JP7286244B2 - Plasma reactor system - Google Patents

Description

The present invention relates to plasma reactor systems.

BACKGROUND ART Conventionally, a plasma reactor is known as a device for decomposing harmful components such as particulate matter (PM) contained in exhaust gas. In the plasma reactor, power is supplied to a pair of electrodes via a control circuit to generate discharge and plasma between the electrodes, thereby decomposing harmful components.

Such a plasma reactor control device, for example, controls a gate drive circuit to switch ON/OFF of energization from a plasma reactor power supply device to the plasma reactor, and to control the voltage applied to the discharge electrode of the plasma reactor. A plasma reactor controller has been proposed that monitors current with a current sensor and determines whether or not abnormal discharge has occurred in the plasma reactor based on detection by the current sensor (see, for example, Patent Document 1).

JP 2017-152341 A

On the other hand, in such a plasma reactor control device, a new circuit (earth leakage circuit) is formed by contacting a conductor (metal part, etc.) with the circuit between the plasma reactor and the power supply device, and leakage is prevented. may occur. In such a case, the conductor forming the leakage circuit may be damaged by the leakage. Furthermore, when an electric leak occurs, if water droplets or carbon adhere to the circuits in the plasma reactor and the insulation resistance is lowered, the electric power that leaks increases and the degree of damage to the conductor increases.

Therefore, when an electric leakage occurs in the plasma reactor, it is required to detect whether or not the insulation resistance has decreased.

The present invention is a plasma reactor system capable of detecting electrical leakage and deterioration of insulation resistance.

The present invention [1] comprises a battery and a plasma reactor, a power supply for supplying power from the battery to the plasma reactor, a ground wire electrically connected to the battery, the power supply and the plasma reactor, and the power supply. and the plasma reactor, a current difference sensor for detecting the difference between the current flowing through the positive wiring and the current flowing through the negative wiring, and the current difference detected by the current difference sensor control means for determining whether or not there is a decrease in insulation resistance in the positive wiring and/or the negative wiring from the current difference, wherein the current difference sensor is connected to the positive wiring and the plasma in the housing of the power supply device; At least a first current difference sensor electrically connected to the negative wiring in the housing of the reactor is provided, and the control device controls, when power is supplied to the plasma reactor, from the power supply device to the plasma reactor. When the rate of change of the voltage applied to is greater than or equal to a predetermined value, the difference between the current flowing through the positive wiring and the current flowing through the negative wiring is detected to determine the current difference detected by the current difference sensor. Based on this, the presence or absence of an electric leakage is determined, and when it is determined that an electric leakage has occurred, the current A plasma reactor system that determines the presence or absence of a decrease in insulation resistance based on the current difference detected by a difference sensor.

In such a plasma reactor system, electric leakage occurs through stray capacitance generated within the housing of the plasma reactor and stray capacitance generated within the housing of the power supply device. That is, a stray capacitance (capacitor component) is interposed in an electric circuit (earth leakage circuit) through which the leaked power flows. A current flows through the floating capacitance (capacitor component) only when the voltage changes (for example, when the voltage is boosted), and no current flows when a constant voltage is applied. Therefore, leakage occurs only when the voltage changes (for example, when boosting).

On the other hand, if the insulation resistance is lowered due to water droplets or carbon adhering to the electric circuit and causing a short circuit, electric power may leak at the portion where the insulation resistance is lowered. In such a case, no stray capacitance is interposed in the circuit (resistance-reduced circuit) where the insulation resistance is reduced. Therefore, power leakage through the resistance reduction circuit occurs not only when the voltage changes (for example, when boosting) but also when a constant voltage is applied.

Therefore, in the plasma reactor system described above, a current difference sensor detects the difference between the current flowing through the positive wiring and the current flowing through the negative wiring when power is supplied to the plasma reactor. Also, the current difference sensor includes a first current difference sensor connected to at least the positive wiring in the housing of the power supply and the negative wiring in the housing of the plasma reactor to detect the current difference therebetween.

In such a plasma reactor system, first, the difference between the current flowing through the positive wiring and the current flowing through the negative wiring is detected during boosting. Then, based on the current difference detected by the current difference sensor, the presence or absence of electric leakage is determined. Furthermore, when it is determined that an electric leak has occurred, the difference between the current flowing through the positive wiring and the current flowing through the negative wiring is detected even when a constant voltage is applied. Then, based on the current difference detected by the current difference sensor, it is determined whether or not the insulation resistance has decreased.

In such a plasma reactor system, when a current difference is detected by the current difference sensor during pressure rise, it can be determined that an electric leakage has occurred. Then, it can be determined that a decrease in insulation resistance also occurs.

As described above, in the above-described plasma reactor system, it is possible to determine the occurrence of electrical leakage and the occurrence of a decrease in insulation resistance by detecting the current difference between when the pressure is increased and when the constant voltage is applied.

The present invention [2] includes the plasma reactor system according to [1] above, wherein the current difference during boosting and the current difference during constant pressure application are detected by the same current difference sensor.

In the plasma reactor system described above, the current difference during boosting and the current difference during constant pressure application are detected by the same first current difference sensor. Therefore, it is possible to reduce the number of parts and detect electric leakage and insulation resistance at low cost.

In the present invention [3], the current difference sensor is further electrically connected to the positive wiring in the housing of the power supply device and to the negative wiring in the housing of the power supply device, and the current difference sensor flows through the positive wiring. A second current difference sensor is provided for detecting a difference between the current and the current flowing through the negative wiring, and the control device is detected by the second current difference sensor when the voltage rises when power is supplied to the plasma reactor. Based on the current difference, the presence or absence of an electric leakage is determined, and when it is determined that an electric leakage has occurred, the insulation resistance is lowered based on the current difference detected by the first current difference sensor when a constant voltage is applied. It includes the plasma reactor system of [1] above, which determines the presence or absence of

In such a plasma reactor system, the current difference during boosting is detected by the second current difference sensor, while the current difference during constant pressure application is detected by the first current difference sensor.

In this way, if different current difference sensors detect current differences at different timings, the detected current differences can be subjected to electrical processing such as amplification processing and peak hold processing. Therefore, it is possible to detect electric leakage and deterioration of insulation resistance more reliably.

According to the plasma reactor system of the present invention, it is possible to detect electric leakage in an electric circuit and a decrease in insulation resistance.

FIG. 1 is a schematic configuration diagram of a vehicle equipped with an embodiment of the plasma reactor system of the present invention. 2 is a circuit diagram showing a power control system in the plasma reactor system shown in FIG. 1. FIG. FIG. 3 is a schematic diagram showing an example of a current flow during boosting in the power control system shown in FIG. 2 when an electric leakage occurs and insulation resistance does not decrease. FIG. 4 is a schematic diagram showing an example of a current flow when a constant voltage is applied in the power control system shown in FIG. FIG. 5 is a schematic diagram showing an example of current flow during boosting when there is an electrical leakage and a decrease in insulation resistance in the power control system shown in FIG. FIG. 6 is a schematic diagram showing an example of a current flow when a constant voltage is applied in the power control system shown in FIG. FIG. 7 is a schematic configuration diagram of a vehicle equipped with another embodiment of the plasma reactor system of the present invention. 8 is a circuit diagram showing a power control system in the plasma reactor system shown in FIG. 7. FIG.

1. Outline of Plasma Reactor System As shown in FIG. 1, a plasma reactor system 1 is mounted on a vehicle 100, for example.

A vehicle 100 includes an engine 101, an intake system (not shown) for drawing air into the engine 101, a fuel injection system (not shown) for supplying fuel to the engine 101, and an exhaust system 103 for discharging exhaust from the engine 101. .

The exhaust system 103 comprises an exhaust pipe 104 .

The exhaust pipe 104 is a pipe for exhausting the exhaust gas discharged from the engine 101 . The exhaust pipe 104 is connected to the engine 101 .

Furthermore, the vehicle 100 has a plasma reactor system 1 .

The plasma reactor system 1 comprises a battery 2 , a plasma reactor 3 and a power control system 4 .

(1) Battery The battery 2 may be, for example, a known secondary battery such as a lead-acid battery, a nickel-metal hydride battery, or a lithium-ion battery. The battery 2 is housed in a housing (case) such as a metal housing, for example.

(2) Plasma Reactor The plasma reactor 3 decomposes harmful components (eg, hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM), etc.) contained in the exhaust gas discharged from the engine 101 . The plasma reactor 3 is interposed in the middle of the exhaust pipe 104 .

The plasma reactor 3 has, as shown in FIG. 2, a housing (case) 31 such as a metal housing, and at least one pair of a positive electrode panel 32 and a negative electrode panel 33 housed in the housing 31. . The positive electrode panel 32 and the negative electrode panel 33 face each other with a gap therebetween. When power is supplied to the plasma reactor 3 via a positive wire 7 (described later) and a negative wire 8 (described later), discharge occurs between the positive electrode panel 32 and the negative electrode panel 33 . Thereby, the gas between the positive electrode panel 32 and the negative electrode panel 33 becomes a plasma state. That is, plasma is generated within the plasma reactor 3 .

Then, as shown in FIG. 1, the harmful components contained in the exhaust gas that has flowed into the plasma reactor 3 through the exhaust pipe 104 are decomposed by the plasma within the plasma reactor 3 . Exhaust gas that has passed through the plasma reactor 3 is discharged outside the vehicle through an exhaust pipe 104 .

Further, in the plasma reactor 3, as shown by the phantom lines in FIG. A stray capacitance 34 is generated between the positive wiring 7 (described later). In other words, electrical continuity can be established between the plus wiring 7 (described later) and the housing 31 .

Such a stray capacitance 34 is generated in a portion where the positive wiring 7 (described later) and the housing 31 are likely to conduct (for example, a portion where the positive wiring 7 (described later) and the housing 31 are close to each other). In other words, by appropriately designing the arrangement of the positive wiring 7 (described later), the shape of the housing 31, and the like, and forming a portion where the positive wiring 7 (described later) and the housing 31 are easily conductive, any desired A stray capacitance 34 can be generated at the location.

Further, in the plasma reactor 3, when power (pulse voltage) is supplied to the plasma reactor 3, when the voltage changes, between the inner surface of the housing 31 of the plasma reactor 3 and the negative wiring 8 (described later), A stray capacitance 35 is produced. In other words, it becomes possible to conduct between the negative wiring 8 (described later) and the housing 31 .

Such a stray capacitance 35 is generated, for example, in a portion where the negative wiring 8 (described later) and the housing 31 are likely to conduct (for example, a portion where the negative wiring 8 (described later) and the housing 31 are close to each other). In other words, by appropriately designing the arrangement of the negative wiring 8 (described later) and the shape of the housing 31, and forming a portion that facilitates conduction between the negative wiring 8 (described later) and the housing 31, any A stray capacitance 35 can be generated at the location.

In FIG. 1, the plus wiring 7 (described later) and the minus wiring 8 (described later) arranged in the housing 31 of the plasma reactor 3 are indicated by dashed lines.

(3) Power Control System The power control system 4 is a system that controls the supply and stop of power supply from the battery 2 to the plasma reactor 3 .

The power control system 4 includes a power supply device 5, a ground wiring 6, a positive wiring 7 and a negative wiring 8, a current difference sensor 11, and a control device 12, as shown in FIGS.

(4) Power Supply Device The power supply device 5 supplies power from the battery 2 to the plasma reactor 3 . Specifically, the power supply device 5 includes a housing (case) 51 such as a metal housing, a booster circuit (e.g., flyback converter, etc.) 52 arranged in the housing 51, and a switch circuit (not shown) (e.g., gate drive circuit, etc.).

The power supply device 5 is electrically connected to the battery 2 via power supply wiring 21 . A switch circuit (not shown) is electrically connected to the control device 12 via a signal wiring 22, as indicated by a dashed line in FIG.

When the controller 12 turns on a switch circuit (not shown), the power supply 5 supplies power from the battery 2 to the plasma reactor 3 . When the control device 12 turns off the switch circuit, the power supply device 5 stops power supply from the battery 2 to the plasma reactor 3 .

Further, in the power supply device 5, as shown by the dashed line in FIG. A stray capacitance 54 is generated between the wiring 7 (described later). In other words, electrical continuity can be established between the plus wiring 7 (described later) and the housing 51 .

Such a stray capacitance 54 is generated in a portion where the positive wiring 7 (described later) and the housing 51 are likely to conduct (for example, a portion where the positive wiring 7 (described later) and the housing 51 are close to each other). In other words, by appropriately designing the arrangement of the positive wiring 7 (described later), the shape of the housing 51, and the like, and forming a portion where the positive wiring 7 (described later) and the housing 51 are easily conductive, any desired A stray capacitance 54 can be generated at the location.

In addition, in the power supply device 5, when power (pulse voltage) is supplied to the plasma reactor 3, there is a A stray capacitance 55 is generated. In other words, the negative wiring 8 (described later) and the housing 51 can be electrically connected.

Such a stray capacitance 55 is generated, for example, in a portion where the negative wiring 8 (described later) and the housing 51 are likely to conduct (for example, a portion where the negative wiring 8 (described later) and the housing 51 are close to each other). In other words, by appropriately designing the arrangement of the negative wiring 8 (described later) and the shape of the housing 51, and forming a portion where the negative wiring 8 (described later) and the housing 51 are easily conductive, any desired A stray capacitance 55 can be generated at the location.

Furthermore, in the power supply device 5, as indicated by the dashed line in FIG. 2, when power (pulse voltage) is supplied to the plasma reactor 3, a stray capacitance 56 is generated in the booster circuit 52 when the voltage changes. More specifically, as shown in FIG. 2, when the booster circuit 52 is a flyback converter, stray capacitance 56 is generated on each of the plus and minus sides of the pair of coils, and the gap between the pair of coils is Conduction becomes possible.

(5) Ground Wiring The ground wiring 6 is a ground electrically connected to the battery 2 , the power supply device 5 and the plasma reactor 3 . The ground wiring 6 connects, for example, the housing (not shown) of the battery 2, the housing 51 of the power supply 5, and the housing 31 of the plasma reactor 3 in parallel.

More specifically, the ground wiring 6 includes a main ground line 60, a first ground 61 that electrically connects between a housing (not shown) of the battery 2 and the main ground line 60, and a housing of the power supply device 5. 51 and the main ground line 60, and a third ground 63, which electrically connects the housing 31 of the plasma reactor 3 and the main ground line 60. As shown in FIG. As a result, the ground wiring 6 can ground the current leaking from the battery 2 , the power supply device 5 and the plasma reactor 3 .

More specifically, the ground wiring 6 may be, for example, a metal body of the vehicle 100 .

That is, by arranging the housing (not shown) of the battery 2, the housing 51 of the power supply device 5, and the housing 31 of the plasma reactor 3 in contact with the metal body of the vehicle 100, the vehicle 100 A metal body can be used as the ground wire 6 .

(6) Plus Wiring and Minus Wiring The plus wiring 7 and the minus wiring 8 are wirings that electrically connect the power supply device 5 and the plasma reactor 3 .

Specifically, the positive wiring 7 is electrically connected to the positive terminal of the power supply 5 in the housing 51 of the power supply 5 and electrically connected to the positive electrode panel 32 in the housing 31 of the plasma reactor 3. Connected.

Further, the negative wire 8 is electrically connected to the negative terminal of the power supply device 5 inside the housing 51 of the power supply device 5 and electrically connected to the negative electrode panel 33 inside the housing 31 of the plasma reactor 3 . be done.

In FIG. 1, the plus wiring 7 and the minus wiring 8 arranged inside the housing 51 of the power supply device 5 are indicated by dashed lines.

(7) Current Difference Sensor The current difference sensor 11 measures the current flowing through the positive wiring 7 and the current flowing through the negative wiring 8, respectively, and detects the difference between the current flowing through the positive wiring 7 and the current flowing through the negative wiring 8. It is a sensor that detects a difference (current difference).

The current difference sensor 11 includes at least a first current difference sensor 13 . In the embodiment shown in FIGS. 1 and 2 , the current difference sensor 11 consists of a first current difference sensor 13 .

The first current difference sensor 13 includes a plus side sensor 17 for measuring the magnitude (current value) of current flowing through the plus wiring 7 and a minus side sensor 17 for measuring the magnitude (current value) of current flowing through the minus wiring 8 . It has a side sensor 18 and an output section 19 that outputs a current difference as an electrical signal.

The plus side sensor 17 is connected to a portion downstream of the stray capacitance 54 on the side of the plus wiring 7 in the electric flow direction inside the housing 51 of the power supply device 5 .

The minus side sensor 18 is connected to a portion downstream of the stray capacitance 33 on the side of the minus wire 8 in the electric flow direction inside the housing 31 of the plasma reactor 3 .

The output section 19 is electrically connected to the plus side sensor 17 and the minus side sensor 18 . That is, the output section 19 is electrically connected to the positive wiring 7 inside the housing 51 of the power supply device 5 and the negative wiring 8 inside the housing 31 of the plasma reactor 3 . The output section 19 is electrically connected to the control device 12 via a signal wiring 23, as indicated by the dashed line in FIG. As a result, the output unit 19 detects the difference between the current flowing through the positive wiring 7 (current value measured by the positive sensor 17) and the current flowing through the negative wiring 8 (current value measured by the negative sensor 18). It is possible to output an electrical signal in response to this. The electrical signal output by the output section 19 is input to the control device 12 via the signal wiring 23 .

(9) Control Device Control device 12 is an ECU (Electronic Control Unit) that executes electrical control in vehicle 100, and includes a CPU, a ROM, a RAM, and the like.

Further, the control device 12 is electrically connected to the current difference sensor 11 as described above. As will be described in detail later, the control device 12 can determine electric leakage and insulation resistance deterioration based on the electrical signal output from the current difference sensor 11 .

2. Operation of Plasma Reactor System The plasma reactor system 1 operates to decompose harmful components in the exhaust gas discharged from the exhaust pipe 104 when the engine 101 is driven, for example.

More specifically, when the engine 101 is driven, power is supplied from the battery 2 to the plasma reactor 3 via the power supply device 5 under the control of the control device 12 at a predetermined timing. Thereby, a discharge occurs between the positive electrode panel 32 and the negative electrode panel 33, and the gas between the positive electrode panel 32 and the negative electrode panel 33 becomes a plasma state. That is, plasma is generated within the plasma reactor 3 . The generated plasma decomposes harmful components in the exhaust gas.

On the other hand, when the plasma reactor 3 is operated as described above, if a conductor such as a metal part comes into contact with the circuit between the plasma reactor 3 and the power supply device 5, an earth leakage circuit 70 is formed, causing electric leakage. In such a case, the conductor forming the leakage circuit 70 may be damaged by the leakage. Furthermore, in the event that electrical leakage occurs, water droplets and carbon adhere to the circuits of the plasma reactor 3 and the power supply device 5, and if the insulation resistance decreases, the electrical power that leaks increases, and the degree of damage to the conductor increases. Become.

Therefore, in the plasma reactor system 1 described above, based on the current difference detected by the current difference sensor 11, the presence or absence of electric leakage and the presence or absence of a decrease in insulation resistance are detected by the following control.

3. Control of Plasma Reactor System A control method for judging whether or not insulation resistance has decreased on the minus wire 8 side when an electrical leakage occurs on the plus wire 7 side will be described in detail below.

Specifically, in the plasma reactor system 1 described above, first, a pulse voltage is applied from the power supply device 5 to the plasma reactor 3 under the control of the control device 12 to operate the plasma reactor 3 .

On the other hand, in this control, power supply to the plasma reactor 3 is divided into boosting and constant pressure application.

More specifically, when power is supplied to the plasma reactor 3, the frequency of the voltage applied from the power supply 5 to the plasma reactor 3 is equal to or higher than a predetermined threshold value (eg, 50 Hz or higher, preferably 10 kHz or higher). Time is defined as boost time. On the other hand, the time during which the frequency of the voltage is less than the above threshold is defined as the constant voltage application time.

In this control, the difference between the current flowing through the positive wiring 7 and the current flowing through the negative wiring 8 is detected by the current difference sensor 11 (first current difference sensor 13 ).

That is, in the plasma reactor system 1 , electric leakage occurs via the stray capacitance generated within the housing 31 of the plasma reactor 3 and the stray capacitance generated within the housing 1 of the power supply device 5 . That is, a stray capacitance (capacitor component) is interposed in an electric circuit (earth leakage circuit) through which the leaked power flows. A current flows through the floating capacitance (capacitor component) only when the voltage changes (for example, when the voltage is boosted), and no current flows when a constant voltage is applied. Therefore, leakage occurs only when the voltage changes (for example, when boosting).

Therefore, during boosting, the magnitude (current value) of the current flowing through the plus wiring 7 is measured by the plus side sensor 17, and the magnitude (current value) of the current flowing through the minus wiring 8 is measured by the minus side sensor 18. measured by An electrical signal corresponding to the difference between them is output from the output section 19 to the control device 12 via the signal wiring 23 .

At this time, as shown in FIG. 2, if there is no leakage between the power supply device 5 and the plasma reactor 3, the current flowing through the positive wire 7 maintains its magnitude (current value). , and flows through the minus wiring 8 .

That is, the difference between the current value measured by the plus side sensor 17 and the current value measured by the minus side sensor 18 is 0 (or its error range). In such a case, the controller 12 determines that there is no electrical leakage.

On the other hand, as shown in FIG. 3, when an electric leakage occurs between the power supply device 5 and the plasma reactor 3, the current leaks to circuits other than the positive wiring 7 and the negative wiring 8. Therefore, the magnitude (current value) of the current in the plus wiring 7 and the magnitude (current value) of the current in the minus wiring 8 are different from each other.

More specifically, for example, as shown in FIG. 3, when a conductor (such as a metal part) contacts the positive wiring 7 and the ground wiring 6 (such as a metal body), a positive leakage circuit 70A is formed. be done.

At this time, the position of the contact α between the plus side leakage circuit 70A and the plus wiring 7 is normally in the middle of the plus wiring 7, downstream of the plus side sensor 17, and between the casing 51 of the power supply device 5 and the contact point α. , and the housing 31 of the plasma reactor 3 .

In such a case, when the plasma reactor 3 is operated, part of the current supplied from the power supply 5 passes through the plus side sensor 17 and then leaks from the contact α to the plus side leakage circuit 70A. . The leaked current passes through, for example, the ground wiring 6 , the housing 31 of the plasma reactor 3 , the housing 51 of the power supply 5 , and returns to the power supply 5 via the stray capacitance 55 .

As an example, the route of the leaked current returning to the power supply device 5 via the positive leakage circuit 70A, the ground main line 60, the second ground 62, the housing 51 of the power supply device 5, and the stray capacitance 55 is shown in FIG. shown in

In other words, when a current leaks from the plus wire 7 side during boosting, the current leaks to the leakage circuit 70 after passing the plus side sensor 17 and returns to the power supply device 5 without passing through the minus side sensor 18 .

Therefore, when the plus side leakage circuit 70A is formed, the current flowing through the plus wiring 7 (the current value measured by the plus side sensor 17) at the time of boosting changes to the current flowing through the minus wiring 8 (the minus side sensor 18 current value measured by

In other words, during boosting, the current flowing through the plus wiring 7 (the current value measured by the plus side sensor 17) is greater than the current flowing through the minus wiring 8 (the current value measured by the minus side sensor 18). If the difference is equal to or greater than the threshold value of the error range, it is determined that a leakage occurs on the side of the plus line 7 and that a plus side leakage circuit 70A is formed. The threshold value of the current difference is, for example, 20 mA or more, preferably 5 mA or more, and for example, 1000 mA or less, preferably 100 mA or less. The current difference detected by the current difference sensor 11 (first current difference sensor 13) can be processed by, for example, an inverting amplifier circuit, a full-wave rectifier circuit, or the like, if necessary.

Subsequently, in this control, the difference between the current flowing through the positive wiring 7 and the current flowing through the negative wiring 8 is detected by the current difference sensor 11 ( It is detected by the first current difference sensor 13).

In other words, when the insulation resistance is lowered due to water droplets or carbon adhering to the electric circuit and causing a short circuit, electric power may leak at the portion where the insulation resistance is lowered. In such a case, no stray capacitance is interposed in the circuit (resistance-reduced circuit) where the insulation resistance is reduced. Therefore, power leakage through the resistance reduction circuit occurs not only when the voltage changes (for example, when boosting) but also when a constant voltage is applied.

Therefore, in this control, even when a constant voltage is applied, the magnitude (current value) of the current flowing through the plus wiring 7 is measured by the plus side sensor 17 and the magnitude of the current flowing through the minus wiring 8 (current value) is measured in the same manner as described above. current value) is measured by the minus side sensor 18 . An electrical signal corresponding to the difference between them is output from the output section 19 to the control device 12 via the signal wiring 23 .

However, when such a constant voltage is applied, as described above, leakage through the stray capacitance does not occur.

Therefore, as shown in FIG. 4, when there is no decrease in insulation resistance between the power supply device 5 and the plasma reactor 3, the magnitude (current value) of the current flowing through the positive wiring 7 is maintained and flows through the minus wiring 8 .

That is, the difference between the current value measured by the plus side sensor 17 and the current value measured by the minus side sensor 18 is 0 (or its error range). In such a case, the controller 12 determines that the insulation resistance has not decreased.

On the other hand, as shown in FIG. 5, when both electric leakage and a decrease in insulation resistance occur between the power supply device 5 and the plasma reactor 3, both during boosting and when applying a constant voltage, Since current leaks into circuits (earth leakage circuit and resistance reduction circuit) other than the positive wiring 7 and the negative wiring 8, the magnitude (current value) of the current in the positive wiring 7 and the magnitude (current value) of the current in the negative wiring 8 (current values) are different from each other.

More specifically, for example, as shown in FIG. 5, when a conductor (such as a metal part) contacts the plus wiring 7 and the ground wiring 6 (such as a metal body), a plus side leakage circuit 70A is formed. be done.

At this time, the position of the contact α between the plus side leakage circuit 70A and the plus wiring 7 is normally in the middle of the plus wiring 7, downstream of the plus side sensor 17, and between the casing 51 of the power supply device 5 and the contact point α. , and the housing 31 of the plasma reactor 3 .

Also, if water droplets or carbon adheres to the minus wire 8 and causes a short circuit, the minus side resistance lowering circuit 70B is formed.

At this time, the position of the contact β between the minus side resistance lowering circuit 70B and the minus wiring 8 is normally in the middle of the minus wiring 8, downstream of the minus side sensor 18, and at the housing 51 of the power supply device 5. and the housing 31 of the plasma reactor 3 .

In such a case, when the plasma reactor 3 is operated, a part of the current supplied from the power supply device 5 passes through the plus side sensor 17 and then leaks from the contact α to the plus side leakage circuit 70A as described above. to (leak) The leaked current passes through, for example, the ground wiring 6 , the housing 31 of the plasma reactor 3 , the housing 51 of the power supply 5 , and returns to the power supply 5 via the stray capacitance 55 .

Furthermore, part of the leaked current returns to the power supply device 5 through the negative side resistance lowering circuit 70B and the contact β.

As an example, the leaked current returns to the power supply device 5 via the plus side leakage circuit 70A, the ground main line 60, the second ground 62, the housing 51 of the power supply device 5, and the stray capacitance 55, and the plus side FIG. 5 shows the route passing through the earth leakage circuit 70A, the earth main line 60, the negative side resistance lowering circuit 70B and the contact β and returning to the power supply device 5. As shown in FIG.

In other words, even when both an electric leakage and a decrease in insulation resistance occur, the electric current leaks to the electric leakage circuit 70 after passing through the plus side sensor 17, and does not pass through the minus side sensor 18 to the power supply device. Go back to 5.

Therefore, when the plus side leakage circuit 70A is formed, the current flowing through the plus wiring 7 (the current value measured by the plus side sensor 17) is reduced to the current flowing through the minus wiring 8 (the value measured by the minus side sensor 18). current value).

In other words, the current flowing through the plus wire 7 (the current value measured by the plus side sensor 17) is greater than the current flowing through the minus wire 8 (the current value measured by the minus side sensor 18), and the difference is the error. If it is equal to or greater than the threshold value of the range, it is determined that a leakage occurs on the side of the plus line 7 and that a plus side leakage circuit 70A is formed.

Subsequently, in this control, even when a constant voltage is applied, the magnitude (current value) of the current flowing through the plus wiring 7 is measured by the plus side sensor 17 and the magnitude of the current flowing through the minus wiring 8 is measured in the same manner as described above. (current value) is measured by the minus side sensor 18 . An electrical signal corresponding to the difference between them is output from the output section 19 to the control device 12 via the signal wiring 23 .

However, when such a constant voltage is applied, as described above, leakage through the stray capacitance does not occur.

On the other hand, however, even when a constant voltage is applied, power leakage occurs through the minus side resistance reduction circuit 70B.

More specifically, in the above-described electrical circuit in which the plus-side leakage circuit 70A is formed, when a constant voltage is applied and the insulation resistance of the minus wiring 8 side is reduced, as shown in FIG. , a part of the current supplied from the power supply device 5 passes through the plus side sensor 17, then leaks from the contact α to the plus side leakage circuit 70A, and flows through the ground main line 60, the minus side resistance reduction circuit 70B and the contact β. It passes through and returns to the power supply device 5 .

That is, even when a constant voltage is applied, electric power leaks from the positive wire 7 side and returns to the power supply device 5 via the negative resistance reduction circuit 70B without passing through the negative sensor 18 .

Therefore, when the plus side earth leakage circuit 70A and the minus side resistance lowering circuit 70B are formed, the current flowing through the plus wiring 7 (the current value measured by the plus side sensor 17) is negative even when a constant voltage is applied. It becomes larger than the current flowing through the wiring 8 (the current value measured by the minus side sensor 18).

In other words, during boosting, the current flowing through the plus wiring 7 (the current value measured by the plus side sensor 17) is greater than the current flowing through the minus wiring 8 (the current value measured by the minus side sensor 18). If the difference is greater than or equal to the threshold value of the error range, it is determined that the insulation resistance has decreased on the minus wire 8 side. The current difference threshold is, for example, 20 mA or more, preferably 5 mA or more, and for example, 1000 mA or less, preferably 100 mA or less. The current difference detected by the current difference sensor 11 (first current difference sensor 13) can be processed by, for example, an inverting amplifier circuit, a full-wave rectifier circuit, or the like, if necessary.

Further, when the insulation resistance is lowered, the voltage difference detected when the constant voltage is applied is usually higher than the voltage difference detected when the voltage is boosted.

As described above, the control device 12 can detect the occurrence of an electric leakage and the occurrence of a decrease in insulation resistance by detecting the current difference when the voltage is boosted and when the constant voltage is applied. Then, the control device 12 executes safety processing such as stopping the plasma reactor 3 as necessary, for example, when an electric leakage and/or a decrease in insulation resistance is detected.

4. Functions and Effects As described above, in the plasma reactor system 1 , the current difference sensor 11 detects the difference between the current flowing through the positive wiring 7 and the current flowing through the negative wiring 7 when power is supplied to the plasma reactor 3 . The current difference sensor 11 is connected to at least the positive wiring 7 in the housing 51 of the power supply 5 and the negative wiring 8 in the housing 31 of the plasma reactor 3, and detects the current difference between them. A current difference sensor 13 is provided.

In such a plasma reactor system, first, the difference between the current flowing through the positive wiring 7 and the current flowing through the negative wiring 8 is detected during boosting. Based on the current difference detected by the current difference sensor 11, the presence or absence of electric leakage is determined. Furthermore, when it is determined that an electric leak has occurred, the difference between the current flowing through the positive wiring 7 and the current flowing through the negative wiring 8 is detected even when a constant voltage is applied. Based on the current difference detected by the current difference sensor 11, it is determined whether or not the insulation resistance has decreased.

In such a plasma reactor system 1, when a current difference is detected by the current difference sensor 11 during boosting, it can be determined that an electric leakage has occurred. is detected, it can be determined that a decrease in insulation resistance has also occurred.

As described above, in the above-described plasma reactor system 1, it is possible to determine the occurrence of electric leakage and the occurrence of a decrease in insulation resistance by detecting the current difference when the pressure is increased and when the constant voltage is applied.

Further, in the plasma reactor system 1 , the same first current difference sensor 13 detects the current difference when the pressure is increased and the current difference when the constant pressure is applied. Therefore, it is possible to reduce the number of parts and detect electric leakage and insulation resistance at low cost.

5. Modification In the plasma reactor system 1 described above, only the first current difference sensor 13 is used as the current difference sensor 11, and the current difference at the time of boosting and the current difference at the time of constant pressure application are detected by the same first current difference sensor. 13 is detected.

On the other hand, as shown in FIGS. 7 and 8, the current difference sensor 11 can further include a second current difference sensor 14 in addition to the first current difference sensor 13 described above.

In this embodiment, the first current difference sensor 13 is, similarly to the above, a plus side sensor 17 for measuring the magnitude (current value) of the current flowing through the plus wiring 7 (hereinafter referred to as the first plus side sensor 17A). ), a negative side sensor 18 (hereinafter referred to as a first negative side sensor 18A) for measuring the magnitude (current value) of the current flowing through the negative wiring 8, and an output that outputs the current difference as an electrical signal. section 19 (hereinafter referred to as a first output section 19A).

The second current difference sensor 14 includes a second positive side sensor 17B for measuring the magnitude (current value) of the current flowing through the positive wiring 7 and a second positive side sensor 17B for measuring the magnitude (current value) of the current flowing through the negative wiring 8. Therefore, a second minus side sensor 18B and a second output section 19B for outputting the current difference as an electric signal are provided.

The second plus side sensor 17B is connected to a portion downstream of the stray capacitance 54 on the side of the plus wiring 7 in the electric flow direction inside the housing 51 of the power supply device 5 . Incidentally, as shown in FIG. 8, for example, the first plus side sensor 17A can also be used as the second plus side sensor 17B.

The second negative side sensor 18B is connected to a portion downstream of the stray capacitance 33 on the side of the negative wiring 8 in the electric flow direction in the housing 51 of the power supply device 5 .

The second output section 19B is electrically connected to the second plus side sensor 17B and the second minus side sensor 18B. That is, the second output section 19B is electrically connected to the positive wiring 7 inside the housing 51 of the power supply device 5 and the negative wiring 8 inside the housing 51 of the power supply device 5 . The second output section 19 is electrically connected to the control device 12 via a signal wiring 24, as indicated by the dashed line in FIG. As a result, the second output unit 19B outputs the current flowing through the positive wiring 7 (current value measured by the second positive sensor 17B) and the current flowing through the negative wiring 8 (current measured by the second negative sensor 18B). It is possible to output an electric signal according to the difference between the The electrical signal output by the second output section 19B is input to the control device 12 via the signal wiring 24 .

In this embodiment, the current difference during boosting is detected by the second current difference sensor 14 instead of the first current difference sensor 13, as described below.

More specifically, as shown in FIG. 8, also in this embodiment, a positive leakage circuit 70A and a negative resistance lowering circuit 70B may be formed in the same manner as described above. In such a case, when the plasma reactor 3 is operated, part of the current supplied from the power supply device 5 passes through the plus side sensor 17 and then flows from the contact α to the plus side leakage circuit 70A at the time of boosting. Electrical leakage (leakage). The leaked current passes through, for example, the ground wiring 6, the housing 31 of the plasma reactor 3, the housing 51 of the power supply 5, and the like, and returns to the power supply 5 via the stray capacitance 55 (see FIG. 5). ).

Further, part of the leaked current passes through the negative side resistance lowering circuit 70B and the contact β, and returns to the power supply device 5 (see FIG. 5).

Therefore, the current value measured by the second plus side sensor 17B becomes larger than the current value measured by the second minus side sensor 18B.

On the other hand, similarly to the above, if the plus side leakage circuit 70A and the minus side resistance lowering circuit 70B are formed, electricity leaks even when a constant voltage is applied.

More specifically, in the above-described electrical circuit in which the plus-side leakage circuit 70A is formed, when a constant voltage is applied and the insulation resistance of the minus wiring 8 side is reduced, as shown in FIG. , a part of the current supplied from the power supply device 5 passes through the plus side sensor 17, then leaks from the contact α to the plus side leakage circuit 70A, and flows through the ground main line 60, the minus side resistance reduction circuit 70B and the contact β. It passes through and returns to the power supply device 5 (see FIG. 6).

That is, even when a constant voltage is applied, electric power leaks from the positive wire 7 side and returns to the power supply device 5 via the negative resistance reduction circuit 70B without passing through the negative sensor 18 .

Therefore, when the plus side earth leakage circuit 70A and the minus side resistance reduction circuit 70B are formed, when the constant voltage is applied, the current value measured by the first plus side sensor 17A is measured by the first minus side sensor 18A. larger than the measured current value.

Therefore, in the same manner as described above, the control device 12 can detect the occurrence of electric leakage and the occurrence of a decrease in insulation resistance by detecting the current difference when the voltage is boosted and when the constant voltage is applied. Then, the control device 12 executes safety processing such as stopping the plasma reactor 3 as necessary, for example, when an electric leakage and/or a decrease in insulation resistance is detected.

Furthermore, in the above embodiment, the second current difference sensor 14 detects the current difference during boosting, while the first current difference sensor 13 detects the current difference during constant voltage application.

In this way, if current differences at different timings are detected by different current difference sensors (the first current difference sensor 13 and the second current difference sensor 14), the detected current differences are subjected to amplification processing and peak hold. Since electrical processing such as treatment can be performed, detection accuracy can be improved, and electric leakage and insulation resistance reduction can be detected more reliably.

In the above description, an earth leakage occurs on the plus wiring 7 side, and a decrease in insulation resistance occurs on the minus wiring 8 side. Electric leakage and a drop in insulation resistance can be detected in the same manner even when a drop in resistance has occurred.

1 plasma reactor system 2 battery 3 plasma reactor 5 power supply 6 ground wiring 7 positive wiring 8 negative wiring 31 housing 51 housing

Claims (3)

a battery and a plasma reactor; and
A power supply unit equipped with a flyback converter as a boost circuit to supply power from the battery to the plasma reactor,
a ground wire electrically connected to the battery, the power supply and the plasma reactor;
a positive wiring and a negative wiring that electrically connect the power supply device and the plasma reactor;
a current difference sensor that detects the difference between the current flowing through the positive wiring and the current flowing through the negative wiring;
a control device for determining whether or not insulation resistance has decreased in the positive wiring and/or the negative wiring from the current difference detected by the current difference sensor;
The current difference sensor is
at least a first current difference sensor electrically connected to the positive wiring in the housing of the power supply device and the negative wiring in the housing of the plasma reactor,
The control device is
When supplying power to the plasma reactor,
The current difference sensor detects the difference between the current flowing through the positive wiring and the current flowing through the negative wiring when the rate of change of the voltage applied to the plasma reactor from the power supply device is equal to or greater than a predetermined value. Based on the current difference detected by
If it is determined that an electric leakage has occurred,
Determining whether or not the insulation resistance has decreased based on the current difference detected by the current difference sensor when a constant voltage is applied at which the change rate of the voltage applied from the power supply to the plasma reactor is less than a predetermined value. A plasma reactor system characterized by: 2. The plasma reactor system according to claim 1, wherein the current difference during boosting and the current difference during constant pressure application are detected by the same first current difference sensor. The current difference sensor is
Further, it is electrically connected to the positive wiring in the housing of the power supply device and the negative wiring in the housing of the power supply device, and detects a difference between a current flowing through the positive wiring and a current flowing through the negative wiring. a second current difference sensor for
The control device is
When supplying power to the plasma reactor,
During boosting, the presence or absence of electric leakage is determined based on the current difference detected by the second current difference sensor, and if it is determined that an electric leakage has occurred,
2. The plasma reactor system according to claim 1, wherein the presence or absence of a decrease in insulation resistance is determined based on the current difference detected by said first current difference sensor when a constant voltage is applied.

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