JP2014211357A - Direct-current leakage detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct-current leakage detection device capable of detecting direct-current leakage with a simple configuration.SOLUTION: A control device 11 is provided with a polarity ratio detection unit 110 and a determination unit 111. The polarity ratio detection unit 110 detects a positive electrode side polarity ratio and a negative electrode side polarity ratio. The determination unit 111 determines, on the basis of a polarity ratio outputted from the polarity ratio detection unit 110, whether there is direct-current leakage. When there is no direct-current leakage, each of the positive electrode side polarity ratio and the negative electrode side polarity ratio is 50%. However, when direct-current leakage occurs between a commercial alternating-current power supply AC1 and a power factor improvement circuit 100, an AC current is offset to the positive electrode side by a voltage drop due to the leakage current, causing the polarity ratio to change. Accordingly, direct-current leakage can be detected on the basis of the polarity ratio. In addition, the polarity ratio can be obtained by detecting an AC current. Therefore, direct-current leakage can be detected with a simple configuration.

Description

  The present invention relates to a DC leakage detection device that detects DC leakage.

  Conventionally, as a DC leakage detection device that detects DC leakage, for example, there is a DC leakage detection device disclosed in Patent Document 1 shown below.

  This DC leakage detection device is a device that detects a DC leakage of a conducting wire for connecting a load and a DC power supply. The DC leakage detection device includes an annular core wound with a coil, a high-frequency output circuit, a current limiting circuit, a rectifier circuit, and a comparison circuit.

  The high frequency output circuit is a circuit that outputs a high frequency current. The high frequency output circuit is connected to the coil. The current limiting circuit is a circuit that limits the current flowing through the coil. The current limiting circuit is connected between the high frequency output circuit and the coil. The rectifier circuit is a circuit that rectifies the voltage induced in the coil and converts it into a DC voltage. The rectifier circuit is connected to the coil. The comparison circuit compares the output voltage of the rectifier circuit with a preset reference voltage, and determines whether or not a DC leakage has occurred. A conductor for connecting a load and a DC power source, which is a detection target, is disposed so as to penetrate a hole formed in the core.

  When a DC leakage occurs, the current flowing through the conducting wire becomes unbalanced to connect the load and the DC power source, and the core is magnetized. As a result, the voltage induced in the coil changes to detect DC leakage.

JP 2000-002738 A

  In the above-described DC leakage detection device, in order to detect DC leakage, a coil-wrapped core, a high-frequency output circuit, a current limiting circuit, a rectifier circuit, and a comparison circuit must be provided separately. For this reason, there is a problem that the physique becomes large and the cost increases.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a DC leakage detection device capable of detecting a DC leakage with a simple configuration.

  The present invention made to solve the above problems is positive in one cycle of the alternating current output from the alternating current power supply in the direct current leakage detecting device that detects the direct current leakage of the electronic device connected to the alternating current power supply. DC leakage occurs based on the polarity ratio detection means that detects the ratio of the period or the polarity ratio that indicates the ratio of the negative polarity period in one cycle of the alternating current, and the polarity ratio detected by the polarity ratio detection means. And determining means for determining whether or not it is present.

  In the electronic device connected to the AC power supply, when no DC leakage occurs, the polarity ratio indicating the ratio of the positive polarity period in one cycle of the AC current output from the AC power supply, and 1 of the AC current The polarity ratios indicating the ratio of the negative polarity period in the cycle are 50%, respectively. However, when a DC leakage occurs between the AC power supply and the electronic device, the AC current is offset due to a voltage drop due to the leakage current, and the polarity ratio changes. Therefore, DC leakage can be detected based on the polarity ratio. Moreover, the polarity ratio can be obtained by detecting an alternating current. There is no need to separately provide a coil-wrapped core, a high-frequency output circuit, a current limiting circuit, a rectifier circuit, and a comparison circuit as in the prior art. Therefore, it is possible to detect DC leakage with a simple configuration.

It is a circuit diagram of the electric power feeder in 1st Embodiment. FIG. 2 is a waveform diagram of an output current of the AC power supply of FIG. 1 and an output voltage of a current transformer when no DC leakage occurs. FIG. 2 is a waveform diagram of an output current of the AC power source of FIG. 1 and an output voltage of a current transformer when a DC leakage occurs. It is a circuit diagram of the electric power feeder in the modification of 1st Embodiment. It is a circuit diagram of the electric power feeder of 2nd Embodiment.

  Next, the present invention will be described in more detail with reference to embodiments. In the present embodiment, an example in which the DC leakage detection device according to the present invention is applied to a power supply device that supplies power to an in-vehicle battery mounted in an electric vehicle or a hybrid vehicle will be described.

(First embodiment)
First, the configuration of the power supply apparatus according to the first embodiment will be described with reference to FIG.

  A power supply device 1 shown in FIG. 1 is a device that converts an alternating current output from a commercial alternating current power supply AC1 (alternating current power supply) outside the vehicle into a direct current, supplies the direct current to the onboard battery B1, and charges the onboard battery B1. The power feeding device 1 includes a conversion device 10 (electronic device) and a control device 11 (DC leakage detection device).

  The conversion device 10 is a device that is mounted on the vehicle, converts the alternating current output from the commercial alternating-current power supply AC1 into direct current, and supplies it to the in-vehicle battery B1. The conversion device 10 includes a power factor correction circuit 100, a rectifier circuit 101, and a converter circuit 102.

  The power factor correction circuit 100 is a circuit for bringing the AC power factor supplied from the commercial AC power supply AC1 to the rectifier circuit 101 close to 1. The power factor correction circuit 100 is a well-known circuit including a reactor (not shown) and a switching element (not shown). One input terminal of the power factor correction circuit 100 is connected to one end of the commercial AC power supply AC1, and the other input terminal is connected to the other end of the commercial AC power supply AC1. One and the other output terminals are connected to the rectifier circuit 101, respectively. Further, the control terminal is connected to the control device 11.

  The rectifier circuit 101 is a circuit that rectifies an alternating current supplied from the commercial AC power supply AC <b> 1 via the power factor correction circuit 100, converts the alternating current into a direct current, and supplies the direct current to the converter circuit 102. The rectifier circuit 101 includes diodes 101a to 101d. The diodes 101a and 101b and the diodes 101c and 101d are respectively connected in series. Specifically, the anodes of the diodes 101a and 101c are connected to the cathodes of the diodes 101b and 101d, respectively. The series connection point of the diodes 101a and 101b is connected to one output terminal of the power factor correction circuit 100, and the series connection point of the diodes 101c and 101d is connected to the other output terminal of the power factor improvement circuit 100. The cathodes of the diodes 101a and 101c and the anodes of the diodes 101b and 101d are connected to the converter circuit 102, respectively.

  The converter circuit 102 is a circuit that converts the direct current supplied from the rectifier circuit 101 into a direct current having a different voltage and supplies the direct current to the in-vehicle battery B1. Specifically, it is a known step-up / down converter circuit. The converter circuit 102 includes a capacitor 102a, a reactor 102b, IGBTs 102c and 102d, and a capacitor 102e.

  The capacitor 102a is an element for smoothing the direct current supplied from the rectifier circuit 101. One end of the capacitor 102a is connected to the cathodes of the diodes 101a and 101c, and the other end is connected to the anodes of the diodes 101b and 101d.

  The reactor 102b is an element for accumulating energy or discharging the accumulated energy. Reactor 102b has one end connected to one end of capacitor 102a and the other end connected to IGBTs 102c and 102d.

  The IGBTs 102c and 102d are elements for storing energy in the reactor 102b or discharging the stored energy from the reactor by switching. A free wheel diode is connected in antiparallel between the collectors and emitters of the IGBTs 102c and 102d. The collector of the IGBT 102c is connected to the other end of the reactor 102b, and the emitter is connected to the other end of the capacitor 102a. The emitter of the IGBT 102d is connected to the other end of the reactor 102b, and the collector is connected to the positive terminal of the in-vehicle battery B1. Furthermore, the gates of the IGBTs 102c and 102d are connected to the control device 11, respectively.

  The capacitor 102e is an element for smoothing the direct current supplied via the IGBT 102d. One end of the capacitor 102e is connected to the collector of the IGBT 102d, and the other end is connected to the emitter of the IGBT 102c. One end of the capacitor 102e is connected to the positive terminal of the in-vehicle battery B1, and the other end is connected to the negative terminal of the in-vehicle battery B1.

  The control device 11 is a device that is mounted on the vehicle and controls the conversion device 10. Moreover, it is also a device that detects DC leakage of the converter 10 connected to the commercial AC power supply AC1. The control device 11 includes a polarity ratio detection unit 110 (polarity ratio detection unit), a determination unit 111 (determination unit), a drive signal generation unit 112, and drive circuits 113 and 114. Here, the determination unit 111 and the drive signal generation unit 112 are configured by a microcomputer and a program.

  The polarity ratio detection unit 110 is a ratio of the positive polarity period in one cycle of the sinusoidal AC current output from the commercial AC power supply AC1, and the negative polarity period in one cycle of the sinusoidal AC current. This is a block for detecting a polarity ratio indicating the ratio of. Specifically, the positive polarity side polarity ratio that is the ratio of the positive polarity period in one cycle of the alternating current and the negative polarity ratio that indicates the proportion of the negative polarity period in one cycle of the alternating current are detected. It is a block to do. The polarity ratio detection unit 110 includes current transformers 110a and 110b (zero cross point detection means) and a polarity ratio calculation unit 110c. Similar to the determination unit 111 and the drive signal generation unit 112, the polarity ratio calculation unit 110c includes a microcomputer and a program.

  The current transformer 110a is an element for detecting a zero cross point where the alternating current output from the commercial alternating-current power supply AC1 switches from negative polarity to positive polarity. Specifically, it is an element that magnetically saturates when a minute current flows through the primary winding and outputs a pulsed voltage from the secondary winding. The primary winding of the current transformer 110a is connected between one end of the commercial AC power supply AC1 and one input terminal of the power factor correction circuit 100. The secondary winding is connected to the polarity ratio calculation unit 110c.

  The current transformer 110b is an element for detecting a zero cross point at which the alternating current output from the commercial alternating-current power supply AC1 switches from positive polarity to negative polarity. Specifically, it is an element that magnetically saturates when a minute current flows through the primary winding and outputs a pulsed voltage from the secondary winding. The primary winding of the current transformer 110b is connected between the other end of the commercial AC power supply AC1 and the other input terminal of the power factor correction circuit 100. The secondary winding is connected to the polarity ratio calculation unit 110c.

  The polarity ratio calculation unit 110c is a block that calculates a polarity ratio based on the zero cross points detected by the current transformers 110a and 110b and outputs the calculated data as data. Specifically, based on the pulsed voltage output from the secondary windings of the current transformers 110a and 110b, the ratio of the positive polarity period in one cycle of the AC current output from the commercial AC power supply AC1, And it is a block which calculates the polarity ratio which shows the ratio of the period which is the negative polarity in 1 period of alternating current, and outputs it as data. More specifically, it is a block that calculates the positive polarity ratio and the negative polarity ratio and outputs them as data. The polarity ratio calculation unit 110c is connected to the secondary windings of the current transformers 110a and 110b, respectively. Further, it is connected to the determination unit 111.

  The determination unit 111 determines whether or not a DC leakage has occurred based on the polarity ratio output from the polarity ratio detection unit 110 and a preset positive electrode side determination reference ratio or negative electrode side determination reference ratio, When it is determined that a DC leakage has occurred, this block outputs an abnormal signal and notifies that fact. Specifically, when the positive polarity ratio calculated by the polarity ratio calculation unit 110c is equal to or higher than the positive determination criterion ratio, or the negative polarity ratio is less than the negative determination criterion ratio than the positive determination criterion ratio. At this time, it is a block that determines that a DC leakage has occurred. The determination unit 111 is connected to the polarity ratio calculation unit 110c. Further, it is connected to the drive signal generation unit 112.

  By the way, when the DC leakage does not occur, the positive polarity ratio and the negative polarity ratio are 50%, respectively. However, when a DC leakage occurs between the commercial AC power supply AC1 and the power factor correction circuit 100, the AC current is offset to the positive electrode side due to a voltage drop due to the leakage current. The positive electrode side determination reference ratio and the negative electrode side determination reference ratio are set based on the positive electrode side polarity ratio and the negative electrode side polarity ratio in the case where the current flowing due to DC leakage is a current that is allowed as the current flowing through the human body. ing. For example, the positive determination criterion ratio is set to 70%, which is greater than 50%, and the negative determination criterion ratio is set to 30%, which is less than 50%.

  The drive signal generation unit 112 is a block that generates and outputs a drive signal for driving the conversion device 10 based on a command input from the outside. Specifically, it is a block that generates and outputs drive signals for driving the power factor correction circuit 100 and the converter circuit 102. However, the drive signal generation unit 112 stops outputting the drive signal when the determination unit 111 outputs an abnormal signal. The drive signal generation unit 112 is connected to the determination unit 111. Further, it is connected to the drive circuits 113 and 114.

  The drive circuit 113 is a circuit that drives the power factor correction circuit 100 based on the drive signal output from the drive signal generation unit 112. The drive circuit 113 is connected to the drive signal generation unit 112. Further, it is connected to the control terminal of the power factor correction circuit 100.

  The drive circuit 114 is a circuit that drives the converter circuit 102 based on the drive signal output from the drive signal generation unit 112. Specifically, this is a circuit for switching the IGBTs 102c and 102d. The drive circuit 114 is connected to the drive signal generation unit 112. Further, the gates of the IGBTs 102c and 102d are connected to each other.

  Next, the operation of the power supply apparatus according to the first embodiment will be described with reference to FIGS. Since converter circuit 102 is a well-known step-up / step-down converter circuit, a detailed description of the operation of the IGBT is omitted.

  The drive signal generator 112 shown in FIG. 1 generates and outputs a drive signal for driving the converter 10 based on a command input from the outside.

  The drive circuit 113 drives the power factor correction circuit 100 based on the drive signal output from the drive signal generation unit 112. As a result, the AC power factor supplied from the commercial AC power supply AC1 to the rectifier circuit 101 approaches 1. The rectifier circuit 101 rectifies the AC supplied from the commercial AC power supply AC <b> 1 via the power factor correction circuit 100, converts it into DC, and supplies the DC to the converter circuit 102.

  The drive circuit 114 drives the converter circuit 102 based on the drive signal output from the drive signal generation unit 112. The converter circuit 102 steps up and down the direct current supplied from the rectifier circuit 101, converts it to direct current with a different voltage, and supplies the direct current to the in-vehicle battery B1. Thereby, the alternating current output from the commercial alternating current power supply AC1 outside the vehicle can be converted into direct current and supplied to the in-vehicle battery B1, and the in-vehicle battery B1 can be charged.

  On the other hand, as shown in FIG. 2, the current transformer 110a outputs a pulsed voltage from the secondary winding at the timing when the alternating current output from the commercial alternating-current power supply AC1 switches from negative polarity to positive polarity. The current transformer 110b outputs a pulsed voltage from the secondary winding at the timing when the AC current output from the commercial AC power supply AC1 switches from positive polarity to negative polarity.

  The polarity ratio calculation unit 110c shown in FIG. 1 calculates the positive polarity ratio and the negative polarity ratio based on the pulse voltage output from the secondary windings of the current transformers 110a and 110b, and outputs it as data. .

  By the way, when the DC leakage does not occur, the positive polarity ratio and the negative polarity ratio are 50% as shown in FIG. However, when a DC leakage occurs between the commercial AC power supply AC1 and the power factor correction circuit 100, the AC current is offset to the positive electrode side due to a voltage drop due to the leakage current as shown in FIG.

  As shown in FIG. 3, the determination unit 111 shown in FIG. 1 has a positive polarity ratio calculated by the polarity ratio calculation unit 110c of 70% or more, or the negative polarity ratio is negative. When the determination reference ratio is 30% or less, it is determined that a DC leakage has occurred between the commercial AC power supply AC1 and the power factor correction circuit 100. When it is determined that a DC leakage has occurred, an abnormal signal is output to notify that effect.

  The drive signal generation unit 112 illustrated in FIG. 1 stops outputting the drive signal when the determination unit 111 outputs an abnormal signal. As a result, the conversion device 10 stops operating.

  Next, effects of the first embodiment will be described.

  According to the first embodiment, the control device 11 includes a polarity ratio detection unit 110 and a determination unit 111. The polarity ratio detector 110 detects the positive polarity ratio and the negative polarity ratio. The determination unit 111 determines whether or not a DC leakage has occurred based on the polarity ratio output from the polarity ratio detection unit 110.

  When no DC leakage occurs, the positive polarity ratio and the negative polarity ratio are 50%, respectively, as shown in FIG. However, when a DC leakage occurs between the commercial AC power supply AC1 and the power factor correction circuit 100, as shown in FIG. 3, the AC current is offset to the positive electrode side due to a voltage drop due to the leakage current, and the polarity ratio changes. Therefore, DC leakage can be detected based on the polarity ratio. Moreover, the polarity ratio can be obtained by detecting an alternating current. There is no need to separately provide a coil-wrapped core, a high-frequency output circuit, a current limiting circuit, a rectifier circuit, and a comparison circuit as in the prior art. Therefore, it is possible to detect DC leakage with a simple configuration.

  According to the first embodiment, the determination unit 111 determines that the positive polarity side polarity ratio calculated by the polarity ratio calculation unit 110c is greater than or equal to the positive determination criterion ratio, or the negative polarity ratio is smaller than the positive determination criterion ratio. When the ratio is less than or equal to the negative determination criterion ratio, it is determined that a DC leakage has occurred. Therefore, it is possible to reliably detect whether or not a DC leakage has occurred.

  According to the first embodiment, the positive determination criterion ratio is set to a value greater than 50%, and the negative determination criterion ratio is set to a value smaller than 50%. Therefore, it can be determined more reliably whether or not a DC leakage has occurred.

  According to the first embodiment, the positive-side determination reference ratio and the negative-side determination reference ratio are the positive-polarity ratio and the negative-electrode ratio when the current flowing through the DC leakage is a current that is allowed as the current flowing through the human body. It is set based on the side polarity ratio. For this reason, it is possible to determine whether or not a DC leakage has occurred before the current flowing due to the DC leakage has a magnitude that adversely affects the human body. Therefore, the human body can be protected from direct current leakage.

  According to the first embodiment, the polarity ratio detection unit 110 includes current transformers 110a and 110b and a polarity ratio calculation unit 110c. The current transformers 110a and 110b detect the zero cross point of the alternating current. The polarity ratio calculation unit 110c calculates the polarity ratio based on the zero-cross points detected by the current transformers 110a and 110b, and outputs it as data. For this reason, the polarity ratio can be reliably detected.

  According to the first embodiment, when the determination unit 111 determines that a DC leakage has occurred, the determination unit 111 outputs an abnormal signal to notify that effect. Therefore, it is possible to reliably notify the occurrence of electric leakage.

  In the first embodiment, the polarity ratio calculation unit 110c calculates the positive polarity side polarity ratio and the negative polarity side polarity ratio, and the determination unit 111 determines that the positive polarity side polarity ratio is greater than or equal to the positive polarity side determination reference ratio, or the negative polarity Although an example is given in which it is determined that a DC leakage has occurred when the side polarity ratio is equal to or less than the negative electrode side determination reference ratio, the present invention is not limited to this. The polarity ratio calculation unit 110c calculates only the positive polarity ratio, and the determination unit 111 determines that a DC leakage has occurred when the positive polarity ratio is equal to or greater than the positive determination criterion ratio. Good. In addition, the polarity ratio calculation unit 110c calculates only the negative polarity ratio, and the determination unit 111 determines that a DC leakage has occurred when the negative polarity ratio is equal to or less than the negative determination criterion ratio. May be.

  In the first embodiment, the primary windings of the current transformers 110a and 110b are connected between the commercial AC power supply AC1 and the power factor correction circuit 100. However, the present invention is not limited to this. . As shown in FIG. 4, the primary windings of the current transformers 110 a and 110 b may be connected between the power factor correction circuit 100 and the rectifier circuit 101. In this case, the same effect can be obtained.

  Further, in the first embodiment, the converter circuit 102 includes the IGBTs 102c and 102d. However, the present invention is not limited to this. You may be comprised by MOFET. What is necessary is just to be comprised by the switching element by which anti-parallel connection of the freewheel diode was carried out.

(Second Embodiment)
Next, the power supply apparatus of 2nd Embodiment is demonstrated. The power supply apparatus according to the second embodiment is configured such that AC is directly supplied from the commercial AC power supply, while AC is directly supplied from the commercial AC power supply. . In addition, the power supply apparatus according to the first embodiment supplies power from the commercial AC power source to the in-vehicle battery, but can also supply power from the in-vehicle battery to the commercial AC power source.

  First, the configuration of the power supply apparatus according to the second embodiment will be described with reference to FIG.

  A power feeding device 2 shown in FIG. 5 is a device that converts AC supplied in a non-contact manner from a commercial AC power supply AC2 (AC power supply) outside the vehicle into DC and supplies it to the in-vehicle battery B2 to charge the in-vehicle battery B2. . Moreover, it is also a device that converts the direct current supplied from the in-vehicle battery B2 into alternating current and supplies it to the commercial AC power supply AC2 in a non-contact manner. Between the commercial AC power supply AC2 and the power feeding device 2, a converter CNV (AC power supply) and coils W1 and W2 (AC power supply) are provided to supply power in a non-contact manner.

  The converter CNV converts AC supplied from the commercial AC power supply AC2 into AC having a different frequency, specifically, higher frequency than the AC frequency of the commercial AC power supply AC2, with the power factor approaching 1. And supplying the coil W1. Further, the alternating current supplied from the coil W1 is converted into an alternating current having a different frequency, specifically, an alternating current having the same frequency as the alternating frequency of the commercial alternating current power supply AC2 with the power factor approaching 1, and the commercial alternating current power supply. It is also a device that supplies AC2. Conversion device CNV is installed outside the vehicle and is connected to commercial AC power supply AC2 and coil W1.

  The coil W1 is an element that generates an alternating magnetic flux when AC is supplied from the converter CNV. It is also an element that generates alternating current by electromagnetic induction by interlinking with the alternating magnetic flux generated by the coil W2. Coil W1 is installed in the predetermined position on the ground surface of a parking space, and is connected to converter CNV.

  The coil W2 is an element that generates alternating current by electromagnetic induction when the alternating magnetic flux generated by the coil W1 is linked. Further, it is an element that generates an alternating magnetic flux when AC is supplied from the power feeding device 2. The coil W <b> 2 is installed at the bottom of the vehicle and connected to the power supply device 2 so as to be arranged facing the coil W <b> 1 with a space in the vertical direction when the vehicle is parked in the parking space.

  The power feeding device 2 includes a conversion device 20 (electronic device) and a control device 21 (DC leakage detection device).

  The conversion device 20 is a device that is mounted on a vehicle, converts the alternating current supplied from the commercial AC power supply AC2 via the conversion device CNV and the coils W1 and W2 into direct current, and supplies the direct current to the in-vehicle battery B2. . Moreover, it is also a device that converts the direct current supplied from the in-vehicle battery B2 into alternating current and supplies it to the commercial AC power supply AC2 via the coils W2, W1 and the converter CNV in a non-contact manner. The conversion device 20 includes a rectifier circuit 201 and a converter circuit 202. However, a circuit corresponding to the power factor correction circuit 100 of the first embodiment is not provided.

  The rectifier circuit 201 is a circuit that rectifies an alternating current supplied from the commercial AC power supply AC2 via the converter CNV and the coils W1 and W2 to convert the alternating current into a direct current, and supplies the direct current to the converter circuit 202. Moreover, it is also a circuit which converts the direct current supplied from the converter circuit 202 into an alternating current and supplies it to the commercial alternating current power supply AC2 via the coils W2, W1 and the converter CNV in a non-contact manner. The rectifier circuit 201 includes IGBTs 201a to 201d. A free wheel diode is connected in antiparallel between the collectors and emitters of the IGBTs 202c and 202d. The rectifier circuit 201 is obtained by replacing the diodes 101a to 101d of the rectifier circuit 101 of the first embodiment with IGBTs 201a to 201d having free wheel diodes. The rectifier circuit 201 rectifies the alternating current supplied from the commercial alternating-current power supply AC2 by the free wheel diode in a state where the IGBTs 201a to 201d are turned off, converts the alternating current to direct current, and supplies the direct current to the converter circuit 202. Further, by switching the IGBTs 201a to 201d, the direct current supplied from the converter circuit 202 is converted into alternating current and supplied to the coil W2. The series connection point of the IGBTs 201a and 201b is connected to one end of the coil W2, and the series connection point of the IGBTs 201c and 201d is connected to the other end of the coil W2.

  The converter circuit 202 is a circuit that converts the direct current supplied from the rectifier circuit 201 into a direct current having a different voltage and supplies the direct current to the in-vehicle battery B2. Further, it is also a circuit that converts the direct current supplied from the in-vehicle battery B2 into a direct current having a different voltage and supplies the direct current to the rectifier circuit 201. Specifically, it is a known bidirectional buck-boost converter circuit. Converter circuit 202 includes a capacitor 202a, a reactor 202b, IGBTs 202c and 202d, and a capacitor 202e. The converter circuit 202 has the same configuration as the converter circuit 102 of the first embodiment. The converter circuit 202 can convert the direct current output from the in-vehicle battery B2 into a direct current with a different voltage and supply the direct current to the rectifier circuit 201 depending on how the IGBTs 202c and 202d are switched.

  The control device 21 is mounted on the vehicle and is a device for controlling the conversion device 20. Moreover, it is also a device that detects a DC leakage of the conversion device 20 connected to the coil W2. The control device 21 includes a polarity ratio detection unit 210 (polarity ratio detection unit), a determination unit 211 (determination unit), a drive signal generation unit 212, and drive circuits 214 and 215.

  The polarity ratio detection unit 210 is a block that detects the positive polarity side polarity ratio and the negative polarity side polarity ratio of the sinusoidal alternating current output from the coil W2. Further, it is also a block that detects the positive polarity ratio and the negative polarity ratio of the sinusoidal alternating current output from the rectifier circuit 201. The polarity ratio detection unit 210 includes current transformers 210a and 210b (zero cross detection means) and a polarity ratio calculation unit 210c. The primary winding of the current transformer 210a is connected between one end of the coil W2 and the series connection point of the IGBTs 201a and 201b. The primary winding of the current transformer 210b is connected between the other end of the coil W2 and the series connection point of the IGBTs 201c and 201d. Other than that, it is the same structure as the polarity ratio detection part 110 of 1st Embodiment.

  The determination unit 211 has the same configuration as the determination unit 111 of the first embodiment.

  The drive signal generation unit 212 is a block that generates and outputs a drive signal for driving the rectifier circuit 201 and the converter circuit 202 based on a command input from the outside. However, when the determination unit 211 outputs an abnormal signal, the drive signal generation unit 212 stops outputting the drive signal. The drive signal generation unit 212 is connected to the determination unit 211. Further, they are connected to the drive circuits 214 and 215, respectively.

The drive circuit 214 has the same configuration as the drive circuit 114 of the first embodiment.
The drive circuit 215 is a circuit that drives the rectifier circuit 201 based on the drive signal output from the drive signal generation unit 212. The drive circuit 215 is connected to the drive signal generation unit 212. The gates of the IGBTs 201a to 201d are connected to each other.

  Next, the operation of the power supply apparatus according to the second embodiment will be described with reference to FIG.

  When the vehicle is parked in the parking space, the coil W1 and the coil W2 shown in FIG. 5 face each other in the vertical direction.

  When power is supplied from the commercial AC power supply AC2 to the vehicle-mounted battery B2, the converter CNV converts the AC supplied from the commercial AC power supply AC2 into an AC having a different frequency and supplies the AC to the coil W1. The coil W1 generates alternating magnetic flux when AC is supplied from the converter CNV. The coil W2 generates an alternating current by electromagnetic induction when the alternating magnetic flux generated by the coil W1 is linked.

  The drive signal generation unit 212 generates and outputs a drive signal for driving the rectifier circuit 201 and the converter circuit 202 based on a command input from the outside.

  The drive circuit 215 drives the rectifier circuit 201 based on the drive signal output from the drive signal generation unit 212. The rectifier circuit 201 rectifies the AC supplied from the commercial AC power supply AC <b> 2 in a contactless manner with a free wheel diode in a state where the IGBTs 201 a to 201 d are turned off, converts the AC into a DC, and supplies the DC to the converter circuit 202.

  The drive circuit 214 drives the converter circuit 202 based on the drive signal output from the drive signal generation unit 212. The converter circuit 202 steps up and down the direct current supplied from the rectifier circuit 201, converts it to direct current with a different voltage, and supplies the direct current to the in-vehicle battery B2. As a result, AC supplied in a non-contact manner from commercial AC power supply AC2 outside the vehicle can be converted to DC and supplied to vehicle battery B2, and vehicle battery B2 can be charged.

  On the other hand, the current transformer 210a outputs a pulsed voltage from the secondary winding at the timing when the alternating current output from the coil W2 switches from negative polarity to positive polarity. The current transformer 210b outputs a pulsed voltage from the secondary winding at a timing when the alternating current output from the coil W2 switches from positive polarity to negative polarity.

  The polarity ratio calculator 210c calculates the positive polarity ratio and the negative polarity ratio based on the pulse voltage output from the secondary windings of the current transformers 210a and 210b, and outputs the calculated data as data.

  When the positive polarity ratio calculated by the polarity ratio calculation unit 210c is equal to or higher than the positive determination criterion ratio, or when the negative polarity ratio is equal to or lower than the negative determination criterion ratio, the determination unit 211 and the rectifier circuit It is determined that a DC leakage has occurred between 201. When it is determined that a DC leakage has occurred, an abnormal signal is output to notify that effect.

  When the determination unit 211 outputs an abnormality signal, the drive signal generation unit 212 stops outputting the drive signal. As a result, the conversion device 20 stops operating.

  Conversely, when power is supplied from the in-vehicle battery B2 to the commercial AC power supply AC2, the drive signal generator 212 generates a drive signal for driving the rectifier circuit 201 and the converter circuit 202 based on a command input from the outside. Output.

  The drive circuit 214 drives the converter circuit 202 based on the drive signal output from the drive signal generation unit 212. The converter circuit 202 converts the direct current output from the in-vehicle battery B2 into direct current with a different voltage and supplies the direct current to the rectifier circuit 201.

  The drive circuit 215 drives the rectifier circuit 201 based on the drive signal output from the drive signal generation unit 212. The rectifier circuit 201 switches the direct current supplied from the converter circuit 202 to alternating current by switching the IGBTs 201a to 201d, and supplies the alternating current to the coil W2.

  The coil W <b> 2 generates an alternating magnetic flux when AC is supplied from the rectifier circuit 201. Coil W1 generates alternating current by electromagnetic induction by interlinking with the alternating magnetic flux generated by coil W2. The converter CNV converts the alternating current supplied from the coil W1 into alternating current having a different frequency and supplies it to the commercial alternating current power supply AC2. Thereby, the direct current supplied from vehicle-mounted battery B2 can be converted into alternating current, and can be supplied to commercial alternating current power supply AC2 non-contactingly.

  On the other hand, the current transformer 210a outputs a pulsed voltage from the secondary winding at the timing when the alternating current output from the rectifier circuit 201 is switched from negative to positive. The current transformer 210b outputs a pulsed voltage from the secondary winding at the timing when the alternating current output from the rectifier circuit 201 switches from positive polarity to negative polarity.

  The polarity ratio calculator 210c calculates the positive polarity ratio and the negative polarity ratio based on the pulse voltage output from the secondary windings of the current transformers 210a and 210b, and outputs the calculated data as data.

  When the positive polarity side polarity ratio calculated by the polarity ratio calculation unit 210c is equal to or higher than the positive polarity side determination reference ratio, or when the negative polarity side polarity ratio is equal to or lower than the negative polarity side determination reference ratio, the determination unit 211 It is determined that a DC leakage has occurred between W2. When it is determined that a DC leakage has occurred, an abnormal signal is output to notify that effect.

  When the determination unit 211 outputs an abnormality signal, the drive signal generation unit 212 stops outputting the drive signal. As a result, the conversion device 20 stops operating.

  Next, effects of the second embodiment will be described. According to the second embodiment, the same effect as that of the first embodiment can be obtained.

  In the second embodiment, an example is described in which the rectifier circuit 201 is configured by the IGBTs 201a to 201d and the converter circuit 202 is configured by the IGBTs 202c and 202d, respectively, but is not limited thereto. You may be comprised by MOFET. What is necessary is just to be comprised by the switching element by which anti-parallel connection of the freewheel diode was carried out.

DESCRIPTION OF SYMBOLS 1 ... Power feeding device, 10 ... Conversion device (electronic device), 100 ... Power factor improvement circuit, 101 ... Rectifier circuit, 102 ... Converter circuit, 11 ... Control device (DC leakage) Detecting device), 110... Polarity ratio detecting unit (polarity ratio detecting means), 110a, 110b... Current transformer (zero cross point detecting means), 110c. Determination means), 112... Drive signal generation unit, 113, 114... Drive circuit, AC1... Commercial AC power supply (AC power supply), B1.

Claims (6)

In a DC leakage detection device that detects a DC leakage of an electronic device connected to an AC power supply,
Polarity ratio detection means for detecting a ratio of a positive polarity period in one cycle of the alternating current output from the alternating current power supply or a polarity ratio indicating a ratio of a negative polarity period in one cycle of the alternating current ( 110)
Determining means (111) for determining whether or not a DC leakage has occurred based on the polarity ratio detected by the polarity ratio detecting means;
A direct current leakage detection device comprising:   When the polarity ratio indicating the ratio of the positive polarity period in one cycle of the alternating current detected by the polarity ratio detection means is equal to or higher than the positive determination criterion ratio, It is determined that a DC leakage has occurred when a polarity ratio indicating a ratio of a negative polarity period in a cycle is equal to or less than a negative determination criterion ratio smaller than the positive determination criterion ratio. Item 4. The DC leakage detection device according to Item 1. The positive electrode side determination reference ratio is a value greater than 50%,
The DC leakage detection device according to claim 2, wherein the negative-side determination criterion ratio is a value smaller than 50%.   The positive-side determination criterion ratio and the negative-side determination criterion ratio are periods of positive polarity in one cycle of alternating current when the current flowing due to DC leakage is a current that is allowed as the current flowing through the human body. The DC leakage current according to claim 2 or 3, wherein the DC leakage current is preset based on a polarity ratio indicating a ratio of a negative current ratio and a polarity ratio indicating a ratio of a negative polarity period in one cycle of an alternating current. Detection device.   The polarity ratio detection means includes zero cross point detection means (110a, 110b) for detecting a zero cross point of an alternating current, and detects the polarity ratio based on the zero cross point detected by the zero cross point detection means. The DC leakage detection device according to any one of claims 1 to 4.   The DC leakage detection device according to claim 1, wherein when the determination unit determines that a DC leakage has occurred, the determination unit notifies the fact.

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