WO2016110932A1 - Vehicle equipped with magnetic fluid magnetic bridge type current sensor - Google Patents

Abstract

A vehicle is equipped with a magnetic fluid magnetic bridge type current sensor and has a motor driven by electric power. The magnetic fluid magnetic bridge type current sensor is provided with: a magnetic circuit in which two separated ring-shaped magnetic paths formed by retaining the shape of a magnetic fluid by a container are coupled via a connecting path made of a magnetic material; and an excitation coil wound around the connecting path and driven by an excitation driving means. The magnetic fluid magnetic bridge type current sensor is also provided with: a magnetic fluid magnetic bridge for obtaining a magnetic equilibrium state by properly selecting the magnetic resistance of the magnetic circuit, said magnetic equilibrium state being a state in which the sum of the magnetic fluxes of the two ring-shaped magnetic paths becomes zero; and a detection coil wound around the magnetic circuit of the magnetic fluid magnetic bridge. In the magnetic fluid magnetic bridge type current sensor, when the magnetic resistance of the magnetic circuit is properly selected and the excitation coil is driven to obtain the magnetic equilibrium state in which the sum of the magnetic fluxes of the two ring-shaped magnetic paths becomes zero, a conducting wire to be detected is disposed in the ring-shaped magnetic paths so as to pass through the ring-shaped magnetic paths and the current to be measured, which flows through the conducting wire, is measured.

Description

Vehicle equipped with magnetic fluid magnetic bridge type current sensor

The present invention relates to a vehicle including a ferrofluid magnetic bridge type current sensor and driving a motor by electric power.

In a vehicle in which a motor is driven by electric power, the charge / discharge amount is much larger than that in a gasoline vehicle, and the current measured by the current sensor is also large. Therefore, such a vehicle is required to detect a large current accurately.

It is known that when current is detected in an electric vehicle or the like, the measurement accuracy of the remaining charge of the battery is lowered due to hysteresis. In order to detect an accurate remaining battery level in consideration of hysteresis, a vehicle including a correction calculation unit in a power remaining amount calculation device has been proposed (for example, “Patent Document 1”).
Further, a secondary battery device that detects an offset error during charging / discharging of a secondary battery and corrects the charging / discharging current to obtain a more appropriate charging / discharging current has been proposed (for example, “Patent Document 2”). ).
A magnetic bridge type current sensor (magnetic fluid magnetic bridge type current sensor) using magnetic fluid has been proposed as a power sensor for measuring and controlling current more precisely (for example, “Patent Document 3”).

Japanese Patent No. 4613605 JP 2002-151165 A Japanese Patent No. 4310373

An object of the present invention is to provide a vehicle that drives a motor with electric power that can accurately detect a large current without using a means for correcting an actual measurement value of a current sensor.
It is another object of the present invention to provide an electric vehicle, a hybrid vehicle, and a fuel cell vehicle capable of accurately detecting a large current without using a means for correcting an actual measurement value of a current sensor.

That is, the present invention provides two separated annular magnetic paths formed by holding a magnetic fluid in a container, a magnetic circuit in which the annular magnetic paths are connected by a connecting magnetic path made of a magnetic material, and the drive driven by the excitation driving means. An excitation coil wound around a connection magnetic path is provided, and a magnetic resistance in the magnetic circuit is appropriately selected so that the sum of magnetic fluxes of the two annular magnetic paths becomes zero (the magnitude of the magnetic flux is the same and the direction is reversed) A magnetic fluid magnetic bridge configured to exhibit a magnetic equilibrium state, and a detection coil wound around the magnetic circuit of the magnetic fluid magnetic bridge, and appropriately selecting a magnetic resistance in the magnetic circuit and the exciting coil. When the magnetic equilibrium state is developed in which the sum of the magnetic fluxes of the two annular magnetic paths becomes zero (the magnitude of the magnetic flux is the same and the direction is reversed). Cover through magnetic path Exits arranged conductors, the measured current flowing through the conductor and adapted to measure, and a magnetic fluid magnetic bridge type current sensor, a vehicle that drives the motor by electric power.

According to the present invention, the magnetic fluid magnetic bridge type current sensor further includes a negative feedback control mechanism. The negative feedback control mechanism includes a variable amplifier for amplifying an excitation signal, and the amplified excitation current as the magnetic fluid magnetic field. A drive circuit that flows through the excitation coil of the bridge type current sensor and an excitation magnetic flux detection signal (electromotive force) proportional to the magnitude of the excitation magnetic flux of the excitation coil are received, and the connection magnetic path of the magnetic fluid magnetic bridge type current sensor or An exciting magnetic flux detection coil wound around an annular magnetic path, an AC amplifier for amplifying the exciting magnetic flux detection signal received by the exciting magnetic flux detection coil to a manageable magnitude, and rectifying the magnitude so that it can be expressed by a direct current And a rectifier circuit. The vehicle drives a motor with vehicle power.

According to the present invention, it is possible to provide a vehicle that can accurately detect a large current and drives a motor with electric power without using a means for correcting an actual measurement value of a current sensor.
In addition, according to the present invention, it is possible to provide an electric vehicle, a hybrid vehicle, and a fuel cell vehicle capable of accurately detecting a large current without using a means for correcting an actual measurement value of a current sensor.

The present invention relates to a vehicle including a ferrofluid magnetic bridge type current sensor and driving a motor by electric power.
Examples of the vehicle that drives the motor with electric power include an electric vehicle, a hybrid vehicle, and a fuel cell vehicle. Among these, an electric vehicle or a hybrid vehicle is particularly preferable.
The magnetic fluid magnetic bridge type current sensor provided in the vehicle of the present invention is used for charge / discharge detection of a battery mounted on the vehicle of the present invention.

The present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of a magnetic fluid magnetic bridge type current sensor applied to a vehicle of the present invention.
The magnetic fluid magnetic bridge type current sensor 1 includes a magnetic fluid magnetic bridge 17 and a detection coil 18 wound around the magnetic circuit of the magnetic fluid magnetic bridge 17.
The magnetic fluid magnetic bridge 17 includes two spaced annular magnetic paths 13a and 13b formed by holding the magnetic fluid 12 in a container and a magnetic circuit in which the annular magnetic paths are connected by connecting magnetic paths 14a and 14b made of a magnetic material. And an exciting coil 15 wound around the connection magnetic path 14a driven by the excitation driving means, and the sum of the magnetic fluxes of the two annular magnetic paths becomes zero by appropriately selecting the magnetic resistance in the magnetic circuit. A magnetic equilibrium state is developed (the direction of the magnetic flux is the same and the direction is reversed).
The magnetic fluid magnetic bridge type current sensor 1 appropriately selects the magnetic resistance in the magnetic circuit and drives the exciting coil 15 to make the sum of the magnetic fluxes of the two annular magnetic paths 13a and 13b become zero (the magnitude of the magnetic flux). When the magnetic equilibrium state is manifested in the same direction but in the opposite direction), the to-be-detected conducting wire 10 penetrating the annular magnetic path is arranged in the annular magnetic paths 13a and 13b, and the measured current flowing in the conducting wire is placed. The current Ix is measured.

FIG. 9 is a block diagram showing an example of a system configuration of a vehicle to which the magnetic fluid magnetic bridge type current sensor of the present invention is applied.
The magnetic fluid magnetic bridge type current sensor 9 of the present invention measures a charge / discharge current of a battery mounted on a vehicle and transmits it to a remaining power amount calculation device, and the remaining power amount calculation device determines the remaining charge amount of the battery in various control devices. To generators and generators.
The magnetic fluid magnetic bridge type current sensor is characterized by no offset due to the use of magnetic fluid, and can detect charge / discharge with high sensitivity without correcting hysteresis even when measuring a large current. it can. Therefore, the power remaining amount calculation device mounted on the vehicle of the present invention can accurately detect charge / discharge without means for correcting the detection value of the current sensor.
Therefore, this invention provides the vehicle which does not have a means to correct | amend the detection value of a current sensor as the one embodiment.

FIG. 3A and FIG. 3B each show a configuration of another embodiment of a magnetic fluid type magnetic bridge type current sensor applied to the vehicle of the present invention.

The magnetic fluid magnetic bridge type current sensor applied to the vehicle of the present invention detects a change in excitation magnetic flux that is affected by an environmental magnetic field or current magnetic field to be measured. Therefore, if the "original excitation magnetic flux" that is affected is unstable, it will not be possible to distinguish whether the original excitation magnetic flux is unstable or whether it is an environmental magnetic field or current magnetic field. It can happen.
This "original excitation magnetic flux" becomes unstable due to changes in permeability due to temperature, and becomes unstable due to changes in permeability due to the strength of the environmental magnetic field or current magnetic field to be measured, resulting in measurement errors. It is considered a thing.
The configuration shown in FIGS. 3A and 3B includes, for example, an exciting magnetic flux detection coil that receives an exciting magnetic flux detection signal (electromotive force) in the magnetic fluid magnetic bridge type current sensor shown in FIG. The sensor unit composed of the magnetic fluid magnetic bridge and the detection coil shown in FIG. By providing the negative feedback control mechanism 20 as shown in FIG. 2 in this configuration, it is possible to suppress the change (unstable) of the excitation magnetic flux and keep the excitation magnetic flux constant (constant excitation magnetic flux system).

The configuration shown in FIGS. 3A and 3B will be described.
The sensor unit 3 a shown in FIG. 3A is composed of a magnetic fluid magnetic bridge 37 and a detection coil 38 wound around the magnetic circuit of the magnetic fluid magnetic bridge, and is wound around the magnetic circuit of the magnetic fluid magnetic bridge 37. An excitation magnetic flux detection coil 36 that receives an excitation magnetic flux detection signal (electromotive force) is provided.
The magnetic fluid magnetic bridge 37 includes two separated annular magnetic paths 33a and 33b formed by holding the magnetic fluid 32 in a container and a magnetic circuit in which the annular magnetic paths are connected by connecting magnetic paths 34a and 34b made of a magnetic material. And an excitation coil 35 wound around the connection magnetic path 34a driven by the excitation drive means, and the sum of the magnetic fluxes of the two annular magnetic paths becomes zero by appropriately selecting the magnetic resistance in the magnetic circuit. A magnetic equilibrium state is developed (the direction of the magnetic flux is the same and the direction is reversed).
The excitation magnetic flux detection coil 36 is wound around the connection magnetic path 34a and detects the excitation magnetic flux in the connection magnetic path at one place.

The sensor unit 3b shown in FIG. 3B is composed of a magnetic fluid magnetic bridge 37 and a detection coil 38 wound around the magnetic circuit of the magnetic fluid magnetic bridge, and is wound around the magnetic circuit of the magnetic fluid magnetic bridge 37. Excitation magnetic flux detection coils 36a and 36b for receiving an excitation magnetic flux detection signal (electromotive force) are provided.
The magnetic fluid magnetic bridge 37 includes two separated annular magnetic paths 33a and 33b formed by holding the magnetic fluid 32 in a container and a magnetic circuit in which the annular magnetic paths are connected by connecting magnetic paths 34a and 34b made of a magnetic material. And an excitation coil 35 wound around the connection magnetic path 34a driven by the excitation drive means, and the sum of the magnetic fluxes of the two annular magnetic paths becomes zero by appropriately selecting the magnetic resistance in the magnetic circuit. A magnetic equilibrium state is developed (the direction of the magnetic flux is the same and the direction is reversed).
The exciting magnetic flux detection coils 36a and 36b are wound around two locations of the annular magnetic paths 33a and 33b, and detect the exciting magnetic flux that flows from the connecting magnetic path 34a in the left-right direction and flows into the annular magnetic path.

The exciting magnetic flux detection coils 36a and 36b detect substantially the same amount of exciting magnetic flux divided into the left and right through the connecting magnetic path by being wound around the connecting magnetic path 34a at a substantially equidistant position in the left and right direction.
When the exciting magnetic flux is detected by the exciting magnetic flux detection coil 34a shown in FIG. 3A, all the exciting magnetic fluxes passing through the connection magnetic path are detected at one place. On the other hand, in the mode shown in FIG. 3B, the excitation magnetic flux that is divided into the left and right and is transmitted through the annular magnetic path 33a and the annular magnetic path 34a is divided into two excitation magnetic detection coils 36a and 36b. It is detected at the place. The amount of excitation magnetic flux of each of the excitation magnetic flux detection coil 36a and the excitation magnetic flux detection coil 36b is approximately one half of the excitation magnetic flux passing through the connection magnetic path.

FIG. 2 is a block diagram showing a configuration of the negative feedback control mechanism 20 of the magnetic fluid magnetic bridge type current sensor applied to the vehicle of the present invention. As described above, in combination with the configuration shown in FIGS. 3A and 3B, the excitation magnetic flux of the magnetic fluid magnetic bridge type current sensor is restrained from changing (unstable), and the excitation magnetic flux is kept constant. (Constant excitation magnetic flux system) is possible.

The negative feedback control mechanism 20 is proportional to the variable amplifier 22 that amplifies the excitation signal, the drive circuit 23 that sends the amplified excitation current to the excitation coil 24 of the magnetic fluid magnetic bridge 21, and the magnitude of the excitation magnetic flux of the excitation coil 24. The exciting magnetic flux detection coil 25 that receives the excited magnetic flux detection signal (electromotive force), the AC amplifier 26 that amplifies the exciting magnetic flux detection signal received by the exciting magnetic flux detection coil 25 to a manageable magnitude, and the magnitude of the exciting magnetic flux detection signal by a direct current. A rectifier circuit 27 is provided for rectification so that it can be expressed.

In the negative feedback control mechanism 20, the excitation signal is amplified and an excitation current is passed through the excitation coil 24 by the drive circuit 23. An exciting magnetic flux detection signal (electromotive force) proportional to the magnitude of the exciting magnetic flux is obtained by the exciting magnetic flux detection coil 25, amplified to a manageable magnitude, and rectified so that the magnitude can be expressed by a DC voltage. .
The amplification degree of the variable amplifier 22 is controlled by this DC voltage. That is, when the excitation magnetic flux detection signal becomes large, the amplification degree of the variable amplifier 22 is lowered. Conversely, when the excitation magnetic flux detection signal becomes small, the amplification degree of the variable amplifier 22 is increased.
By appropriately adjusting with such a circuit that performs negative feedback control (constant magnetic flux excitation method), it is possible to keep the excitation magnetic flux constant by suppressing the change (instability) of the excitation magnetic flux. The change in the excitation magnetic flux affected by only the current magnetic field can be detected as the electromotive force. Further, the increase / decrease of the excitation current in the negative feedback control is about several percent, and a large current unlike the magnetic balance type sensor is not required.

FIG. 4 is a front sectional view of the ferrofluid magnetic bridge 17, 37 of FIGS. 1, 3 (a), and 3 (b). FIG. 5 is a cross-sectional view taken along line AA in FIG. 6 is a cross-sectional view taken along line BB in FIG.

The ferrofluid magnetic bridges 17 and 37 constituting the present invention will be described below with reference to FIGS.
The magnetic path casing MC illustrated in FIGS. 4 to 6 is attached to an annular container main body 41 having a substantially H-shaped cross section and an annular open surface above and below the container main body 41 to close the main body 41. Two annular channels are formed in the cross section, and the upper lid body 42 and the lower lid body 43 are formed.

The annular container body 41 is separated from the partition bottom 41c by 180 degrees with the partition inner bottom 41c in a form in which the opposing surfaces of the inner and outer peripheral walls 41a and 41b and the inner and outer peripheral walls 41a and 41b are connected at the intermediate portion of the height. Two holes 41d and 41e are provided. On the other hand, the upper and lower lid bodies 42 and 43 are attached to the upper and lower annular open surfaces of the container main body 41, and the container main body 41 is further partitioned by a partition middle bottom 41c, but is communicated by two communication holes 41d and 41e. In addition, the lower two closed annular spaces (annular passages) are formed. In the lid bodies 42 and 13, concave portions 42a and 42b and concave portions 43a and 43b are formed in the surfaces of the lid bodies 42 and 43 facing the two communication holes 41d and 41e provided in the partition bottom 41c, respectively. Yes. Further, although not shown in the drawing, each of the recesses 42a to 43b is formed in an air chamber stretched with a thin film such as a flexible film. Thus, an example of the magnetic path casing MC is formed. The function and role of each component will be described below.

In the magnetic path casing MC, as an example, the partition plate 41c is communicated by two communication holes 41d and 41e separated by 180 degrees, and the bottom two annular paths are covered with a lid 43 serving as a bottom, so that the magnetic fluid 2 The lid 42 is applied and sealed as a canopy. In the present invention, after the upper and lower lid bodies 42 and 43 are attached, the magnetic fluid 2 may be injected into the annular passage by an injection needle to seal the injection hole. In this way, two spaced annular magnetic paths 13a and 13b are formed by the magnetic fluid 2 in the upper and lower two annular paths. And the magnetic fluid 2 which exists in the communicating holes 41d and 41e of the partition middle bottom 41c which connects these two magnetic paths 13a and 13b forms two connection magnetic paths 14a and 14b.

In the present invention, the recesses 42a to 43b are formed in the air chamber with a resilient film (not shown) so as to cover it, but this configuration (the recess and the film) is hermetically sealed. This is to cope with the expansion and contraction of the magnetic fluid 2 in the magnetic path casing MC. That is, if the magnetic fluid 2 expands or contracts, the casing MC may be destroyed. However, the presence of this air chamber causes an extreme change in internal pressure due to the elasticity of the air (or gas) in the air chamber and the film. This is because it can be absorbed. Since the action of the air chamber by the recesses 42a to 43b and the film stretched thereon is the adjustment of the internal pressure in the casing magnetic path as described above, the position where the recesses 42a to 43b are provided is within the magnetic path casing MC. It can be anywhere and at least one.
When the magnetic circuit 2 formed by the magnetic fluid 2 enclosed in the magnetic path casing MC of FIGS. 4 to 6 is shown by only the magnetic fluid 2 with the magnetic path casing MC omitted, as schematically shown in FIG. The upper and lower annular magnetic paths 13a and 13b are formed in a magnetic circuit in which these magnetic paths 13a and 13b are connected by two connection magnetic paths 14a and 14b.

FIG. 7 is a graph showing typical basic input / output characteristics (solid line) and ideal characteristics (broken line) of the magnetic fluid type magnetic bridge type current sensor.
This figure shows the input / output characteristics when measuring ± 100 amperes, but the solid line of the S-curve showing the basic input / output characteristics is the most inclined near OA (the center point where the solid line graph and the dotted line intersect). It shows large sensitivity. The inclination becomes gentler as the absolute value of the current (input) to be measured increases. This indicates that the measurement sensitivity decreases as the absolute value of the current (input) increases. A broken line (straight line) indicates an ideal characteristic.

FIG. 8A is a graph showing the input / output characteristics of the current sensor of the present invention shown in FIGS. 3A and 3B. As described above, since the ideal characteristic is the broken line (straight line) shown in FIG. 7, the current sensor according to the present invention improves the linearity of the input / output characteristic of the sensor and can keep the measurement sensitivity substantially constant. . FIG. 8B is a graph showing the linearity error of the value of FIG. As can be seen from the graph, the linearity error is within 0.5%.

According to the present invention, in a vehicle that drives a motor with electric power, the charge / discharge current can be detected more accurately without using correction means. Therefore, it is possible to provide a vehicle that can accurately calculate the remaining mileage by accurately grasping the remaining charge amount of the battery, and further, it is possible to greatly increase the battery usage capacity, thereby reducing the cost of the battery. . That is, it is possible to calculate an appropriate installation interval (number of installations) of the charging station, and further reduce the cost of the vehicle. Therefore, it is possible to promote the introduction of vehicles that drive motors with electric power, such as electric vehicles, hybrid vehicles, and fuel cell vehicles.

It is the perspective view which showed typically the structure of one Embodiment of the magnetic fluid type magnetic bridge type current sensor applied to the vehicle of this invention. It is a block diagram which shows the structure of the negative feedback control mechanism 20 of the magnetic fluid type | mold magnetic bridge type current sensor applied to the vehicle of this invention. 3 (a) and 3 (b) are perspective views schematically showing the configuration of another embodiment of the magnetic fluid type magnetic bridge type current sensor applied to the vehicle of the present invention. 2 is a front sectional view of a ferrofluid magnetic bridge 17, 21, and 37. FIG. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. FIG. 6 is a cross-sectional view taken along line BB in FIG. 5. It is a graph which shows the typical basic input / output characteristic (solid line) and ideal characteristic (broken line) of a magnetic fluid magnetic bridge type current sensor. FIG. 8A is a graph showing input / output characteristics of the magnetic fluid type magnetic bridge type current sensor of the present invention. FIG. 8B is a graph showing the linearity error of the value of FIG. 1 is a block diagram showing an example of a system configuration of a vehicle to which a magnetic fluid magnetic bridge type current sensor according to the present invention is applied.

DESCRIPTION OF SYMBOLS 1, 3a, 3b Sensor part 2, 12, 32 of magnetic fluid magnetic bridge type current sensor Magnetic fluid 9 Magnetic fluid magnetic bridge type current sensor 10 Conducted wire Ix Current measured 12, 32 Magnetic fluid 13a, 13b, 33a, 33b Ring magnetic path 14a, 14b, 34a, 34b Connection magnetic path 15, 35 Excitation coil 36a, 36b Excitation magnetic flux detection coil 17, 21, 37 Magnetic fluid magnetic bridge 18, 38 Detection coil 20 Negative feedback control mechanism 22 Variable amplifier 23 Drive circuit 24 AC amplifier 25 Rectifier circuit

Claims (8)

1. Two separated annular magnetic paths formed by holding a magnetic fluid in a container, a magnetic circuit in which the annular magnetic path is connected by a connecting magnetic path made of a magnetic material, and the connecting magnetic path driven by excitation driving means are wound around the connecting magnetic path. A magnetic equilibrium state in which a rotating excitation coil is provided and the magnetic resistance in the magnetic circuit is appropriately selected so that the sum of the magnetic fluxes of the two annular magnetic paths becomes zero (the magnitude of the magnetic flux is the same and the direction is reversed) And a detection coil wound around the magnetic circuit of the ferrofluid magnetic bridge, appropriately selecting a magnetic resistance in the magnetic circuit and driving the excitation coil to When a magnetic equilibrium state is developed in which the sum of the magnetic fluxes of the two annular magnetic paths becomes zero (the magnetic flux is the same size and the direction is reversed), the annular magnetic path passes through the annular magnetic path. Place the detected conductor, Flowing through the conductor line comprises a magnetic fluid magnetic bridge type current sensor so as to measure the current to be measured, the vehicle for driving the motor by electric power.
2. The vehicle according to claim 1, wherein the vehicle that drives the motor by the electric power is one of an electric vehicle, a hybrid vehicle, and a fuel cell vehicle.
3. The vehicle according to claim 1, wherein the vehicle that drives the motor by the electric power is an electric vehicle or a hybrid vehicle.
4. The magnetic fluid magnetic bridge type current sensor is provided between a battery mounted on the vehicle and a power remaining amount calculating device, and the power remaining amount calculating device does not have means for correcting a detection value of the sensor. The vehicle according to any one of claims 1 to 3, wherein
5. The magnetic fluid magnetic bridge type current sensor further includes a negative feedback control mechanism, and the negative feedback control mechanism includes a variable amplifier that amplifies an excitation signal, and an amplified excitation current of the magnetic fluid magnetic bridge type current sensor. A drive circuit that flows through the exciting coil and an exciting magnetic flux detection signal (electromotive force) proportional to the magnitude of the exciting magnetic flux of the exciting coil are received and wound around a connecting magnetic path or an annular magnetic path of the magnetic fluid magnetic bridge type current sensor. A rotating excitation magnetic flux detection coil; an AC amplifier that amplifies the excitation magnetic flux detection signal received by the excitation magnetic flux detection coil to a manageable magnitude; and a rectifier circuit that rectifies the magnitude so that the magnitude can be expressed by a direct current. The vehicle according to any one of claims 1 to 4, characterized in that:
6. The vehicle according to claim 5, wherein the excitation magnetic flux detection coil is wound around the connection magnetic path.
7. The vehicle according to claim 5, wherein the excitation magnetic flux detection coil is wound around two places of the annular magnetic path.
8. The vehicle according to claim 7, wherein the exciting magnetic flux detection coil is wound at two locations of the annular magnetic path that are substantially equidistant from the connecting magnetic path in the left-right direction.

Images