JP2011015532A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charger for detecting battery voltage with a simple structure.SOLUTION: The charger is provided with a smoothing capacitor generating first output voltage, a power converting part outputting power used for converting inputted power and generating the first output voltage to the capacitor, a relay part which is driven in accordance with an applied relay signal and permits or does not permit relay of the first output voltage, a charging battery charged by applying the first output voltage when relay of the first output voltage is permitted in the relay part, a battery information managing unit detecting second output voltage which is actually outputted from the charging battery and outputs it as battery information obtained by making the second output voltage into digital information, a power converting part information managing unit receiving the battery information via a communication line, and a control part controlling the power converting part based on the first output voltage inputted via an analog signal line and generating and outputting the relay signal by using the first output voltage and using the battery information received via the power converting part managing unit.

Description

  The present invention relates to a vehicle-mounted charging device, and is particularly suitable for use in preventing the occurrence of an inrush current or discharging of a rechargeable battery.

  Conventionally, rechargeable rechargeable batteries have been used as power supply means for devices mounted on vehicles. Such a rechargeable battery is charged by a charging device that converts external power from a commercial power source into DC power.

  Japanese Patent Application Laid-Open No. 02-303335 (Patent Document 1) introduces a method for controlling such a charging device. As shown in FIG. 7, the charging device 10 includes a charger 11 (a power converter in the claims), a capacitor 12 provided at a subsequent stage of the charger 11, and a battery switch 13 connected to the power supply line La. (Relay part in a claim), the battery 14 connected via the battery switch 13, and the control circuit 15 which compares the capacitor voltage Vc and the battery voltage Vb, and controls the battery switch 13. In addition, the charging device 10 is connected to the AC power AC on the input side, and connected to the inverter INV and the load LD on the output side. With this configuration, the charger 11 is controlled by the control circuit 15, and the load LD is appropriately adjusted. It is a device to be controlled.

  In such a charging device 10, the capacitor voltage Vc and the battery voltage Vb are compared, and the charger 11 is controlled so that both voltages match. Then, the charging device 10 opens the battery switch 13 when the voltage values of the capacitor voltage Vc and the battery voltage Vb are different, and when the voltage values of the capacitor voltage Vc and the battery voltage Vb match, 13 is in a closed state, thereby preventing the occurrence of an inrush current.

Japanese Patent Laid-Open No. 02-303335

  However, the technique according to Patent Document 1 requires a signal line Ld for detecting the battery voltage Vb, which causes a problem that the circuit configuration is complicated. In addition, since an analog signal is transmitted through the signal line Ld, if noise is superimposed on the signal, the control circuit 15 cannot appropriately perform the comparison process between the capacitor voltage Vc and the battery voltage Vb. Occurs. In particular, since the signal line Ld for detecting the battery voltage Vb is longer than the signal line Lb for detecting the capacitor voltage, the signal line Ld is easily affected by noise. At this time, even if it is determined by the control circuit 15 that both voltages are the same, there may be an erroneous determination due to noise, so if the actual battery voltage Vb is greater than the capacitor voltage Vc, A problem arises in that the battery voltage is discharged and an inrush current flows into the capacitor 12.

  In view of the above problems, a first object of the present invention is to provide a charging device capable of detecting a battery voltage with a simple configuration. A second object of the present invention is to provide a charging device that can prevent the occurrence of an inrush current or the discharge of a rechargeable battery.

  In order to solve the above problems, the present invention has the following configuration of the charging device. That is, a smoothing capacitor that generates a first output voltage, a power conversion unit that converts input power and outputs power used to generate the first output voltage to the capacitor, and an applied relay A relay unit that is driven in response to a signal and permits or disallows relaying of the first output voltage; and when the relay unit permits relaying of the first output voltage, the first output voltage And a battery information management unit that detects a second output voltage that is actually output from the charging battery and outputs the second output voltage as battery information that has been converted into digital information. And a power conversion unit information management unit that receives the battery information via a communication line, and a first output voltage based on the first output voltage that is input via an analog signal line. And further comprising a control unit for generating and outputting said relay signal using the battery information received through the power conversion unit management unit to test the use of and the first output voltage to control the power conversion unit.

  Preferably, the battery information is transmitted and received using a digital signal line by CAN communication.

  Preferably, the control circuit is less than an allowable voltage value calculated by a sum of a maximum error that can occur when the first output voltage digitizes the second output voltage and a voltage value indicated by the battery information. In this case, the relay unit outputs a relay signal that disallows relaying of the first output voltage. When the first output voltage is equal to or higher than the allowable voltage, the relay unit outputs the first signal. A relay signal that allows relaying of the output voltage is output.

  According to the charging device of the present invention, since the battery information transmitted from the battery information management unit is constituted by a digital signal, an error check of the information is performed at the time of reception. Therefore, the accuracy of the received information is sufficiently guaranteed.

  In such a charging apparatus, when the capacitor voltage is applied to the rechargeable battery, even if the actual battery voltage becomes larger than the capacitor voltage, the potential difference between the two is suppressed to less than 1 LSB of the resolution defined by the battery information management unit. Therefore, the inrush current that flows from the battery voltage to the smoothing capacitor is suppressed sufficiently low, and the discharge of the rechargeable battery is suppressed.

  According to the charging device of the present invention, the battery information detected by the battery information management unit is shared in the control circuit of the power conversion unit by using a digital communication line by CAN communication installed in a recent vehicle. This eliminates the need for an additional signal line for receiving the battery voltage Vb.

1 is a diagram illustrating a circuit configuration of a charging device according to Embodiment 1. FIG. 3 is a flowchart illustrating operation processing according to the first embodiment. 3 is a time chart showing a battery voltage and a capacitor voltage according to the first embodiment. FIG. 6 is a diagram illustrating a circuit configuration of a charging device according to a second embodiment. 9 is a flowchart illustrating operation processing according to the second embodiment. 5 is a time chart showing battery voltage and capacitor voltage according to Embodiment 2. The figure which shows the circuit structure of the charging device which concerns on a prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the charging device 100 includes a power conversion unit 110, a smoothing capacitor 120, a relay unit 130, a rechargeable battery, and a control unit 150. The control unit 150 includes a power conversion unit information management unit CMU and Another information management unit PMU is built in. In addition, a battery information management unit BMU and a host control unit HCU are connected to the power conversion unit information management unit CMU via a digital communication line. Further, a power line La is provided on the output side of the power conversion unit 110, a signal line Lb is provided between the control unit 150 and the smoothing capacitor 120, and a signal is provided between the control unit 150 and the relay unit 130. A line Lc is provided, and a digital signal line Ld by CAN communication is provided between the battery information management unit BMU and the built-in ECU (Electric Control Unit) of the control unit 150. As shown in the figure, an AC power source AC and a filter circuit FL, which are commercial power sources, are shown on the input side of the charging apparatus 100 for convenience, and a load LD is shown on the output side. Further, a power conversion circuit such as a DC-DC conversion circuit or an inverter circuit may be appropriately provided between the output side of the charging apparatus 100 and the load LD according to the type of load. Further, the load LD at the rear stage may be a wheel driving motor for an electric vehicle or the like, and the application thereof such as a fuel pump motor and other actuators is not limited.

  The power conversion unit 110 converts the power input from the filter circuit FL and outputs the power used to generate the first output voltage to the smoothing capacitor 120. Here, the first output voltage is hereinafter referred to as a capacitor voltage Vc. The power conversion unit 110 according to the present embodiment includes a power factor correction circuit 111 and a step-up / down circuit 113. Of these, the power factor correction circuit 111 adjusts the phase of voltage and current to improve the power factor. The power factor correction circuit 111 has a function of making the current phase and voltage phase of the input power coincide with each other and giving a voltage boosting action. The step-up / down circuit 113 includes an H-bridge circuit that converts a DC voltage into a pulse voltage, a transformer circuit that changes the voltage level of the pulse voltage, and an output that changes the pulse width of the pulse voltage and appropriately adjusts the capacitor voltage Vc. And a voltage adjusting circuit.

  The smoothing capacitor 120 smoothes the pulse voltage output from the power converter 110, thereby generating and outputting the capacitor voltage Vc adjusted to a substantially constant value. The smoothing capacitor 120 is not limited to the type of electric field capacitor, film capacitor, ceramic capacitor, or the like. However, in order to reduce the size, it is preferable to use an appropriate type of capacitor.

  The relay unit 130 is driven according to the applied relay signal, and switches the relay of the capacitor voltage Vc to a permitted or not permitted state. The relay unit 130 includes terminals for a signal input unit, a voltage input unit, and a voltage output unit. The relay unit 130 has a signal input terminal connected to the control unit 150 through the signal line Lc, a voltage input unit connected to the power conversion unit 110 through one power supply line La, and the other power supply line La. The voltage output unit is connected to the circuit on the load side via. When a relay signal (hereinafter referred to as an “off signal”) that prohibits relaying of the capacitor voltage Vc in the relay unit 130 is input, in the relay unit 130, the electrical connection between the voltage input unit and the voltage output unit is performed. The connection of the capacitor voltage Vc is disallowed. On the other hand, when a relay signal (hereinafter referred to as an ON signal) that permits relaying of the capacitor voltage Vc in the relay unit 130 is input, the relay unit 130 electrically connects the voltage input unit and the voltage output unit. Connection is made and relaying of the capacitor voltage Vc is permitted.

  The rechargeable battery 140 has one end connected to the power supply line La and the other end connected to the ground potential. In the charging battery 140, when the relay unit 130 is switched on, the capacitor voltage Vc is applied to the anode of the charging battery 140, and the charging battery 140 is charged. As the rechargeable battery 140, a lithium ion battery, a nickel cadmium battery, a nickel metal hydride battery, and various other rechargeable batteries are used.

The control unit 150 includes a primary side control circuit 151, a serial interface circuit 152, and a secondary side control circuit 153 as shown in the figure. Further, the primary side control circuit 151 is connected to the secondary side control circuit 153 via the serial interface circuit 152. Further, the secondary side control circuit 153 is connected to the analog signal line Lb, the signal line Lc, and the communication line Ld. Among these, the secondary side control circuit 153 plays a role of controlling the operation of the step-up / down circuit 113 and appropriately controls the power conversion unit 110 based on the capacitor voltage Vc input via the analog signal line Lb. Further, the secondary side control circuit 153 has a built-in power conversion unit information management unit CMU (Battery-Charging Management Unit) to communicate digital information required by the primary side control circuit 151 and the secondary side control circuit 153. Information received from the line Ld and further generated by the control circuits 151 and 153 is transmitted to the communication line Ld as digital information. Note that the information necessary for the secondary control circuit 153 refers to digital information such as battery information, for example. The secondary side control circuit 153 uses the input capacitor voltage Vc and uses the battery information received via the power conversion unit management unit CMU to generate a relay signal indicating either an on signal or an off signal. Generate and output. The primary control circuit 151 includes an information management unit PMU (Power-Factor-Correction Management Unit) that manages information required by the power factor correction circuit 111. Such information is assigned sharable information from the information acquired by the power conversion unit information management unit CMU by connecting both information management units CMU and PMU via the serial interface circuit 152. Then, the primary side control circuit 151 controls the operation of the power factor correction circuit 111 by using information shared with the power conversion unit information management unit CMU and the parameters generated by the secondary side control circuit 153. In recent technology, the primary side control circuit or the secondary side control circuit is a one-chip DSP (Digital Signal Processor) or microcomputer (Micro
Computer) is used. These elements are hereinafter referred to as DSPs.

  The voltage value of the capacitor voltage Vc detected by the secondary side control circuit 153 is digitized by an AD conversion circuit built in the secondary side control circuit 153. Such a digitized voltage value is made close to the actual voltage value of the capacitor voltage Vc by improving the resolution of the AD conversion circuit. Further, since the distance between the secondary side control circuit 153 and the smoothing capacitor 120 is laid out at a relatively close position, the analog signal line Lb for transmitting the capacitor voltage Vc is also shortened. Therefore, the capacitor voltage close to the actual voltage value with less noise is input to the secondary side control circuit 153.

  The battery information management unit BMU (Battery Management Unit) detects the second output voltage actually output from the rechargeable battery 140, and outputs the second output voltage as a voltage information value converted into digital information. The second output voltage is hereinafter referred to as battery voltage Vb, and information corresponding to the battery voltage Vb output from the battery information management unit BMU is hereinafter referred to as battery information.

  Assuming that the data frame length constituting the digital information is 10 bits, the battery information is expressed with a voltage value in a predetermined range with a resolution corresponding to 10 bits. Therefore, when the range of 0V to 1023V is expressed with a resolution of 10 bits, the interval between the latest voltage information values of the digital information is set to 1V, so that the detection error from the actual battery voltage Vb can be suppressed to less than 1V. . In addition, the battery information digitized in this way generally has an error frame as a configuration data in addition to a data frame. Bit errors, ACK errors, format errors, and the like are assigned to the error frames, and the battery information including the error frames is appropriately detected by the transmission side or reception side ECU. In other words, since the digitized information is also checked for errors by the ECU on the receiving side, battery information including noise that occurred later in the circuit is eliminated, and only battery information without damage is controlled on the secondary side. Processed by the circuit 153. Therefore, the quality of the battery information permitted to be received by the secondary side control circuit 153 is maintained regardless of the length of the communication line.

  The charging device 100 having such a configuration operates as follows. That is, when electric power subjected to full-wave rectification from the filter circuit FL is input to the charging device 100, the power converter 110 outputs a pulse voltage set to a predetermined pulse width. The smoothing capacitor 120 smoothes the pulse voltage and outputs a substantially constant capacitor voltage Vc.

  At this time, when the relay signal output from the control unit 150 is an ON signal, the capacitor voltage Vc is applied to the rechargeable battery 140 and the load LD, whereby the rechargeable battery 140 is charged and the subsequent load LD. Is driven.

  On the other hand, when the relay signal output from the control unit 150 is an off signal, the capacitor voltage Vc is not applied to the power line La downstream from the relay unit 130, and the capacitor voltage Vc is not applied to the rechargeable battery 140 and the load LD. .

  In any case, the control unit 150 detects the capacitor voltage Vc via the signal line Lb and detects the battery information via the communication line Ld. Thereafter, the control unit 150 performs logical operation processing based on the capacitor voltage Vc and the battery information, switches the relay signal to an ON signal or an OFF signal, and outputs the appropriate relay signal.

  As described above, according to the charging device 100 according to the present embodiment, the battery information transmitted from the battery information management unit BMU is constituted by a digital signal, so that an error check of the information is also performed at the time of reception. Thus, the accuracy of the received information is sufficiently ensured regardless of the length of the communication line. Further, the voltage value of the capacitor voltage Vc detected by the control unit 150 is close to the actual voltage value of the capacitor voltage Vc by improving the resolution of the AD conversion circuit that digitizes the voltage value. Thus, in the control unit 150, the comparison processing of both voltages is accurately performed.

  In such a charging apparatus 100, even if the actual battery voltage Vb becomes larger than the capacitor voltage Vc, the potential difference between the two is suppressed to less than 1 LSB of the resolution defined by the battery information management unit BMU. The inrush current flowing into the capacitor 120 is sufficiently low.

  The communication line described above is preferably a digital communication line based on CAN communication (Controller Area Network), and the battery information is preferably transmitted / received using the digital communication line based on the CAN communication. Such a digital communication line by CAN communication is also called a CAN bus, and is widely used in industrial robots, FA devices, medical devices, ships, vehicles and the like in recent technologies.

  For example, a CAN communication (Controller Area Network) used in a vehicle will be described. Various devices (battery pack, speedometer, charging device, ignition device, etc.) constituting the vehicle are controlled by an ECU (Electric Control). Unit) is provided, and these ECUs can share information by CAN communication. As described above, in a vehicle in which a network by CAN communication is constructed, unlike modern automobile technology that relies on mechanical control, each device can be controlled based on various information by using electrical signal communication technology. Realized.

  Further, such a network by CAN communication is already deployed in a modern vehicle or the like, and does not newly establish CAN communication by mounting the charging device 100 according to the present embodiment. That is, when the charging apparatus 100 according to the present embodiment is mounted on a vehicle, the communication line shown in FIG. 5 is obtained by connecting the CAN communication network and the power conversion unit information management unit CMU of the secondary side control circuit 153. Is easily realized. In addition, a program that defines transmission / reception of signals in the power conversion unit information management unit CMU is required, and the program can be easily updated by connecting the reprogramming device to the CAN communication network.

  According to the charging device 100 using CAN communication, the control unit 150 that controls the power conversion unit 110 can share battery information detected by the battery information management unit BMU. Thus, the unnecessary signal line for receiving the battery voltage Vb is avoided. That is, the charging device 100 can simplify the circuit network related to the signal line and the communication line.

  As described above, in battery charger 100 according to the embodiment, since battery information is decomposed by a predetermined number of bits, a detection error of battery voltage Vb corresponding to 1 LSB occurs. Therefore, in charging device 100 according to the present embodiment, a voltage detection error corresponding to a maximum of 1 LSB occurs, and a phenomenon may occur in which current flows into the capacitor even though it is suppressed to a low value ( So-called inrush current). Therefore, in this embodiment, a modification example of the charging device that has been studied to avoid such a problem will be described. In the following embodiments, the maximum detection error among the detection errors that can occur when the battery voltage Vb is digitized will be described as the maximum error Δα. The maximum error Δα indicates a potential difference corresponding to 1 LSB when a potential difference in a predetermined range is decomposed by a predetermined bit. A voltage value calculated by the sum of the maximum error Δα and the voltage value indicated by the battery information is referred to as an allowable voltage Va.

  Hereinafter, the charging apparatus according to the present embodiment will be described with reference to FIGS. 2 and 3. In addition, the charging device 100 applied to a present Example is the same as that of the structure of the charging device demonstrated in FIG. Further, as described above, the secondary side control circuit 153 and the primary control circuit 151 are a one-chip DSP or the like, and a CPU, a memory circuit, an AD conversion circuit, a clock circuit, and the like are appropriately incorporated therein. . Among these, the memory circuit appropriately stores a control program or parameters. Then, the secondary side control circuit 153 activates the control program and executes processing instructed by the control program.

  FIG. 2 shows an operation process of the secondary side control circuit realized by the control program. First, when power is turned on to the secondary side control circuit 153 that is turned off, the control program is started at a predetermined timing. Immediately thereafter, the secondary-side control circuit 153 outputs the relay signal that has been turned off, and causes the relay unit 130 to be turned off (S11). In such a scene, the capacitor voltage Vc from the smoothing capacitor 120 is not applied to the rechargeable battery 140.

  Thereafter, the precharge process (S12) is executed, and the primary side control circuit 151 drives the power factor correction circuit 111, while the secondary side control circuit 153 drives the step-up / down circuit 153. In the secondary side control circuit 153, the operation of the step-up / down circuit 113 is controlled by the serial interface circuit 152 in synchronization with the operation of the primary control circuit 151. In such a process, since the relay unit 130 is cut off, the smoothing capacitor 120 is charged to the specified value relatively quickly.

  Thereafter, the secondary control circuit 153 accesses the AD conversion circuit and detects the value of the capacitor voltage Vc (S13). Further, the secondary side control circuit 153 recognizes the battery information through the power conversion unit information management unit CMU (S14).

  After this process, a precharge determination process is performed to determine whether or not the capacitor voltage Vc has reached a specified value (S15). In this process, when the battery voltage Vc is less than the allowable voltage value (Vi + Δα), the process returns to the process of S11. Therefore, the secondary control circuit 153 outputs a relay signal indicating an off signal, and the relay unit 130 The relay of the voltage Vc is not permitted. In this case, the processes from S11 to S15 are repeated until the battery voltage Vc is charged to the allowable voltage Va or higher.

  On the other hand, when the battery voltage Vc is equal to or higher than the allowable voltage Va, the process proceeds to S16. Therefore, the secondary control circuit 153 outputs a relay signal indicating an ON signal, and the relay unit 130 relays the capacitor voltage Vc. Is allowed. In this case, the power factor correction circuit 111 and the step-up / step-down circuit 113 are controlled so as to charge the rechargeable battery 140 and drive the load LD (S17).

  FIG. 3A shows the capacitor voltage Vc, the battery information Vi, and the actual battery voltage Vb output from the rechargeable battery. FIG. 3B shows the state of the relay signal output from the secondary side control circuit 151. Note that the period from time t1 to t2 is a period during which the precharge process S11 is performed, and the normal control process S17 is performed after the time t2.

  As shown in FIG. 3 (a), the battery voltage Vb does not fluctuate abruptly, and thus changes to a substantially constant value. Even in the battery information Vi, the battery information Vi is maintained at a substantially constant value following the battery voltage Vb. Since the capacitor voltage Vc is charged with the smoothing capacitor 120 in accordance with the precharge process, the voltage value increases from time t1 to time t2, as shown in the figure. At this time, the relay signal is an off signal.

  Thereafter, referring to time t2, the capacitor voltage Vc reaches the allowable voltage Va, and at this time, the relay signal is switched from the off signal to the on signal. Further, after time t2, the relay signal is kept on, and the control unit 150 performs the normal control process S17. Therefore, as shown in the figure, the capacitor voltage Vc is an allowable voltage Va having a substantially constant value. Maintained.

  The information value of the battery information Vi is a discrete value due to the nature of digital information. Therefore, when the battery information represents the actual battery voltage Vb, the voltage values decomposed according to the number of bits (for example, V0 = 0 [v], V1 = 1 [v],..., Vn = n [v], Vn + 1 = n + 1 [v]), a predetermined value is selected by program processing. Here, when the actual battery voltage Vb is a voltage value between the nth voltage information value and the (n + 1) th voltage information value, the battery information Vi is the nth voltage information value or the (n + 1) th voltage information. One of the values will be expressed. In the same figure, when the battery voltage Vb is an intermediate voltage value, the battery voltage Vi is detected from the voltage information values set in a plurality of stages in which the lowest voltage information value on the lower value side corresponds to the battery voltage Vb. Value. In such a case, the battery voltage Vb indicating between the nth voltage information value and the (n + 1) th voltage information value is recognized as the nth voltage information value by the battery information management unit BMU. The voltage value is always larger than the indicated voltage information value.

  However, in the charging apparatus 100 according to the present embodiment, since the capacitor voltage Vc is controlled so as to match the allowable voltage Va corresponding to the (n + 1) th voltage information value, the relay unit 130 is turned on in the capacitor voltage Vc. During the period, the actual battery voltage Vb cannot fall below.

  Further, when the battery voltage Vb is an intermediate voltage value, a process in which the latest voltage value among the voltage values set in a plurality of stages is set as the battery information Vi can be considered. In this case, the battery voltage Vb between the nth voltage information value and the n + 1th voltage information value is represented by Vb <(, where the nth voltage information value is Vn and the n + 1th voltage information value is Vn + 1. When Vn + Vn + 1) / 2, it is recognized as the nth voltage information value, and when Vb ≧ (Vn + Vn + 1) / 2, it is recognized as the n + 1th voltage information value. In this case, when Vb <(Vn + Vn + 1) / 2, the battery information Vi indicates the nth voltage information value. However, in the charging device 100 according to the present embodiment, as described above, the capacitor voltage Vc is the n + 1th voltage information value. Since the control is performed so as to match the allowable voltage Va corresponding to the voltage information value, the capacitor voltage Vc cannot fall below the actual battery voltage Vb during the period when the relay unit 130 is turned on.

  Further, when the capacitor voltage Vc falls below the allowable voltage Va corresponding to the (n + 1) th voltage value, the inrush current flows from the rechargeable battery 140 to the smoothing capacitor 120 because the relay unit 130 is turned off. Nor.

  As described above, according to the charging device 100 according to the present embodiment, the relay unit 130 is turned on only when the capacitor voltage Vc exceeds the battery information Vi corresponding to the battery voltage Vb by the maximum error Δα. In such a charging device 100, the capacitor voltage Vc is always higher than the battery voltage Vb when the smoothing capacitor 120 and the rechargeable battery 140 are in conduction, thereby generating an inrush current flowing from the rechargeable battery Vb into the smoothing capacitor 120. Is prevented, and discharging of the rechargeable battery is suppressed.

  In the charging apparatus 100 according to the present embodiment, the allowable voltage Va = battery information Vi + maximum error Δα, and the maximum error Δα is a voltage information value corresponding to 1 LSB of a predetermined resolution. However, the charging device described in the scope of claims is not limited to such a technique. For example, assuming that N ≧ 1, (allowable voltage Va) = (battery information Vi) + {N × (maximum error Δα)} may be used. In addition, the maximum error Δα is a voltage equal to or higher than 1LSB with a predetermined resolution. It may be set as an information value. Further, the power conversion unit 110 may be controlled by the control unit 150 such that the capacitor voltage Vc is equal to or higher than the allowable voltage Va.

  FIG. 4 shows a modification of the charging device according to the first embodiment. In the charging apparatus 200, as shown in the figure, the control unit 150 of the first embodiment is replaced with a control unit 250, and the relay unit 130 of the first embodiment is replaced with a relay unit 230. Further, signal lines Lc1 and Lc2 are provided instead of the signal line Lc in the first embodiment. Hereinafter, the same reference numerals will be given to the same components described above, and description of such components will be omitted.

  As shown in FIG. 4, the charging device 200 includes a power conversion unit 110, a smoothing capacitor 120, a relay unit 230, a rechargeable battery 140, and a control unit 250. The control unit 250 includes a power conversion unit information management unit CMU. And other information management unit PMU. In addition, a battery information management unit BMU and a host control unit HCU are connected to the power conversion unit information management unit CMU via a digital communication line. Further, a power supply line La is provided on the output side of the power conversion unit 110, a signal line Lb is provided between the control unit 250 and the smoothing capacitor 120, and a signal is provided between the control unit 250 and the relay unit 230. Lines Lc1 and Lc2 are provided, and a digital signal line Ld by CAN communication is provided between the battery voltage information management unit BMU and the built-in ECU of the control unit 250.

  The relay unit 230 includes a first relay path Rt1 including only the relay device 231 and a second relay path Rt2 that is a series circuit of the relay device 232 and the resistor 233. The first relay path Rt1 The second relay path Rt2 is connected in parallel. Further, the relay unit 230 is inserted in the power supply line La, and is laid out between the smoothing capacitor 120 and the rechargeable battery 140. Further, the signal line Lc 1 is connected to the signal input unit of the relay device 231, and the signal line Lc 2 is connected to the signal input unit of the relay device 232.

  The control unit 250 includes a primary side control circuit 151, a serial interface circuit 152, and a secondary side control circuit 253 as shown in the figure. Further, the primary side control circuit 151 is connected to the secondary side control circuit 153 via the serial interface circuit 152. Further, the secondary side control circuit 253 is connected to the signal line Lb, the signal lines Lc1 and Lc2, and the communication line Ld. That is, the secondary side control circuit 253 is connected to the relay device 231 via the signal line Lc1, and is connected to the relay device 232 via the signal line Lc2. The secondary side control circuit 253 plays a role of controlling the operation of the step-up / down circuit 113 and appropriately controls the step-up / down circuit 113 based on the capacitor voltage Vc inputted through the signal line Lb. Further, the secondary side control circuit 253 includes a power conversion unit information management unit CMU (Battery-Charging Management Unit), and transmits digital information required by the primary side control circuit 151 and the secondary side control circuit 253 to the communication line. The information received from Ld and further generated by both control circuits 151 and 253 is transmitted as digital information to the communication line Ld. The secondary side control circuit 253 uses the input capacitor voltage Vc and also uses the battery information received via the power conversion unit management unit CMU and uses either the on signal or the off signal to indicate the relay signal S1. , S2 is generated and output. Here, the relay signal S1 is a signal for driving the relay device 231 and is output to the signal line Lc1. The relay signal S2 is a signal for driving the relay device 232 and is output to the signal line Lc2.

  The charging device 100 having such a configuration operates as follows. That is, when electric power subjected to full-wave rectification from the filter circuit FL is input to the charging device 100, the power converter 110 outputs a pulse voltage set to a predetermined pulse width. The smoothing capacitor 120 smoothes the pulse voltage and outputs a substantially constant capacitor voltage Vc.

  At this time, when the relay signal S1 is an ON signal and the relay signal S2 is an OFF signal (hereinafter, S = ON∩OFF), the capacitor voltage Vc is supplied to the rechargeable battery 140 and the load LD via the first relay path Rt1. As a result, when the rechargeable battery 140 is charged, the subsequent load LD is driven. In this case, since the power consumed from the smoothing capacitor 120 to the rechargeable battery 140 is small, a voltage substantially equal to the capacitor voltage Vc is applied to the rechargeable battery 140.

  On the other hand, when the relay signal S1 is an OFF signal and the relay signal S2 is an ON signal (hereinafter, S = OFF∩ON), the capacitor voltage Vc is applied to the rechargeable battery 140 and the load LD via the second relay path Rt2. In this case as well, when the rechargeable battery 140 is charged, the subsequent load LD is driven. However, since the resistor 233 is provided in the second relay path Rt2, the power consumed from the smoothing capacitor 120 to the rechargeable battery 140 is larger than in the previous case. Therefore, a low voltage that is subjected to a predetermined voltage drop from the capacitor voltage Vc is applied to the rechargeable battery 140.

  On the other hand, when the relay signals output from the control unit 250 are both off signals (hereinafter referred to as S = OFF∩OFF), the capacitor voltage Vc is not applied to the power supply line La downstream from the relay unit 230. The capacitor voltage Vc is not applied to the rechargeable battery 140 and the load LD.

  In any case, the control unit 250 detects the capacitor voltage Vc through the signal line Lb and detects the battery information Vi through the communication line Ld. Thereafter, the control unit 250 performs logic operation processing based on the capacitor voltage Vc and the battery information, switches the relay signals S1 and S2 to the ON signal or the OFF signal, respectively, and outputs the relay signals in an appropriate combination.

As in the first embodiment, the communication line Ld for transmitting battery information is connected to CAN communication (Controller Area
The battery information Vi is preferably transmitted / received using the digital communication line by CAN communication.

  As described above, the secondary side control circuit 253 and the primary control circuit 151 are a one-chip DSP or the like, and a CPU, a memory circuit, an AD conversion circuit, a clock circuit, and the like are appropriately incorporated therein. Among these, the memory circuit appropriately stores a control program or parameters. Then, the secondary side control circuit 253 activates the control program and executes processing instructed by the control program.

  FIG. 5 shows an operation process of the secondary side control circuit realized by the control program. First, when power is turned on to the secondary side control circuit 253 that is turned off, the control program is started at a predetermined timing. Immediately thereafter, the secondary side control circuit 253 outputs a relay signal [S = OFF∩OFF], and turns off any path of the relay unit 230 (S21). In such a scene, the voltage from the smoothing capacitor 120 is not applied to the rechargeable battery 140.

  Thereafter, as in the first embodiment, the precharge process (S12) is executed, the value of the capacitor voltage Vc is detected (S13), and the battery information Vi is recognized (S14).

  After this process, a precharge determination process for determining the relationship between the capacitor voltage Vc and the allowable voltage (Vi + Δα) is executed (S25). In this process, when the battery voltage Vc is less than the allowable voltage value (Vi + Δα), the process returns to the process of S12. Therefore, the secondary control circuit 253 outputs the relay signal [S = OFF∩OFF], and the relay unit 230 The relay of the capacitor voltage Vc is prohibited.

  On the other hand, when the battery voltage Vc becomes equal to the allowable voltage (Vi + Δα), the process proceeds to S26. Therefore, the secondary side control circuit 253 outputs the relay signal [S = ON〕 OFF], and the first The relay of the capacitor voltage Vc is permitted through the relay path Rt1. In this case, the power factor correction circuit 111 and the step-up / step-down circuit 113 are controlled so as to charge the rechargeable battery 140 and drive the load LD (S27).

  On the other hand, when the battery voltage Vc further exceeds the allowable voltage Va, the process proceeds to S28. The secondary side control circuit 253 outputs a relay signal [S = OFF∩ON], and permits the relay of the capacitor voltage Vc through the second relay path Rt2. In this case, the power factor correction circuit 111 and the step-up / step-down circuit 113 perform control to reduce the capacitor voltage Vc (S29), and the control process at the time of abnormality of the charging device is performed until the capacitor voltage Vc matches the allowable voltage value Va. Is maintained (S30).

  Next, a case where the capacitor voltage Vc matches the allowable voltage Va with good response will be described with reference to FIG. FIG. 6A shows the capacitor voltage Vc, the battery information Vi, and the actual battery voltage Vb output from the rechargeable battery. FIG. 6B shows the states of the relay signals S1 and S2 output from the secondary side control circuit 253. Note that the period from time t1 to t2 is a period in which the precharge process S12 is performed, the normal control process S27 is performed after the time t2, and the abnormality control process S29 is performed after the time t3. Shall be implemented,

  As shown in FIG. 6A, since the capacitor voltage Vc is charged with the smoothing capacitor 120 in accordance with the precharge process, the voltage value rises from time t1 to time t2, as shown. At this time, the secondary side control circuit 253 outputs a relay signal [S = OFF∩OFF].

  Thereafter, referring to time t2, the capacitor voltage Vc reaches the allowable voltage value Va, and at this time, the relay signal [S = OFF∩OFF] is switched to the relay signal [S = ON∩OFF]. Since the relay signal [S = ON∩OFF] is maintained after time t2, the control unit 250 executes the normal control process S27, whereby the capacitor voltage Vc is allowed to be a substantially constant value. The voltage Va is maintained.

  Next, a case where the capacitor voltage Vc becomes higher than the allowable voltage Va for some reason will be described. FIG. 6C shows the capacitor voltage Vc, the battery information Vi, and the actual battery voltage Vb output from the rechargeable battery 140. FIG. 6D shows the states of the relay signals S1 and S2 output from the secondary side control circuit 253.

  As shown in FIG. 6C, since the capacitor voltage Vc is charged with the capacitor according to the precharge process, the voltage value increases from time t1 to time t2, as shown. At this time, the secondary control circuit 253 outputs a relay signal [S = OFF∩OFF].

  Thereafter, referring to time t2, the capacitor voltage Vc reaches a voltage value higher than the allowable voltage value Va, and at this time, the relay signal [S = OFF∩OFF] changes to the relay signal [S = OFF∩ON]. It has been switched. Since the relay signal [S = OFF∩ON] after time t2 in such a case, the control unit 250 performs the abnormality control process S29, and the capacitor voltage Vc is the voltage as shown in the figure. The value will decrease. After that, when the time t3 is reached, the relay signal [S = ON〕 OFF] is switched, and the control unit 250 performs the normal control process S27, so that the capacitor voltage Vc is maintained at a substantially constant allowable voltage Va. Is done. Note that referring to FIG. 6C, the capacitor voltage Vc in the precharge period rises more rapidly than the capacitor voltage in FIG. Such a phenomenon is seen when the battery temperature is low, such as in winter, and is one of the causes that the capacitor voltage Vc becomes higher than the allowable voltage Va.

  As described above, an optimum value is selected as the battery information Vi from the discretized voltage information values. Therefore, since the battery information Vi is expressed by either the nth voltage information value or the n + 1th voltage information value, it may be lower than the actual battery voltage Vb.

  However, even in the charging device 200 that controls the relay unit 230, the capacitor voltage Vc is controlled to be equal to or higher than the allowable voltage Va corresponding to the (n + 1) th voltage information value. During the period in which 130 is turned on, the actual battery voltage Vb cannot be lowered. Further, when the capacitor voltage Vc is lower than the allowable voltage Va corresponding to the (n + 1) th voltage information value, the capacitor voltage Vc has an inrush current from the rechargeable battery 140 to the smoothing capacitor 120 because all relay paths are turned off. There is no flow.

  According to the charging device 200 according to the present embodiment, the relay unit 130 is turned on only when the capacitor voltage Vc exceeds the maximum error Δα with respect to the battery information Vi corresponding to the battery voltage Vb. In the charging device 100, when the smoothing capacitor 120 and the charging battery 140 are in conduction, the capacitor voltage Vc is always higher than the battery voltage Vb, thereby preventing an inrush current flowing from the charging battery Vb into the smoothing capacitor 120. Is done.

  The above-described embodiment is merely a specific example of the present invention, and the present invention is not limited to the technical scope described in the embodiment. For example, in the present embodiment, CAN communication is specifically cited as a communication protocol, but the present invention is not limited to this, and LIN (Local Interconnect Network), FlexRay, MOST, and the like can also be applied.

DESCRIPTION OF SYMBOLS 100 Charging device 110 Power conversion part 120 Smoothing capacitor 130 Relay part 140 Rechargeable battery 150 Control part BMU Battery information management unit CMU Power conversion part information management unit Ld Communication line Δα Maximum error Va Allowable voltage

Claims (3)

  A smoothing capacitor that generates a first output voltage; a power converter that converts input power to generate the first output voltage; and a power converter that outputs the power to the capacitor; and an applied relay signal And a relay unit that is driven in response to permitting or disallowing relaying of the first output voltage, and when the relay unit permits relaying of the first output voltage, the first output voltage is applied And a battery information management unit that detects a second output voltage that is actually output from the rechargeable battery and outputs the second output voltage as battery information that is converted into digital information. A power conversion unit information management unit that receives the battery information via a communication line; and the power based on the first output voltage input via an analog signal line. And a controller that generates and outputs the relay signal using the battery information received through the power converter management unit when the converter is controlled and the first output voltage is used. Charging device.   The charging apparatus according to claim 1, wherein the battery information is transmitted and received using a digital signal line by CAN communication.   The control circuit, when the first output voltage is less than the allowable voltage calculated by the sum of the maximum error that can occur when digitizing the second output voltage and the voltage value indicated by the battery information, When the relay unit outputs a relay signal that disallows relaying of the first output voltage, and the first output voltage is greater than or equal to the allowable voltage, the relay unit relays the first output voltage. The charging device according to claim 1 or 2, wherein a relay signal for permitting the operation is output.

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