JP4122858B2 - Earth leakage detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a leakage detection device, and in particular, includes a power supply, power conversion means capable of converting power from the power supply into AC power by switching a switching element and supplying the power to a load, and the power supply and the power conversion means. The present invention relates to a leakage detection device that detects a leakage in a drive system that includes a relay that is provided between the relay and disconnects a power line from the power source, and a control unit that drives and controls the load based on a required output.
[0002]
[Prior art]
Conventionally, as this type of leakage detection device, one that specifies the location of the leakage of the system according to the operation of the ignition key of the vehicle (for example, Japanese Patent Laid-Open No. 7-274303) or the service prior to the vehicle running inspection A device that specifies a leakage point of a system of an in-vehicle device using a tool (for example, Japanese Patent Laid-Open No. 10-149493) has been proposed.
[0003]
[Problems to be solved by the invention]
However, in such a leakage detection device, since the timing of leakage detection is limited, it may not be possible to identify the location of the leakage with respect to the leakage occurring during system operation.
[0004]
An object of the leakage detection device of the present invention is to discover the occurrence of leakage during operation of the drive system and to identify the location of the leakage. Another object of the leakage detection device of the present invention is to more accurately identify the leakage point during operation of the drive system.
[0005]
[Means for solving the problems and their functions and effects]
In order to achieve at least a part of the above object, the leakage detection apparatus of the present invention employs the following means.
[0006]
The leakage detection device of the present invention is
A power supply, power conversion means capable of converting the power from the power supply into desired power by switching of a switching element and supplying the power to a load, and a power line provided between the power supply and the power conversion means A leakage detecting device for detecting the occurrence of leakage in a drive system, comprising: a relay that cuts off the power; and a control means that drives and controls at least the power conversion means and the relay based on a drive command,
A leakage detecting means provided between the power source and the relay for detecting a leakage of the drive system;
Operation state detection means for detecting an operation state of the drive system according to drive control by the control means;
An electrical leakage location determination means for determining an electrical leakage location based on detection results of the electrical leakage detection means and the operating state detection means;
With The leakage point determination means, when the leakage point is not specified over a predetermined time, instructs the control means of the drive system to perform a predetermined operation for specifying the leakage point, and based on the command A means for determining the location of leakage based on a detection result of the leakage detection means in an operating state of the drive system; This is the gist.
[0007]
In the leakage detection device of the present invention, the leakage detection means provided between the power source of the drive system and the relay detects the leakage of the drive system, and the operation state detection means performs drive control by the control means of the drive system. The operating state of the corresponding drive system is detected. And a leak location determination means determines a leak location based on the detection result of a leak detection means and an operation state detection means. Therefore, by monitoring the leakage detection by the leakage detection means and the operating state of the drive system according to the control by the control means, the location where leakage occurs, for example, between the power supply and the relay, It is possible to determine in which location the electric leakage has occurred between the conversion means and between the power conversion means and the load. Here, the “operation of the drive system” includes at least the operation of the relay and the operation of the switching element of the power conversion means.
[0008]
In such a leakage detection device of the present invention, the leakage point determination unit may be a unit that determines the leakage point based on a plurality of types of detection results obtained by the leakage detection unit and the operation state detection unit. . If it carries out like this, a leak location can be pinpointed more correctly from multiple types of detection results.
[0010]
Furthermore, in the leakage detection device of the present invention, the load includes an electric motor that is driven to rotate by polyphase alternating current, and the power conversion means converts electric power from the power source into polyphase alternating current power by switching of a switching element. An inverter circuit that can be supplied to the electric motor may be included.
[0011]
Further, in the leakage detection device of the present invention, the control means sequentially provides a connection switching signal to the relay and the power conversion means, and the leakage point determination means determines the leakage point based on the detection result at this time. It is preferable to determine. Thereby, a leak location can be specified quickly within a short time.
[0012]
Here, based on the change in the detection result by the leakage detection means before and after the control means gives the connection switching signal to the relay or power conversion means, the leakage point determination means is given a connection switching signal. In addition, it is preferable to determine the presence or absence of a leakage location on the downstream side of the relay or power conversion means. That is, when the detection result changes, it can be determined that there is a leakage location on the downstream side, and when the detection result does not change, it can be determined that there is no leakage location on the downstream side.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described using examples. FIG. 1 is a configuration diagram showing an outline of a configuration when an electric leakage detection device 20 according to the first embodiment of the present invention is applied to a drive system 10 that drives motors MG1 and MG2. For convenience of explanation, the drive system 10 will be described first, and then the leakage detection device 20 of the embodiment will be described. The drive system 10 includes a battery 12 that can input and output DC power, an inverter circuit INV1 that converts the DC power from the battery 12 into three-phase AC power by switching a switching element, and an output from the inverter circuit INV1. The motor MG1 that rotates by receiving three-phase AC and the positive bus 16 and the negative bus 17 of the inverter circuit INV1 are configured to share DC power from the battery 12 into three-phase AC power by switching the switching element. Output from the inverter circuit INV2, the motor MG2 that rotates by receiving the three-phase alternating current output from the inverter circuit INV2, and the battery 12 and the inverter circuits INV1 and INV2, provided between the battery 12 and the power line. The relay 14 to be disconnected and the required power is the motor M And a drive system control unit 18 for controlling the entire system to be output from the 1, MG2. The inverter circuits INV1 and INV2 are composed of six switching elements, and are arranged in pairs so that they are on the source side and the sink side with respect to the positive electrode bus 16 and the negative electrode bus 17, and the motor MG1 is connected to the connection point. , MG2 are connected to each phase (U, V, W). The motors MG1 and MG2 are configured as a synchronous generator motor capable of generating electric power, for example, including a rotor having a permanent magnet attached to an outer surface and a stator around which a three-phase coil is wound. Although not shown, the drive system control unit 18 is configured as a microprocessor centered on a CPU. The drive system control unit 18 includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. Prepare. The drive system control unit 18 outputs an on / off signal to the relay 14 and a switching control signal for performing switching control of the switching elements to the inverter circuits INV1 and INV2 through an output port. The leakage detection device 20 according to the embodiment is a device that detects the leakage of the drive system 10 and identifies the leakage point.
[0014]
As shown in the figure, the leakage detection device 20 of the embodiment includes a leakage detection circuit 22 provided between the battery 12 and the relay 14 to detect leakage of the drive system 10, the state of the relay 14, and the inverter circuits INV 1 and INV 2. An electronic control unit 30 that determines a leakage point from the state and a monitor 40 as a display device are provided. Although the electronic control unit 30 is provided separately from the drive system control unit 18 described above, the drive system control unit 18 may be configured to also serve as the electronic control unit 30. As the leakage detection circuit 22, various known circuits disclosed in, for example, JP-A-8-70503 can be used. Therefore, detailed description of the leakage detection circuit 22 is omitted.
[0015]
The electronic control unit 30 is configured as a microprocessor centered on a CPU 32, and includes a ROM 34 that stores a processing program, a RAM 36 that temporarily stores data, an input / output port (not shown), and a communication port ( (Not shown). The electronic control unit 30 can communicate with the drive system control unit 18 described above via a communication port. In addition, a leakage detection signal from the leakage detection circuit 22 is input to the electronic control unit 30 via an input port, and a display signal to the monitor 40 is input from the electronic control unit 30 via an output port. It is output.
[0016]
The operation of the leakage detection device 20 of the embodiment configured in this way, particularly the operation of determining a leakage point when a leakage is detected will be described. FIG. 2 is a flowchart illustrating an example of a leakage location determination processing routine executed by the electronic control unit 30 of the leakage detection device 20 of the embodiment. This routine is executed when a leakage detection signal indicating the occurrence of leakage is input from the leakage detection circuit 22.
[0017]
When the leakage location determination routine is executed, the CPU 32 of the electronic control unit 30 firstly has information about the operating state of the drive system 10 from the drive system control unit 18 and the presence or absence of leakage from the leakage detection circuit 22 via the communication port. Is read (step S100), and a process of determining the location of leakage from the read operation state and information on the presence or absence of leakage is performed (step S102). The operating state of the drive system 10 is an ON / OFF state of the relay 14 or an ON / OFF state of the switching elements of the inverter circuits INV1, INV2 (whether all six switching elements are OFF or not (shutdown state)). is there. Hereinafter, the process which determines an electrical leakage location is demonstrated.
[0018]
In the drive system 10, the process for determining the location of the electric leakage includes a power line from the battery 12 to the relay 14, a DC line from the relay 14 to the inverter circuits INV 1 and INV 2, a first AC line from the inverter circuit INV 1 to the motor MG 1, an inverter This is a process for determining in which part of the second AC line from the circuit INV2 to the motor MG2 an electric leakage has occurred. For example, in the first routine, when the occurrence of leakage is detected by the leakage detection circuit 22 and the OFF state of the relay 14 is detected, the power from the battery 12 is cut off by the relay 14. It can be determined that there is a leakage in the power line. Further, when the occurrence of electric leakage is detected and the relay 14 is turned on and the shutdown state of both inverter circuits INV1, INV2 is detected, the power from the battery 12 is cut off by the inverter circuits INV1, INV2. , It can be determined that a leakage has occurred in either the power line or the DC line. Further, when the occurrence of electric leakage is detected and the ON state of the relay 14 and the driving of one of the inverter circuits INV1 and INV2 and the shutdown state of the other are detected, the above-described power supply line or DC line, It can be determined that a leakage has occurred in any of the AC lines corresponding to the inverter circuit being driven out of the two AC lines. Further, when the occurrence of electric leakage is detected and the ON state of the relay 14 and the driving state of both inverter circuits INV1 and INV2 are detected, either the power line, the DC line, or the first and second AC lines are detected. It can be determined that a leakage has occurred. In this way, the location of leakage is determined based on the operating state of the drive system 10 when leakage is detected. However, as described above, depending on the operating state of the drive system 10, there may be a case where the location of electric leakage cannot be specified as one location.
[0019]
As a result of the leak location determination process, it is determined whether or not the leak location is specified as one location (step S104). When it is determined that the leak location is specified as one location, the specified leak location is output to the monitor 40. (Step S106), and this routine is finished. For example, when the occurrence of leakage is detected and the relay 14 is turned off, the power supply line can be specified as the leakage point, and the leakage point is output to the monitor 40. On the other hand, when it is not possible to specify a single location of leakage, the determination information of the leakage location determination process in step S102 is stored (step S108). That is, leakage occurs at any of a plurality of locations where there is a possibility of leakage (for example, a power line and a DC line, a power line and a DC line, a first AC line, or a power line, a DC line, and a second AC line) Information). Then, it is determined whether or not a predetermined time has elapsed since the execution of this routine was started (step S110), and when it is determined that it has not elapsed, the process returns to step S100. Thereby, the process of step S100 is performed again. For example, when information indicating that a leakage has occurred in either the power supply line or the DC line is stored in step S108, the occurrence of a leakage in the drive system 10 is not detected again in the process of step S100, and the relay is performed. When the 14 OFF state is read as information, it can be determined in the leakage point determination process in step S102 that a leakage has occurred in the DC line. In addition, when information indicating that a leakage has occurred in any of the power supply line, the DC line, and the first AC line is stored in step S108, the leakage of the drive system 10 is generated again in the process of step S100. When the ON state of the relay 14 and the shutdown state of the inverter circuits INV1, INV2 are detected without being detected, it can be determined that a leakage has occurred in the first AC line. Therefore, at this time, it is determined that the leakage point has been specified in step S104, and the leakage point is output to the monitor 40 in step S106. As described above, even when the leak location is not specified in the first routine, the leak locations are narrowed down by repeating the processes of steps S100 to S108 several times, and finally the leak location is specified.
[0020]
When it is determined in step S110 that the predetermined time has elapsed, the test mode is shifted (step S112), and a predetermined operation command is output to the drive system control unit 18 of the drive system 10 (step S114). The predetermined operation command is a process for instructing the operation of the drive system 10 for specifying the leak point when the leak point cannot be specified even though the predetermined time has elapsed. For example, when the above-mentioned predetermined time has passed with the information indicating that a leakage has occurred in any of the power supply line, the DC line, and the first AC line as the determination information in step S108, the process proceeds to step S114. As the drive command, for example, the electronic control unit 30 turns on the relay 14 and outputs a command for shutting down both the inverter circuits INV1 and INV2 to the drive system control unit 18. At this time, the occurrence of leakage is detected ( When the occurrence of electric leakage is not detected), it can be specified that electric leakage has occurred in the first AC line. Further, even when a leakage is detected, it can be determined that a leakage has occurred in either the power line or the DC line, that is, the first AC line can be excluded from the target of the leakage location determination. When the leak location is thus identified (step S104), the leak location is output to the monitor 40 (step S106), and this routine is terminated. Note that the operation command to the drive system control unit 18 of the drive system 10 is preferably performed within a range that does not affect the normal drive of the drive system 10, and thus the command that affects the normal drive of the drive system 10. This routine may be terminated without performing any other operation command or as it is as if the leakage location is unspecified.
[0021]
According to the leakage detection device 20 of the embodiment described above, the leakage point is narrowed down by monitoring the leakage state by the leakage detection circuit 22 and the operating state of the drive system 10, and the final leakage point is determined. Therefore, it is possible to discover a leakage while the drive system 10 is operating and to identify the leakage point. Therefore, since the leakage of the drive system 10 can be detected earlier and the location of the leakage can be specified, the safety of the system can be further improved. In addition, since a special operation command is not sent to the drive system control unit 18 of the drive system 10 until a predetermined time has elapsed after the processing for determining the location of electric leakage is started, normal drive of the drive system 10 is performed. It is possible to specify the location of electric leakage without affecting it. In addition, when a predetermined time has elapsed since the process of determining the leakage location has started, the operation of the drive system 10 is controlled to identify the leakage location, and the leakage location is determined from the state of the leakage by the leakage detection circuit 22 at this time. Since it identifies, a leak location can be determined more correctly.
[0022]
In the leakage detection device 20 of the embodiment, when a predetermined time has elapsed since the process of determining the leakage point has started, the operation of the drive system 10 is controlled to identify the leakage point, but is not controlled. There is no problem. In this way, the normal drive of the drive system 10 is not affected when executing the process of specifying the leakage point.
[0023]
In the leakage detecting device 20 of the embodiment, the DC power output from the battery 12 through the relay 14 is converted into three-phase AC power suitable for driving the motors MG1 and MG2 by switching the switching elements of the inverter circuits INV1 and INV2. The electric power supplied to the motors MG1 and MG2 in the system supplied to the motors MG1 and MG2 is converted into desired power by switching the switching elements of the power converter. The present invention may be applied to leakage detection in a system that supplies (load). Also, the number of loads may be one or two or more.
[0024]
Next, a second embodiment of the present invention will be described. FIG. 3 is a configuration diagram showing a schematic configuration when the leakage detection device 60 according to the second embodiment is applied to the power supply system 50 including the drive system. The power supply system 50 is mounted on the vehicle and constitutes a part of the vehicle. For convenience of explanation, first, the power supply system 50 will be described, and then the leakage detection device 60 of the embodiment will be described.
[0025]
The power supply system 50 includes a drive system including inverters INV1 and INV2 that convert a DC current supplied from the battery 52 into an AC current, and motors MG1 and MG2 that are driven by the AC current. A DC supply system including DC-DC converters CON1 and CON2 for converting the direct current of the current into a predetermined direct current, and electric devices D1 and D2 to which the direct current is supplied, and relays 54 and 56 of each system, And a system control unit 58 for providing a connection switching signal for turning on / off the connection to the inverters INV1, INV2 and converters CON1, CON2.
[0026]
The drive system has substantially the same configuration as that of the first embodiment. A relay 54 is connected to a conductive wire extending from the battery 52, and inverters INV1, INV2 and motors MG1, MG2 which are power conversion means are further connected to the conductive wire extended from the relay 54. In addition, although the connection line of the battery 52, the relay 54, and the inverters INV1 and INV2 is simplified and shown as one line, in reality, there are two lines as in the first embodiment.
[0027]
Further, in the DC supply system, a relay 56 is connected to a conductive wire extending from the battery 52, and the DC-DC converters CON1 and CON2 which are power conversion means are further connected to the conductive wire extending from the relay 56. It is connected. Each converter CON1, CON2 is connected to electric devices D1, D2, and supplies a direct current to electric devices D1, D2. Here, the electrical equipment is various equipment that operates by receiving a DC voltage. Converters CON1 and CON2 are composed of a plurality of switching elements and the like, and when all the switching elements are turned off, the battery 52 and the electric devices D1 and D2 are disconnected from each other and brought into a shutdown state.
[0028]
Next, the leakage detection device 60 of the present embodiment will be described. The leakage detection device 60 is connected between the battery 52 and the relays 54 and 56, detects the leakage of the power supply system 50, the state of the relays 54 and 56, the inverters INV1 and INV2, the converter CON1, It consists of an electronic control unit 70 that determines the location of electric leakage from the state of CON2 and a monitor 80. The leakage detection circuit 62 detects the peak value, and if the detected peak value is small, the insulation resistance is large. Therefore, the leakage is detected when this state continues for a predetermined time (generally about 30 seconds). The reason why the predetermined time is required until detection is that the detected peak value may be instantaneously reduced due to the influence of other devices mounted on the vehicle.
[0029]
This leakage detection device 60 performs the processing described below. First, the system control unit 58 gives an off signal for turning off the connection to the relays 54 and 56, and gives an off signal for shutting down the inverters INV1 and INV2 and the converters CON1 and CON2.
[0030]
Next, an ON signal and an OFF signal are sequentially supplied to the relays 54 and 56, the inverters INV1 and INV2, and the converters CON1 and CON2. The drive system will be described as an example. First, an ON signal is given to the relay 54 on the upstream side to turn it on. In this state, an ON signal is given to the inverter INV1 downstream from the relay 54, and an OFF signal is given to the inverter INV1 after a predetermined time. Similarly, an ON signal and an OFF signal are given to the inverter INV2. Next, an ON signal is given to the relay 54 on the upstream side of the inverters INV1 and INV2, and an OFF signal is given after a predetermined time. Similarly for the DC supply system, an ON signal and an OFF signal are sequentially given from the downstream switches or converters CON1 and CON2.
[0031]
The electronic control unit 70 gives an ON signal or an OFF signal when the system control unit 58 gives an ON signal and an OFF signal to the relays 54, 56 and the power conversion means INV1, INV2, CON1, CON2 in the above-described procedure. A change in the detected peak value before and after is detected by the leakage detection circuit 62, and a process for specifying a leakage point is performed based on the change in the detected peak value. This process will be described below.
[0032]
FIG. 4 shows an example of a change in the detected peak value detected by the electronic control unit 70. In the example of FIG. 4A, the detected peak value changes only when the relay 54 is turned on / off. In this case, it is determined that there is a leakage location on the downstream side of the relay 54 where the detection result changes. Further, it is determined that there is no leakage point in the downstream side of the inverters INV1 and INV2 and the DC supply system where the detection result does not change. Therefore, it is determined that there is a leakage point on the conductive line connecting the relay 54 and each of the inverters INV1 and INV2.
[0033]
In the example of FIG. 4B, the detected peak value changes only when the inverter INV2 is turned on / off. In this case, it is determined that there is a leakage location on the downstream side of the inverter INV2 where the detection result changes. Further, it is determined that there is no leakage point in the downstream side of the inverter INV1 where the detection result does not change, between the relay 54 and each of the inverters INV1 and INV2, and in the DC supply system. The leak location is specified by the process described above.
[0034]
In the present embodiment described above, the ON signal and the OFF signal are sequentially given to the relays 54 and 56 and the power conversion means INV1, INV2, CON1, and CON2, one by one, and the detection result by the leakage detection circuit 62 at that time Since the leakage location is determined based on the above, there is an effect that the leakage location can be quickly identified within a short time. For this reason, the processing of the present embodiment is performed in a short time zone such as a time zone from when the key is inserted into the vehicle to start and the motor is driven, or a time zone from when the motor is stopped until the vehicle is completely stopped. Can also be done.
[0035]
At this time, the presence / absence of a leakage location on the downstream side is determined based on the change in the detection result by the leakage detection circuit 62 before and after the system control unit 58 outputs the connection switching signal. Since the information on the change in the detection result can be acquired only by the time until the detected peak value changes, the location of the leakage point can be determined more quickly.
[0036]
In the present embodiment, changes in the detected peak values are stored for all the relays 54 and 56 and the power conversion units INV1, INV2, CON1, and CON2, and processing for specifying the location of the electric leakage from the stored information is performed. However, in another embodiment, only the relays 54 and 56 or the power conversion units INV1, INV2, CON1, and CON2 when the detected peak value changes may be stored, and the location of the leakage may be specified from the information.
[0037]
The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments and can be implemented in various forms without departing from the gist of the present invention. Of course you get.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of a configuration when a leakage detection device 20 of a first embodiment of the present invention is applied to a drive system 10 that drives motors MG1 and MG2.
FIG. 2 is a flowchart illustrating an example of a leakage location determination processing routine executed by the electronic control unit 30 of the leakage detection device 20 of the embodiment.
FIG. 3 is a configuration diagram showing an outline of a configuration when a leakage detection device 60 of the second embodiment is applied to a power supply system 50;
FIG. 4 is an explanatory diagram showing an example of a change in a detected peak value detected by an electronic control unit.
[Explanation of symbols]
10 drive system, 12 battery, 14 relay, 16 positive bus, 17 negative bus, 18 drive system control unit, 20 leakage detection device, 22 leakage detection circuit, 30 electronic control unit, 32 CPU, 34 ROM, 36 RAM, 40 monitor , INV1, INV2 inverter circuit, MG1, MG2 motor.

Claims (7)

A power supply, power conversion means capable of converting the power from the power supply into desired power by switching of a switching element and supplying the power to a load, and a power line provided between the power supply and the power conversion means A leakage detecting device for detecting the occurrence of leakage in a drive system, comprising: a relay that cuts off the power; and a control means that drives and controls at least the power conversion means and the relay based on a drive command,
A leakage detecting means provided between the power source and the relay for detecting a leakage of the drive system;
Operation state detection means for detecting an operation state of the drive system according to drive control by the control means;
An electrical leakage location determination means for determining an electrical leakage location based on detection results of the electrical leakage detection means and the operating state detection means;
Equipped with a,
When the leakage location is not specified over a predetermined time, the leakage location determination means instructs a predetermined operation for specifying the leakage location to the control means of the drive system, and the drive based on the command A leakage detection device which is means for determining the leakage point based on a detection result of the leakage detection means in an operating state of the system. The leakage detection device according to claim 1,
The leakage detection device is a leakage detection device which is a device which determines the leakage point based on a plurality of types of detection results obtained by the leakage detection unit and the operation state detection unit. The leakage detection device according to claim 1 or 2,
The load includes an electric motor that is rotationally driven by polyphase alternating current,
The electric power conversion means is a leakage detecting device including an inverter circuit capable of converting electric power from the power source into polyphase AC electric power by switching of a switching element and supplying the electric power to the electric motor. The leakage detection device according to claim 1,
The control means sequentially provides a connection switching signal to the relay and the power conversion means,
The earth leakage detection device, wherein the earth leakage location determination means determines an earth leakage location based on a detection result at this time. The leakage detection device according to any one of claims 1 to 4,
Based on the change in the detection result by the leakage detection means before and after the control means gives the connection switching signal to the relay or the power conversion means, the leakage point determination means determines whether the connection switching signal is given to the relay or A leakage detecting apparatus for determining whether or not there is a leakage point on the downstream side of the power conversion means. The leakage detection device according to claim 5,
When the detection result by the leakage detection means changes, the leakage detection section determination means determines that there is a leakage section downstream from the relay or power conversion means to which the connection switching signal is given. apparatus. The leakage detection device according to claim 5,
If the detection result by the leak detection means does not change, the leak detection section determination means determines that there is no leak section downstream from the relay or power conversion means to which the switching signal is given. apparatus.

Images