 1M enters light emitted when a current flows through the photodiode PD1M and shifts from the off state to the on state.

On the other hand, the control unit 13 controls ON / OFF switching of each switch S, and when the switch Sa is turned on, a low level alarm signal SA is emitted from the emitter of the phototransistor PT2N.
Is output, each switch S is controlled to the off state.

Next, the operating principle of the transfer device 11 will be described. First, after connecting the connecting connector 3 to the connecting connector 21 on the battery BT side, the power switch (not shown) in the transfer device 11 is operated to the ON state. In this case, the positive side terminal of the battery BT is connected to the connection terminal Ta of the connection connector 3, and the negative side terminal of the battery BT is connected to the connection terminal Tb of the connection connector 3.
At this time, the battery voltage of the battery BT is input to the control unit 13 via the resistor Ra and the photodiodes PD11 to PD1N. Therefore, the control unit 13 detects the connection of the connection connector 3 and the connection connector 21 and controls the switches S to be in the ON state in synchronization. In this case, since the battery voltage is not input when the connection terminals Ta and Tb of the connection connector 3 are not reliably connected to the connection terminals of the connection connector 21, the control unit 13
Maintains the OFF state of each switch S without starting switching control for each switch S. As a result, erroneous operation start of the transfer device 11 is avoided when the connection connector 3 and the connection connector 21 are in the unconnected state or the poor contact state, or when the wiring abnormality occurs in the connection cable WC1.

On the other hand, when each switch S is turned on by the control unit 13, the capacitor C having a high terminal voltage among the capacitors C has its plus terminal, the winding W, the switch S, and the capacitor C. The current is output through the current path composed of the negative terminal of C. In this case, a voltage approximately equal to the terminal voltage of the capacitor C is induced at both ends of each winding W, and the transformer 12 is excited. At the same time, the current based on each of the induced voltages continues to flow in the current path consisting of the winding start side terminal of the winding W, the capacitor C, the switch S, and the winding end side terminal of the winding W, whereby
The other capacitors C are charged respectively. Then, the capacitor C whose terminal voltage has reached a voltage equal to the induced voltage
As a result of the sequential charging being stopped from a part of the stored energy of the capacitor C having a high terminal voltage,
Will be distributed and transferred to.

Next, when the control section 13 controls the switch S to the off state, a current based on the excitation energy of the transformer 12 causes the winding end terminal of the winding W (N + 1), the series circuit of the capacitors C1 to CN, and the diode D. , And a winding start side terminal of the winding W (N + 1), and the excitation energy of the transformer 12 is distributed and transferred to each capacitor C. As described above, by synchronously performing on / off switching control of each switch S, a part of the energy stored in the capacitor C having a high terminal voltage is dispersed and transferred to another capacitor C, resulting in a simple configuration. However, the voltage across the terminals of each capacitor C can be made uniform.

When the switch Sa is turned on,
The voltage monitoring process is performed while each switch S is in the off state. The voltage monitoring process can also be started from the control device side outside the device. In this case, the switch inside the control device is operated to connect the control connection terminal to the ground potential. In this process, the cathode of the photodiode PD1N is connected to the ground potential via the switch Sa, so the control unit 13 first detects the closing operation of the switch Sa. At the same time, since the battery voltage of the battery BT is applied between the resistor Ra and the photodiodes PD11 to PD1N, the photodiodes PD11 to PD1 are
Each N emits light. At this time, each phototransistor PT1M corresponding to each photodiode PD1M is turned on. In this case, each capacitor CM,
The corresponding switch SM and the first series circuit of the winding WM are connected to the connecting connectors 3 and 21 and the connecting cable WC.
When it is surely connected via 1, the terminal voltage of the capacitor CM is applied to both ends of the corresponding voltage detection circuit AM. Therefore, while each switch S is in the OFF state, the current based on the voltage across the terminals of the capacitor CM flows through the current path formed by the resistor RM, the photodiode PD2M, and the phototransistor PT1M, whereby the photodiode PD2M emits light. At this time, the phototransistor PT2M corresponding to the photodiode PD2M is turned on.

In this case, all phototransistors P
When T21 to PT2N are turned on, a high level alarm signal SA, which means a normal state, is output. At this time, the control unit 13 continues on / off switching for each switch S. On the contrary, if a connection abnormality such as disconnection of the connection cable WC1 occurs,
Capacitor CM and corresponding switch SM and winding W
When the first series circuit of M is not connected, the voltage across the terminals of the capacitor CM becomes the drive circuit AM.
Photodiode PD2M because it is not applied to both ends of
Turns off. At this time, the corresponding phototransistor PT2M is maintained in the off state. As a result, at this time, a low level alarm signal SA is output. On the other hand, when the low-level alarm signal SA is output, the control unit 13 determines that a connection abnormality has occurred, and controls each switch S to the off state. As a result, it is possible to reliably avoid an abnormal increase in the inter-terminal voltage of the specific capacitor C due to the abnormal connection. At the same time, since the alarm signal SA is output to the outside of the device, the control device outside the device can reliably detect that the connection abnormality has occurred between the battery BT and the transfer device 11.

Thus, according to the transfer device 11,
The voltage monitoring process is started only when the switch Sa is operated. Therefore, the power consumption of the transfer device 11 can be reduced and the power consumption of the battery BT can be reduced as compared with the method in which the voltage monitoring process is always performed with the power switch turned on. Further, when the connection abnormality occurs between the battery BT and the transfer device 11, the control unit 13 immediately controls the switches S to be in the off state, so that the abnormal increase in the inter-terminal voltage of the capacitor C is promptly avoided. be able to.

The present invention is not limited to the above-described embodiments of the invention, and its configuration can be modified as appropriate. For example, in the embodiment of the present invention, the electric double layer type capacitor has been described as an example of the energy storage means, but the energy storage means is not limited to this, and various types of capacitors and secondary batteries are included. Further, each energy storage means is not limited to the case of being connected in series, but can be applied to a case where each energy storage means is isolated and independent of each other. Further, it can be applied even when the rated charging voltage of each energy storage means is different. In such a case, the winding ratio of each winding W may be specified so as to be proportional to the rated charging voltage of each energy storage means. Further, in the embodiment of the present invention, the example in which the battery BT and the transfer device 1 (or 11) are connected via the connection cable WC (or WC1) has been described, but various connecting means such as a print type flexible cable is used. Can be connected.
In addition, in the embodiment of the present invention, the connecting connector 3,
Although the example in which the battery BT and the transfer device 1 (or 11) are connected via 21 has been described, it goes without saying that the present invention can also be applied to a method in which a connection cable WC (or WC1) is soldered to both of them and directly connected. Is.

The configuration of the voltage monitoring means is not limited to that of the embodiment of the present invention. For example, a Zener diode or the like is used, and the first coil is composed of the winding W and the switch S while the switch S is in the off state. It is also possible to adopt a configuration in which the alarm signal SA can be output when the voltage across the series circuit of is about 0V. Furthermore, it is also possible to adopt a configuration in which the voltage monitoring means constantly or periodically monitors when the power is on. Further, it is also possible to adopt a configuration in which the voltage monitoring means outputs the monitoring result to the outside of the device via an insulating circuit composed of a phototransistor or the like. In addition, the application range of the present invention is not limited to the use for equalizing the terminal voltage of the capacitor as each cell of the automobile battery, and, for example, in a power storage system in which a large capacity power storage means is connected in series, Needless to say, it can be applied to various uses, such as when the voltages across the large-capacity storage means are made uniform.

[0029]

As it is evident from the foregoing description, according to the energy transfer device of claim 1, which between the ends of the plurality of first series circuits each consisting of at least windings and switching means
The first photodiode connected to each of the first photodiodes and each first photodiode
When the photodiode emits light, it goes to ON state.
A plurality of first phototransistors, and a plurality of first phototransistors
Each monitors the respective voltages between both ends of the series circuit each
By providing the voltage monitoring means for outputting the monitoring result in accordance with the operating state of the first phototransistor, the monitoring result output from the voltage monitoring means is further monitored, thereby connecting with the energy storage means. It is possible to avoid an abnormal increase in the inter-terminal voltage in the energy storage means due to an abnormality or the like. In addition, a plurality of first photos
The diode and the plurality of first phototransistors are electrically connected.
By configuring the pressure monitoring means, voltage can be easily and inexpensively.
The monitoring means can be configured. In this case, the first
Energy of the collector and emitter of the phototransistor
By insulating the transfer device from the energy transfer device,
It is also possible to output the monitoring result in an insulated state.

Further, according to the energy transfer device of the present invention, when the control section determines that at least one of the voltages is substantially 0 volt during the period when the switch means is in the off state based on the monitoring result of the voltage monitoring means. Moreover, by stopping the switching of the switch means, it is possible to quickly avoid an abnormal rise in the inter-terminal voltage in the energy storage means due to the connection abnormality of the connection means.

Further, according to the energy transfer apparatus of the third aspect, the power consumption of the energy transfer apparatus is reduced by providing the monitoring control switch means for controlling the start and stop of the monitoring operation by the voltage monitoring means. It can be reduced.

[Brief description of drawings]

FIG. 1 is a transfer device 1 for explaining the operation principle of the present invention.
It is a basic principle figure of.

FIG. 2 is a circuit diagram of the transfer device 11 according to the embodiment of the present invention.

FIG. 3 is a circuit diagram of a transfer device 31 already proposed by the applicant.

[Explanation of symbols]

1, 11 Transfer device 2, 12 Transformer 12 Transformer 13 Control unit A1 to AN Voltage detection circuit BT Battery C1 to CN Capacitor S1 to SN Switch SA Warning signal Ta, Tb, T11 to TN1, T12 to TN2 Connection terminal W1 to WN Winding line

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fujio Matsui 1-7-2 Nishishinjuku, Shinjuku-ku, Tokyo Within Fuji Heavy Industries Ltd. (56) Reference US Patent 5821729 (US, A) US Patent 5666041 (US) , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02J 1/00-1/16 H02J ⁷ /00-7/12 H02J ⁷ /34-7/36

Claims (3)

(57) [Claims] 1. A transformer comprising a plurality of windings magnetically coupled to each other, and a plurality of switch means connected in series to each of the windings and switched in synchronization with each other, at least the winding and the winding. An energy transfer device configured such that each of the first series circuits including switch means can be connected in parallel to each of the plurality of energy storage means, and the energy transfer device is connected between both ends of the plurality of first series circuits. It
A first photodiode, and each of the first photodiodes
A plurality of devices that each turn on when emitting an ion
And a first phototransistor, the monitors the respective voltages between both ends of the plurality of first series circuits each
An energy transfer device comprising a voltage monitoring means for outputting a monitoring result according to an operating state of each first phototransistor . 2. A control unit for stopping switching to the switch means when at least one of the voltages is determined to be substantially 0 volt during a period in which the switch means is in an off state based on the monitoring result of the voltage monitoring means. The energy transfer device according to claim 1, wherein the energy transfer device is provided. 3. The energy transfer device according to claim 1, further comprising monitoring control switch means for controlling the start and stop of the monitoring operation by the voltage monitoring means.