JP2013115998A - Charging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly protect a contactor and a charge circuit by preventing welding at a contactor terminal part by a large current when a current is cut off.SOLUTION: The charging system includes an emergency stop abnormality detecting means 12 and a low current detecting means 17 in a charge circuit 1. It includes a first switching means 5 which cuts off a power source 4 that is driving a part of or entire charge circuit 1 when emergency stop abnormality is detected, thereby a current value in the charge circuit 1 decreases, and a second switching means 6 which, in a case where a cut off command is issued from a control means 3 to cut off connection by a contactor 2 or the emergency stop abnormality is detected by the emergency stop abnormality detecting means 12, holds the cut off command, and transmits the cut off command that is held to a drive circuit 18 of the contactor 2 only when the low current detecting means 17 detects that a current value in the charge circuit 1 has a predetermined value or less. Thus, the contactor 2 and the charge circuit 1 are properly protected.

Description

  The present invention relates to a charging system provided with a mechanism that ensures that a current value in a charging circuit is equal to or less than a predetermined value when disconnected by a contactor, and prevents contactor welding and other equipment damage.

  Conventionally, there are two types of charging methods for electric vehicles such as electric vehicles and hybrid vehicles: normal charging and quick charging. Examples of such a charging system capable of rapid charging include those described in Patent Document 1. The charging system has a charging circuit for normal charging and a charging circuit for quick charging, and can be switched between each other.

  In such a charging circuit, there are cases where contactors having relay contacts are provided on the charging circuit side and the vehicle side to be charged, respectively, and the charging circuit and the vehicle are connected through both contactors.

  On the other hand, in rapid charging, a vehicular battery is charged in a short time, and thus a very large current flows in the charging circuit. Therefore, when a large current flows through the circuit when disconnecting the contactor, there is a problem that arc discharge occurs at the terminal portion of the contactor and the terminal portion is welded.

  In order to prevent such a problem, as an example of the quick charge standard, it is determined to confirm that the current in the circuit is equal to or less than a predetermined value (for example, ◯ A or less) when the vehicle-side contactor is disconnected.

JP 2010-213535 A

  However, since there is no such standard for the contactor on the charging circuit side, there is a possibility that the contactor is disconnected while a large current is flowing through the charging circuit. For this reason, in order to protect the contactor appropriately, it is desirable to ensure that a large current does not flow through the charging circuit when the charging circuit side contactor is disconnected, and to prevent welding of the terminal portion.

  Also, when an emergency stop abnormality such as electric leakage or ground fault occurs, the power supply to the charging circuit is normally stopped and the contactor is disconnected almost simultaneously, but even if the power supply stop timing is delayed, Contactor may be welded by large current. Therefore, in such a case, it is desirable that charging can be stopped quickly while protecting the contactor terminal portion.

  An object of the present invention is to solve the above problems and to provide a charging system that enables appropriate protection of a contactor and a charging circuit.

  In order to achieve this object, the present invention takes the following measures.

  That is, the charging system of the present invention includes a charging circuit, a contactor that connects and disconnects the charging circuit and a charging target by a relay contact, and a control unit that controls connection and disconnection by the contactor and driving of the charging circuit. The emergency stop abnormality detecting means for detecting the occurrence of an emergency stop abnormality in the charging circuit, and the low current detecting means for detecting that the current value in the charging circuit is a predetermined value or less, further comprising the emergency A first switching unit that cuts off a power source that drives part or all of the charging circuit and detects a current value in the charging circuit when an emergency stop abnormality is detected by the stop abnormality detecting unit. And when the disconnection command for disconnecting the contactor is issued by the control means, or the emergency stop abnormality is detected by the emergency stop abnormality detection means. The cutting command is held, and the holding command is held only when the current value in the charging circuit is detected to be a certain value or less by the low current detecting means. And a second switching means adapted to transmit to the terminal.

  An emergency stop abnormality is a failure that requires an emergency stop of charging, including electric leakage and ground faults. The emergency stop abnormality detection means detects the emergency stop abnormality at one or more places / means.

  By configuring in this way, it is possible to ensure that the current value in the charging circuit is below a certain value when disconnected by the contactor. For this reason, it is possible to avoid the conventional problem that the relay contact portion of the contactor is welded due to a large current at the time of disconnection, and to protect the contactor with certainty.

  Further, when an emergency stop abnormality is detected, in order to reduce the current in the charging circuit by cutting off the power supply in the charging circuit by the first switching means in parallel with the second switching means, Both the contactor and the charging circuit can be adequately protected.

  Further, in order to quickly shut off the power supply of the charging circuit and appropriately protect the charging circuit with the detection of an emergency stop abnormality, the charging system has a hardware component independent of the control means, It is desirable that the hardware component realizes the first switching means without going through the control means.

  Further, in order to easily realize such a hardware component, a switch is provided between the power source and the charging circuit driven by the power source as the first switching unit, and the emergency stop abnormality detection is performed. The detection result of the means is held as a constant voltage, and the current flowing into the charging circuit is controlled by switching the switch according to a deviation between the voltage and the voltage of the power source or a current caused by the deviation It is preferable to do.

  In order to reduce the burden on the control means and to quickly transmit the held disconnection command or connection command to the contactor in realizing the second switching means, the charging system is independent of the control means. It is desirable to have a hardware component, and that the hardware component receives a disconnection command or a connection command from the control unit, and realizes the second switching unit without using the control unit based on the command. .

  Further, in order to easily realize such a hardware component and prevent the charging circuit and the charging target from being connected in an emergency stop abnormal state even when connected by a contactor, the second switching is performed. As a means, the instruction to be held is generated by a logical operation of the detection result by the emergency stop abnormality detection means and the instruction to the contactor by the control means, and the instruction and the detection result by the low current detection means are It is preferable to configure so that a command to be transmitted to the contactor is obtained as an output by using the input.

  Since the charging system of the present invention has the configuration described above, it is possible to ensure that the current value in the charging circuit is below a certain value when disconnected by the contactor, and to reliably prevent welding of the contact points of the contactor. Is possible.

The circuit diagram and block diagram showing the whole charging system which concerns on one Embodiment of this invention. The circuit diagram of the hardware component part which implement | achieves a 1st switching means in the charging system. The circuit diagram of the hardware component part which implement | achieves a 2nd switching means in the charging system. A graph schematically showing a typical operation pattern of the charging system.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the charging system 7 according to the present embodiment includes a charging circuit 1, a contactor 2 attached to a connection terminal between the charging circuit 1 and a charging target, driving of the charging circuit 1 and the contactor 2. Control means 3 for controlling connection / disconnection, power supply 4 used for driving the charging circuit 1, emergency stop abnormality detecting means 12 and low current detecting means 17 installed in the charging circuit 1, and first switching means 5 And the second switching means 6.

  The charging circuit 1 converts the current obtained from the direct current power source 11 into alternating current by the converter 13, converts it to an appropriate voltage by the transformer 15, converts it to direct current again using the full-wave rectifier circuit 16, and This is a general charging circuit that transmits a direct current to a charging target. The converter 13 includes an IGBT 14 (insulated gate bipolar transistor), and plays a role of a switch that opens and closes by a voltage applied to the gate terminal.

  The contactor 2 is a device for connecting / disconnecting the charging circuit 1 and the charging target by a relay contact, and includes a contactor driving circuit 18 for controlling the connection / disconnection.

  The control means 3 is a part in charge of driving the charging circuit 1 by controlling the voltage applied to the gate terminal of the IGBT 14 and connection / disconnection control of the contactor 2 by issuing a disconnection command or a connection command to the contactor 2. Typically, a BMU (Battery Management Unit), a CPU (Central Processing Unit), or the like is used.

  The power supply 4 supplies at least power related to the control of the IGBT 14 through the charging circuit drive board 22 of FIG. For this reason, by cutting off the power supply 4, all the IGBTs do not pass current, and the current value in the charging circuit can be reduced.

  The emergency stop abnormality detection means 12 measures the current value of the corresponding part in the charging circuit 1, and sends an emergency stop abnormality detection signal S1 when a current greater than a certain value is measured. However, the emergency stop abnormality in the present invention is not limited to such an overcurrent, and the emergency stop abnormality detection means 12 may be composed of a plurality of emergency stop abnormality detectors. In that case, one emergency stop abnormality detection signal S1 is generated by a logical operation of signals generated by the respective detectors.

  The low current detection means 17 measures the current value of the corresponding part in the charging circuit 1 and issues a low current detection signal S2 when it is detected that the current value is below a certain value. The low current detection means 17 may be composed of a plurality of low current detectors. In that case, one low current detection signal S2 is generated by logical operation of signals generated by the respective detectors.

  Next, specific configurations of the first switching unit 5 and the second switching unit 6 will be described. The hardware configuration part 105 of the first switching means is realized by the circuit configuration of FIG. Hereinafter, the circuits in FIGS. 2 and 3 are digital circuits, and the voltage takes one of H and L values. The transistor 21 is used as a switch, and typically a PNP transistor is used. Only when the emergency stop abnormality detection signal S1 is H (normal state), a current flows between the power source 4 and the emitter-collector of the transistor 21, so that the power source 4 can be energized to the charging circuit drive substrate 22. Become. On the other hand, the wiring for supplying power to the charging circuit drive board 22 is connected to the control means 3, and power is supplied to the charging circuit drive board 22 only when the voltage sent from the control means 3 is H (gate drive state). It has a configuration. A relay or the like may be used for the switch portion.

  The hardware configuration part 106 of the second switching means is realized by the circuit configuration of FIG. The AND gate 31 receives the emergency stop abnormality detection signal S1 and the contactor connection / disconnection signal S3 from the control means 3 (H represents a connection command, L represents a disconnection command), and an output is one of latch circuits D The input of the latch 32. On the other hand, the D-latch 32 receives the low current detection signal S2 (H represents a low current state) as a latch signal, and transmits the input signal to the contactor drive circuit 18 as an output only when the latch signal is H. The D-latch 32 is typically realized by an integrated circuit having this function.

  Next, a typical operation when the charging system 7 configured as described above is stopped will be described with reference to FIG.

  A graph 41 on the left side of FIG. 4 shows a typical operation of the charging system 7 at the time of a normal stop due to the completion of charging or when a normal stop abnormality occurs. Here, the normal stop abnormality refers to an abnormality that stops the charging operation by the same process as the normal stop due to the end of charging. When the charging operation is stopped by the control means 3 at time A in the figure due to the completion of charging or the occurrence of a normal stop abnormality, the output current decreases. When the output current becomes 5A at time B, the low current detection signal S3 becomes H. However, since the contactor disconnection signal S3 by the control means 3 is still H (connection command is issued), the contactor 2 is connected. Keep. When the contactor connection / disconnection signal S3 by the control means 3 becomes L (disconnect command is issued) at time C, the output signal of the D-latch 32 becomes L and the contactor 2 is safely disconnected.

  A graph 42 on the right side of FIG. 4 shows a typical operation of the charging system 7 in the case of an emergency stop. When a serious failure is detected, the charging operation stop process by the control means 3 is started at the point D in the figure, and at the same time, the power source 4 is shut off by the first switching means 5 and the drive power supply to the IGBT 14 is stopped. To do. For this reason, the output current rapidly decreases. When the output current becomes 5 A at the time point E, the low current detection signal S3 becomes H and the output signal of the D-latch 32 becomes L, so that the contactor 2 is safely disconnected.

  As described above, the charging system 7 according to the present embodiment includes the charging circuit 1, the contactor 2 that connects and disconnects the charging circuit 1 and the charging target by the relay contact, the connection and disconnection by the contactor 2, and the charging circuit 1. In the charging system having the control means 3 for controlling the driving, the emergency stop abnormality detecting means 12 for detecting the occurrence of the emergency stop abnormality in the charging circuit 1 and the current value in the charging circuit 1 are below a certain value. And a low-current detection means 17 for detecting this, and further, when the emergency stop abnormality is detected by the emergency stop abnormality detection means 12, the power supply 4 driving part or all of the charging circuit 1 is shut off. The first switching means 5 that reduces the current value in the charging circuit 1 and the disconnection command for disconnecting the contactor 2 from the control means 3 are issued. If the emergency stop abnormality detection means 12 detects an emergency stop abnormality, the disconnection command is held, and the current value in the charging circuit 1 is less than a predetermined value by the low current detection means 17. The second switching means 6 is configured to transmit the held cutting command to the contactor 2 only when it is detected.

  By configuring in this way, it is possible to ensure that the current value in the charging circuit 1 is below a certain value when disconnected by the contactor 2. Therefore, it is possible to avoid the conventional problem that the relay contact portion of the contactor 2 is welded due to a large current at the time of disconnection, and to protect the contactor 2 with certainty.

  In addition, when an emergency stop abnormality is detected, the power source 4 in the charging circuit 1 is shut off by the first switching unit 5 in parallel with the second switching unit 6 and the current in the charging circuit 1 is Therefore, both the charging circuit 1 and the contactor 2 can be properly protected.

  The charging system 7 includes a hardware component 105 independent of the control unit 3, and the hardware component 105 realizes the first switching unit 5 without the control unit 3. Therefore, the power supply 4 of the charging circuit 1 can be quickly shut down with the detection of an emergency stop abnormality, and the charging circuit 1 can be appropriately protected.

  Further, the hardware component 105 includes a transistor 21 used as a switch between the power source 4 and the charging circuit 1 driven by the power source 4 as the first switching unit 5, and the emergency stop abnormality The detection result of the detection means 12 is held as a constant voltage, and the charging is performed through the charging circuit drive substrate 22 by switching the transistor 21 by a deviation between the voltage and the voltage of the power supply 4 or a current generated by the deviation. The circuit is configured to control the current flowing into the circuit 1 and is configured by a simple hardware circuit.

  The charging system 7 has a hardware component 106 that is independent of the control means 3, and the hardware component 106 receives a disconnection command or a connection command from the control means 3, and based on the command. Since the second switching unit 6 is realized without the control unit 3, the burden on the control unit 3 can be reduced and the held disconnection command or connection command can be quickly transmitted to the contactor 2. it can.

  Further, the hardware component 106 described above is a logical operation by the AND gate 31 of the detection result by the emergency stop abnormality detecting unit 12 and the command to the contactor 2 by the control unit 3 as the second switching unit 6. The command to be held is generated, and the command to be transmitted to the contactor 2 is obtained as an output by using the command and the detection result by the low current detection means 17 as an input of a logic circuit, that is, the D-latch 32. In addition, it is configured by a simple hardware circuit and prevents the charging circuit and the charging target from being connected in an emergency stop abnormal state even when connected by a contactor.

  The specific configuration of each unit is not limited to the above-described embodiment, and other configurations can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Charging circuit 2 ... Contactor 3 ... Control means 4 ... Power supply 5 ... 1st switching means 6 ... 2nd switching means 7 ... Charging system 11 ... DC power source 12 ... Emergency stop abnormality detection means 13 ... Converter 14 ... IGBT (Insulated gate bipolar transistor)
DESCRIPTION OF SYMBOLS 15 ... Transformer 16 ... Full wave rectifier circuit 17 ... Low current detection means 18 ... Contactor drive circuit 21 ... Transistor 22 ... Charging circuit drive board 31 ... AND gate 32 ... D-latch 41 ... When a normal stop or a normal stop abnormality occurs Operation graph 42 ... Operation graph 105 at emergency stop ... Hardware component 106 of the first switching means 106 Hardware component of the second switching means

Claims (5)

In a charging system comprising: a charging circuit; a contactor for connecting and disconnecting the charging circuit and a charging target by a relay contact; and a control means for controlling connection and disconnection by the contactor and driving of the charging circuit. An emergency stop abnormality detecting means for detecting the occurrence of an abnormality and a low current detecting means for detecting that the current value in the charging circuit is equal to or less than a predetermined value, and further, an emergency stop abnormality is detected by the emergency stop abnormality detecting means. A first switching unit that cuts off a power source that drives a part or all of the charging circuit as it is detected, and a current value in the charging circuit decreases; and a connection by a contactor by the control unit The disconnection command is held when a disconnection command for disconnecting is issued or when an emergency stop abnormality is detected by the emergency stop abnormality detection means. Second switching means configured to transmit the disconnection command held only when the current value in the charging circuit is detected to be equal to or less than a predetermined value by the low current detection means, to the contactor; A charging system comprising: 2. The charging system according to claim 1, further comprising a hardware component independent of the control unit, wherein the hardware component realizes the first switching unit without the control unit. Characteristic charging system. The charging system according to claim 2, wherein the first switching unit includes a switch between the power source and the charging circuit driven by the power source, and the detection result of the emergency stop abnormality detecting unit is constant. And the current flowing into the charging circuit is controlled by switching the switch according to a deviation between the voltage and the voltage of the power source or a current generated by the deviation. system. 4. The charging system according to claim 1, further comprising a hardware component independent of the control unit, wherein the hardware component receives a disconnection command or a connection command from the control unit. A charging system that realizes the second switching means without using the control means based on the command. 5. The charging system according to claim 4, wherein the command to be held is generated by a logical operation of a detection result by the emergency stop abnormality detection unit and a command to the contactor by the control unit as the second switching unit. The charging system is configured to obtain, as an output, a command to be transmitted to the contactor by using the command and the detection result by the low current detection means as an input of a logic circuit.

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