JP2021164241A - Current detector and current detection method - Google Patents

Abstract

To provide a current detector that actively uses a leakage magnetic flux.SOLUTION: A sensor unit 160 comprises a plurality of detection sections 161, 162, 163. Each detection section comprises a plurality of bus bars 165 and a plurality of elements 167. The elements 167 are coreless current sensors. The elements 167 are expected to detect normal magnetic fluxes flowing through the bus bars 165. Current flowing through one bus bar 165 generates a leakage magnetic flux in addition to a normal magnetic flux. For example, a leakage magnetic flux from a bus bar in the detection section 161 is also detected by an element of the other detection section 162 and influences output of the element of the other detection section. A leakage observation signal of the element is observed when the other detection section 162 is not energized. The leakage observation signal can be used for evaluation of the element.SELECTED DRAWING: Figure 3

Description

The disclosure in this specification relates to a current detection device and a current detection method.

Patent Document 1 discloses a power conversion device that uses a cored current sensor and a coreless current sensor. The power conversion device includes a group of switching elements for controlling the currents of a plurality of load circuits.

Japanese Unexamined Patent Publication No. 2015-186317

The sensor unit may include a plurality of elements for current detection. In this case, the magnetic flux that causes noise includes an external magnetic flux arriving from the outside of the sensor unit and an internal leakage flux generated by an electric conductor placed inside the sensor unit. Negative improvements have been attempted to suppress or prevent noise magnetic flux. Further improvements are required in the current detection device and the current detection method in the above-mentioned viewpoints or in other viewpoints not mentioned.

One object disclosed is to provide a current detection device that positively utilizes the internal leakage flux and a current detection method.

The current detection device disclosed herein is a plurality of bus bars (165) including at least a first bus bar (65a) and a second bus bar (65d), and a first bus bar (165) that detects a normal magnetic flux caused by a current flowing through the first bus bar. A plurality of elements (167) including one element (67a) and a second element (167d) for detecting a normal magnetic flux caused by a current flowing through the second bus bar, and a signal indicating the current are acquired from the first element. , A control system (170, 175) that acquires a signal indicating the current from the second element, and the control system satisfies the leakage observation condition in which the first current flows through the first bus bar and no current flows through the second bus bar. When the leakage observation condition is satisfied, the condition determination unit (181) for determining the above, and the leakage observation signal (Im) for detecting the leakage magnetic flux interlinking with the second element, which is generated due to the first current, are second. It has a leakage acquisition unit (185) acquired from the element and an evaluation unit (186) for evaluating the second element by the leakage observation signal.

According to the disclosed current detector, the leakage flux is actively utilized, the control system determines the establishment of the leakage observation condition. Thereby, the state in which only the leakage flux from the first bus bar acts on the second element is specified. The control system observes the output of the second element that detects the leakage flux as a leakage observation signal. Further, the control system evaluates the second element by the leak observation signal. As a result, a current detection device that positively utilizes the leakage flux is provided.

In the current detection method disclosed herein, the first element (67a) detects a normal magnetic flux generated by the current flowing through the first bus bar (65a), and the normal observation signal (In) indicating the current from the first element. Or, the normal magnetic flux generated by the current flowing in the second bus bar (65d) is detected by the second element (67d), and the normal observation signal (In) indicating the current is obtained from the second element. When the acquisition step (188), the condition determination step (181) for determining the establishment of the leakage observation condition in which the first current flows in the first bus bar and no current flows in the second bus bar, and the leakage observation condition are satisfied. , The leak acquisition step (185) of acquiring the leak observation signal (Im) for detecting the leakage magnetic flux interlinking with the second element generated by the first current from the second element, and the second by the leak observation signal. It has an evaluation step (186) for evaluating the element.

The disclosed current detection method actively utilizes the leakage flux. In the normal acquisition step, the current flowing through the first bus bar is detected by the first element, and the current flowing through the second bus bar is detected by the second element. When the leakage observation condition is satisfied in which the first current flows through the first bus bar and no current flows through the second bus bar, only the leakage flux from the first bus bar acts on the second element. As a result, a leakage observation signal indicating the leakage flux is acquired. The leak observation signal can be used to evaluate the second element. As a result, a current detection method that positively utilizes the leakage flux is provided.

The plurality of forms disclosed herein employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses described in this section exemplify the correspondence with the parts of the embodiments described later, and are not intended to limit the technical scope. The objectives, features, and effects disclosed herein will be made clearer by reference to the subsequent detailed description and accompanying drawings.

It is a circuit diagram of the power conversion apparatus which concerns on 1st Embodiment. It is a side view which shows the power conversion apparatus. It is a top view which shows the power conversion apparatus. It is sectional drawing which shows the interference of a plurality of elements. It is a flowchart which shows the control process.

A plurality of embodiments will be described with reference to the drawings. In a plurality of embodiments, functionally and / or structurally corresponding parts and / or related parts may be designated with the same reference code or reference codes having a hundreds or more different digits. For the corresponding and / or associated part, the description of other embodiments can be referred to.

First Embodiment In FIG. 1, the power conversion device 100 is mounted on an electric vehicle. The power conversion device 100 controls the electric power supplied to the rotary electric machine in the electric vehicle and the electric power regenerated from the rotary electric machine. The electric vehicle includes a hybrid vehicle powered by an internal combustion engine and a rotary electric machine, and an electric vehicle powered only by a rotary electric machine. The power conversion device 100 provides power conversion between a plurality of devices including the first rotary electric machine 1, the second rotary electric machine 2, and the DC power supply 3. The power conversion device 100 includes a current detection device. In the power converter 100, the current detection method is executed.

The first rotary electric machine 1 and the second rotary electric machine 2 are three-phase AC type rotary electric machines. The first rotary electric machine 1 is mainly used as a traveling drive source of a vehicle, for example. The second rotary electric machine 2 is used, for example, as a generator that generates electricity mainly by utilizing a rotational driving force output from an internal combustion engine of a vehicle. The DC power supply 3 is a power supply unit that outputs a DC voltage, including a rechargeable secondary battery such as a lithium ion battery. The DC power supply 3 may be, for example, a fuel cell.

The power conversion device 100 includes a capacitor 110 as a filter, a converter 120, a smoothing capacitor 130, a first inverter 140a, a second inverter 140b, a sensor unit 160, and a control circuit 170 (CNTR).

The capacitor 110 is provided between the positive electrode line 10P and the negative electrode line 10N. The positive electrode line 10P is a power line connected to the positive electrode of the DC power supply 3, and is provided by an electric wire and / or a bus bar. The negative electrode line 10N is a power line connected to the negative electrode of the DC power supply 3, and is provided by an electric wire and / or a bus bar. The capacitor 110 functions as a filter for removing noise of the DC voltage supplied from the DC power supply 3 to the converter 120.

The converter 120 is a voltage conversion circuit. The converter 120 provides a voltage conversion between the voltage between the positive electrode line 10P and the negative electrode line 10N and the voltage between the high potential line 20H and the low potential line 20L. The high-potential line 20H and the low-potential line 20L are lines for high power flowing through the first rotary electric machine 1 and the second rotary electric machine 2. The converter 120 is a conversion circuit that converts a DC voltage into a DC voltage having a different voltage. The converter 120 is used for converting the DC voltage between the DC power supply 3 and the first inverter 140a and between the DC power supply 3 and the second inverter 140b. The converter 120 functions as a booster circuit that boosts the DC voltage supplied from the DC power supply 3. The converter 120 may function as a step-down circuit for stepping down the voltage between the high-potential line 20H and the low-potential line 20L.

The converter 120 includes a semiconductor switching element and a reactor 60. The semiconductor switching device is provided by the reverse conduction insulated gate bipolar transistor shown. The semiconductor switching element can be provided by various elements such as a power MOSFET and a SiC transistor. The converter 120 has two semiconductor switching elements connected in series between the high potential line 20H and the low potential line 20L. The plurality of semiconductor switching elements are provided by a module 40 in which the plurality of semiconductor switching elements are housed in one package. The converter 120 has a module 43. The converter 120 has a reactor 60. The reactor 60 is arranged in series between the connection point between the high-side semiconductor switching element and the low-side semiconductor switching element and the positive electrode line 10P.

The smoothing capacitor 130 is provided between the high potential line 20H and the low potential line 20L. The smoothing capacitor 130 has a function of smoothing the voltage between the high potential line 20H and the low potential line 20L.

The first inverter 140a is arranged between the high potential line 20H and the low potential line 20L and between the first rotary electric machine 1. The first inverter 140a provides DC AC conversion between DC power and three-phase AC power. The first inverter 140a converts the electric power flowing through the first rotary electric machine 1.

The second inverter 140b is arranged between the high potential line 20H and the low potential line 20L and between the second rotary electric machine 2. The second inverter 140b provides DC AC conversion between DC power and three-phase AC power. The second inverter 140b converts the electric power flowing through the second rotary electric machine 2.

The first inverter 140a and the second inverter 140b include a plurality of semiconductor switching elements. The plurality of semiconductor switching elements provides two sets of three-phase bridge circuits. The high-side semiconductor switching element and the low-side semiconductor switching element in the first inverter 140a and the second inverter 140b are provided by the module 40. The first inverter 140a and the second inverter 140b include a plurality of modules 40. The first inverter 140a has three modules 41. The second inverter 140b has three modules 42. In the illustrated example, the power converter 100 has seven modules 40.

In the illustrated example, one module 40 has two semiconductor switching elements. Instead, one module 40 can include a diverse number of semiconductor switching elements. One module 40 may contain, for example, a set of three-phase bridge circuits. Further, one module 40 may accommodate a plurality of high-side or low-side semiconductor switching elements. The number of semiconductor switching elements accommodated in one module 40 and the circuit configuration can be changed in various ways.

The sensor unit 160 detects the current flowing through each part of the power conversion device 100. The sensor unit 160 detects the first current I1 between the first inverter 140a and the first rotary electric machine 1. The sensor unit 160 detects the second current I2 between the second inverter 140b and the second rotary electric machine 2. The sensor unit 160 detects the third current I3 flowing through the converter 120. The sensor unit 160 includes a coreless current sensor arranged in the vicinity of the conductor to be detected. The sensor unit 160 includes a plurality of bus bars as a plurality of conductors. The sensor unit 160 includes a plurality of coreless current sensors. The coreless current sensor detects the magnetic flux generated by the current to be detected without providing a large magnetic flux core for focusing the magnetic flux generated by the current to be detected.

The control circuit 170 is a circuit or a group of circuits. The control circuit 170 is also called a control device. The control circuit 170 exerts a function of controlling the operation of a plurality of semiconductor switching elements in the converter 120, the first inverter 140a, and the second inverter 140b. The control circuit 170 includes, for example, a memory that records software for control and a microcomputer that includes a processor that executes the software. The control circuit 170 controls power conversion by controlling the operation of a plurality of semiconductor switching elements based on the current detected by the sensor unit 160 and the like. The control circuit 170 is configured to respond to a command from a higher-level control device installed inside or outside the vehicle, for example. The control circuit 170 sets, for example, a target fluctuation pattern of the current flowing through each phase of the first rotary electric machine 1 and / or the second rotary electric machine 2 based on the output torque request signal from the host control device. The control circuit 170 monitors the current flowing through the first rotary electric machine 1, the second rotary electric machine 2, and the converter 120 by the sensor unit 160. The control circuit 170 feedback-controls the first inverter 140a and / or the second inverter 140b so as to realize the target fluctuation pattern.

The power conversion device 100 includes an external control device 175 (EXCT) installed outside the case 90, which will be described later. The external control device 175, together with the control circuit 170, constitutes the control system of the power conversion device 100. The control system is provided by (a) an algorithm as a plurality of logics called if-then-else form, or (b) a trained model tuned by machine learning, for example, an algorithm as a neural network.

The control system is provided by a control system that includes at least one computer. The control system may include multiple computers linked by data communication equipment. A computer includes at least one processor (hardware processor) which is hardware. The hardware processor can be provided by (i), (ii), or (iii) below.

(I) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is called a CPU: Central Processing Unit, a GPU: Graphics Processing Unit, RISC-CPU, or the like. Memory is also called a storage medium. A memory is a non-transitional and substantive storage medium that non-temporarily stores "programs and / or data" that can be read by a processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. The program may be distributed by itself or as a storage medium in which the program is stored.

(Ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit that includes a large number of programmed logic units (gate circuits). The digital circuit is a logic circuit array, for example, ASIC: Application-Special Integrated Circuit, FPGA: Field Programmable Gate Array, SoC: System on a Chip, PGA: Programmable Cable. Digital circuits may include memory for storing programs and / or data. Computers may be provided by analog circuits. Computers may be provided by a combination of digital and analog circuits.

(Iii) The hardware processor may be a combination of the above (i) and the above (ii). (I) and (ii) are arranged on different chips or on a common chip. In these cases, the part (ii) is also called an accelerator.

The controls and methods thereof described in this disclosure are realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. May be done. Alternatively, the controls and methods thereof described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the controls and techniques described in this disclosure include a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured by a combination. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer.

The control system executes a detection process that processes a signal indicating the current detected from the sensor unit 160. The control system performs a calibration process on the sensor unit 160. The control system executes an abnormality detection process for determining an abnormality in the sensor unit 160. The control system executes a protection process for protecting the power conversion device 100 or the vehicle according to the detected abnormality. Further, the control system executes a traveling process of traveling the vehicle by controlling the first rotating electric machine 1 and the second rotating electric machine 2. The control system causes the power conversion device 100 to function by executing a plurality of processes.

The power conversion device 100 converts, for example, the DC voltage supplied from the DC power supply 3 into a three-phase alternating current and supplies it to the first rotary electric machine 1. The power conversion device 100 uses the electric power charged in the DC power supply 3 to drive the vehicle by the first rotary electric machine 1. This operation mode is called an EV drive mode. For example, the power conversion device 100 converts the three-phase alternating current supplied from the second rotating electric machine 2 that generates electricity by the rotational driving force of the internal combustion engine into three-phase alternating current having a different frequency and the like, and converts the first rotating electric machine 1 into three-phase alternating current. Supply to. The power conversion device 100 uses the electric power generated by using the rotational driving force of the internal combustion engine to drive the vehicle by the first rotating electric machine 1. This operation mode is called an in-line HV drive mode.

Further, the power conversion device 100 may provide, for example, a regenerative drive mode in which the first rotary electric machine 1 and / or the second rotary electric machine 2 functions as a generator and charges the DC power supply 3. The current relationship may be provided in the regenerative drive mode. The applications of the first rotary electric machine 1 and the second rotary electric machine 2 are not limited to those described above, and can be appropriately changed, added, or replaced according to the design of the vehicle to be used. Therefore, the operation of the power conversion device 100 is not limited to that described above, and can be appropriately changed, added, or replaced.

The circuit including the first rotary electric machine 1 and the first inverter 140a provides a first switch circuit LD1 through which a controllable first current I1 flows. The first switch circuit LD1 includes an electric wire and / or a bus bar that provides an energization path. In other words, the first switch circuit LD1 controls the first first current. The circuit including the second rotary electric machine 2 and the second inverter 140b provides a second switch circuit LD2 through which a controllable second current I2 flows. The second switch circuit LD2 includes an electric wire and / or a bus bar that provides an energization path. In other words, the second switch circuit LD2 controls the second current I2. The converter 120 provides a third switch circuit LD3 through which a controllable third current I3 flows. The third switch circuit LD3 includes an electric wire and / or a bus bar that provides an energization path. In other words, the third switch circuit LD3 controls the third current I3. The plurality of switch circuits LD1, LD2, and LD3 are also called load circuits. Therefore, the first switch circuit LD1 includes a first inverter 140a that controls the electric power of the first rotary electric machine 1. The second switch circuit LD2 includes a second inverter 140b that controls the electric power of the second rotary electric machine 2. The third switch circuit LD3 includes a converter 120 that provides voltage conversion between the DC power source 3 and the first inverter 140a and between the DC power source 3 and the second inverter 140b.

The current relationship of the currents flowing through the plurality of switch circuits satisfies the following first condition and second condition (Equations (1) and (2)).

First condition: I1> I2 ... (1) formula Second condition: I1> I3 ... (2) formula The current relationship represented by the above formulas (1) and (2) is the first rotary electric machine 1. This can be achieved by setting the roles of the second rotary electric machine 2 and the converter 120. For example, the above current relationship can be realized by using the first rotary electric machine 1 as the main power source for traveling. Further, the above current relationship can also be realized by the configuration of the power transmission system arranged between the first rotary electric machine 1 and the second rotary electric machine 2 and the drive wheels of the vehicle. Various configurations such as planetary gears can be used for the configuration of the power transmission system. The current relationship represented by the above equations (1) and (2) may be realized by the control by the control circuit 170. The power converter 100 provides a plurality of different operating modes by controlling, for example, the converter 120, the first inverter 140a, and the second inverter 140b. The plurality of operation modes are the first current of the first current I1 flowing through the first switch circuit LD1, the second current I2 flowing through the second switch circuit LD2, and the third current I3 flowing through the third switch circuit LD3. It may include a high current drive mode in which I1 is maximized. The current relationship may be provided in the EV drive mode. The current relationship may be provided in the inline HV drive mode.

Further, the current relationship represented by the above equations (1) and (2) also appears in the current flowing between the plurality of switch circuits LD1, LD2, LD3 (switch unit 140 described later) and the smoothing capacitor 130. The current flowing between the first switch circuit LD1 and the smoothing capacitor 130 is larger than the current flowing between the second switch circuit LD2 and the smoothing capacitor 130. The current flowing between the first switch circuit LD1 and the smoothing capacitor 130 is larger than the current flowing between the third switch circuit LD3 and the smoothing capacitor 130. According to the illustrated configuration, in the first switch circuit LD1, the amount of heat generated due to Joule heat is the largest. Further, due to the magnitude of the first current I1, the surge voltage due to the inductance component is the largest in the first switch circuit LD1.

2 and 3 show the arrangement of a plurality of components in the power conversion device 100. FIG. 2 is a side view in the direction of arrow II of FIG. FIG. 3 is a plan view of arrow III in FIG. In FIGS. 2 and 3, for convenience, a Cartesian coordinate system including the height direction XD, the width direction YD, and the depth direction ZD is shown. The names of height, width, and depth are for convenience only and do not limit the installation posture of the power conversion device 100. The power conversion device 100 can take various postures with respect to the direction of gravity. The power converter 100 has a case 90. The case 90 houses a plurality of parts for the power converter 100.

The power conversion device 100 includes a plurality of modules 40. Each module 40 is a flat plate semiconductor module. Each module 40 includes three power terminals 44 including a high potential terminal 44H, a low potential terminal 44L, and a connection point terminal 44M. The power terminal 44 is also called a main terminal. The high potential terminal 44H is connected to the high potential line 20H. The low potential terminal 44L is connected to the low potential line 20L. The connection point terminal 44M is a connection point between the high-side semiconductor switching element and the low-side semiconductor switching element. The connection point terminal 44M is connected to the first rotary electric machine 1, the second rotary electric machine 2, or the reactor 60. Each module 40 includes a plurality of control terminals 45 for control signals and monitor signals. The plurality of control terminals 45 are connected to the control circuit 170. The plurality of power terminals 44 and the plurality of control terminals 45 extend from the edge of the module 40 along the height direction XD.

The plurality of modules 40 are arranged in a stacked manner along the depth direction ZD. The plurality of modules 40 are arranged so that their respective plate-shaped main planes are parallel to each other and their respective plate-shaped main planes overlap. The plurality of modules 40 are arranged so that their edges are aligned along the depth direction ZD. The plurality of modules 40 provide a plurality of power terminals 44 including at least a high potential terminal 44H and a low potential terminal 44L. The plurality of power terminals 44 are arranged so as to form a plurality of rows. The three power terminals 44 project in the height direction XD from the side surface of the module 40 facing the height direction XD. Similar power terminals 44 projecting from different modules 40 are arranged to form a row along the depth direction ZD. In other words, the plurality of modules 40 are arranged along the depth direction ZD so that the plurality of power terminals 44 form a plurality of rows. In the following description, the depth direction ZD is also referred to as an arrangement direction. Further, the range in which the plurality of power terminals 44 are positioned in the arrangement direction is also referred to as an arrangement range RG.

The power conversion device 100 includes a cooler 50 for cooling a plurality of modules 40. The cooler 50 has a flow path through which a cooling medium such as water flows. The plurality of modules 40 and the cooler 50 provide a liquid-cooled switch unit 140. Therefore, the switch unit 140 includes a plurality of modules 40 that accommodate semiconductor switching elements and have power terminals 44. The switch unit 140 includes a cooler 50 that cools a plurality of modules 40.

The switch unit 140 includes a converter 120, a first inverter 140a, and a plurality of modules 40 for the second inverter 140b. In other words, the switch unit 140 includes a first switch circuit LD1, a second switch circuit LD2, and a plurality of modules 40 which are main heat generating components in the third switch circuit LD3. As a result, the switch unit 140 has a plurality of power terminals 44 arranged along the arrangement direction. In the switch unit 140, the plurality of power terminals 44 are arranged in three rows along the arrangement direction. The plurality of power terminals 44 may be arranged in various numbers of rows such as one row, two rows, three rows, and four rows.

In other words, in the switch unit 140, a plurality of power terminals 44 of the first switch circuit LD1, the second switch circuit LD2, and the third switch circuit LD3 are arranged in a predetermined order over the arrangement range RG. The plurality of power terminals 44 are arranged so that the power terminals 44 of the second switch circuit LD2 and the power terminals 44 of the third switch circuit LD3 are located on both sides of the power terminals 44 of the first switch circuit LD1. .. In other words, the predetermined order is the order of the second switch circuit LD2, the first switch circuit LD1, and the third switch circuit LD3.

The first switch circuit LD1 includes a plurality of modules 41. The second switch circuit LD2 includes a plurality of modules 42. The third switch circuit LD3 includes a module 43. The third switch circuit LD3 may include a plurality of modules 43. The module 42 is located at the end of the switch unit 140. The module 43 is located at the end of the switch unit 140. The module 41 is located between the module 42 and the module 43 in the switch unit 140. The module 41 through which the first current I1 flows is located between the module 42 through which the second current I2 smaller than the first current I1 flows and the module 43 through which the third current I3 smaller than the first current I1 flows. The module 41 is positioned in the intermediate region of the switch unit 140, and the modules 42 and 43 are positioned in both end regions, respectively.

The capacitor unit 30 and the sensor unit 160 are arranged next to the switch unit 140 in the width direction YD. The capacitor unit 30 and the sensor unit 160 are separately arranged on both sides of the switch unit 140. In other words, the sensor unit 160 and the capacitor unit 30 are arranged on both sides of the switch unit 140 apart from each other. The plurality of high potential terminals 44H are arranged at positions closest to the capacitor unit 30 among the three power terminals 44. The plurality of low-potential terminals 44L are arranged between the connection point terminal 44M and the high-potential terminal 44H in the three power terminals 44. The plurality of connection point terminals 44M are arranged at positions closest to the sensor unit 160 among the three power terminals 44. The arrangement of the plurality of power terminals 44 can be interchanged with each other.

The sensor unit 160 has a plurality of detection units 161, 162, and 163. The detection units 161, 162, and 163 detect the current flowing through the connection point terminal 44M and output the detection signal to the control circuit 170. The sensor unit 160 is connected to the control circuit 170. In the sensor unit 160, the respective detection units 161, 162, and 163 include elements shown as partial fracture views in FIG. The sensor unit 160 accommodates a plurality of detection units 161, 162, and 163 in a body made of an insulating resin. The sensor unit 160 also serves as a terminal block.

Each of the plurality of detection units 161, 162, and 163 has a bus bar 165. The bus bar 165 has a terminal 165a for external connection and a terminal 165b for connection with the connection point terminal 44M. The bus bar 165 has at least one bend. The bus bar 165 is, for example, crank-shaped. The sensor unit 160 has a magnetic shield plate 169, 169 that extends across a plurality of detection units 161, 162, 163. The shield plates 169 and 169 provide shielding against external magnetic flux coming from the outside of the sensor unit 160. The sensor unit 160 has a circuit board 168 as a support member that extends over a plurality of detection units 161, 162, and 163. Each of the plurality of detection units 161, 162, and 163 has an element 167 which is a coreless type current sensor mounted on the circuit board 168. The element 167 detects the first current I1, the second current I2, and the third current I3. The element 167 is arranged close to the bus bar 165. The element 167 outputs a signal indicating the current by detecting the magnetic flux caused by the current flowing through the bus bar 165.

The detection unit 161 detects the first current I1 flowing through the first switch circuit LD1. The bus bar 165 in the detection unit 161 belongs to the first switch circuit LD1. The sensor unit 160 includes three detection units 161 for detecting three-phase power. The three detection units 161 are arranged so as to form a group of detection units 161. A group of detection units 161 are arranged next to the switch unit 140. A group of detection units 161 are arranged next to a plurality of connection point terminals 44M belonging to the first switch circuit LD1.

The detection unit 162 detects the second current I2 flowing through the second switch circuit LD2. The bus bar 165 in the detection unit 162 belongs to the second switch circuit LD2. The sensor unit 160 includes three detection units 162 for detecting three-phase power. The three detection units 162 are arranged so as to form a group of detection units 162. A group of detection units 162 are arranged next to the switch unit 140. A group of detection units 162 are arranged next to a plurality of connection point terminals 44M belonging to the second switch circuit LD2.

The detection unit 163 detects the third current I3 flowing through the third switch circuit LD3. The bus bar 165 in the detection unit 163 belongs to the third switch circuit LD3. The sensor unit 160 includes one detection unit 163 for detecting the single-phase power in the converter 120. When the converter 120 has a plurality of detection targets, the sensor unit 160 may include a plurality of detection units 163. The detection units 163 are arranged so as to form a group of detection units 163. A group of detection units 163 are arranged next to the switch unit 140. A group of detection units 163 are arranged next to the connection point terminal 44M belonging to the third switch circuit LD3.

The group of detection units 161 is arranged between the group of detection units 162 and the group of detection units 163 in the arrangement direction. The sensor unit 160 extends along the arrangement direction of the plurality of power terminals 44 over the arrangement range RG of the plurality of power terminals 44. In the illustrated example, the sensor unit 160 extends along the depth direction ZD over all connection point terminals 44M. This arrangement may have an advantageous effect on the noise suppression effect in the sensor unit 160 or the heat concentration avoidance effect.

The reactor 60 is arranged next to the switch unit 140 in the depth direction ZD. The reactor 60 is arranged over the capacitor unit 30, the switch unit 140, and the sensor unit 160. The control circuit 170 is arranged on the switch unit 140 in the height direction XD. The circuit board in the control circuit 170 is connected to a plurality of control terminals 45 on the switch unit 140. The arrangement of the capacitor unit 30, the reactor 60, the sensor unit 160, and the control circuit 170 with respect to the switch unit 140 is not limited to the arrangement shown in the drawing.

The high potential line 20H is provided by the bus bar 131. The bus bar 131 is electrically connected to a plurality of high potential terminals 44H. The bus bar 131 has a plurality of connections 132 for electrical connections. The connecting portion 132 is provided by a cut-up piece provided in the bus bar 131. The low potential line 20L is provided by the bus bar 133. The bus bar 133 is electrically connected to a plurality of low potential terminals 44L. The bus bar 133 has a plurality of connections 134 for electrical connections. The connecting portion 134 is provided by a cut-up piece provided in the bus bar 131. The bus bar 133 is slightly longer than the bus bar 131.

The bus bar 131 has a bridge portion 136 between the parallel connection portion 135, which will be described later, and the plurality of power terminals 44. The bus bar 133 also has a bridge portion 136. The bridge portion of the bus bar 131 and the bridge portion of the bus bar 133 overlap with each other. The bridge portion of the bus bar 131 and the bridge portion of the bus bar 133 have the same shape. The bridge portion 136 has a flat plate shape. The bridge portion 136 is a quadrilateral having a width over the arrangement range RG. The bridge portion 136 has a width slightly wider than the arrangement range RG. The bridge portion 136 provides a conductive path throughout the quadrilateral. The bridge portion 136 electrically connects the parallel connection portion 135, which will be described later, and the plurality of power terminals 44 at least in the intermediate portion of the arrangement range RG. The quadrilateral bridge portion 136 electrically connects the parallel connection portion 135, which will be described later, and the plurality of power terminals 44 in the entire array range RG including the intermediate portion. The bridge portion 136 provides innumerable conductive paths over the entire array range RG between the plurality of capacitor elements 30a and the plurality of power terminals 44.

The bus bars 131 and 133 are arranged in parallel so as to overlap each other. In the illustration, in order to show the existence of the two bus bars 131 and 133, the bus bars 131 and the bus bars 133 are shown slightly offset from each other. The bus bars 131 and 133 are spread out in a two-dimensional manner over a two-dimensional range in which a plurality of high-potential terminals 44H and a plurality of low-potential terminals 44L are arranged. The bus bars 131 and 133 extend along the arrangement direction of the plurality of power terminals 44 over the arrangement range RG of the plurality of power terminals 44. The bus bars 131 and 133 may include electrical insulating members arranged between them.

The bus bars 131 and 133 are also bus bars for connecting the capacitor element 30a housed in the capacitor unit 30. The bus bars 131 and 133 are also called condenser bus bars. The bus bars 131 and 133 have a parallel connection portion 135 for connecting a plurality of capacitor elements 30a in parallel. A plurality of capacitor elements 30a are connected in parallel between the parallel connection portion 135 of the bus bar 131 and the parallel connection portion 135 of the bus bar 133.

The capacitor unit 30 extends along the arrangement direction of the plurality of power terminals 44 over the arrangement range RG of the plurality of power terminals 44. The capacitor unit 30 extends beyond the array range RG in the depth direction. The parallel connection portion 135 extends along the arrangement direction of the plurality of power terminals 44 over the arrangement range RG of the plurality of power terminals 44.

The capacitor unit 30 has a plurality of capacitor elements 30a connected in parallel. In the figure, three capacitor elements 30a are illustrated. The capacitor unit 30 may have one, two, or four or more capacitor elements 30a. Further, the capacitor unit 30 may accommodate a capacitor 110 in addition to the smoothing capacitor 130.

The bus bar 131 has a plurality of connecting portions 132 electrically connected to the plurality of power terminals 44. The bus bar 133 has a plurality of connecting portions 134 that are electrically connected to the plurality of power terminals 44. The bus bar 131 has a parallel connection portion 135 for connecting a plurality of capacitor elements 30a in parallel. The bus bar 133 has a parallel connection portion 135 for connecting a plurality of capacitor elements 30a in parallel. The bridge portion 136 is arranged between the plurality of connecting portions 132 and 134 and the parallel connecting portion 135. Each of the bus bars 131 and 133 has a wide depth direction ZD width over the arrangement range RG, and the plurality of power terminals 44 and the parallel connection portion 135 are electrically connected over this width.

Each of the buses 131 and 133 includes a bridge portion 136 that connects the plurality of power terminals 44 and the capacitor unit 30 at least in the intermediate range in the arrangement range RG. The illustrated bridge portion 136 shows a conductor portion virtualized in a part of a wide plate-shaped bus bar 131 and 133. Therefore, the bus bars 131 and 133 have a width over the array range RG. The bridge portion 136 is a conductor portion virtualized in a part of the bus bars 131 and 133. The bridge portion 136 linearly connects the plurality of power terminals 44 and the capacitor unit 30 in an intermediate range in which a plurality of power terminals 44 included in the first switch circuit LD1 are arranged.

In FIG. 4, a single sensor unit 160 including a plurality of detectors is illustrated as an outer shape for ease of understanding. Hatchings showing the resin material forming the sensor unit 160 are not shown. In the following description, in order to facilitate understanding, an example in which one leakage flux generated from a current flowing through one bus bar interlinks with one element will be mainly described. Instead of this, an example may be assumed in which a plurality of leakage fluxes are generated from the currents flowing through the plurality of bus bars, and the plurality of leakage flux fluxes are interlinked with one element. Such extensions are possible based on the usual electromagnetic knowledge of those skilled in the art.

In the sensor unit 160, the shield plate 169 suppresses the external noise magnetic flux caused by the outside of the sensor unit 160. Each of the plurality of bus bars 165 included in the sensor unit 160 generates magnetic flux due to the current flowing therethrough. The current flowing through one bus bar 165 produces a regular magnetic flux to be detected and a leakage flux. The regular magnetic flux is also called the main magnetic flux. The leakage flux can also be called a secondary magnetic flux.

The normal magnetic flux interlinks with the element 167 associated with the bus bar 165. The element 167 generates and outputs an electric signal corresponding to a normal magnetic flux. This electric signal is used as a signal indicating the current flowing through the bus bar 165.

The leakage flux interlinks with another element 167 provided for the other bus bar 165. The leakage flux functions as an internal noise flux in the sensor unit 160. The other element 167 generates and outputs an electric signal corresponding to the leakage flux. This electric signal is output as noise different from the current to be detected. As a result, the output of any element 167 included in the sensor unit 160 leaks from not only the electrical signal due to the magnetic flux from the associated specific bus bar 165 but also from the other bus bars 165 included in the sensor unit 160. Includes noise signals due to magnetic flux.

FIG. 4 illustrates a case where a current is flowing through the first switch circuit LD1 as the current to be detected. In the following description, the relationship between the bus bar 65a and the element 67d is mainly described. However, this relationship should also be understood as applying between the plurality of bus bars 165 and the plurality of elements 167.

In the case of FIG. 4, each of the plurality of bus bars 165 belonging to the plurality of detection units 161 generates a normal magnetic flux M1. Each of the plurality of elements 167 belonging to the plurality of detection units 161 outputs an electric signal caused by the magnetic flux M1. At this time, the plurality of bus bars 165 belonging to the first switch circuit LD1 supply the leakage flux ML1, ML2 ... MLn to the detection units 162 and 163 belonging to the other switch circuits.

Typically, the central bus bar 65a in the figure and the detection unit 162 will be described as an example. The bus bar 65a provides a first bus bar. The bus bar 65d provides a second bus bar. The current flowing through the bus bar 65a is called the first current. The current flowing through the bus bar 65d is called the second current. The element 67a provides a first element that detects a magnetic flux generated due to a first current flowing through the first bus bar. The element 67d provides a second element that detects the magnetic flux generated by the second current flowing through the second bus bar. The control system acquires a signal indicating the first current from the first element. The control system acquires a signal indicating the second current from the second element. In this way, the current detection device including the sensor unit 160 of the power conversion device 100 detects the current flowing through the arbitrary bus bar.

In this case, the bus bar 65a generates the leakage flux ML1 indicated by the broken line, the leakage flux ML2 indicated by the alternate long and short dash line, and the leakage flux ML3 indicated by the alternate long and short dash line toward the detection unit 162 of the second switch circuit LD2. do. The maximum number of leakage flux MLn may reach the number of bus bars 165 included in the sensor unit 160. In the case of illustration, the leakage flux MLn may reach ML6.

In the figure, the leakage flux ML3 is interlinked with the element 67d located at the leftmost end. Both the leakage flux ML2 and the leakage flux ML3 are linked to the second element 67c from the left. Further, all of the leakage flux ML1, the leakage flux ML2, and the leakage flux ML3 are linked to the third element 67b from the left.

As described above, the leakage flux is known in advance according to the current flowing through one bus bar 65a and the geometric positional relationship between one bus bar 65a and the elements 67b, 67c, 67d belonging to the other detection unit 162. be able to. As a result, the leakage flux acting on the second element 67d under a predetermined observation condition can be known in advance as a known value. For example, when there is no energization to the second bus bar 65d associated with the second element 67d and a known energization is executed to the first bus bar 65a which is another bus bar, the output of the second element 67d is preliminarily output. Can be predicted. For example, the output of the second element 67d can be estimated based on the known energization of the first bus bar 65a. This description applies to all of the plurality of elements 167. This is of course understandable to those skilled in the art. Therefore, it is naturally understood that the processing according to the flowchart described later can be applied to each of the plurality of elements 167.

In the disclosure in this specification, the output of the second element 67d under a predetermined leak observation condition is observed as a leak observation signal. The leak observation condition is defined by the energization state of the plurality of bus bars 165. The leak observation condition is when the bus bar 65d associated with the second element 67d is not energized and the bus bar 65a associated with the first element 67a is energized. At this time, the output of the second element 67d includes only the influence of the leakage flux from the other bus bar 65a. Therefore, by observing the output of the second element 67d, the influence of the leakage flux is determined. The output of the second element 67d, that is, the electric signal observed at this time shows the basic performance of the second element 67d. In other words, the observed electrical signal is used as a leak observation signal indicating the basic performance of the second element 67d.

In one example, the leak observation signal is used to determine at least normal or abnormal of the second element 67d. The leak observation signal is used, for example, to determine whether or not it is 0 (zero). 0 (zero) is a reference value to be compared with the leak observation signal. 0 (zero) suggests a failure related to an electric circuit such as a disconnection. Alternatively or additionally, the leak observation signal is used, for example, to determine whether or not it is a power supply voltage (Vcc). In this case, the power supply voltage is used as a reference value. The power supply voltage suggests a failure related to the electric circuit such as a short circuit.

In one example, the leak observation signal is used to determine at least normal or abnormal of element 167. The leak observation signal is used, for example, to determine whether or not it is within a specified reference range. The specified reference range as a reference value can be set according to the geometrical positional relationship between the bus bar 165 on which the above-mentioned known energization is executed and the plurality of bus bars 165. The leak observation signal is used, for example, to determine whether or not the specified minimum value is exceeded. The specified minimum value as a reference value can be set predictively according to the geometrical positional relationship between the bus bar 165 on which the above-mentioned known energization is executed and the plurality of bus bars 165. The leak observation signal is used, for example, to determine whether or not the value is below the specified maximum value. The specified maximum value as a reference value can be set predictively according to the geometrical positional relationship between the bus bar 165 on which the above-mentioned known energization is executed and the plurality of bus bars 165.

In one example, the leak observation signal is used to indicate the degree of anomaly when element 167 is anomalous. The leak observation signal is used as it is, for example, to correct the normal observation signal caused by the normal magnetic flux. Instead of this, the normal observation signal caused by the normal magnetic flux may be corrected by a predetermined ratio of the leak observation signal.

In FIG. 5, the process 180 of the arbitrary element 167 in the arbitrary nth circuit LDn is shown. FIG. 5 shows a current detection method for the power converter 100. The process 180 can also be referred to as an output process or a calibration process for any element 167. The process 180 may be executed periodically at a predetermined time interval, or may be executed interruptively when a predetermined event occurs. The process 180 is executed, for example, when the power conversion device 100 is started.

In the following description, the bus bar 65a will be referred to as a first bus bar, and the bus bar 65d will be referred to as a second bus bar. The flowchart illustrated in FIG. 5 can be executed for each of the plurality of elements 167 included in the sensor unit 160. Flow charts are executed centrally or decentralized in the control system.

In step 181 the control system determines that the leak observation condition for processing the element 67d is satisfied. Step 181 includes step 181a for determining the energized state in the first switch circuit LD1 which is the first circuit, and step 181b for determining the energized state in the second switch circuit LD2 which is the second circuit. Step 181a determines whether or not the condition that the element 67d to be processed is affected only by the leakage flux is satisfied. Step 181b determines whether or not an energized state is generated in which the leakage flux acting on the element 67d can be predictively set. Step 181 provides a condition determination unit for determining whether or not the leakage observation condition is satisfied, and a condition determination step. The leak observation condition is a state in which the first current flows through the first bus bar and no current flows through the second bus bar.

In step 181a, the control system determines whether or not the second switch circuit LD2 is energized. If the result is positive in step 181a, the process branches to YES and step 188 is executed. If a negative determination is made in step 181a, the process branches to NO and step 181b is executed.

In step 181b, the control system determines whether or not one circuit other than the second switch circuit LD2 is energized. If the result is positive in step 181b, the process branches to YES and step 182 is executed. If a negative determination is made in step 181b, the process branches to NO and step 181a is executed again. In the illustrated example, since the element 67d of the second switch circuit LD2 is the evaluation target, the process proceeds to step 182 when the first switch circuit LD1 or the third switch circuit LD3 is energized.

The case of proceeding from step 181 to step 188 is a case where the second switch circuit LD2 is energized. In this case, the element 67d outputs a normal observation signal In indicating a normal magnetic flux caused by the current actually flowing in the bus bar 65d in order to observe the second current flowing in the second switch circuit LD2. In step 188, the control system acquires a normal observation signal In indicating the second current flowing through the second switch circuit LD2 from the element 67d. Step 188 provides a regular acquisition unit and a regular acquisition step when the leak observation condition is not satisfied. The control system detects the normal magnetic flux generated by the current flowing through the first bus bar 65a by the first element 67a, and acquires the normal observation signal In indicating the current flowing through the first bus bar 65a from the first element 67a. The control system detects the normal magnetic flux generated by the current flowing through the second bus bar 65d by the second element 67d, and acquires the normal observation signal In indicating the current flowing through the second bus bar 65d from the second element 67d.

In step 181 it is determined whether or not both conditions are satisfied, in which the second bus bar 65d associated with the second element 67d is not energized and the first bus bar 65a is energized with the first current. .. When this determination is affirmative, the signal Im appearing in the output of the element 67d is the signal Im caused by the leakage flux. The signal Im caused by the leakage flux can also be called a noise signal or a ghost signal. In the disclosure in this specification, the signal Im caused by the leakage flux is also referred to as a leakage observation signal indicating the performance of the element 67d.

In step 182, the control system acquires a signal Ia indicating a current actually applied to the first switch circuit LD1 other than the second switch circuit LD2, that is, in the case of the drawing, from the first element 67a. The signal caused by the leakage flux in the second element 67d is the geometrical positional relationship between the current Ia that generates the leakage flux and the first bus bar 65a that generates the leakage flux and the second element 67d. It can be decided based on. For example, when considering the relationship between the second element 67d and the first bus bar 65a, the geometric positional relationship can be defined as a coefficient or a function. On the other hand, the current flowing through the first bus bar 65a can be acquired as a signal of the first element 67a. As a result, the signal caused by the leakage flux in the second element 67d can be determined by the current flowing through the first bus bar 65a observed by the first element 67a, the above coefficient, or the above function. Step 182 provides a normal acquisition unit that acquires a normal observation signal Ia that detects a normal magnetic flux caused by the first current from the first element 67a when the leakage observation condition is satisfied, and a normal acquisition step. There is.

Note that step 182 may be set according to the operation mode of the power conversion device 100. For example, in the operation mode in which a predetermined current flows through the first switch circuit LD1, a predetermined signal Ia may be set instead of the step 182.

In step 183, the control system calculates a theoretical signal output by the second element 67d due to the leakage flux caused by the current Ia flowing through the first bus bar 65a. For example, if the above function is f (), the theoretical signal is given as f (Ia). The theoretical signal is a theoretical signal to be compared with the leak observation signal Im observed from the second element 67d. The theoretical signal is a reference signal. In other words, in step 183, the control system calculates the reference signal THm based on the signal Ia indicating the current actually applied to other than the second switch circuit LD2. In this embodiment, the reference signal THm is given as a range value including an upper limit and a lower limit for evaluating the leak observation signal Im. Instead, the reference signal may be given as a single numerical value. Step 183 provides a reference setting unit for setting a reference signal THm which is a reference to be compared with the leak observation signal Im when the leak observation condition is satisfied. Further, step 183 sets the reference signal THm based on the normal observation signal Ia. In step 183, when the leak observation condition is satisfied, the reference signal THm to be compared with the leak observation signal Im is set based on the normal observation signal Ia.

The arithmetic processing in step 183 may be executed by a map processing that refers to a map associated with the signal Ia and the reference signal THm instead of the function. The relationship between the signal Ia and the reference signal THm can be obtained by the above-mentioned geometrical positional relationship or experimentally.

In step 184, the control system sets an output reference signal for discriminating between the output enable state and the output impossible state of the second element 67d. The unoutput state is, for example, a failure related to an electric circuit. The unoutput state is, for example, a disconnection of the circuit, a short circuit to the ground potential, or a short circuit to the power supply potential. 0 (zero) is set as the reference signal THc indicating the disconnection. The regulated voltage Vcc is set as the reference signal THs indicating a short circuit to the power supply potential. Step 184 provides an output reference setting unit and an output reference setting step.

In step 185, the control system acquires the leakage observation signal Im due to the leakage flux from the second element 67d. The leakage observation signal Im is caused by the leakage flux from the first bus bar 65a, and is not the current actually flowing through the second bus bar 65d. However, the leak observation signal Im is an effective signal indicating the performance of the second element 67d. In particular, the leak observation signal Im indicates the sensitivity of the second element 67d to a weak magnetic flux. Step 185 provides a leak acquisition unit that acquires the leak observation signal Im from the second element, and a leak acquisition step. The leakage observation signal Im is a signal that detects the leakage flux that is generated due to the first current and interlinks with the second element 67d when the leakage observation condition is satisfied.

In step 186, the control system evaluates the second element 67d based on the comparison between the leak observation signal Im and the reference signal THm. Step 186 provides an evaluation unit and an evaluation step. The control system performs three types of evaluation in step 186. Step 186 includes step 186a, step 186b, and step 186c. Step 186 can include one or two of steps 186a, 186b, and 186c. Step 186 can be adopted by changing the order of steps 186a, 186b, and 186c.

The first evaluation is to determine whether the output of the element 67d is quantitatively normal or abnormal. This evaluation is performed based on the comparison between the leak observation signal Im and the reference signal THm. This evaluation is performed based on whether or not the leak observation signal Im can be evaluated to be equivalent to the reference signal THm. Equivalence includes not only the same numerical value, but also the match within the specified numerical range.

The control system performs the first evaluation in step 186a. The control system compares the leak observation signal Im with the reference signal THm in step 186a. The process branches according to the evaluation result in step 186a. When the leak observation signal Im and the reference signal THm are equal (Im = THm), the leak observation signal Im is considered to be correct. In this case, the process returns to step 181a. When the leak observation signal Im and the reference signal THm are not equal (Im ≠ THm), the leak observation signal Im is considered to include some error. In this case, the process proceeds to step 186b. The process of step 186a is a process of determining whether the element 67d is normal (Im = THm) or the element 67d is abnormal (Im ≠ THm). Step 186a provides a normal / abnormal identification unit that discriminates between normal and abnormal of the second element 67d based on the comparison between the reference signal THm and the leak observation signal Im.

The second evaluation is to determine whether the element 67d is normal or abnormal as an electric circuit. This evaluation is performed based on the comparison between the leak observation signal Im and the reference signals THc and THs. The reference signal THc is set to 0 (zero) indicating a disconnection of the circuit related to the element 67d or a ground fault. The reference signal THs is set to Vcc indicating a short circuit to the power supply level of the circuit with respect to the element 67d.

The control system performs a second evaluation in step 186b. In step 186b, the control system compares the leak observation signal Im with the reference signals THc, THs. The process branches according to the evaluation result in step 186b. When the leak observation signal Im is 0 (zero), the element 67d is considered to be in an output-disabled state. In this case, the process proceeds to step 187a. When the leak observation signal Im is Vcc, the element 67d is considered to be in an output-disabled state. In this case, the process proceeds to step 187a. When the leak observation signal Im is neither 0 (zero) nor Vcc, the element 67d is considered to be in an output ready state. In this case, the process proceeds to step 186c. Step 186b provides an output identification unit that discriminates between an output enable state and an output impossible state of the second element 67d based on the comparison between the reference signal THm and the leak observation signal Im.

The third evaluation is to specify the amount of error of the element 67d. This evaluation is performed by the leak observation signal Im itself. That is, the leak observation signal Im itself indicates the amount of error.

The control system performs a third evaluation in step 186c. The control system compares the leak observation signal Im with the reference signal THm in step 186c. The process branches according to the evaluation result in step 186c. When the leak observation signal Im is larger than the reference signal THm (Im> THm), it is considered that the element 67d is reacting more sensitively than the expected sensitivity. In other words, it is considered that the failure mode of the element 67d tends to have an excessive output. In this case, the process proceeds to step 187b. When the leak observation signal Im is smaller than the reference signal THm (Im <THm), it is considered that the element 67d is reacting slower than the expected sensitivity. In other words, it is considered that the failure mode of the element 67d tends to cause the output to be too small. In this case, the process proceeds to step 187c. Step 186c provides a sensitivity discriminator that discriminates between a hypersensitive reaction and a dull reaction of the second element 67d based on a comparison between the reference signal THm and the leak observation signal Im.

In step 187, the control system executes countermeasure processing according to the failure mode of the element 67d. The countermeasure process is a process for suppressing a functional deterioration of the power conversion device 100 due to a failure of the element 67d. The countermeasure process may include, for example, a process of limiting the output of the element 67d so as to suppress the influence of the power conversion device 100. The countermeasure process may include, for example, a process of controlling the power conversion device 100 so that the vehicle can exert a minimum traveling function. This process is also called limp home process. Step 187 includes step 187a, step 187b, and step 187c. Step 187 provides a countermeasure processing unit that suppresses a functional deterioration of the power conversion device 100 due to a failure of the element 67d.

In step 187a, the control system executes a countermeasure process when the element 67d is in an output-disabled state. The countermeasure process may include, for example, a process of stopping the use of the element 67d. In this case, the power conversion device 100 can process so as not to utilize the output of the element 67d. The power converter 100 can, for example, shift to open-loop control without current control. The power conversion device 100 can limit the drive duty of the switching element, for example.

In step 187b, the control system executes a countermeasure process when the element 67d is hypersensitive. In this case, it can be considered that the normal observation signal In of the element 67d observed in the subsequent step 188 is deviated by the leakage observation signal Im. The countermeasure process may include, for example, a process of continuing to use the element 67d by adding a reduction correction for the leak observation signal Im. The countermeasure process may include, for example, a process of limiting the output torque of the rotary electric machine to the extent that the power converter 100 and the vehicle are not damaged.

In step 187c, the control system executes a countermeasure process when the element 67d reacts slowly. In this case, it can be considered that the normal observation signal In of the element 67d observed in the subsequent step 188 is deviated by the leakage observation signal Im. The countermeasure process may include, for example, a process of continuing to use the element 67d by adding an increase correction for the leak observation signal Im. The countermeasure process may include, for example, a process of limiting the output torque of the rotary electric machine to the extent that the power converter 100 and the vehicle are not damaged.

According to the embodiment described above, the current detection device in the power conversion device 100 not only observes the output from the element 167 due to the normal magnetic flux due to the current to be detected, but also the element 167 due to the leakage flux. The output from is observed and used to evaluate the element 167. In particular, the reference signal THm and the leak observation signal Im are compared. As a result, a current detection device that positively utilizes the leakage flux and a current detection method are provided. In this embodiment, the influence of the leakage flux that inevitably increases by using the coreless current sensor can be effectively utilized. Further, by using a weak leakage flux as compared with the case of using a normal magnetic flux, it is possible to determine whether the element 167 is normal or abnormal in the minute signal region of the element 167.

Other Embodiments The disclosure in this specification, drawings and the like is not limited to the exemplified embodiments. Disclosures include exemplary embodiments and modifications by those skilled in the art based on them. For example, disclosure is not limited to the parts and / or element combinations shown in the embodiments. Disclosure can be carried out in various combinations. The disclosure can have additional parts that can be added to the embodiment. Disclosures include those in which the parts and / or elements of the embodiment are omitted. Disclosures include the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some technical scopes disclosed are indicated by the claims description and should be understood to include all modifications within the meaning and scope equivalent to the claims statement.

Disclosure in the description, drawings, etc. is not limited by the description of the scope of claims. The disclosure in the description, drawings, etc. includes the technical ideas described in the claims, and further covers a wider variety of technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the description, drawings, etc. without being bound by the description of the claims.

In the above embodiment, the case where the leakage flux from the bus bar in one detection unit is detected by the elements in the other detection units in the single sensor unit 160 provided in the power conversion device 100 has been described. Instead of this, leakage flux may act between a plurality of sensor units provided in the power conversion device 100. For example, the leakage flux from the bus bar in the detection unit of one sensor unit may be detected by an element in the detection unit of another sensor unit.

In the above embodiment, the leakage flux and the leakage observation signal Im are described by taking one bus bar 65a and one element 67d as an example. Instead of this, a plurality of leakage flux acting on one element from a plurality of bus bars may be considered. For example, when evaluating an element belonging to one switch circuit, the leakage flux from the bus bar belonging to the other two switch circuits can be considered.

1 1st rotary electric machine, 2 2nd rotary electric machine, 3 DC power supply,
30 capacitor unit, 30a capacitor element,
40, 41, 42, 43 modules, 44 power terminals,
44H high potential terminal, 44L low potential terminal, 44M connection point terminal,
45 control terminals, 50 coolers, 60 reactors, 90 cases,
100 power converter, 110 capacitor, 120 converter,
130 smoothing capacitor, 131, 133 bus bar,
132, 134 connection, 135 parallel connection, 136 bridge,
140 switch unit, 140a first inverter,
140b 2nd inverter, 160 sensor unit,
161, 162, 163 detectors, 165 bus bars, 167 elements,
168 circuit board, 169 shield plate, 170 control circuit,
LD1, LD2, LD3 switch circuit, RG array range,
XD height range, YD width range, ZD depth range.

Claims (10)

A plurality of bus bars (165) including at least a first bus bar (65a) and a second bus bar (65d).
A plurality of devices including a first element (67a) for detecting a normal magnetic flux caused by a current flowing through the first bus bar and a second element (67d) for detecting a normal magnetic flux caused by a current flowing through the second bus bar. Element (167) and
A control system (170, 175) for acquiring a signal indicating the current from the first element and acquiring a signal indicating the current from the second element is provided.
The control system
A condition determination unit (181) for determining the establishment of a leak observation condition in which a first current flows through the first bus bar and no current flows through the second bus bar.
When the leak observation condition is satisfied, a leak acquisition unit that acquires a leak observation signal (Im) that detects a leakage flux generated due to the first current and interlinks with the second element from the second element. (185) and
A current detection device having an evaluation unit (186) that evaluates the second element based on the leak observation signal. The current detection device according to claim 1, wherein the first element and the second element are coreless current sensors. The current detection device according to claim 1 or 2, wherein the first element and the second element are housed in a single sensor unit (160). The control system further
It has a reference setting unit (183) for setting a reference signal (THm) as a reference to be compared with the leak observation signal when the leak observation condition is satisfied.
The current detection device according to any one of claims 1 to 3, wherein the evaluation unit evaluates the second element based on a comparison between the reference signal and the leak observation signal. The control system further
It has a normal acquisition unit (182) that acquires a normal observation signal (Ia) that detects the normal magnetic flux caused by the first current when the leak observation condition is satisfied from the first element.
The current detection device according to claim 4, wherein the reference setting unit sets the reference signal based on the normal observation signal. The fourth or fifth aspect of the present invention includes a normal abnormality identification unit (186a) for discriminating between normal and abnormal of the second element based on a comparison between the reference signal and the leak observation signal. Current detector. Claims 4 to 6 include a sensitivity identification unit (186c) in which the evaluation unit discriminates between a hypersensitive reaction and a dull reaction of the second element based on a comparison between the reference signal and the leak observation signal. The current detector according to any one of. The control system further
It has an output reference setting unit (184) for setting an output reference signal (0, Vcc) for distinguishing between an output enable state and an output impossible state of the second element.
1. The evaluation unit includes an output identification unit (186b) that discriminates between the output enable state and the output impossible state of the second element based on the comparison between the output reference signal and the leak observation signal. The current detection device according to any one of claims 7. The normal magnetic flux generated by the current flowing through the first bus bar (65a) is detected by the first element (67a), and the normal observation signal (In) indicating the current is acquired from the first element, or the second With the normal acquisition step (188), the normal magnetic flux generated by the current flowing in the bus bar (65d) is detected by the second element (67d), and the normal observation signal (In) indicating the current is acquired from the second element. ,
A condition determination step (181) for determining the establishment of a leak observation condition in which the first current flows through the first bus bar and no current flows through the second bus bar.
When the leak observation condition is satisfied, a leak acquisition step of acquiring a leak observation signal (Im) that detects a leakage flux generated due to the first current and interlinking with the second element from the second element. (185) and
A current detection method including an evaluation step (186) for evaluating the second element by the leak observation signal. Moreover,
When the leak observation condition is satisfied, the normal acquisition step (182) of acquiring the normal observation signal (Ia) for detecting the normal magnetic flux caused by the first current from the first element, and
A reference setting step (183) for setting a reference signal (THm) to be compared with the leak observation signal based on the normal observation signal when the leak observation condition is satisfied is included.
The current detection method according to claim 9, wherein the evaluation step compares the reference signal with the leak observation signal.

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