Power supply system

Abstract

The present invention provides a power supply system capable of appropriately eliminating poor conduction of a relay. The power supply system comprises: a power supply; a load connected to the power supply via a relay; a switch connected in series with the load and disconnecting or connecting the power supply from the power supply to the load when the relay is in a closed state; and a control device that controls the operation of the relay and the operation of the switch, wherein the control device performs forced drive control when the relay is closed, and in the forced drive control, the switch is locked so that power is supplied from the power supply to the load regardless of whether there is a drive request for the load.

Description

Technical Field

[0001] The present invention relates to a power supply system. Background Art

[0002] In the past, in a power supply system for supplying power to a load, the following operation was performed: by opening and closing a relay provided between a power supply and a load as required, the electrical connection between the power supply and the load was cut off or connected. Here, there is a case where a poor conduction in which the conduction of the relay is not appropriate is generated as a relay failure. In order to properly supply power to the load, it is necessary to properly eliminate the poor conduction of the relay. For example, Patent Document 1 discloses the following technology: in order to eliminate the poor conduction caused by an oxide film formed on the relay, a large current is passed through the relay, thereby breaking down the insulation of the oxide film formed on the relay.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-073239 Summary of the invention

[0006] Technical issues

[0007] However, even in the case where the relay is formed with an oxide film, it is expected that when the relay is closed, an inrush current flows through the relay and the oxide film is broken down. However, when a switch that cuts off or connects the power supply from the power source to the load when the relay is in a closed state is connected in series with the load, since the switch is basically locked according to the drive request of the load, it is presumed that when the relay is closed, the inrush current does not flow because the switch is in an open state. Therefore, in such a power supply system, there is a situation where when the relay is closed, the oxide film is not broken down and it is difficult to eliminate the poor conduction of the relay.

[0008] Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a new and improved power supply system capable of appropriately solving the conduction failure of a relay.

[0009] Technical Solution

[0010] In order to solve the above-mentioned problems, according to one aspect of the present invention, there is provided a power supply system, comprising: a power supply; a load connected to the power supply via a relay; a switch connected in series with the load and disconnecting or connecting the power supply from the power supply to the load when the relay is in a closed state; and a control device, which controls the operation of the relay and the operation of the switch, wherein the control device performs forced drive control when the relay is closed, and in the forced drive control, the switch is locked so that power is supplied from the power supply to the load regardless of whether there is a drive request for the load.

[0011] The control device may determine whether the conduction of the relay is appropriate when the relay performs a closing operation, and execute the forced drive control when it is determined that the conduction of the relay is inappropriate.

[0012] The control device may determine again whether the conduction of the relay is appropriate after executing the forced drive control, and execute vibration control for repeatedly opening and closing the relay when it is determined again that the conduction of the relay is inappropriate.

[0013] The load may be a multi-phase motor, the switch may be provided for each phase of the motor, and the control device may lock the switch provided for at least a part of the phases of the motor during the forced drive control.

[0014] The rotation angle of the motor can be limited to a predetermined angle. When the relay is in a disconnected state, the motor can be in a state where the rotation angle of the motor is limited to the predetermined angle. The control device can lock the switch set relative to the phase of the motor to which current was last applied in the forced drive control.

[0015] The control device may control, during the forced drive control, a current value of the current applied to a phase of the motor to which current was applied last time to a current value corresponding to a current value of the current applied to the phase when the last current application was completed.

[0016] The control device can adjust the current value of the current applied to the phase of the motor where current was applied last, based on the relationship between an indicator associated with the temperature of the motor at the end of the last current application and the current indicator, in the forced drive control, so that the torque of the motor is close to the torque at the end of the last current application.

[0017] Technical Effects

[0018] As described above, according to the present invention, the conduction failure of the relay can be appropriately resolved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram showing a simplified configuration of a power supply system according to an embodiment of the present invention.

[0020] Figure 2 Schematic diagram showing the relationship between the rotation angle of the motor and the gear position according to this embodiment.

[0021] Figure 3 This is a flowchart showing an example of the flow of the overall processing performed by the control device of this embodiment.

[0022] Figure 4 This is a schematic diagram showing an example of the current flow in the forced drive control.

[0023] Figure 5 This is a flowchart showing an example of the flow of processing in the forced drive control performed by the control device of this embodiment.

[0024] Figure 6 This is a schematic diagram showing an example of changes in the current value of the current flowing to each phase of the motor when the gear shift is performed to the P range.

[0025] Explanation of symbols

[0026] 1 Power supply system

[0027] 10 Auxiliary battery

[0028] 20 Motor

[0029] 21U, 21V, 21W Coil

[0030] 30 Relay

[0031] 40, 40U, 40V, 40W switch

[0032] 50 Solenoid coil

[0033] 60 Switch

[0034] 71 Voltage sensor

[0035] 72 Current sensor

[0036] 73 Temperature sensor

[0037] 80 Rod body

[0038] 100 Control device DETAILED DESCRIPTION

[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in this specification and the accompanying drawings, components having substantially the same functional structure are denoted by the same reference numerals to omit repeated description.

[0040] It should be noted that, although the power supply system 1 having the motor 20 as the load of the present invention is described below, the load of the present invention is not particularly limited to such an example as described later. In addition, although the power supply system 1 having the auxiliary battery 10 as the power source of the present invention is described below, the power source of the present invention can be any device that stores electric power and is not particularly limited to such an example. In addition, although the power supply system 1 mounted on a vehicle is described below as an example of the power supply system of the present invention, the power supply system of the present invention is not particularly limited to such an example and can be mounted on various devices other than vehicles.

[0041] <1. Configuration of the power supply system>

[0042] Reference Figure 1 and Figure 2 , the configuration of the power supply system 1 according to the embodiment of the present invention will be described.

[0043] Figure 1 It is a schematic diagram showing a simplified configuration of the power supply system 1 .

[0044] The power supply system 1 is mounted on a vehicle and is a system for supplying power to a motor 20 for switching the gear positions of the vehicle.

[0045] Specifically, if Figure 1 As shown, the power supply system 1 includes an auxiliary battery 10, a relay 30, a motor 20, a switch 40, and a control device 100 that controls the operation of the relay 30 and the switch 40. In addition, the power supply system 1 includes a voltage sensor 71, a current sensor 72, and a temperature sensor 73. It should be noted that the auxiliary battery 10 corresponds to an example of a power source of the present invention, the motor 20 corresponds to an example of a load of the present invention connected to the auxiliary battery 10 via the relay 30, and the switch 40 corresponds to an example of a switch of the present invention connected in series with the motor.

[0046] When the power supply system 1 is stopped, the relay 30 is in an open state, and the auxiliary battery 10 and the motor 20 are in an electrically disconnected state. Then, when a request to start the power supply system 1 is generated (for example, when the driver performs a specific operation on the ignition switch), the relay 30 is locked (that is, the relay 30 is closed), and the auxiliary battery 10 and the motor 20 are in an electrically connected state. Thereafter, the switch 40 is operated in accordance with the drive request of the motor 20, and the motor 20 is driven by the power supplied from the auxiliary battery 10 to the motor 20.

[0047] Auxiliary battery 10 is a battery for storing power supplied to auxiliary machines in the vehicle including motor 20, and is, for example, a 12 V battery. Auxiliary battery 10 may be a secondary battery such as a lithium battery, a lithium ion polymer battery, a nickel metal hydride battery, a nickel cadmium battery, or a lead storage battery.

[0048] The motor 20 has a function as a power source for switching the gear of the vehicle, and is specifically a multi-phase motor. More specifically, the motor 20 is a three-phase four-wire motor having three phases, namely, a U phase, a V phase, and a W phase, and has a U-phase coil 21U, a V-phase coil 21V, and a W-phase coil 21W as an excitation coil. Moreover, the neutral point connecting each coil is connected to the relay 30. In the motor, power is generated by applying current to each coil.

[0049] Specifically, the gear of the vehicle is switched according to the rotation angle θ of the motor 20. For example, when the driver selects the gear using an input device such as a button, information indicating the selected gear is output from the input device to the control device 100, and the operation of the motor 20 is controlled by the control device 100 so that the rotation angle θ of the motor 20 becomes an angle corresponding to the selected gear. By controlling the operation of the motor 20 in this way, the gear switching using a technology called so-called shift-by-wire is realized.

[0050] Figure 2 Schematic diagram showing the relationship between the rotation angle θ of the motor 20 and the gear position.

[0051] For example, Figure 2 As shown, a lever body 80 is fixed to the output shaft of the motor 20, and various clutches in the power transmission mechanism of the vehicle operate in conjunction with the rotation of the lever body 80. Thus, the gear position is switched according to the rotation angle θ of the motor 20.

[0052] Figure 2The example shown is equivalent to an example in which the vehicle equipped with the power supply system 1 is an electric vehicle having only a drive motor as a drive source. Therefore, the gear is switched between the P gear, in which the transmission of power from the drive motor to the drive wheels is cut off, and the NotP gear, in which the power can be transmitted from the drive motor to the drive wheels. Specifically, Figure 2 , the rotation angle θ of the motor 20 is limited to the angle corresponding to the P range (in Figure 2 In the example, 0[°]) to the angle corresponding to the NotP position (in Figure 2 In the example of θ, the rotation angle θ is within the range of θ1 [°]). That is, the rotation angle θ is limited to the angle corresponding to the P range in the decreasing direction and is limited to the angle corresponding to the NotP range in the increasing direction.

[0053] Here, the power supply system 1 is stopped when the gear position is in the P position. In addition, when the power supply system 1 is stopped, as described above, the relay 30 is in the open state. Therefore, when the relay is in the open state, the rotation angle θ of the motor 20 is limited to the angle corresponding to the P position (in Figure 2 In the example, it is the state of 0[°]).

[0054] As described above, the rotation angle θ of the motor 20 is limited to a predetermined angle (specifically, an angle corresponding to the P range), and when the relay 30 is in the off state, the rotation angle θ of the motor 20 is limited to the predetermined angle.

[0055] Relay 30 is a relay provided for disconnecting or connecting the electrical connection between auxiliary battery 10 and motor 20. Specifically, when the relay is in an open state, auxiliary battery 10 and motor 20 are in an electrically disconnected state, and when the relay is in a closed state, auxiliary battery 10 and motor 20 are in an electrically connected state.

[0056] Specifically, the relay 30 is provided with an electromagnetic coil 50 that generates a magnetic field that locks the relay 30. The electromagnetic coil 50 is wound around an iron core, and the magnetic field generated by the current flowing through the electromagnetic coil 50 magnetizes the iron core, so that the movable part of the relay 30 is closed. As a result, the relay 30 is in a closed state (that is, the relay is in a state of being energized). On the other hand, when no current flows through the electromagnetic coil 50, the restoring force generated by a spring or the like acts on the movable part of the relay 30, so that the relay is in an open state (that is, the relay is in a state of being de-energized).

[0057] One side of the electromagnetic coil 50 is connected to the electric wire L1 via the switch 60, and the other side of the electromagnetic coil 50 is grounded. For example, power is supplied from the auxiliary battery 10 to the electric wire L1, and the switch 60 cuts off or connects the electrical connection between the electric wire L1 and the electromagnetic coil 50. Therefore, according to the operation of the switch 60, the state in which power is being supplied from the electric wire L1 to the electromagnetic coil 50 and the state in which the power supply is stopped are switched. For example, a semiconductor switch is used as the switch 60.

[0058] Switch 40 is connected in series with motor 20 and interrupts or connects power supplied from auxiliary battery 10 to motor 20 when relay 30 is closed. Specifically, when relay 30 is closed, switch 40 is locked to supply power from auxiliary battery 10 to motor 20.

[0059] In detail, the switch 40 is provided for each phase of the motor 20. Specifically, in the power supply system 1, as the switch 40, a switch 40U connected to the coil 21U is provided for the U phase, a switch 40V connected to the coil 21V is provided for the V phase, and a switch 40W connected to the coil 21W is provided for the W phase. These switches 40U, 40V, and 40W are connected in parallel with each other. For example, semiconductor switches are used as the switches 40U, 40V, and 40W. It should be noted that, hereinafter, when the switches 40U, 40V, and 40W are not particularly distinguished, they are simply referred to as switches 40.

[0060] For example, when the relay 30 is in the closed state, the current is applied to the U phase by closing the switch 40U (i.e., the current flows through the coil 21U). In addition, the current is applied to the V phase by closing the switch 40V (i.e., the current flows through the coil 21V). In addition, the current is applied to the W phase by closing the switch 40W (i.e., the current flows through the coil 21W). The generation of power of the motor 20 is specifically achieved by appropriately controlling the timing of applying current to each phase in this way.

[0061] The voltage sensor 71 detects the voltage of each phase of the motor 20 , and outputs the detection result to the control device 100 .

[0062] The current sensor 72 detects the current value of the current applied to each phase of the motor 20 , and outputs the detection result to the control device 100 .

[0063] The temperature sensor 73 detects the temperature of the motor 20 and outputs the detection result to the control device 100 .

[0064] It should be noted that the temperature of the motor 20 itself detected by the temperature sensor 73 is an example of an index associated with the temperature of the motor 20, but the index is not particularly limited to this example. For example, the index associated with the temperature of the motor 20 may be the temperature of the motor 20 itself as described above, or the temperature of other components near the motor 20, or the outside air temperature.

[0065] The control device 100 is composed of a CPU (Central Processing Unit) as a calculation processing device, a ROM (Read only Memory) as a storage element for storing programs and / or calculation parameters used by the CPU, and a RAM (Random Access Memory) as a storage element for temporarily storing parameters that appropriately change during the execution of the CPU.

[0066] The control device 100 communicates with each device (for example, the switch 40U, the switch 40V, the switch 40W, and the switch 60) in the power supply system 1. The communication between the control device 100 and each device is realized by, for example, CAN (Controller Area Network) communication.

[0067] It should be noted that the functions of the control device 100 may be divided among a plurality of control devices, in which case the plurality of control devices may be connected to each other via a communication bus such as CAN. In addition, the control device 100 may additionally have other functions than those described below.

[0068] Specifically, the control device 100 controls the supply of electric power to the power supply system 1. Specifically, the control device 100 controls the operation of the switch 60 by outputting an operation instruction to the switch 60 using an electric signal. Thus, the power supplied from the electric wire L1 to the electromagnetic coil 50 is controlled, thereby controlling the operation of the relay 30. In addition, when the relay 30 is in a closed state, the control device 100 outputs an operation instruction to the switches 40U, 40V, 40W using an electric signal, thereby controlling the operation of the switches 40U, 40V, 40W. Thus, the current application to each phase of the motor 20 is controlled, thereby controlling the operation of the motor 20. Here, the control device 100 basically controls the operation of the switches 40U, 40V, 40W in a manner to drive the motor 20 when a drive request for the motor 20 is generated (specifically, when there is a driver's request for a change of gear).

[0069] As described above, in the power supply system 1, the control device 100 controls the operation of the relay 30 and the switch 40 to control the supply of power in the power supply system 1. Here, when the relay 30 is closed, the control device 100 performs forced drive control. In the forced drive control, the switch 40 is locked to supply power from the auxiliary battery 10 to the motor 20 regardless of whether there is a drive request for the motor 20. In this way, the conduction failure of the relay 30 can be appropriately eliminated. The details of the control when the relay 30 is closed by such a control device 100 will be described later.

[0070] <2. Operation of the power supply system>

[0071] Next, refer to Figure 3 to Figure 6 , the operation of the power supply system 1 according to the embodiment of the present invention will be described.

[0072] Figure 3 : is a flowchart showing an example of the process flow performed by the control device 100. Specifically, Figure 3 The control flow shown starts when a request to start the power supply system 1 is generated (for example, when the driver performs a specific operation on the ignition switch). Figure 3 At the time point when the control flow shown starts, the relay 30 is in the open state, and the switches 40U, 40V, and 40W are all in the open state.

[0073] like Figure 3 When the control flow shown starts, first, in step S510 , the control device 100 closes the relay 30 .

[0074] Specifically, the control device 100 latches the switch 60 to supply power to the electromagnetic coil 50 , thereby latching the relay 30 (that is, performing a closing operation on the relay 30 ).

[0075] Next, in step S520, the control device 100 determines whether the conduction of the relay 30 is appropriate. If it is determined that the conduction of the relay 30 is appropriate (step S520 / Yes), Figure 3 On the other hand, when it is determined that the conduction of relay 30 is inappropriate (step S520 / No), the process proceeds to step S530.

[0076] For example, when the relay 30 performs a closing action, the control device 100 can determine whether the conduction of the relay 30 is appropriate based on the voltage of each phase of the motor 20 detected by the voltage sensor 71. Specifically, when the relay is closed, but the voltage of each phase of the motor 20 does not reach a voltage as high as expected when the auxiliary battery 10 and the motor 20 are electrically connected, it can be determined that the conduction of the relay 30 is inappropriate.

[0077] If the determination in step S520 is negative, control device 100 executes forced drive control in step S530 . As described above, forced drive control is control for closing switch 40 to supply power from auxiliary battery 10 to motor 20 regardless of the presence or absence of a drive request for motor 20 .

[0078] Specifically, the control device 100 locks the switch 40 (that is, at least one of the switches 40U, 40V, and 40W) provided for at least a part of the phases of the motor 20 during the forced drive control.

[0079] Figure 4 FIG. 1 is a schematic diagram showing an example of the flow of current during forced drive control. Figure 4 In FIG. 1 , arrow F1 is used to indicate the flow of current when the switch 40U provided for the U phase is closed in the forced drive control. Figure 4 In the figure, the on / off state of each switch 40 is represented by on or off, where on represents a closed state and off represents an open state.

[0080] When the relay 30 is closed, even if a conduction failure occurs due to, for example, an oxide film formed on the relay 30, the auxiliary battery 10 and the motor 20 are physically connected via the relay 30. Figure 4 As shown, for example, when the switch 40U is in the closed state, a closed circuit is formed in which the auxiliary battery 10, the relay 30, the coil 21U of the motor 20, and the switch 40U are connected in series in this order. Therefore, power can be supplied from the auxiliary battery 10 to the motor 20, and a large current equivalent to the inrush current can flow through the relay 30.

[0081] Thus, by executing forced drive control when the relay 30 performs a closing operation, even if the relay 30 has a poor conduction, a large current equivalent to the inrush current can flow through the relay 30. Thus, since the oxide film formed on the relay 30 can be dielectrically broken, the poor conduction of the relay 30 can be appropriately eliminated.

[0082] Here, in the forced drive control, as described above, power is supplied to the motor 20 regardless of whether there is a drive request for the motor 20. Therefore, it is preferable to suppress the operation of the motor 20 that is contrary to the original intention. Figure 5 and Figure 6 , a preferred process from the viewpoint of suppressing the operation of the motor 20 contrary to the original intention in the forced drive control will be described.

[0083] Figure 5 1 is a flowchart showing an example of the process flow in the forced drive control performed by the control device 100. Specifically, Figure 5 The control flow shown is equivalent to Figure 4 This is an example of the flow of the processing in step S530.

[0084] like Figure 5 When the control flow shown starts, first, in step S531, the control device 100 identifies the phase to which current was applied last (hereinafter also referred to as the last applied phase) among the phases of the motor 20.

[0085] Figure 6 2 is a schematic diagram showing an example of changes in the current value of the current flowing through each phase of the motor 20 when the gear is shifted to the P range. Figure 6 , changes in the current value iU of the current flowing through the U phase, the current value iV of the current flowing through the V phase, and the current value iW of the current flowing through the W phase are shown.

[0086] As described above, the power supply system 1 is stopped when the gear position is in the P gear. Therefore, the most recent drive of the motor 20 is a drive for shifting to the P gear. Figure 6 In the example shown, before time t1, the motor 20 rotates in such a manner that the rotation angle θ of the motor 20 approaches the angle corresponding to the P gear, and the current values ​​iU, iV, iW change in such a manner that the state in which the current mainly flows through the V phase and the W phase among the U phase, the V phase and the W phase, the state in which the current mainly flows through the U phase and the V phase, and the state in which the current mainly flows through the W phase and the U phase are switched in sequence.

[0087] Then, at time t1, the rotation angle θ of the motor 20 reaches the angle corresponding to the P gear. After time t1, as the rotation of the motor 20 stops (hereinafter also referred to as the locked state), two phases (in the U phase, the V phase, and the W phase) of the motor 20 are locked. Figure 6 In the example, the V phase and the W phase continue to flow a relatively large current. Figure 6 2 shows a state where the current value iV and the current value iW are kept at relatively high values ​​after time t1. Thereafter, at time t2, the power supply to the motor 20 is stopped by detecting the above-mentioned locking state as a trigger.

[0088] For example, the control device 100 uses a storage element to store information indicating whether a current was applied to any phase (i.e., the last current application), which was the last current application performed in the most recent drive of the motor 20 for shifting to the P gear. Figure 6 In the example shown in FIG. 1 , the control device 100 stores information indicating that current was applied to the V phase and the W phase last time. Thus, the control device 100 determines the last applied phase (for example, in the example Figure 6 In the example shown, these are the V phase and the W phase).

[0089] Next, in step S532 , the control device 100 determines the current value of the current applied to the previous application phase (hereinafter also referred to as the previous current value) when the previous current application is completed.

[0090] For example, the control device 100 uses a storage element to store information indicating a current value (i.e., a previous current value) of current application that was last performed in the most recent drive of the motor 20 for shifting to the P gear. Figure 6 In the example shown, the control device 100 stores information indicating the previous current value iV0 of the V phase and the previous current value iW0 of the W phase. Therefore, the control device 100 can determine the previous current value (for example, Figure 6 In the example shown, the previous current value iV0 of the V phase and the previous current value iW0 of the W phase).

[0091] Next, in step S533 , the control device 100 determines a target value of the current value applied to the motor 20 in the forced drive control (hereinafter also referred to as a target current value).

[0092] As described later, according to Figure 5 In the control flow shown, current is applied to the last applied phase in the forced drive control. Therefore, the target current value determined in step S533 corresponds to the target current value of the current applied to the last applied phase in the forced drive control.

[0093] Here, from the viewpoint of effectively suppressing the action of the motor 20 contrary to the intention, it is preferable that the control device 100 controls the current value of the current applied to the last applied phase to the target current value determined by determining the current value corresponding to the last current value as the target current value. For example, the current value corresponding to the last current value includes not only the current value consistent with the last current value, but also the current value obtained by appropriately adjusting the current value consistent with the last current value.

[0094] Therefore, by determining the target current value as described above, the current value of the current applied to the last applied phase can be made close to the last current value. Therefore, in the forced drive control, the current flowing through the relay 30 can be suppressed from being too small, and the torque of the motor 20 can be suppressed from being too large. Thus, damage to components and / or the generation of vibration and noise can be appropriately suppressed.

[0095] In addition, from the viewpoint of more effectively suppressing the action of the motor 20 contrary to the intention, it is preferred that the control device 100 determines the current value adjusted based on the relationship between the index associated with the temperature of the motor 20 at the end of the previous current application (for example, the temperature of the motor 20 itself) and the current index as the target current value, thereby controlling the current value of the current applied to the previous application phase to the target current value determined in this way. In the adjustment of the current value using the above-mentioned index, the current value is adjusted in such a way that the torque of the motor 20 approaches the torque at the end of the previous current application. Here, since the higher the temperature of the motor 20, the greater the resistance value of each coil of the motor 20, the torque of the motor 20 becomes smaller when the applied current is constant. Therefore, when the current value of the current applied to the previous application phase is controlled to be a current value consistent with the previous current value, a torque difference corresponding to the temperature difference of the motor 20 is generated between the end of the previous current application and the current.

[0096] Therefore, by determining the target current value as described above, the torque of the motor 20 generated in the forced drive control can be made close to the torque at the end of the previous current application. Therefore, it is possible to more appropriately suppress the current flowing through the relay 30 from being too small in the forced drive control, and suppress the torque of the motor 20 from being too large. Therefore, it is possible to more appropriately suppress damage to components and / or the generation of vibration and noise.

[0097] Next, in step S534 , the control device 100 closes the switch 40 provided for the previous application phase, thereby applying the current to the previous application phase.

[0098] For example, in Figure 6 In the example shown, since the V phase and the W phase are determined as the previous applied phases, the switch 40V provided for the V phase and the switch 40W provided for the W phase are locked, so that current is applied to the V phase and the W phase. Figure 6In the example shown, in the previous current application, current flows through the V phase and the W phase in the locked state of the motor 20. Therefore, in the forced drive control, when current is applied to the V phase and the W phase, which are the previous applied phases, the torque of the motor 20 is generated but the motor 20 does not rotate. Therefore, in the forced drive control, by applying current to the previous applied phase, the rotation of the motor 20 corresponding to the action of the motor 20 contrary to the intention can be suppressed. Thus, damage to components or the generation of vibration and noise can be suppressed.

[0099] Here, in step S534, specifically, the control device 100 uses the target current value determined in step S533 as the target value of the current value of the current applied to the last applied phase. Therefore, the control device 100 can, for example, control the current value of the current applied to the last applied phase to a current value corresponding to the last current value. In addition, for example, the control device 100 can adjust the current value of the current applied to the last applied phase based on the relationship between an indicator associated with the temperature of the motor 20 at the end of the last current application (for example, the temperature of the motor 20 itself) and the current indicator in a manner that makes the torque of the motor 20 close to the torque at the end of the last current application.

[0100] It should be noted that the control device 100 can adjust the current value of the current applied to each phase by, for example, controlling the voltage of the electric signal output to each switch 40. It should be noted that the current value of the current applied to each phase can also be adjusted by providing a variable resistor in series with each switch 40 and controlling the resistance value of the variable resistor.

[0101] Next, Figure 5 The control flow shown ends.

[0102] Then, return Figure 3 , the processing after step S530 is described. After step S530, in step S540, the control device 100 again determines whether the conduction of the relay 30 is appropriate. When it is determined that the conduction of the relay 30 is appropriate (step S540 / Yes), Figure 3 The control flow shown ends. On the other hand, when it is determined again that the conduction of relay 30 is inappropriate (step S540 / No), the process proceeds to step S550.

[0103] If the determination result in step S540 is negative, control device 100 executes vibration control in step S550. Vibration control is control for repeatedly opening and closing relay 30.

[0104] Specifically, the control device 100 repeatedly opens and closes the switch 60 during vibration control to repeatedly switch between supplying power from the electric wire L1 to the electromagnetic coil 50 and cutting off the power supply from the electric wire L1 to the electric wire L1 .

[0105] The case where vibration control is performed is equivalent to the case where the conduction failure of the relay 30 is not eliminated even though the forced drive control is performed. Here, as a main cause of the conduction failure of the relay 30, in addition to the cause of the formation of an oxide film in the relay 30, there is also the cause of ice adhering to the relay 30 due to the freezing of the vapor around the relay 30. In the case where the conduction failure of the relay 30 is caused by the ice adhering to the relay 30, since it is difficult to eliminate the conduction failure of the relay 30 by the forced drive control, there may be a situation where the conduction failure of the relay 30 is not eliminated even though the forced drive control is performed. Therefore, in such a situation, since the ice adhering to the relay 30 can be broken by performing vibration control, the conduction failure of the relay 30 can be eliminated. It should be noted that, for example, by continuing the vibration control until it is determined that the conduction vibration control of the relay 30 is appropriate, it is possible to appropriately achieve the breaking of ice adhering to the relay 30.

[0106] Next, Figure 3 The control flow shown ends.

[0107] <3. Effects of the power supply system>

[0108] Next, effects of the power supply system 1 according to the embodiment of the present invention will be described.

[0109] In the power supply system 1 of the present embodiment, the control device 100 performs forced drive control when the relay 30 performs a closing operation. In the forced drive control, the switch 40 is locked to supply power from the auxiliary battery 10 to the motor 20 regardless of whether there is a drive request for the motor 20. As a result, when the relay 30 performs a closing operation, even if a poor conduction of the relay 30 occurs, a large current equivalent to the inrush current can flow through the relay 30. Therefore, the oxide film formed on the relay 30 can be dielectrically broken. Therefore, the poor conduction of the relay 30 can be appropriately eliminated.

[0110] In addition, in the power supply system 1 of the present embodiment, it is preferred that the control device 100 determines whether the conduction of the relay 30 is appropriate when the relay 30 performs a closing action, and performs forced drive control when it is determined that the conduction of the relay 30 is inappropriate. Thereby, it is possible to suppress unnecessary execution of forced drive control, and thus it is possible to suppress driving the motor 20 contrary to the intention when the relay 30 performs a closing action.

[0111] In addition, in the power supply system 1 of the present embodiment, it is preferred that the control device 100 re-determines whether the conduction of the relay 30 is appropriate after executing the forced drive control, and when it is again determined that the conduction of the relay 30 is inappropriate, performs vibration control to repeatedly open and close the relay 30. Thus, even when the conduction of the relay 30 is poor due to ice adhering to the relay 30, the conduction of the relay 30 can be eliminated. In addition, when the control is performed according to the above-mentioned process flow, the forced drive control is performed before the vibration control is performed, so it is possible to suppress unnecessary execution of the vibration control when the conduction of the relay 30 is poor due to the formation of an oxide film on the relay 30. Therefore, it is possible to suppress the relay 30 from being worn out prematurely.

[0112] In addition, in the power supply system 1 of the present embodiment, it is preferred that the control device 100 locks the switch 40 provided for at least a part of the phases of the motor 20 during the forced drive control. Thus, as in the power supply system 1, when the load to which power is supplied during the forced drive control is a multi-phase motor and a switch is provided for each phase of the motor, it is possible to appropriately realize a large current equivalent to the inrush current flowing through the relay by the forced drive control.

[0113] In addition, in the power supply system 1 of the present embodiment, preferably, when the relay 30 is in the disconnected state, the motor 20 is in a state where the rotation angle θ is limited to a predetermined angle (specifically, an angle corresponding to the P gear), and preferably, the control device 100 locks the switch 40 provided with respect to the phase to which current was applied last time (i.e., the last applied phase) among the phases of the motor 20 during the forced drive control. Thus, the rotation of the motor 20 due to the execution of the forced drive control can be suppressed. Therefore, damage to components and / or the generation of vibration and noise can be suppressed.

[0114] In addition, in the power supply system 1 of the present embodiment, the control device 100 preferably controls the current value of the current applied to the phase of the motor 20 to which current was applied last (i.e., the last applied phase) in the forced drive control to a current value corresponding to the current value of the current applied to the phase at the end of the last current application (i.e., the last current value). Thus, the current value of the current applied to the last applied phase can be made close to the last current value. Thus, in the forced drive control, the current flowing in the relay 30 can be suppressed from becoming excessively small, and the torque of the motor 20 can be suppressed from becoming excessively large. Thus, damage to components and / or the generation of vibration and noise can be effectively suppressed.

[0115] In addition, in the power supply system 1 of the present embodiment, the control device 100 preferably adjusts the current value of the current applied to the phase to which current was applied last (i.e., the last applied phase) of the phases of the motor 20 in the forced drive control in such a manner that the torque of the motor 20 is close to the torque at the end of the last current application, based on the relationship between an index associated with the temperature of the motor 20 at the end of the last current application and the current index. Thus, the torque of the motor 20 generated in the forced drive control can be made close to the torque at the end of the last current application. Therefore, in the forced drive control, it is possible to more appropriately suppress the current flowing through the relay 30 from becoming excessively smaller and suppress the torque of the motor 20 from becoming excessively larger. Thus, it is possible to more appropriately suppress damage to components and / or the generation of vibration and noise.

[0116] <4. Conclusion>

[0117] As described above, in the power supply system 1 of the present embodiment, the control device 100 performs forced drive control when the relay 30 performs a closing operation. In the forced drive control, the switch 40 is locked regardless of whether there is a drive request for the motor 20, so that power is supplied from the auxiliary battery 10 to the motor 20. Thus, when the relay 30 performs a closing operation, a large current equivalent to the inrush current flows through the relay 30, so that the oxide film formed on the relay 30 can be dielectrically broken, and thus the conduction failure of the relay 30 can be appropriately eliminated.

[0118] Although the preferred embodiments of the present invention are described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. Those skilled in the art of the present invention should understand that various variations or application examples can be thought of within the scope of the technical concept described in the claims, and understand that these variations or application examples also obviously fall within the technical scope of the present invention.

[0119] For example, although the above description describes an example in which the motor 20 corresponds to the load of the present invention, the load of the present invention may be other loads. The load of the present invention may be any load that at least consumes the supplied power, for example, it may be another motor different from the motor 20 (for example, a three-phase three-wire motor connected to the power supply via an inverter or a motor used for purposes other than so-called shift-by-wire), or a load other than a motor.

[0120] In addition, for example, the power supply system of the present invention may be Figure 1 The power supply system 1 shown is a system in which components are added, or may be a system in which some components are omitted from the power supply system 1 .

[0121] In addition, for example, the processing described using the flowcharts in this specification does not necessarily need to be performed in the order shown in the flowcharts. In addition, additional processing steps may be used, and some processing steps may be omitted.

Claims

1. A power supply system, characterized in that: have: power supply; a load connected to the power source via a relay; a switch connected in series with the load and disconnecting or connecting the power supplied from the power source to the load when the relay is in a closed state; as well as a control device, which controls the operation of the relay and the operation of the switch, When the relay performs a closing operation, the control device performs forced drive control, in which the switch is locked to supply power from the power supply to the load regardless of whether there is a drive request for the load. The load is a multiphase motor, The switches are arranged relative to the respective phases of the motor, The rotation angle of the motor is limited to a predetermined angle. When the relay is in an off state, the motor is in a state where the rotation angle of the motor is limited to the predetermined angle. The control device locks the switch provided for the phase to which current was applied last among the phases of the motor during the forced drive control.

2. The power supply system according to claim 1, characterized in that: The control device determines whether the conduction of the relay is appropriate when the relay performs a closing action. The control device executes the forced drive control when determining that conduction of the relay is inappropriate.

3. The power supply system according to claim 2, characterized in that: After executing the forced drive control, the control device determines again whether the conduction of the relay is appropriate. The control device executes vibration control for repeatedly opening and closing the relay when it is determined again that the conduction of the relay is inappropriate.

4. The power supply system according to any one of claims 1 to 3, characterized in that: The control device locks the switch provided for at least a part of the phases of the motor during the forced drive control.

5. The power supply system according to claim 1, characterized in that: The control device controls, during the forced drive control, a current value of the current applied to a phase of the motor to which current was applied last time to a current value corresponding to a current value of the current applied to the phase when the last current application was completed.

6. The power supply system according to claim 5, characterized in that: In the forced drive control, the control device adjusts the current value of the current applied to the phase of the motor to which current was applied last, based on the relationship between an indicator associated with the temperature of the motor at the end of the last current application and the current indicator, in such a manner that the torque of the motor approaches the torque at the end of the last current application.

Images