JP2018164339A - Power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system capable of appropriately protecting a power supply system when an overcurrent occurs. SOLUTION: Switches SW2A and SW2B have a plurality of switch units 25 to 28 connected in parallel to each other. In the power supply system, the current detection units 61 and 62 for detecting the current flowing through the switch units 25 to 28 and the detection signals of the current detection units 61 and 62 are input, and the detection signal is compared with a predetermined overcurrent determination value. Based on the result of the comparison, the comparison circuit unit 42 that outputs an overcurrent signal indicating that an overcurrent has occurred, and the switch SW2A independent of the open command by the control unit 100 when the overcurrent signal is input. , SW2B includes cutoff parts 40A and 40B having a cutoff circuit part 43 that opens the switch parts 25 to 28 and cuts off the overcurrent, and at least one of the plurality of switch parts 25 to 28. Is provided with blocking portions 40A and 40B. [Selection diagram] Fig. 1

Description

  The present invention relates to a power supply system applied to a vehicle or the like.

  Conventionally, a technique has been proposed in which a switch is provided in an electric path connecting a storage battery and an electric load, and the charge / discharge of the storage battery is optimized by opening and closing the switch. For example, in Patent Document 1, in a power supply system including two power sources of a lead storage battery and a lithium ion storage battery connected in parallel to an electrical load, a switch is provided for each electrical path connecting the electrical load, the lead storage battery, and the lithium ion storage battery. Is provided. Each switch is opened and closed by a control unit (microcomputer) based on the state of charge of each storage battery.

JP, 2006-203792, A

  For example, in the power supply system described above, in order to increase the power supply current from the storage battery to the electric load, a configuration in which switches provided in the electric path are connected in parallel can be considered. In this case, when power is supplied to the electric load, it is possible to flow a larger current by simultaneously closing (turning on) a plurality of switches connected in parallel.

  By the way, in such a configuration, when a ground fault occurs in the electric load during load feeding, an overcurrent flows through the electrically conductive path. At this time, an overcurrent also flows through a plurality of switches connected in parallel. In such a case, the occurrence of overcurrent is determined by the control unit, and the overcurrent is interrupted by opening the switch of the electrical path through which the overcurrent flows. However, when the overcurrent is interrupted by the control unit, it is considered that a determination process for determining that the overcurrent generation state continues for a predetermined time is performed, thereby causing a delay in opening the switch. As a result, there is a concern that a plurality of switches connected in parallel are damaged.

  The present invention has been made in view of the above circumstances, and a main object thereof is to provide a power supply system capable of appropriately protecting the power supply system when an overcurrent occurs.

In the first means,
Provided in a voltage source (11, 12, 16), an electric load (15) supplied with electric power from the voltage source, and an electric path (L2, L3) connecting the voltage source and the electric load; An opening / closing part (SW2A, SW2B, SW11, SW12) for opening or closing an electrical path, and a control part (100 for controlling opening / closing of the opening / closing part by an opening command for opening the opening / closing part and a closing command for closing the opening / closing part) ) And
The control unit determines that an overcurrent flows through the opening / closing unit at the time of load feeding when power is supplied from the voltage source to the electrical load via the opening / closing unit, and the opening command based on the determination A power supply system for opening the opening / closing part by:
The opening / closing part has a plurality of switch parts (25-28, 81-84) connected in parallel to each other,
A current detection unit (61-64) for detecting a current flowing through the switch unit;
A comparison circuit unit that receives a detection signal of the current detection unit, compares the detection signal with a predetermined overcurrent determination value, and outputs an overcurrent signal indicating the occurrence of overcurrent based on the comparison result (42), and when the overcurrent signal is input, a shut-off circuit unit (43) that opens the switch unit in the open / close unit and shuts off the overcurrent independently of an open command from the control unit; A blocking portion (40, 40A, 40B) having
With
Among the plurality of switch units, at least one of the switch units is provided with the blocking unit.

  In the interruption process by the control unit when an overcurrent occurs in the power supply system, it takes time for the overcurrent determination process and the like, so it takes time until the opening / closing unit is actually opened after the overcurrent occurs. Therefore, there is a possibility that a plurality of switch parts in the opening / closing part may be damaged.

  In this regard, in the above configuration, when an overcurrent occurs, at least one of the plurality of switch units is provided with a blocking unit (electric circuit) that opens the switch unit with a mechanism different from the control unit. In this case, it is possible to quickly shut off the overcurrent flowing through the switch unit by detecting the overcurrent and opening the switch unit using a circuit unit of a different system different from the shutoff process by the control unit. Thereby, a switch part can be protected.

  In the second means, the open / close section has n (n is an integer of 2 or more) switch sections as the plurality of switch sections, and the blocking section is zero among the n switch sections. And n-1 or less switch sections.

  In the above configuration, the blocking unit is provided in the n switch units that are larger than zero and n−1 or less switch units. That is, at least one switch unit is not provided with a blocking unit. In this case, the opening / closing part has a switch part that is not provided with a shut-off part. For example, an instantaneous overcurrent (noise) is generated at the time of load feeding, and some switches are turned on by the shut-off part in response to the noise. Even if the unit is opened, the power supply to the electric load can be continued by another switch unit. Thereby, it is possible to supply power stably to the electric load while protecting the switch unit.

  In the third means, a fuse (51, 53) is provided on the electrical load side of the electrical path with respect to the connection point (N2A, N2B) between the electrical load and the switch unit.

  In the said structure, it was set as the structure provided with a fuse in the electrical load side rather than the connection point of an electrical load and switch parts in an electrical path | route. In this case, when an overcurrent is generated, the fuse is blown, so that the overcurrent is cut off, and the switch portion without the cut-off portion can be protected. In addition, by providing a fuse on the electrical load side of the connection point between the switch parts, it is possible to prevent damage to the switch part provided with the cutoff part in the unlikely event that the cutoff part does not operate normally. . Thereby, each switch part in an opening-and-closing part can be protected suitably.

  In a fourth means, a fuse (52A) is provided in the parallel path of the switch part in which the blocking part is not provided among the parallel paths of the switch parts in the electrical path.

  In the above configuration, since the fuse is provided in the parallel path of the switch unit not provided with the blocking unit, the switch unit can be protected by melting the fuse when an overcurrent occurs. Thereby, each switch part in an opening-and-closing part can be protected suitably. Even when the fuse is blown, when the abnormal state of the overcurrent is resolved, it is possible to supply power to the electric load via the switch unit provided with the interrupting unit.

  In a fifth means, the electrical path includes a first fuse (51) on the electrical load side of the electrical load and the connection point (N2A, N2B) between the electrical load and the switch unit, and the switch in the electrical path A second fuse (52A) is provided in the parallel path of the switch part in which the interrupting part is not provided among the parallel paths between the parts, and the allowable energization current of the first fuse is the allowable value of the second fuse It is set larger than the energizing current.

  In the above configuration, since the second fuse is provided in the parallel path of the switch part not provided with the interruption part and the first fuse is provided on the electric load side from the connection point between the electric load and the switch part, when an overcurrent occurs When the second fuse is blown, the switch part not provided with the interrupting part can be protected, and if the interrupting part does not operate normally, the switch part provided with the interrupting part. Can also be protected.

  Further, in the above configuration, the allowable energization current of the first fuse is made larger than the allowable energization current of the second fuse. In this case, when an overcurrent occurs, the second fuse is first blown and the first fuse is not blown. Therefore, when the abnormal state of the overcurrent is resolved thereafter, power can be supplied to the electric load via the switch unit provided with the blocking unit.

  In the sixth means, as the voltage source, the first storage battery (11) and the second storage battery (12) connected in parallel to each other are provided, and the open / close section is provided in an electric path between the first storage battery and the second storage battery. As a first opening / closing part (SW2A, SW11) and a second opening / closing part (SW2B, SW12) provided in series, and at the intermediate point (N2, N5) between the first opening / closing part and the second opening / closing part, A load is connected, and the control unit controls opening and closing of each opening / closing unit according to the closing command and the opening command, and the first opening / closing unit among the first opening / closing unit and the second opening / closing unit includes the plurality of opening / closing units. N switch units (n is an integer greater than or equal to 2) first switch units (25, 26, 81, 82), and the blocking unit is zero of the n first switch units. Greater than and n-1 or less first It is provided in the switch unit.

  In the above configuration, at least one first switch unit is not provided with a blocking unit in the first opening / closing unit. As a result, for example, even when a momentary overcurrent (noise) occurs at the time of load feeding via the first opening / closing part, even if some of the first switch parts are opened by the interrupting part in response to the noise. The power supply to the electric load can be continued by the other first switch unit. Thereby, it is possible to supply power stably to the electric load while protecting the switch unit.

  In the seventh means, a fuse (51, 53) is provided on the electrical load side of the electrical path from the intermediate point.

  In the said structure, it was set as the structure provided with a fuse in the electrical load side rather than an intermediate point in an electrical path | route. In this case, if an overcurrent occurs during load feeding via the first opening / closing part, the fuse is blown to cut off the overcurrent and protect the first switch part without the interruption part. can do. Further, by providing the fuse on the electric load side with respect to the intermediate point, in the unlikely event that the interrupting part does not operate normally, the first switch part provided with the interrupting part can also be protected. On the other hand, since the fuse is blown even when an overcurrent is generated during load feeding via the second opening / closing part, in this case, each switch of the second opening / closing part can be protected. Thereby, each switch part in each opening-and-closing part can be protected suitably.

  According to an eighth means, a fuse (52A) is provided in the parallel path of the first switch part in which the blocking part is not provided among the parallel paths of the first switch parts in the electrical path.

  In the above configuration, since the fuse is provided in the parallel path of the first switch unit that is not provided with the interrupting unit, the fuse is blown if an overcurrent occurs during the load feeding through the first opening / closing unit. Thus, the first switch part can be protected. Thereby, each 1st switch part in a 1st opening-and-closing part can be protected suitably. Even when the fuse is blown, when the abnormal state of the overcurrent is resolved, power can be supplied to the electric load via the first switch portion provided with the interrupting portion.

  In a ninth means, the open / close section has n (n is an integer of 2 or more) switch sections as the plurality of switch sections, and the current detection section receives a current flowing through each switch section. The detecting unit is individually detected, and the blocking unit is provided in each of the n switch units, and opens the switch unit based on a current flowing through each switch unit detected by the current detection unit.

  In the above configuration, since all the n switch units are provided with the shut-off units, all the switch units of the open / close unit can be quickly opened when an overcurrent occurs. Moreover, since the interruption | blocking part is each provided in each switch part and opens the said switch part based on the electric current which flows through each switch part, it has a mutually independent structure. Therefore, for example, even when a part of the interrupting parts break down and the switch part is opened unintentionally at the time of load power supply, the power supply to the electric load can be continued by another switch part. Thereby, it is possible to supply power stably to the electric load while protecting the switch unit.

The electric circuit diagram which shows the power supply system of 1st Embodiment. The figure for demonstrating the structure of a interruption | blocking part. The figure which shows the electric power supply to an electric load from a lead storage battery. The time chart for demonstrating protection of the switch part in 1st Embodiment. The electric circuit diagram which shows the power supply system of 2nd Embodiment. The electric circuit diagram which shows the power supply system of 3rd Embodiment. The electric circuit diagram which shows the power supply system of 4th Embodiment. The electric circuit diagram which shows the power supply system of 5th Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In the present embodiment, an in-vehicle power supply system that supplies power to various devices of the vehicle in a vehicle that runs using an engine (internal combustion engine) as a drive source is embodied. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings, and the description of the same reference numerals is used.

(First embodiment)
As shown in FIG. 1, this power supply system is a dual power supply system having a lead storage battery 11 as a first storage battery and a lithium ion storage battery 12 as a second storage battery. Each storage battery 11, 12 can supply power to the starter 13, various electric loads 14, 15, and the rotating electrical machine 16. In addition, each of the storage batteries 11 and 12 can be charged by the rotating electrical machine 16. In this system, the lead storage battery 11 and the lithium ion storage battery 12 are connected in parallel to the rotating electrical machine 16, and the lead storage battery 11 and the lithium ion storage battery 12 are connected in parallel to the electrical loads 14 and 15.

  Although the detailed description by illustration is omitted, the lithium ion storage battery 12 is housed in a housing case and configured as a battery unit U integrated with a substrate. The battery unit U has output terminals P1, P2, P3, P0. Among these, the lead storage battery 11, the starter 13, and the electric load 14 are connected to the output terminals P1, P0, and the rotating electrical machine 16 is connected to the output terminal P2. Are connected, and the electrical load 15 is connected to the output terminal P3.

  The electric loads 14 and 15 have different requirements for the voltage of the supplied power supplied from the storage batteries 11 and 12. Among these, the electric load 15 includes a constant voltage required load that is required to be stable so that the voltage of the supplied power is constant or at least fluctuates within a predetermined range. On the other hand, the electric load 14 is a general electric load other than the constant voltage request load. It can be said that the electric load 15 is a protected load. In addition, it can be said that the electric load 15 is a load that does not allow a power supply failure, and the electric load 14 is a load that allows a power supply failure compared to the electric load 15.

  Specific examples of the electric load 15 that is a constant voltage required load include various ECUs such as a navigation device, an audio device, a meter device, and an engine ECU. In this case, by suppressing the voltage fluctuation of the supplied power, it is possible to suppress an unnecessary reset or the like in each of the above devices, and to realize a stable operation. The electric load 15 may include a travel system actuator such as an electric steering device or a brake device. Specific examples of the electric load 14 include a seat heater, a heater for a defroster for a rear window, a headlight, a wiper for a front window, and a blower fan for an air conditioner.

  The rotating electrical machine 16 is a generator with a motor function having a three-phase AC motor and a motor control unit that controls driving of the motor, and is configured as an electromechanical integrated ISG (Integrated Starter Generator). The rotating electrical machine 16 includes a power generation function that generates power (regenerative power generation) by rotating the engine output shaft and the axle, and a power running function that applies rotational force to the engine output shaft. Due to the power running function of the rotating electrical machine 16, during the idling stop, a rotational force is applied to the engine when the automatically stopped engine is restarted. The rotating electrical machine 16 supplies generated power to the storage batteries 11 and 12 and the electric loads 14 and 15.

  Next, the electrical configuration of the battery unit U will be described.

  The battery unit U has a first electric path L1 that connects the output terminal P1 and the lithium ion storage battery 12 as an in-unit electric path, and outputs to a connection point N1 that is an intermediate point of the first electric path L1. Terminal P2 is connected. In this case, the first electrical path L1 is a path that electrically connects the lead storage battery 11 and the lithium ion storage battery 12, and the rotating electrical machine 16 is connected to the connection point N1 on the first electrical path L1. In the first electrical path L1, the first A switch SW1A is provided closer to the lead storage battery 11 than the connection point N1, and the first B switch SW1B is provided closer to the lithium ion storage battery 12 than the connection point N1.

  The battery unit U is provided with a second electrical path L2 in parallel with the first electrical path L1, and an output terminal P3 is connected to a connection point N2 that is an intermediate point of the second electrical path L2. . One end of the second electrical path L2 is connected to the branch point N3 between the output terminal P1 and the first A switch SW1A on the first electrical path L1, and the other end is the first B on the first electrical path L1. It is connected to a branch point N4 between the switch SW1B and the lithium ion storage battery 12. In the second electrical path L2, the second A switch SW2A is provided closer to the lead storage battery 11 than the connection point N2, and the second B switch SW2B is provided closer to the lithium ion storage battery 12 than the connection point N2. In this case, the second electrical path L2 is a path that electrically connects each of the storage batteries 11, 12 and the electrical load 15.

  Each of the switches SW1A, SW1B, SW2A, SW2B is configured using a semiconductor switching element such as a MOSFET, that is, a normally open switch. Specifically, for example, the second A switch SW2A includes a switch unit 25 composed of semiconductor switching elements connected in series with the directions of the parasitic diodes reversed from each other, and a semiconductor connected in series with the directions of the parasitic diodes reversed from each other. The switch unit 26 includes a switching element, and the switch units 25 and 26 are connected to each other in parallel. More specifically, one end of the parallel path provided with the switch unit 25 and the parallel path provided with the switch unit 26 are connected at the branch point N3 and the connection point N3A between the switch units 25 and 26, and the other end is electrically connected. The load 15 and the switch units 25 and 26 are connected at a connection point N2A.

  The other switches have the same configuration. That is, the first A switch SW1A is configured by connecting the switch units 21 and 22 in parallel, the first B switch SW1B is configured by connecting the switch units 23 and 24 in parallel, and the second B switch SW2B is The switch parts 27 and 28 are connected in parallel.

  Since each of the switch units 21 to 28 includes a pair of semiconductor switching elements that reverse the directions of the parasitic diodes, for example, when the first A switch SW1A is turned off (opened), that is, each semiconductor switching element. When is turned off, current flow through the parasitic diode is completely blocked. That is, it is possible to avoid an unintended flow of current in each of the electrical paths L1 and L2.

  In FIG. 1, in each of the switch units 21 to 28, the semiconductor switching elements are such that the parasitic diodes are connected to each other by the anodes, but the cathodes of the parasitic diodes may be connected to each other. As the semiconductor switching element, an IGBT, a bipolar transistor, or the like can be used instead of the MOSFET. When an IGBT or a bipolar transistor is used, a diode serving as a substitute for the parasitic diode may be connected to each semiconductor switching element in parallel.

  Further, a bypass path L11 is provided between one end side and the other end side of the first A switch SW1A in the first electrical path L1, and a normally closed bypass relay 31 and a fuse 32 are provided in the bypass path L11. Is provided. Further, a bypass relay 33 is provided in the bypass route L12 that connects the connection point N1 and the connection point N2. In this configuration, a bypass relay 31 and a bypass relay 33 are provided in series between the lead storage battery 11 and the electric load 15. The fuse 32 may be provided outside the battery unit U, or may be provided inside the battery unit U.

  By closing the bypass relay 31, the lead storage battery 11 and the rotating electrical machine 16 are electrically connected even when the first A switch SW1A is off (open). Further, by closing both bypass relays 31 and 33, the lead storage battery 11 and the electrical load 15 are electrically connected even when all the switches SW1A, SW1B, SW2A, and SW2B are off (open). For example, when the power switch (ignition switch) of the vehicle is turned off, each switch SW1A, SW1B, SW2A, SW2B is turned off (closed), and in this state, the electric load is passed through the bypass relays 31 and 33. 15 is supplied with dark current.

  The battery unit U includes a control unit 100 that controls opening and closing of the switches SW1A, SW1B, SW2A, SW2B, and the bypass relays 31 and 33. The control unit 100 is configured by a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like. An ECU 200 outside the battery unit U is connected to the control unit 100. That is, the control unit 100 and the ECU 200 are connected via a communication network such as CAN and can communicate with each other, and various data stored in the control unit 100 and the ECU 200 can be shared with each other.

  The control unit 100 controls the opening / closing of the switches SW1A, SW1B, SW2A, SW2B, and the bypass relays 31 and 33 based on the storage state of the storage batteries 11 and 12 and a command signal from the ECU 200 that is the host controller. To do. Specifically, the control unit 100 controls opening and closing of each switch by an opening command for opening each switch SW1A, SW1B, SW2A, SW2B and a closing command for closing each switch SW1A, SW1B, SW2A, SW2B.

  The opening and closing of the switch will be described with reference to FIG. When closing the switch, the control unit 100 outputs a close command to the drive circuit 72. Then, the drive circuit 72 outputs the gate signal of the semiconductor switching element of the corresponding switch (the second A switch SW2A in FIG. 2), that is, the closing drive signal. Specifically, for example, when the gate voltage boosted to 10 V is output, the corresponding switch, that is, each semiconductor switch is turned on. On the other hand, when opening the switch, the control unit 100 stops outputting the close command to the drive circuit 72.

  The control unit 100 is configured to selectively supply power from the lead storage battery 11 or the lithium ion storage battery 12 to the electric load 15 by selectively closing the second A switch SW2A and the second B switch SW2B. For example, FIG. 3 shows a state where the second A switch SW2A is closed (turned on) and power is supplied from the lead storage battery 11 to the electrical load 15.

  By the way, when a ground fault occurs in the electric load 15 when power is supplied to the electric load 15, an overcurrent flows through the electrically conductive path. For example, in the case of FIG. 3, an overcurrent flows through a path from the lead storage battery 11 to the electric load 15 via the second A switch SW2A. Thus, when overcurrent arises, in the conventional power supply system, the fail safe process (shut-off process) by the control part 100 is implemented. Such fail-safe processing will be described below.

  The second electric path L2 is provided with a current detection unit that detects a current flowing through each of the switches SW2A and SW2B. In FIG. 2, a current detection unit 61 is provided between the switching element 26a and the switching element 26b constituting the switch part 26 of the second A switch SW2A, and the switching element 28a and the switching element 28a constituting the switch part 28 of the second B switch SW2B are switched. A current detector 62 is provided between the element 28b.

  The detection value (current value) output from the current detection unit 61 is input to the first filter 71 during load feeding via the second A switch SW2A. The first filter 71 is a low-pass filter, and here, a first smoothing process is performed to suppress a change in the detected value. And the detection signal in which the 1st annealing process was implemented is input into the control part 100, and it determines with the overcurrent flowing based on the detection signal. Specifically, it is determined that an overcurrent is flowing when a state where the input current value (detection signal) is larger than the threshold value Th1 continues for a predetermined time. When the control unit 100 determines that an overcurrent is flowing, the control unit 100 outputs a command to open the second A switch SW2A, that is, the switch units 25 and 26, to the drive circuit 72. Then, the second current switch SW2A is opened (turned off) based on the opening command, so that the overcurrent is interrupted. Similarly, the fail safe process by the control unit 100 is performed for the other switches.

  In the fail-safe process, a process for determining that the state of occurrence of overcurrent continues for a predetermined time is performed, and it takes time until the switch is actually opened after the overcurrent occurs. For this reason, when an overcurrent occurs, for example, the switch units 25 and 26 of the second A switch SW2A and the switch units 27 and 28 of the second B switch SW2B may fail. Further, depending on the calculation load in the control unit 100, the fail safe process itself may be delayed, and the opening of each switch unit may be further delayed.

  Therefore, in the present embodiment, a blocking unit 40 (electric circuit) that opens a switch unit with a mechanism different from the control unit 100 with respect to at least one of the plurality of switch units in each of the switches SW2A and SW2B. Was established. Specifically, as shown in FIG. 2, in the second A switch SW2A, a blocking unit 40A is provided for the switch unit 26 of the switch units 25 and 26, and in the second B switch SW2B, the switch unit of the switch units 27 and 28 is switched. 28 is provided with a blocking portion 40B. In this case, by using the interrupting units 40A and 40B that are hardware configured by an electric circuit, it is possible to interrupt the overcurrent flowing through the switch unit more quickly than the fail-safe process by the control unit 100.

  In the present embodiment, the second A switch SW2A corresponds to a “first opening / closing part”, and the second B switch SW2B corresponds to a “second opening / closing part”. In addition, the switch units 25 and 26 correspond to the “first switch unit”, and the switch units 27 and 28 correspond to the “second switch unit”. In FIG. 2, for convenience of explanation, the blocking unit 40 is set as blocking units 40 </ b> A and 40 </ b> B, respectively.

  Here, the interruption unit 40A compares the detection signal of the current detection unit 61 with a predetermined overcurrent determination value, and outputs an overcurrent signal indicating the occurrence of overcurrent based on the comparison result. 42 and a cutoff circuit unit 43 that opens the switch unit 26 and shuts off the overcurrent independently of the opening command from the control unit 100 when an overcurrent signal is input. Although not shown in FIG. 2, the blocking part 40B has the same configuration.

  Below, the forced interruption | blocking of the switch part 26 by the interruption | blocking part 40A is demonstrated. Here, the detection value (current value) output from the current detection unit 61 is input to the first filter 71 and also to the second filter 41. The second filter 41 is a low-pass filter, and here, a second smoothing process is performed to suppress a change in the detected value. In the present embodiment, the degree of smoothing of the second smoothing process is set to be smaller than the degree of smoothing of the first smoothing process. That is, the detection signal (current value Ib) output from the second filter 41 is more responsive than the detection signal (current value Ia) output from the first filter 71.

  The detection signal output from the second filter 41 is input to the comparison circuit unit 42. The comparison circuit unit 42 includes a comparator 42a and a latch circuit 42b. The comparator 42a compares the current value Ib that has been subjected to the second smoothing process with the threshold value Th2. The threshold value Th <b> 2 is provided as an overcurrent determination value that can determine that an overcurrent is flowing, and is a value that takes into account the variation of the current detection unit in the normal current use region. Here, the threshold Th2 is set to several hundred A. The threshold value Th2 and the threshold value Th1 may be the same value or different values. For example, the threshold value Th2 may be a value greater than the threshold value Th1, and the threshold value Th2 may be a value smaller than the threshold value Th1. When the input current value Ib exceeds the threshold value Th2, the comparator 42a outputs a high state signal, that is, an overcurrent signal to the latch circuit 42b.

  The latch circuit 42b is configured by using, for example, a flip-flop circuit, and can hold a signal output from the comparator 42a. Therefore, while the signal output from the comparator 42a is a high state signal, the high state signal is held. That is, when an overcurrent is detected, an overcurrent signal is output from the comparison circuit unit 42.

  The overcurrent signal output from the comparison circuit unit 42 is input to the interruption circuit unit 43. The cutoff circuit unit 43 includes a cutoff circuit 43a and a bipolar transistor 43b. The cutoff circuit 43a outputs the base signal of the bipolar transistor 43b based on the overcurrent signal. As a result, the bipolar transistor 43b is closed (turned on). The collector side of the bipolar transistor 43 b is connected to the signal path of the gate signal of the switch unit 26 output from the drive circuit 72. On the other hand, the emitter side is connected to the ground. Therefore, when an overcurrent signal is input to the interruption circuit unit 43, the bipolar transistor 43b is turned on, and the voltage based on the closing drive signal of the switch unit 26 falls to the ground level. That is, the closing command for the switch unit 26 is forcibly invalidated (stopped). Thereby, the switch part 26 is opened and the overcurrent is interrupted. In place of the bipolar transistor 43b, an IGBT, a MOSFET, or the like can be used.

  Thus, in the forced shut-off by the shut-off units 40A and 40B, the power supply system can be protected more quickly than the fail-safe process of the control unit 100. In this case, the fail-safe process of the control unit 100 is a control that prioritizes certainty, whereas the forced interruption in the present embodiment can be regarded as a control that prioritizes rapidity.

  In this embodiment, in each of the switches SW2A and SW2B, one of the two parallel switch units is provided with a blocking unit 40A and 40B, and the other switch unit 25 and 27 is provided with a blocking unit. Absent. That is, the blocking unit 40 is provided in n (n is an integer greater than or equal to 2) switch units in each switch. In other words, at least one switch unit is not provided with the blocking unit 40 in each switch. Here, since the interruption part 40 is an electric circuit giving priority to quickness, it is considered that the switch part is unintentionally opened in response to an instantaneous overcurrent (noise) at the time of load feeding, for example. It is done. For this reason, by not providing a shut-off unit for the switch units 25 and 27, even if noise occurs during load power supply, power supply to the electrical load 15 is continued via the switch unit 25 or the switch unit 27. can do.

  In the power supply system according to the present embodiment, the fuse 51 is provided on the electric load 15 side with respect to the connection point N2 in the second electric path L2. More specifically, a fuse 51 is provided between the output terminal P3 and the electric load 15. Therefore, when an overcurrent occurs, the fuses 51 are blown to protect the switch portions 25 and 27. In this case, regarding the second A switch SW2A, the switch unit 26 is protected by being opened by the blocking unit 40A, and the switch unit 25 is protected by being blown by the fuse 51. Also, in the unlikely event that the interrupting part 40A does not operate normally, the switch part 26 is protected by the fuse 51 being blown.

  Next, protection of the switch units 25 and 26 in the present embodiment will be described using the timing chart of FIG. In FIG. 4, it is assumed that a ground fault occurs in the electric load 15 when power is supplied from the lead storage battery 11 to the electric load 15. At the start of the timing chart, the second A switch SW <b> 2 </ b> A (switch units 25 and 26) is In the on state, the second B switch SW2B (switch units 27 and 28) is in the off state. Note that the solid line of the graph showing the current values of the switch units 25 and 26 in the figure indicates the value Ib based on the detection signal input to the comparison circuit unit 42. That is, the current value obtained by performing the second annealing process is shown. A one-dot chain line in the graph indicates a value Ia based on the detection signal input to the control unit 100.

  When a ground fault occurs at the electric load 15 at the timing t11, the current flowing through the switch units 25 and 26 increases. When the current value Ib of the switch unit 26 exceeds the threshold Th2 at the timing t12, the output signal of the comparator 42a of the comparison circuit unit 42 is in a high state, and is immediately output to the cutoff circuit unit 43 as an overcurrent signal.

  Then, based on the overcurrent signal, the shut-off circuit unit 43 stops the closing command of the switch unit 26 at the timing t13, so that the switch unit 26 is opened (off). Thereby, the overcurrent in the switch part 26 is interrupted | blocked and the switch part 26 is protected. On the other hand, current continues to flow through the switch unit 25 where the blocking unit 40A is not provided. When the fuse 51 is blown at the timing t14, the overcurrent in the switch unit 25 is cut off, and the switch unit 25 is protected. Note that the forced cutoff by the cutoff part 40A is faster than the fusing of the fuse 51.

  From FIG. 4, the timing at which the switch units 25 and 26 are protected is earlier than the timing t15 at which the control unit 100 determines that an overcurrent is flowing. That is, in the present embodiment, the switch units 25 and 26 can be protected more quickly than the fail safe process of the control unit 100.

  According to the embodiment described in detail above, the following excellent effects can be obtained.

  In the power supply system, the control unit 100 supplies power from the storage batteries 11 and 12 to the electric load 15 by selectively closing the second A switch SW2A and the second B switch SW2B. When an overcurrent occurs at the time of load power supply, a fail safe process is performed by the control unit 100. However, since an overcurrent determination process or the like takes time, each switch SW2A, It takes time to open SW2B. Considering this point, when an overcurrent occurs, at least one of the plurality of switch units is provided with a blocking unit 40 (electric circuit) that opens the switch unit by a mechanism different from the control unit 100. . In this case, the overcurrent flowing through the switch unit can be quickly cut off by detecting the overcurrent and opening the switch unit using a circuit unit of a different system different from the fail-safe process by the control unit 100. Thereby, a switch part can be protected.

  Specifically, in the switches SW2A and SW2B, one of the two parallel switch units is provided with the blocking units 40A and 40B in one switch unit 26 and 28, and the other switch unit 25 and 27 is not provided with a blocking unit. It was. In this case, the switches SW2A and SW2B include the switch units 25 and 27 that are not provided with the cutoff unit. For example, an instantaneous overcurrent (noise) is generated during load feeding, and the cutoff unit responds to the noise. Even if the switch units 26 and 28 are opened by 40A and 40B, the power supply to the electric load 15 can be continued by the other switch units 25 and 27. Thereby, the stable electric power feeding to the electric load 15 can be performed while protecting the switch unit.

  In the above configuration, the fuse 51 is provided on the electrical load 15 side of the second electrical path L2 with respect to the electrical load 15 and the connection point N2A between the switch portions 25 and 26. More specifically, in the second electric path L2, the fuse 51 is provided closer to the electric load 15 than the connection point N2. In this case, when an overcurrent occurs during load feeding via the second A switch SW2A, the fuse 51 is blown to cut off the overcurrent and protect the switch unit 25 that is not provided with a blocking unit. be able to. In addition, by providing the fuse 51 on the electric load 15 side with respect to the connection point N2, in the unlikely event that the blocking unit 40A does not operate normally, the switch unit 26 provided with the blocking unit 40A can also be protected. it can. On the other hand, since the fuse 51 is blown even when an overcurrent is generated during power feeding via the second B switch SW2B, the switch sections 27 and 28 of the second B switch SW2B can be protected in such a case. . Thereby, each switch part 25-28 in each switch SW2A and SW2B can be protected suitably.

(Another example of the first embodiment)
In the above embodiment, the switches SW2A and SW2B are configured in such a manner that two switch units are connected in parallel to each other. However, a configuration in which three or more switch units are connected in parallel may be used. In this case, in each of the switches SW2A and SW2B, it is preferable that at least one switch unit is not provided with a blocking unit.

  In the power supply system, the fuse 51 may be provided between the connection point N2 and the electric load 15. For example, the fuse 51 may be provided in the battery unit U and provided at the connection point N2 and the output terminal P3.

  In the above power supply system, another fuse may be provided between the connection point N2A and the connection point N2 instead of or in addition to the fuse 51. Similarly, instead of or in addition to the fuse 51, another fuse may be provided between the connection point N2B and the connection point N2.

  Hereinafter, embodiments other than the first embodiment will be described. In addition, about each following embodiment, it demonstrates centering around difference with the said 1st Embodiment.

(Second Embodiment)
The power supply system of 2nd Embodiment is shown in FIG. In FIG. 5, the configuration regarding the fuse is different from that in FIG. 1. That is, the fuse 52A is provided in the parallel path of the switch part 25 where the blocking part 40 is not provided among the parallel paths of the switch parts 25 and 26 in the second electric path L2. Specifically, a fuse 52A is provided between the switch unit 25 and the connection point N2A. In the configuration of FIG. 5, the fuse 51 in the configuration of FIG. 1 is not provided. That is, the connection point N2 is connected to the electric load 15 without a fuse.

  In the second embodiment, when a ground fault occurs in the electrical load 15 during load feeding via the second A switch SW2A, an overcurrent also flows through the second A switch SW2A. In such a case, as described above, the switch unit 26 is protected by being opened by the blocking unit 40. On the other hand, the switch unit 25 is protected by melting the fuse 52A provided in the parallel path. Thereby, each switch part 25 and 26 in 2A switch SW2A can be protected. That is, as the protection means for the switch units 25 and 26 connected in parallel, the blocking unit 40 and the fuse 52A having different configurations are provided. As a result, the robustness is improved.

  On the other hand, when the abnormal state due to the overcurrent is resolved (such as the ground fault is resolved), the control unit 100 outputs a reset signal to the latch circuit 42b. The reset signal resets the overcurrent signal output from the latch circuit 42b. As a result, the forced cutoff of the switch unit 26 is released, and normal opening / closing control by the control unit 100 is performed. In this case, even if the fuse 52 </ b> A is blown, power can be supplied from the lead storage battery 11 to the electric load 15 via the switch unit 26.

  Although omitted in FIG. 5, the second B switch SW2B may also be provided with a fuse in the same manner as the second A switch SW2A. In this case, for example, the fuse 52B is provided in the parallel path of the switch unit 27 in which the blocking unit 40 is not provided in the second B switch SW2B.

  In the above configuration, since the fuse 52A is provided in the parallel path of the switch unit 25 in which the interrupting unit 40 is not provided, the fuse 52A is blown if an overcurrent occurs during load feeding via the second A switch SW2A. Thus, the switch unit 25 can be protected. Thereby, each switch part 25 and 26 in 2A switch SW2A can be protected suitably. Even when the fuse 52A is blown, when the abnormal state of the overcurrent is resolved, the electric load 15 can be supplied with power through the switch unit 26 provided with the blocking unit 40. .

(Another example of the second embodiment)
In the above power supply system, the fuse 52A only needs to be provided in the parallel path of the switch unit 25. For example, the fuse 52A may be provided between the switch unit 25 and the connection point N3A. It may be provided between the switching elements.

(Third embodiment)
A power supply system according to the third embodiment is shown in FIG. In FIG. 6, the configuration regarding the fuse is different from that in FIG. 1. That is, a configuration in which a fuse 52A is further provided with respect to FIG. Specifically, a fuse 52A is provided in the parallel path of the switch unit 25 in the second A switch SW2A. The fuse 51 corresponds to a “first fuse”, and the fuse 52A corresponds to a “second fuse”.

  In the third embodiment, the allowable energization current of the fuse 51 is set larger than the allowable energization current of the fuse 52A. For example, the allowable energization current of the fuse 51 is set based on the allowable energization current of the switch units 25 and 26, and the allowable energization current of the fuse 52A is set based on the current value of the switch units 25 and 26 in the normal state. Is done. For example, when an overcurrent occurs in the second A switch SW2A, the switch unit 26 is protected by forcibly shutting off the cut-off unit 40, and the switch unit 25 is protected by blowing the fuse 52A. In this case, the fuse 51 is not melted due to the allowable energization current of the fuses 51 and 52A.

  Thereafter, when the abnormal state of the overcurrent is resolved, a reset signal is output from the control unit 100 to the latch circuit 42b. Thereby, the forced cutoff of the switch unit 26 is released. In such a case, since the fuse 51 is not blown, power can be supplied from the lead storage battery 11 to the electric load 15 via the switch unit 26.

  On the other hand, when an overcurrent occurs, if the forced cutoff of the cutoff unit 40 is not performed, the fuse unit 51 is blown to protect the switch unit 26. In other words, the blocking unit 40 and the fuse 52A are provided as protection means for the switch units 25 and 26 connected in parallel, respectively, and a common electric path (between the connection point N2A and the electric load 15) of the switch units 25 and 26 is provided. By providing the fuse 51 in the electrical path), the design is made redundant in terms of switch protection.

  Although omitted in FIG. 6, the second B switch SW2B may be provided with a fuse in the same manner as the second A switch SW2A. In this case, for example, the fuse 52B is provided in the parallel path of the switch unit 27 in which the blocking unit 40 is not provided in the second B switch SW2B.

  In the above configuration, the fuse 52A is provided in the parallel path of the switch unit 25 where the blocking unit 40 is not provided, and the fuse 51 is provided on the electric load side from the connection point N2A between the electric load 15 and the switch units 25 and 26. When the overcurrent is generated, the fuse 52A is blown to protect the switch unit 25 where the blocking unit 40 is not provided. Also, if the blocking unit 40 does not operate normally, the blocking unit The switch part 26 provided with 40 can also be protected. Further, in the above configuration, the allowable energization current of the fuse 51 is made larger than the allowable energization current of the fuse 52A. In this case, when an overcurrent occurs, the fuse 52A is first blown and the fuse 51 is not blown. Therefore, when the abnormal state of the overcurrent is resolved thereafter, power can be supplied to the electric load 15 via the switch unit 26 provided with the blocking unit 40.

(Fourth embodiment)
A power supply system of the fourth embodiment is shown in FIG. In the first to third embodiments, the lead storage battery 11, the starter 13, and the electric load 14 are connected to the output terminals P1 and P0, the rotating electrical machine 16 is connected to the output terminal P2, and the electric load 15 is connected to the output terminal P3. Although the connected power supply system was used, in this embodiment, a power supply system in which the lead storage battery 11, the starter 13, and the electrical load 14 are connected to the output terminals P1 and P0 and the electrical load 15 is connected to the output terminal P2. Use. In FIG. 7, for convenience of explanation, the same reference numerals are given to configurations similar to those in FIG. 1, and description thereof is omitted as appropriate.

  The battery unit U has a third electric path L3 that connects the output terminal P1 and the lithium ion storage battery 12 as an in-unit electric path, and outputs to a connection point N5 that is an intermediate point of the third electric path L3. Terminal P2 is connected. In this case, the third electrical path L3 is a path that electrically connects the lead storage battery 11 and the lithium ion storage battery 12, and the electrical load 15 is connected to the connection point N5 on the third electrical path L3. In the third electrical path L3, the switch SW11 is provided closer to the lead storage battery 11 than the connection point N5, and the switch SW12 is provided closer to the lithium ion storage battery 12 than the connection point N5.

  The switch SW11 includes a switch unit 81 composed of semiconductor switching elements connected in series with the directions of the parasitic diodes reversed, and a switch unit 82 composed of semiconductor switching elements connected in series with the directions of the parasitic diodes reversed to each other. These switch sections 81 and 82 are connected in parallel to each other. The switch SW12 is similarly configured. That is, the switch SW12 is configured by connecting the switch units 83 and 84 in parallel.

  Further, in the third electrical path L3, a bypass path L13 is provided between one end side and the other end side of the switch SW11, and a normally closed bypass relay 34 and a fuse 35 are provided in the bypass path L13. ing.

  In the fourth embodiment, the control unit 100 selectively supplies power to the electric load 15 from the lead storage battery 11 or the lithium ion storage battery 12 by selectively closing the switch SW11 and the switch SW12. There is a concern that an overcurrent may flow through each of the switches SW11 and SW12 due to a ground fault or the like occurring in the electric load 15 during such load feeding.

  Therefore, in the fourth embodiment, the cutoff unit 40 is provided in the switch unit 82 of the switch units 81 and 82 of the switch SW11, and the cutoff unit 40 is provided in the switch unit 84 of the switch units 83 and 84 of the switch SW12. In this case, the power supply system of FIG. 7 is provided with a current detection unit 63 for detecting a current flowing through the switch unit 82 and a current detection unit 64 for detecting a current flowing through the switch unit 84, respectively. Based on the detection values of the units 63 and 64, the switch units 82 and 84 are opened by the blocking unit 40, respectively. Thereby, when an overcurrent occurs, each switch part 82, 84 is protected by being quickly opened.

  In the power supply system according to the fourth embodiment, the fuse 53 is provided on the electric load 15 side of the connection point N5 in the third electric path L3. More specifically, a fuse 53 is provided between the output terminal P <b> 2 and the electric load 15. When an overcurrent is generated, the fuse 53 is blown to protect the switch portions 81 and 83 where the interrupting portion 40 is not provided.

  In the fourth embodiment, the switch SW11 corresponds to a “first opening / closing part”, and the switch SW12 corresponds to a “second opening / closing part”. In addition, the switch units 81 and 82 correspond to the “first switch unit”, and the switch units 83 and 84 correspond to the “second switch unit”.

(Modification of the fourth embodiment)
In place of or in addition to the fuse 53 in the fourth embodiment, another fuse may be provided in the parallel path of the switch unit 81 where the blocking unit 40 is not provided in the switch SW11. Similarly, instead of or in addition to the fuse 53, another fuse may be provided in the parallel path of the switch unit 83 in which the blocking unit 40 is not provided in the switch SW12.

(Fifth embodiment)
A power supply system of the fifth embodiment is shown in FIG. In FIG. 8, compared with FIG. 7, the structure regarding the interruption | blocking part is different. That is, the blocking unit 40 is provided in each of the two parallel switch units 81 and 82. In addition, a blocking unit 40 is provided in each of the two parallel switch units 83 and 84.

  In 5th Embodiment, the interruption | blocking part 40 is provided in all the switch parts 81-84 of each switch SW11 and SW12. Moreover, each interruption | blocking part 40 is mutually independent, and opens each switch part 81-84, respectively. In FIG. 8, the current flowing through the switch units 81 and 82 in the switch SW11 is individually detected by the current detection unit 63, and the current flowing through the switch units 83 and 84 in the switch SW12 is detected individually by the current detection unit 64. . And based on each electric current value detected by the electric current detection parts 63 and 64, each switch part 81-84 is each open | released by the interruption | blocking part 40. FIG. Thereby, when overcurrent occurs, each switch part 81-84 is protected by opening rapidly.

  In the said structure, it was set as the structure which provided the interruption | blocking part 40 in each switch part 81-84 of 2 parallel in each switch SW11 and SW12. In this case, when an overcurrent occurs, all the switch units 81 to 84 in each of the switches SW11 and SW12 can be quickly opened. Moreover, since the interruption | blocking part 40 opens the corresponding switch parts 81-84 based on the electric current which each flows into each switch part 81-84, it has a mutually independent structure. For this reason, for example, even when a part of the interrupting parts 40 break down and the switch part is opened unintentionally at the time of load power supply, the power supply to the electric load 15 can be continued by another switch part. Thereby, the stable electric power feeding to the electric load 15 can be performed while protecting the switch unit.

  DESCRIPTION OF SYMBOLS 11 ... Lead storage battery (1st storage battery), 12 ... Lithium ion storage battery (2nd storage battery), 15 ... Electric load, 16 ... Rotating electric machine, 25-28 ... Switch part, 40, 40A, 40B ... Shut-off part, 42 ... Comparison Circuit part, 43 ... Interrupting circuit part, 61-64 ... Current detection part, 81-84 ... Switch part, 100 ... Control part, L2 ... Second electric path, L3 ... Third electric path, SW2A ... Second A switch, SW2B ... 2B switch, SW11 ... switch, SW12 ... switch.

Claims (9)

Provided in a voltage source (11, 12, 16), an electric load (15) supplied with electric power from the voltage source, and an electric path (L2, L3) connecting the voltage source and the electric load; An opening / closing part (SW2A, SW2B, SW11, SW12) for opening or closing an electrical path, and a control part (100 for controlling opening / closing of the opening / closing part by an opening command for opening the opening / closing part and a closing command for closing the opening / closing part) ) And
The control unit determines that an overcurrent flows through the opening / closing unit at the time of load feeding when power is supplied from the voltage source to the electrical load via the opening / closing unit, and the opening command based on the determination A power supply system for opening the opening / closing part by:
The opening / closing part has a plurality of switch parts (25-28, 81-84) connected in parallel to each other,
A current detection unit (61-64) for detecting a current flowing through the switch unit;
A comparison circuit unit that receives a detection signal of the current detection unit, compares the detection signal with a predetermined overcurrent determination value, and outputs an overcurrent signal indicating the occurrence of overcurrent based on the comparison result (42), and when the overcurrent signal is input, a shut-off circuit unit (43) that opens the switch unit in the open / close unit and shuts off the overcurrent independently of an open command from the control unit; A blocking portion (40, 40A, 40B) having
With
The power supply system in which the said interruption | blocking part is provided in at least any one switch part among these switch parts. The opening / closing unit has n (n is an integer of 2 or more) switch units as the plurality of switch units,
2. The power supply system according to claim 1, wherein the blocking unit is provided in a switch unit that is larger than zero and not more than n−1 out of the n switch units.   3. The power supply system according to claim 2, wherein a fuse (51, 53) is provided on the electrical load side of the electrical path with respect to a connection point (N <b> 2 </ b> A, N <b> 2 </ b> B) between the electrical load and the switch unit.   The power supply system according to claim 2, wherein a fuse (52A) is provided in the parallel path of the switch part in which the blocking part is not provided among the parallel paths of the switch parts in the electrical path. The electrical path includes a first fuse (51) closer to the electrical load than a connection point (N2A, N2B) between the electrical load and the switch parts, and each parallel path between the switch parts in the electrical path. Among them, a second fuse (52A) is provided in the parallel path of the switch unit that is not provided with the blocking unit,
The power supply system according to claim 2, wherein an allowable energization current of the first fuse is set larger than an allowable energization current of the second fuse. The voltage source includes a first storage battery (11) and a second storage battery (12) connected in parallel with each other, and is provided in series in the electrical path between the first storage battery and the second storage battery as the open / close section. 1 opening and closing part (SW2A, SW11) and second opening and closing part (SW2B, SW12), the electrical load is connected to the intermediate point (N2, N5) between the first opening and closing part and the second opening and closing part,
The control unit controls the opening and closing of each opening and closing unit by the close command and the open command,
Of the first opening / closing part and the second opening / closing part, the first opening / closing part includes n (n is an integer of 2 or more) first switch parts (25, 26, 81, 82) as the plurality of switch parts. Have
2. The power supply system according to claim 1, wherein the blocking unit is provided in a first switch unit that is larger than zero and not more than n−1 out of the n first switch units.   The power supply system according to claim 6, wherein a fuse (51, 53) is provided on the electrical load side of the electrical path with respect to the intermediate point.   The power supply according to claim 6 or 7, wherein a fuse (52A) is provided in the parallel path of the first switch part in which the blocking part is not provided among the parallel paths of the first switch parts in the electrical path. system. The opening / closing unit has n (n is an integer of 2 or more) switch units as the plurality of switch units,
The current detection unit individually detects a current flowing through each switch unit,
2. The power supply system according to claim 1, wherein the blocking unit is provided in each of the n switch units, and opens the switch unit based on a current flowing through each switch unit detected by the current detection unit.

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