JP2019053896A - Power supply system for plasma reactor - Google Patents

Abstract

To provide a power supply system for a plasma reactor, in which electric leakage can be surely detected.SOLUTION: A power supply system 1 for a plasma reactor is provided that comprises: a power supply device 2 which supplies power from a battery 102 to a plasma reactor 105; a plus wiring 3 and a minus wiring 4 which electrically connect the power supply device 2 and the plasma reactor 105 to each other; and a current sensor 5 which outputs an electric signal according to difference between a current passing through the plus wiring 3 and a current passing through the minus wiring 4. The power supply system for a plasma reactor further comprises: a full wave rectifier circuit 13 which performs full wave rectification on an input electric signal; a peak hold circuit 14 which holds and outputs the maximum value of the electric signal subjected to the full wave rectification; and a control device 6 which determines that electric leakage occurs and performs necessary processing under the condition that the maximum value becomes the prescribed threshold or more.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power supply system for a plasma reactor.

  Conventionally, a plasma reactor is known as an apparatus for decomposing harmful components such as particulate matter (PM) contained in exhaust gas.

  In addition, as a control device for the plasma reactor, the current applied to the discharge electrode of the plasma reactor is monitored with a current sensor, and abnormal discharge has occurred in the plasma reactor during the period when the output signal from the current sensor takes a positive value. There has been proposed a plasma reactor control device for determining whether or not (see, for example, Patent Document 1).

JP 2017-152341 A

  However, in the plasma reactor control device described in Patent Document 1, when the output signal from the current sensor takes a negative value due to leakage (abnormal discharge), the output signal from the current sensor cannot be read, and Cannot be detected.

  Therefore, an object of the present invention is to provide a power source system for a plasma reactor that can reliably detect a leakage.

  The present invention provides a power supply device that supplies power from a battery to a plasma reactor, a positive wiring and a negative wiring that electrically connect the power supply device and the plasma reactor, and an electrical connection to the positive wiring and the negative wiring. A current sensor that outputs an electrical signal corresponding to a difference between a current that flows through the positive wiring and a current that flows through the negative wiring; and an electrical sensor that receives the electrical signal and performs full-wave rectification on the input electrical signal. A wave rectifier circuit, a full-wave rectified electric signal is input, a peak hold circuit that holds and outputs the maximum value of the input electric signal, and the maximum value exceeds a predetermined threshold value And a power supply system for a plasma reactor, which includes a control device that treats the leakage as a condition.

  According to such a configuration, the full-wave rectifier circuit to which the electric signal from the current sensor is input is provided.

  Therefore, even when the current sensor outputs a negative electrical signal, the negative electrical signal can be input to the control device as a positive electrical signal by full-wave rectification by the full-wave rectifier circuit.

  As a result, the leakage can be reliably detected and processed regardless of the location where the leakage occurs.

  Moreover, according to such a structure, the peak hold circuit into which the electric signal from a full wave rectifier circuit is input is provided.

  Therefore, even when the leakage occurs and the timing at which the maximum value output from the peak hold circuit is equal to or greater than the predetermined threshold and the timing at which the control device reads the maximum value output from the peak hold circuit are different, the control device The maximum value held by the peak hold circuit can be read.

  Thereby, it is possible to reliably detect a leakage at an arbitrary timing.

  According to the present invention, leakage can be reliably detected.

FIG. 1 is a schematic configuration diagram of a vehicle including an embodiment of a power supply system for a plasma reactor according to the present invention. FIG. 2 is a block diagram showing a circuit interposed between the current sensor shown in FIG. 1 and the control device. FIG. 3 is a flowchart showing control of the plasma reactor power supply system. FIG. 4 is a graph showing the change over time of the voltage of the electrical signal output from the current sensor and the voltage of the electrical signal output from the full-wave rectifier circuit. The electrical signal output from the current sensor is a positive electrical signal. Indicates a case. FIG. 5 is a graph showing the change over time of the voltage of the electrical signal output from the current sensor and the voltage of the electrical signal output from the full-wave rectifier circuit. The electrical signal output from the current sensor is a negative electrical signal. Indicates a case.

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

  The vehicle 100 includes an engine 101, an electric system including a battery 102 and a plasma reactor power supply system 1, an unillustrated intake system for inhaling the engine 101, and a unillustrated fuel injection system for supplying fuel to the engine 101. And an exhaust system 103 for exhausting from the engine 101. Examples of the battery 102 include known secondary batteries such as a lead storage battery, a nickel metal hydride battery, and a lithium ion battery.

  The exhaust system 103 includes an exhaust pipe 104 and a plasma reactor 105.

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

  The plasma reactor 105 decomposes harmful components (for example, hydrocarbon (HC), nitrogen oxide (NOx), particulate matter (PM), etc.) contained in the exhaust gas discharged from the engine 101. The plasma reactor 105 is interposed in the middle of the exhaust pipe 104. The plasma reactor 105 has at least one pair of a positive electrode panel and a negative electrode panel (not shown). The positive electrode panel and the negative electrode panel are opposed to each other with an interval. When power is supplied to the plasma reactor 105, discharge occurs between the positive electrode panel and the negative electrode panel. Thereby, the gas between a positive electrode panel and a negative electrode panel will be in a plasma state. That is, plasma is generated in the plasma reactor 105. Then, harmful components contained in the exhaust gas flowing into the plasma reactor 105 through the exhaust pipe 104 are decomposed by the plasma in the plasma reactor 105. The exhaust gas that has passed through the plasma reactor 105 is discharged outside the vehicle through the exhaust pipe 104.

  The plasma reactor power supply system 1 controls power supply from the battery 102 to the plasma reactor 105. The plasma reactor power supply system 1 includes a power supply device 2, a positive wiring 3 and a negative wiring 4, a current sensor 5, and a control device 6.

(1) Power Supply Device The power supply device 2 supplies power from the battery 102 to the plasma reactor 105. Specifically, the power supply device 2 includes a booster circuit (for example, a flyback converter) and a switch. The power supply device 2 is electrically connected to the battery 102 via the power supply wiring 7.

  The switch is electrically connected to the control device 6 via the signal wiring 8. When the control device 6 turns on the switch, the power supply device 2 supplies power from the battery 102 to the plasma reactor 105. Further, when the control device 6 turns off the switch, the power supply device 2 stops the power supply from the battery 102 to the plasma reactor 105.

(2) Positive wiring and negative wiring The positive wiring 3 and the negative wiring 4 electrically connect the power supply device 2 and the plasma reactor 105. Specifically, the positive wiring 3 is electrically connected to the positive terminal of the power supply device 2 and is also electrically connected to the positive electrode panel of the plasma reactor 105. Further, the minus wiring 4 is electrically connected to the minus terminal of the power supply device 2 and is also electrically connected to the negative electrode panel of the plasma reactor 105.

(3) Current sensor The current sensor 5 is electrically connected to the middle of the plus wiring 3 and the middle of the minus wiring 4. The current sensor 5 outputs an electrical signal corresponding to the difference between the current flowing in the plus wiring 3 and the current flowing in the minus wiring 4. Specifically, the current sensor 5 outputs a voltage corresponding to the difference between the current flowing in the plus wiring 3 and the current flowing in the minus wiring 4. The current sensor 5 is electrically connected to the control device 6 through the signal wiring 9. As will be described in detail later, the electrical signal output from the current sensor 5 is input to the control device 6 via the signal wiring 9.

(4) Control Device As will be described in detail later, the control device 6 switches the switch of the power supply device 2 based on the electrical signal output from the current sensor 5. The control device 6 is an ECU (Electronic Control Unit) that performs electrical control in the vehicle 100, and includes a CPU, a ROM, a RAM, and the like.

2. Details of Plasma Reactor Power Supply System As shown in FIG. 2, the plasma reactor power supply system 1 includes a high-pass filter circuit 11, an inverting amplifier circuit 12, a full-wave rectifier circuit in the middle of the signal wiring 9 (see FIG. 1). 13 (absolute value circuit) and a peak hold circuit 14.

(1) High-pass filter circuit The high-pass filter circuit 11 is interposed between the current sensor 5 and the inverting amplifier circuit 12. An electric signal output from the current sensor 5 is input to the high pass filter circuit 11 via the signal wiring 9. The high pass filter circuit 11 outputs a component having a frequency higher than the cut-off frequency in the input electric signal.

(2) Inverting Amplifier Circuit The inverting amplifier circuit 12 is interposed between the high-pass filter circuit 11 and the full-wave rectifier circuit 13. The electric signal output from the high-pass filter circuit 11 is input to the inverting amplifier circuit 12. The inverting amplifier circuit 12 inverts the phase of the input electrical signal and amplifies the voltage.

(3) Full-wave rectifier circuit The full-wave rectifier circuit (absolute value circuit) 13 is interposed between the inverting amplifier circuit 12 and the peak hold circuit 14. The electric signal output from the inverting amplifier circuit 12 is input to the full-wave rectifier circuit 13. That is, the electric signal output from the current sensor 5 is input to the full-wave rectifier circuit 13 via the high-pass filter circuit 11 and the inverting amplifier circuit 12. The full-wave rectification circuit 13 performs full-wave rectification on the input electrical signal. As a result, the full-wave rectifier circuit 13 outputs a positive electrical signal regardless of whether the input electrical signal is positive or negative. The full-wave rectifier circuit 13 may amplify the voltage of the input electric signal.

  The voltage of the electrical signal output from the full-wave rectifier circuit 13 is, for example, 70 times or more, for example, 90 times or less, with respect to the voltage of the electrical signal output from the current sensor 5.

(4) Peak Hold Circuit The peak hold circuit 14 receives the electrical signal output from the full wave rectifier circuit 13. That is, the full-wave rectified electrical signal is input to the peak hold circuit 14. The peak hold circuit 14 holds and outputs the maximum value of the input electric signal. Specifically, when the voltage of the electric signal input to the peak hold circuit 14 is larger than the voltage of the hold capacitor of the peak hold circuit 14, the hold capacitor is charged. In addition, when the voltage of the electric signal input to the peak hold circuit 14 is equal to or lower than the voltage of the hold capacitor, the voltage of the hold capacitor is held. That is, the peak hold circuit 14 holds the maximum value of the voltage of the input electric signal. The peak hold circuit 14 outputs the voltage of the hold capacitor. Thereby, the peak hold circuit 14 outputs the maximum value of the voltage of the input electrical signal.

  The peak hold circuit 14 may be combined with a reset circuit and configured as a peak hold / reset circuit. In this case, the reset circuit is provided in parallel with the hold capacitor. The reset circuit releases (discharges) the electric charge accumulated in the hold capacitor when a reset signal is input.

3. Control of Plasma Reactor Power Supply System 1 As shown in FIG. 3, the control device 6 reads the voltage (output voltage V) output by the peak hold circuit 14 at every predetermined elapsed time (S1).

Then, the control device 6 that the output voltage V reaches a predetermined threshold value _{V 1} above condition (S2: YES), the process as being electric leakage (S3, S4).

Specifically, the control device 6, when the output voltage V is the predetermined threshold value _{V 1} or (S2: YES), the off switch power supply 2 (S3). Thereby, the power supply from the battery 102 to the plasma reactor 105 is stopped.

Threshold _{V 1} was, for example, a 2800MV.

  Next, the control device 6 notifies the user that the plasma reactor 105 is turned off, for example, by turning on a lamp provided on the instrument panel of the vehicle 100 (S4).

The control device 6, when the output voltage V is less than the predetermined threshold value V ₁ (S2: NO), without turning off the switching power supply 2, after a predetermined time has elapsed again, the peak hold circuit 14 The output voltage (output voltage V) is read (S1).

4). As shown in FIG. 1, in the configuration in which the current sensor 5 is electrically connected in the middle of the plus wiring 3 and in the middle of the minus wiring 4, the electric signal output from the current sensor 5 depends on the location where the leakage occurs. Polarity is different.

  Specifically, when a leakage occurs in the portion 3B of the plus wiring 3, the portion 4A of the minus wiring 4, or the portion 4B of the minus wiring 4, the current sensor 5 is a positive electric signal (the current sensor shown in FIG. 4). Output voltage). The portion 3B is interposed between the plasma reactor 105 and the connecting portion C1 between the plus wiring 3 and the current sensor 5. The portion 4 </ b> A is interposed between the connection portion C <b> 2 between the minus wiring 4 and the current sensor 5 and the power supply device 2. The portion 4B is interposed between the plasma reactor 105 and the connection portion C2 between the negative wiring 4 and the current sensor 5. In FIG. 4, an electric leakage occurs at time t1.

  On the other hand, when a leakage occurs in the portion 3A of the plus wiring 3, the current sensor 5 outputs a negative electrical signal (current sensor output voltage shown in FIG. 5). The portion 3 </ b> A is interposed between the connection portion C <b> 1 between the plus wiring 3 and the current sensor 5 and the power supply device 2. In FIG. 5, an electric leakage occurs at time t2.

  Here, as shown in FIG. 2, the plasma reactor power supply system 1 includes the full-wave rectifier circuit 13 between the current sensor 5 and the control device 6.

  Therefore, even when the current sensor 5 outputs a negative electric signal, the negative electric signal is full-wave rectified by the full-wave rectifier circuit 13 to generate a positive electric signal (full-wave rectifier circuit output voltage shown in FIG. 5). Can be input to the control device 6.

  As a result, the leakage can be reliably detected and processed regardless of the location where the leakage occurs.

  In addition, according to the plasma reactor power supply system 1, the peak hold circuit 14 is provided between the full-wave rectifier circuit 13 and the control device 6.

Therefore, even when the timing at which the output voltage V reaches a predetermined threshold value V ₁ or more leakage occurs, the timing at which the control unit 6 reads the output voltage V is different, the control device 6, held by the peak hold circuit 14 The output voltage V thus read can be read.

  Thereby, it is possible to reliably detect a leakage at an arbitrary timing.

DESCRIPTION OF SYMBOLS 1 Power supply system for plasma reactors 2 Power supply device 3 Positive wiring 4 Negative wiring 5 Current sensor 6 Control device 13 Full wave rectification circuit 14 Peak hold circuit

Claims (1)

A power supply for supplying power from the battery to the plasma reactor;
A positive wiring and a negative wiring for electrically connecting the power supply device and the plasma reactor;
A current sensor that is electrically connected to the plus wiring and the minus wiring and outputs an electrical signal corresponding to a difference between a current flowing through the plus wiring and a current flowing through the minus wiring;
A full-wave rectifier circuit that receives the electrical signal and full-wave rectifies the input electrical signal;
A peak hold circuit that receives the full-wave rectified electrical signal, holds and outputs the maximum value of the inputted electrical signal,
A power supply system for a plasma reactor, comprising: a control device that performs processing assuming that electric leakage is caused on the condition that the maximum value is equal to or greater than a predetermined threshold value.

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