Anomaly detection device, battery charging device, and anomaly detection method

Abstract

To enable detection of abnormality in three-phase AC signals through a simple configuration.SOLUTION: An abnormality detection device is provided, comprising a square wave conversion unit configured to convert an AC signal of each phase of a three-phase AC signal into a binarized square wave signal, an interference unit configured to output interference signals obtained by causing a square wave signal of each of the three phases to interfere with a square signal of another phase different from the phase, and a smoothing unit configured to generate a smoothed signal of each phase obtained by integrating and smoothing the interference signal of each phase generated by the interference unit.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an abnormality detection device, a battery charging device, and an abnormality detection method.

Background Art

[0002] Techniques for detecting abnormalities in three-phase AC signals are known (see, for example, Patent Document 1). Further, as another conventional technique for detecting abnormalities in three-phase AC signals, for example, there is a technique in which the waveforms of voltages obtained by dividing the signals of each phase of a three-phase AC signal with resistors are detected by an ADC (Analog-to-Digital Converter) to detect abnormalities.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described conventional technique in which an ADC detects the waveforms of voltages obtained by dividing the signals of each phase of a three-phase AC signal with resistors, it is necessary to detect the voltages with a sampling period sufficiently shorter than the period of the three-phase AC signal. Therefore, the above-described conventional technique has a problem that an ADC capable of high-speed sampling and a software design corresponding to high-speed sampling are required.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an abnormality detection device, a battery charging device, and an abnormality detection method capable of detecting an abnormality in a three-phase AC signal with a simple configuration.

Means for Solving the Problems

[0006] In order to solve the above problems, one aspect of the present invention is to use the AC signals of each phase of a three-phase AC signalDepending on whether the AC signal of each phase is above a predetermined threshold, A square wave conversion unit that converts to a binarized square wave signal; an interference unit that outputs an interference signal obtained by interfering the square wave signal of each of the three phases with one square wave signal of another phase different from the current phase; and a smoothing unit that generates smoothed signals for each phase by integrating and smoothing the interference signals of each phase output by the interference unit. The detection control unit detects an abnormality in the three-phase AC signal based on the voltage value of the smoothed signal of each phase smoothed by the smoothing unit. This is an anomaly detection device characterized by having the following features:

[0008] Furthermore, in one aspect of the present invention, in the above-mentioned abnormality detection device, the detection control unit determines the voltage value of the smoothing signal for each phase, predetermined The method is characterized by determining that the three-phase AC signal is normal when it is within the first voltage range.

[0009] Furthermore, in one aspect of the present invention, in the above-described abnormality detection device, the detection control unit, when one of the voltage values ​​of the smoothing signals of each phase is greater than or equal to a first threshold higher than the first voltage range, and one of the remaining voltage values ​​of the smoothing signals is within a second voltage range lower than the first voltage range, then one of the AC signals of each phase is Short circuit to power line Power fault abnormality also This system is characterized by determining that a ground fault anomaly has occurred.

[0010] Furthermore, in one aspect of the present invention, the abnormality detection device described above is characterized in that the detection control unit determines that a disconnection abnormality has occurred, in which one of the AC signals of each phase is disconnected, or a short-circuit abnormality has occurred, in which the remaining two phases are short-circuited, when one of the voltage values ​​of the smoothing signals of each phase is above a second threshold, which is higher than the first voltage range, and the voltage values ​​of the smoothing signals of the remaining two phases are both within a third voltage range, which is lower than the first voltage range.

[0011] Furthermore, in one aspect of the present invention, in the above-mentioned abnormality detection device, the square wave conversion unit converts the AC signal of each phase The logical state of whether the AC signal of each phase is above a predetermined threshold isThe signal is converted into a logically inverted square wave signal for each phase, and the interference unit has a first switch connected between the signal line of the first phase square wave signal of the three phases and the ground line, the signal line of the third phase square wave signal is connected to the control terminal, and the conduction state is controlled according to the third phase square wave signal, and is interfered with by the third phase square wave signal. The The device comprises a first interference unit that outputs a one-phase interference signal, a second switch connected between the signal line of the second phase of the three-phase rectangular wave signal and the ground line, the signal line of the first phase rectangular wave signal connected to the control terminal, and the conduction state of the switch being controlled according to the first phase rectangular wave signal, and is interfered with by the first phase rectangular wave signal. The The device has a second interference unit that outputs a two-phase interference signal, a third switch connected between the signal line of the third-phase rectangular wave signal and the ground line, the signal line of the second-phase rectangular wave signal connected to a control terminal, and the conduction state of the switch is controlled according to the second-phase rectangular wave signal, and is interfered with by the second-phase rectangular wave signal. The The device comprises a third interference unit that outputs a three-phase interference signal, and the smoothing unit is characterized in that it generates smoothed signals for each phase by integrating the logic inverted signals of each phase of the first phase interference signal, the second phase interference signal, and the third phase interference signal.

[0012] Furthermore, in one aspect of the present invention, the abnormality detection device described above is characterized in that the square wave conversion unit has a Zener diode that clamps the AC signal of each phase to a voltage below the input withstand voltage of the square wave conversion unit, and converts the AC signal of each phase, which has been clamped to a voltage below the input withstand voltage, into the square wave signal of each phase.

[0013] Furthermore, one aspect of the present invention is a battery charging device comprising the abnormality detection device described above, a rectifier unit that supplies DC power rectified from the three-phase AC signal to a battery as charging power by conducting switch elements connected to each signal line of the three-phase AC signal output by the generator in accordance with the rotation of the rotor, and a control unit that controls the conduction of the switch elements so that the voltage of the DC power output by the rectifier unit becomes a predetermined voltage, wherein the abnormality detection device detects an abnormality in the three-phase AC signal.

[0014] Furthermore, in one aspect of the present invention, the square wave conversion unit converts the AC signals of each phase of the three-phase AC signal Depending on whether the AC signal of each phase is above a predetermined threshold, The process includes a square wave conversion step of converting to a binarized square wave signal, an interference step in which an interference unit outputs an interference signal obtained by interfering each of the three phases' square wave signals with one other phase's square wave signal that is different from the current phase, and a smoothing step in which a smoothing unit generates smoothed signals for each phase by integrating and smoothing the interference signals for each phase output by the interference step. The detection control step involves the detection control unit detecting an abnormality in the three-phase AC signal based on the voltage value of the smoothed signal for each phase that has been smoothed by the smoothing step. This is an anomaly detection method characterized by including [a specific element]. [Effects of the Invention]

[0015] According to the present invention, a square wave conversion unit converts the AC signals of each phase of a three-phase AC signal into binarized square wave signals, and an interference unit outputs an interference signal obtained by interfering the square wave signal of each phase with a square wave signal of another phase different from the current phase. Furthermore, a smoothing unit generates smoothed signals for each phase by integrating the interference signals of each phase. As a result, the anomaly detection device can detect anomalies in the three-phase AC signal by detecting the voltage of the smoothed signals of each phase. Therefore, the anomaly detection device can detect anomalies in the three-phase AC signal with a simple configuration without requiring an ADC capable of high-speed sampling or software design that supports high-speed sampling. [Brief explanation of the drawing]

[0016] [Figure 1] This block diagram shows an example of a battery charging device and an abnormality detection device according to this embodiment. [Figure 2] This is a timing chart showing an example of the normal operation of the abnormality detection device according to this embodiment. [Figure 3] This is a timing chart showing an example of the operation of the anomaly detection device according to this embodiment when it is in a junction state. [Figure 4] This is a timing chart showing an example of the operation of the abnormality detection device according to this embodiment in the event of a ground fault. [Figure 5]This is a timing chart showing an example of the operation of the correlation short - circuit state of the abnormality detection device according to this embodiment. [Figure 6] This is a flowchart showing an example of the operation of the abnormality determination process of the abnormality detection device according to this embodiment.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, an abnormality detection device, a battery charging device, and an abnormality detection method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of a battery charging device 100 and an abnormality detection device 1 according to this embodiment.

[0018] As shown in FIG. 1, the battery charging device 100 includes a generator 2, a rectifier unit 10, a U - phase driver 13, a V - phase driver 14, a W - phase driver 15, a rectangular - wave conversion unit 20, an interference unit 30, a smoothing unit 40, a control unit 50, and a battery 3. The battery charging device 100 is, for example, mounted on a vehicle such as a motorcycle, and rectifies the AC power generated by the generator 2 to charge the battery 3. Also, a load unit (not shown) is connected to the battery charging device 100, and the power generated by the generator 2 or the output power of the battery 3 is supplied to the load unit.

[0019] The generator 2 is, for example, a three - phase AC generator, generates electricity in response to the rotation of a rotor (not shown), and outputs three - phase AC power (three - phase AC signals) corresponding to the generated electricity. Here, the rotor is, for example, a crankshaft connected to the rotation shaft of an internal combustion engine (engine) of a motorcycle. Also, the three - phase AC signals here are, for example, AC signals of the U - phase, V - phase, and W - phase.

[0020] Here, the signal line of the U - phase AC signal generated by the generator 2 is connected to the node N1, the signal line of the V - phase AC signal generated by the generator 2 is connected to the node N2. Also, the signal line of the W - phase AC signal generated by the generator 2 is connected to the node N3.

[0021] Battery 3 is, for example, a lead-acid battery and is connected between the signal line L1, which outputs the output voltage Vout of the rectifier unit 10, and the GND line L2 (ground line). The positive electrode (+) of battery 3 is connected to the signal line L1 of the output voltage Vout, and the negative electrode (-) is connected to the GND line L2. Battery 3 is charged by the power generated by the generator 2 supplied via the signal line L1, and the charged power is supplied to the load unit (not shown) via the signal line L1.

[0022] The rectifier unit 10 outputs DC power by rectifying the three-phase AC power through the conduction of thyristors (11, 12) connected to each signal line of the three-phase AC signal output by the generator 2. The rectifier unit 10 comprises upper thyristors 11 (11-1 to 11-3) and lower thyristors 12 (12-1 to 12-3). Thyristors 11 and 12 are examples of switching elements.

[0023] In this embodiment, thyristors 11-1, 11-2, and 11-3 each refer to the upper thyristor (upper switching element), and when referring to any upper thyristor provided by the rectifier unit 10, or when not making a distinction, they are referred to as thyristor 11.

[0024] Furthermore, thyristors 12-1, 12-2, and 12-3 each refer to the lower thyristor (upper switching element), and when referring to any lower thyristor provided by the rectifier unit 10, or when no particular distinction is made, they are referred to as thyristor 12.

[0025] Thyristor 11-1 is the upper switching element for the U-phase, with its anode terminal connected to node N1, its cathode terminal connected to signal line L1, and its control terminal (gate terminal) connected to the signal line of the upper control signal of the U-phase driver 13.

[0026] Furthermore, the thyristor 11-2 is the upper switching element for the V phase, with its anode terminal connected to node N2, its cathode terminal connected to signal line L1, and its control terminal connected to the signal line of the upper control signal of the V phase driver 14.

[0027] Furthermore, the thyristor 11-3 is the upper switching element for the W phase, with its anode terminal connected to node N3, its cathode terminal connected to signal line L1, and its control terminal connected to the signal line of the upper control signal of the W phase driver 15.

[0028] Furthermore, the thyristor 12-1 is the lower switching element for the U-phase, with its anode terminal connected to the GND line L2, its cathode terminal connected to node N1, and its control terminal connected to the signal line of the lower control signal of the U-phase driver 13.

[0029] Furthermore, the thyristor 12-2 is the lower switching element for the V phase, with its anode terminal connected to the GND line L2, its cathode terminal connected to node N2, and its control terminal connected to the signal line of the lower control signal of the V phase driver 14.

[0030] Furthermore, the thyristor 12-3 is the lower switching element for the W phase, with its anode terminal connected to the GND line L2, its cathode terminal connected to node N3, and its control terminal connected to the signal line of the lower control signal of the W phase driver 15.

[0031] The U-phase driver 13 is a driver that generates control signals for thyristors 11-1 and 12-1. Based on the OFF signal (stop signal) output from the control unit 50 (described later), the U-phase driver 13 generates control signals for thyristors 11-1 and 12-1.

[0032] The V-phase driver 14 is a driver that generates control signals for thyristors 11-2 and 12-2. Based on the OFF signal output from the control unit 50 (described later), the V-phase driver 14 generates control signals for thyristors 11-2 and 12-2.

[0033] The W-phase driver 15 is a driver that generates control signals for thyristors 11-3 and 12-3. Based on the OFF signal output from the control unit 50 (described later), the W-phase driver 15 generates control signals for thyristors 11-3 and 12-3.

[0034] The control unit 50 is, for example, a processor including a CPU (Central Processing Unit), and controls the battery charging device 100. When the voltage of the DC power output by the rectifier unit 10 (output voltage Vout) exceeds a predetermined voltage (above the threshold voltage), the control unit 50 outputs an OFF signal (stop signal) that stops the conduction of the thyristors (11, 12). Here, the OFF signal (stop signal) indicates a state in which the output signal is in the H state (high logic state). The predetermined voltage (above the threshold voltage) is, for example, a voltage value that prevents the battery 3 from being overcharged.

[0035] The control unit 50 controls the conduction of the thyristors (11, 12) of the rectifier unit 10 so that the output voltage Vout is less than a predetermined voltage. Here, when the signal line of the OFF signal is in the L state (low logic state), the control unit 50 controls the thyristors (11, 12) to the ON state (conducting state), and when it is in the H state (output state of the OFF signal), the control unit 50 controls the thyristors (11, 12) to the OFF state. For example, when the output voltage Vout is less than a predetermined voltage (less than threshold voltage), the control unit 50 sets the signal line of the OFF signal to the L state, and when the output voltage Vout is above the predetermined voltage, it sets the signal line of the OFF signal to the H state and outputs an OFF signal.

[0036] Furthermore, the control unit 50 includes an ADC unit 51 and a detection control unit 52. The ADC unit 51 and the detection control unit 52 are part of the abnormality detection device 1, and their details will be described later.

[0037] The abnormality detection device 1 is a device that detects abnormalities in the three-phase AC signal, and in this embodiment, it detects abnormalities in the three-phase AC signal output by the generator 2. The anomaly detection device 1 comprises a rectangular wave conversion unit 20, an interference unit 30, a smoothing unit 40, an ADC unit 51, and a detection control unit 52.

[0038] The square wave conversion unit 20 converts the AC signals of each phase of the three-phase AC signal into binarized square wave signals. The square wave conversion unit 20 generates a U-phase square wave signal by binarizing the U-phase AC signal, and also generates a V-phase square wave signal by binarizing the V-phase AC signal. Furthermore, the square wave conversion unit 20 generates a W-phase square wave signal by binarizing the W-phase AC signal. In addition, the square wave conversion unit 20 converts the AC signals of each phase into logically inverted square wave signals for each phase (U-phase square wave signal, V-phase square wave signal, and W-phase square wave signal). Furthermore, the square wave conversion unit 20 includes resistors 21 (21-1 to 21-3), Zener diodes 22 (22-1 to 22-3), and inverter circuits 23 (23-1 to 23-3).

[0039] In this embodiment, resistors 21-1 to 21-3 each have the same configuration and will be described as resistor 21 when they represent any resistor provided by the square wave conversion unit 20, or when no particular distinction is made.

[0040] Furthermore, in this embodiment, each of the Zener diodes 22-1 to 22-3 has the same configuration, and when referring to any Zener diode provided in the square wave conversion unit 20, or when not particularly distinguishing between them, they will be described as Zener diode 22.

[0041] Furthermore, in this embodiment, each of the inverter circuits 23-1 to 23-3 has the same configuration, and when referring to any inverter circuit provided by the square wave conversion unit 20, or when not particularly distinguishing between them, they will be described as inverter circuit 23.

[0042] Resistor 21-1 is connected between the signal line of the U-phase AC signal (node ​​N1) and node N4. Zener diode 22-1 has its anode terminal connected to the GND terminal (ground wire) and its cathode terminal connected to node N4. Zener diode 22-1 conducts when a voltage exceeding the input withstand voltage of inverter circuit 23-1 is supplied, limiting the U-phase AC signal to a voltage below the input withstand voltage of inverter circuit 23-1.

[0043] The inverter circuit 23-1 is an inverting output circuit, with its input terminal connected to node N4 and its output terminal connected to node N5. The inverter circuit 23-1 binarizes the U-phase AC signal and converts it into a U-phase square wave signal. In other words, the inverter circuit 23-1 outputs a square wave signal obtained by logically inverting the U-phase AC signal as a U-phase square wave signal.

[0044] Resistor 21-2 is connected between the signal line of the V-phase AC signal (node ​​N2) and node N8. Zener diode 22-2 has its anode terminal connected to the GND terminal (ground wire) and its cathode terminal connected to node N9. Zener diode 22-2 conducts when a voltage exceeding the input breakdown voltage of inverter circuit 23-2 is supplied, limiting the V-phase AC signal to a voltage below the input breakdown voltage of inverter circuit 23-2.

[0045] The inverter circuit 23-2 is an inverting output circuit, with its input terminal connected to node N9 and its output terminal connected to node N10. The inverter circuit 23-2 binarizes the V-phase AC signal and converts it into a V-phase square wave signal. In other words, the inverter circuit 23-2 outputs a square wave signal obtained by logically inverting the V-phase AC signal as a V-phase square wave signal.

[0046] Resistor 21-3 is connected between the signal line of the W-phase AC signal (node ​​N3) and node N12. Zener diode 22-3 has its anode terminal connected to the GND terminal (ground wire) and its cathode terminal connected to node N13. Zener diode 22-3 conducts when a voltage exceeding the input withstand voltage of inverter circuit 23-3 is supplied, limiting the W-phase AC signal to a voltage below the input withstand voltage of inverter circuit 23-3.

[0047] The inverter circuit 23-3 is an inverting output circuit, with its input terminal connected to node N13 and its output terminal connected to node N14. The inverter circuit 23-3 binarizes the W-phase AC signal and converts it into a W-phase square wave signal. In other words, the inverter circuit 23-3 outputs a square wave signal obtained by logically inverting the W-phase AC signal as a W-phase square wave signal.

[0048] Thus, the square wave conversion unit 20 has a Zener diode 22 that clamps (limits) the AC signal of each phase to a voltage below the input breakdown voltage of the square wave conversion unit 20, and converts the AC signal of each phase, which has been clamped to a voltage below the input breakdown voltage, into a square wave signal for each phase.

[0049] The interference unit 30 outputs an interference signal obtained by interfering the square wave signal of each of the three phases with a square wave signal of another phase that is different from the current phase. For example, the interference unit 30 generates a U-phase interference signal by interfering the U-phase square wave signal with a W-phase square wave signal, and also generates a V-phase interference signal by interfering the V-phase square wave signal with a U-phase square wave signal. Furthermore, the interference unit 30 generates a W-phase interference signal by interfering the W-phase square wave signal with a V-phase square wave signal. The interference section 30 comprises resistors 31 (31-1 to 31-3) and switch sections 32 (32-1 to 32-3).

[0050] In this embodiment, resistors 31-1 to 31-3 each have the same configuration and will be described as resistor 21 when the interference section 30 represents any resistor provided in the input section, or when no particular distinction is made.

[0051] Furthermore, in this embodiment, each of the switch sections 32-1 to 32-3 has the same configuration, and when referring to any switch section provided by the interference section 30, or when not particularly distinguishing between them, they will be described as switch section 32.

[0052] Resistor 31-1 is connected between the signal line of the U-phase square wave signal (node ​​N5) and node N6. The switch section 32-1 (an example of the first switch) is, for example, an NPN bipolar transistor, with its collector terminal connected to node N6, its base terminal connected via a resistor to the signal line of the W-phase square wave signal (node ​​N13), and its collector terminal connected to the GND terminal (ground wire). Furthermore, the base terminal and collector terminal are connected via a resistor (pull-down resistor).

[0053] The switch unit 32-1 is connected between the signal line (node ​​N6) of the U-phase square wave signal (first-phase square wave signal) and the GND terminal (ground wire), and the signal line (node ​​N13) of the W-phase square wave signal (third-phase square wave signal) is connected to the control terminal (base terminal), and the conduction state is controlled according to the W-phase square wave signal.

[0054] In this embodiment, the resistor 31-1 and the switch unit 32-1 correspond to the first interference unit. The first interference unit has the switch unit 32-1 (first switch) and is interfered with by a W-phase square wave signal. U It outputs a phase interference signal (the interference signal of the first phase).

[0055] Resistor 31-2 is connected between the signal line of the V-phase square wave signal (node ​​N9) and node N10. The switch section 32-2 (an example of a second switch) is, for example, an NPN bipolar transistor, with its collector terminal connected to node N10, its base terminal connected via a resistor to the signal line of the U-phase square wave signal (node ​​N5), and its collector terminal connected to the GND terminal (ground wire). Furthermore, the base terminal and collector terminal are connected via a resistor (pull-down resistor).

[0056] The switch unit 32-2 is connected between the signal line (node ​​N10) of the V-phase square wave signal (second-phase square wave signal) and the GND terminal (ground wire), and the signal line (node ​​N6) of the U-phase square wave signal (first-phase square wave signal) is connected to the control terminal (base terminal), and the conduction state is controlled according to the U-phase square wave signal.

[0057] In this embodiment, the resistor 31-2 and the switch unit 32-2 correspond to the second interference unit. The second interference unit has a switch unit 32-2 (second switch) and is interfered with by a U-phase square wave signal. V It outputs a phase interference signal (second phase interference signal).

[0058] Resistor 31-3 is connected between the signal line of the W-phase square wave signal (node ​​N13) and node N14. The switch section 32-3 (an example of a third switch) is, for example, an NPN bipolar transistor, with its collector terminal connected to node N14, its base terminal connected via a resistor to the signal line of the V-phase square wave signal (node ​​N9), and its collector terminal connected to the GND terminal (ground wire). Furthermore, the base terminal and collector terminal are connected via a resistor (pull-down resistor).

[0059] The switch unit 32-3 is connected between the signal line (node ​​N14) for the W-phase square wave signal (third-phase square wave signal) and the GND terminal (ground wire), and the signal line (node ​​N9) for the V-phase square wave signal (second-phase square wave signal) is connected to the control terminal (base terminal), and the conduction state is controlled according to the V-phase square wave signal.

[0060] In this embodiment, the resistor 31-3 and the switch unit 32-3 correspond to the third interference unit. The third interference unit has a switch unit 32-3 (third switch) and is interfered with by a V-phase square wave signal. W It outputs a phase interference signal (third phase interference signal).

[0061] The smoothing unit 40 generates smoothed signals for each phase by integrating and smoothing the interference signals of each phase output by the interference unit 30. For example, the smoothing unit 40 generates a smoothed U-phase signal by integrating and smoothing the U-phase interference signal, and also generates a smoothed V-phase signal by integrating and smoothing the V-phase interference signal. Furthermore, the smoothing unit 40 generates a smoothed W-phase signal by integrating and smoothing the W-phase interference signal. The smoothing unit 40 comprises an inverter circuit 41 (41-1 to 41-3), resistors 42 (42-1 to 42-3), and capacitors 43 (43-1 to 43-3).

[0062] In this embodiment, inverter circuits 41-1 to 41-3 each have the same configuration, and when referring to any inverter circuit provided by the smoothing unit 40, or when not specifically distinguishing between them, they will be described as inverter circuit 41.

[0063] Furthermore, in this embodiment, resistors 42-1 to 42-3 each have the same configuration and will be described as resistor 42 when they represent any resistor provided by the smoothing unit 40, or when no particular distinction is made.

[0064] Furthermore, in this embodiment, each of the capacitors 43-1 to 43-3 has the same configuration, and when referring to any capacitor provided by the smoothing unit 40, or when not particularly distinguishing between them, they will be described as capacitor 43.

[0065] The inverter circuit 41-1 is, for example, an inverting output circuit, with its input terminal connected to node N6 and its output terminal connected to node N7 via resistor 42-1. The inverter circuit 41-1 outputs a square wave signal obtained by logically inverting the U-phase interference signal.

[0066] Resistor 42-1 is connected between the output terminal of inverter circuit 41-1 and node N7, and functions as part of the RC integrator circuit. Capacitor 43-1 is connected between node N7 and the GND terminal (ground wire) and functions as part of the RC integrating circuit. Furthermore, resistor 42-1 and capacitor 43-1 form an RC integrating circuit, which integrates and smooths the output of inverter circuit 41-1, and outputs a U-phase smoothed signal to node N7.

[0067] The inverter circuit 41-2 is, for example, an inverting output circuit, with its input terminal connected to node N10 and its output terminal connected to node N11 via resistor 42-2. The inverter circuit 41-2 outputs a square wave signal obtained by logically inverting the V-phase interference signal.

[0068] Resistor 42-2 is connected between the output terminal of inverter circuit 41-2 and node N11, and functions as part of an RC integrator circuit. Capacitor 43-2 is connected between node N11 and the GND terminal (ground wire) and functions as part of the RC integrating circuit. Furthermore, resistor 42-2 and capacitor 43-2 form an RC integrating circuit, which integrates and smooths the output of inverter circuit 41-2, and outputs a V-phase smoothed signal to node N11.

[0069] The inverter circuit 41-3 is, for example, an inverting output circuit, with its input terminal connected to node N14 and its output terminal connected to node N15 via resistor 42-3. The inverter circuit 41-3 outputs a square wave signal obtained by logically inverting the W-phase interference signal.

[0070] Resistor 42-3 is connected between the output terminal of inverter circuit 41-3 and node N15, and functions as part of an RC integrator circuit. Capacitor 43-3 is connected between node N15 and the GND terminal (ground wire) and functions as part of the RC integrating circuit. Furthermore, resistor 42-3 and capacitor 43-3 form an RC integrating circuit, which integrates and smooths the output of inverter circuit 41-3, and outputs a W-phase smoothed signal to node N15.

[0071] In this way, the smoothing unit 40 generates smoothed signals for each phase by integrating and smoothing the logic inverted signals of each phase: the U-phase interference signal (first phase interference signal), the V-phase interference signal (second phase interference signal), and the W-phase interference signal (third phase interference signal).

[0072] The ADC unit 51 detects the voltage of the smoothing signal for each phase and converts it into a digital value. For example, the ADC unit 51 detects the voltage of the U-phase smoothing signal (voltage at node N7) and obtains the voltage value of the U-phase smoothing signal. The ADC unit 51 also detects the voltage of the V-phase smoothing signal (voltage at node N11) and obtains the voltage value of the V-phase smoothing signal. The ADC unit 51 also detects the voltage of the W-phase smoothing signal (voltage at node N15) and obtains the voltage value of the W-phase smoothing signal.

[0073] The detection control unit 52 detects abnormalities in the three-phase AC signal based on the voltage values ​​of the smoothed signals of each phase smoothed by the smoothing unit 40. The detection control unit 52 determines that the three-phase AC signal is normal if the voltage values ​​of the smoothed signals of each phase are within a first voltage range, which is the intermediate voltage of the power supply voltage VDD of the smoothing unit 40. Here, the theoretical value of the voltage value of the smoothed signals of each phase under normal conditions is (2 / 3VDD), and the first voltage range is, for example, (2 / 3VDD ± 10%). The detection control unit 52 determines that the three-phase AC signal is normal if all the voltage values ​​of the smoothed signals of each phase obtained from the ADC unit 51 are within the first voltage range (for example, 2 / 3VDD ± 10%).

[0074] Furthermore, the detection control unit 52 determines that one of the AC signals for each phase is experiencing a ceiling fault or a ground fault if one of the voltage values ​​of the smoothed signals for each phase is above a first threshold, which is higher than the first voltage range (2 / 3VDD ± 10%), and one of the remaining voltage values ​​of the smoothed signals is within a second voltage range, which is lower than the first voltage range. Here, the first threshold is, for example, (VDD - 10%), and the second voltage range is, for example, (1 / 2VDD ± 10%). Also, a ceiling fault indicates, for example, a short circuit with the power supply voltage VDD signal line, and a ground fault indicates, for example, a short circuit with the GND line (earth wire).

[0075] The detection control unit 52 determines that one of the AC signals for each phase is experiencing a ceiling fault or ground fault if the voltage value of one of the smoothed signals for each phase acquired from the ADC unit 51 is greater than or equal to a first threshold (e.g., VDD-10%), and one of the remaining smoothed signals is within a second voltage range (e.g., 1 / 2VDD±10%).

[0076] Furthermore, the detection control unit 52 determines that a disconnection abnormality has occurred, where one of the AC signals of each phase is disconnected, or a short-circuit abnormality has occurred, where the remaining two phases are short-circuited, if one of the voltage values ​​of the smoothing signals of each phase is above a second threshold, which is higher than the first voltage range (2 / 3VDD ± 10%), and the voltage values ​​of the smoothing signals of the remaining two phases are all within a third voltage range, which is lower than the first voltage range.

[0077] Here, the second threshold is, for example, (VDD-10%), and the third voltage range is, for example, (1 / 2VDD±10%). In this embodiment, an example in which the second threshold is set to be equal to the first threshold has been described, but the second threshold and the first threshold may be set to different values. Also, in this embodiment, an example in which the third voltage range is set to be equal to the second voltage range has been described, but the third voltage range and the second voltage range may be set to different ranges.

[0078] The detection control unit 52 determines that a disconnection abnormality has occurred, where one of the AC signals of each phase is disconnected, or a short-circuit abnormality has occurred, where the remaining two phases are short-circuited, if the voltage value of one phase of the smoothed signal voltage obtained from the ADC unit 51 is greater than or equal to a second threshold (e.g., VDD-10%), and the voltage values ​​of the remaining two phases of the smoothed signal are all within a third voltage range (e.g., 1 / 2VDD±10%).

[0079] Next, the operation of the abnormality detection device 1 according to this embodiment will be described with reference to the drawings. Here, we will first describe the smoothed signal of the abnormality detection device 1 in its normal state, referring to Figure 2.

[0080] Figure 2 is a timing chart showing an example of the normal operation of the abnormality detection device 1 according to this embodiment. In Figure 2, waveforms W1 to W3 show the waveforms of the three-phase AC signal, from top to bottom being the U-phase AC signal (voltage at node N1), the V-phase AC signal (voltage at node N2), and the W-phase AC signal (voltage at node N2). Waveforms W4 to W6 show the waveforms of the square wave signals for each phase, which are the output of the square wave conversion unit 20, from top to bottom being the U-phase square wave signal (voltage at node N5), the V-phase square wave signal (voltage at node N9), and the W-phase square wave signal (voltage at node N13).

[0081] Waveforms W7 to W9 show the waveforms of the interference signals for each phase, which are the output of the interference unit 30. From top to bottom, they show the U-phase interference signal (voltage at node N6), the V-phase interference signal (voltage at node N10), and the W-phase interference signal (voltage at node N14). Waveforms W10 to W12 show the waveforms of the inverted signals for each phase, which are the output of the inverter circuit 41. From top to bottom, they show the U-phase inverted signal, the V-phase inverted signal, and the W-phase inverted signal.

[0082] Waveforms W13 to W15 show the waveforms of the smoothing signals for each phase, which are the output of the smoothing unit 40. From top to bottom, they show the U-phase smoothing signal (voltage at node N7), the V-phase smoothing signal (voltage at node N11), and the W-phase smoothing signal (voltage at node N15). In each graph, the vertical axis represents voltage, and the horizontal axis represents time.

[0083] As shown in waveforms W1 to W3 in Figure 2, the three-phase AC signal (U-phase AC signal (voltage at node N1), V-phase AC signal (voltage at node N2), W-phase AC signal (voltage at node N2)) is a sinusoidal signal with a phase difference of 120 degrees.

[0084] First, the square wave conversion unit 20 generates a U-phase square wave signal (waveform W4) based on the U-phase AC signal (waveform W1) that falls at times T2 and T8 and rises at time T5. The square wave conversion unit 20 also generates a V-phase square wave signal (waveform W5) based on the V-phase AC signal (waveform W2) that rises at times T1 and T7 and falls at times T4 and T10. Furthermore, the square wave conversion unit 20 generates a W-phase square wave signal (waveform W6) based on the W-phase AC signal (waveform W3) that rises at times T3 and T9 and falls at time T6.

[0085] The three-phase AC signal (U-phase AC signal (voltage at node N1), V-phase AC signal (voltage at node N2), W-phase AC signal (voltage at node N2)) is a square wave signal with a ratio of approximately (1:1) between the high (H) state and the low (L) state, as shown in waveforms W1 to W3 (duty cycle 50%).

[0086] Next, the interference unit 30 generates a U-phase interference signal (waveform W7) by changing the period during which the W-phase square wave signal (waveform W6) is in the H state of the U-phase square wave signal (waveform W4) to the L state. For example, since the W-phase square wave signal is in the H state from time T5 to time T6, the interference unit 30 converts the H state of the U-phase square wave signal to the L state during this period from time T5 to time T6 to generate a U-phase interference signal.

[0087] Furthermore, the interference unit 30 generates a V-phase interference signal (waveform W8) by changing the period during which the U-phase square wave signal (waveform W4) is in the H state of the V-phase square wave signal (waveform W5) to the L state. For example, since the U-phase square wave signal is in the H state during the period from time T1 to time T2 and from time T7 to time T8, the interference unit 30 converts the H state of the V-phase square wave signal to the L state during this period to generate a V-phase interference signal.

[0088] Furthermore, the interference unit 30 generates a W-phase interference signal (waveform W9) by changing the period during which the V-phase square wave signal (waveform W5) is in the H state of the W-phase square wave signal (waveform W6) to the L state. For example, since the V-phase square wave signal is in the H state during the period from time T3 to time T4 and from time T9 to time T10, the interference unit 30 converts the H state of the W-phase square wave signal to the L state during this period to generate a W-phase interference signal.

[0089] Next, the inverter circuits 41 (41-1 to 41-3) of the smoothing unit 40 logically invert the U-phase interference signal, V-phase interference signal, and W-phase interference signal, respectively, to generate inverted signals (U-phase determination signal, V-phase inversion signal, and W-phase inversion signal) as shown in waveforms W10 to W12. Here, the U-phase determination signal (waveform W10), the V-phase inversion signal (waveform W11), and the W-phase inversion signal (waveform W12) are square waves with a ratio of approximately (2:1) between the H state and the L state (duty cycle of approximately 66%).

[0090] Next, the smoothing unit 40 outputs signals (U-phase smoothed signal, V-phase smoothed signal, and W-phase smoothed signal) obtained by integrating the U-phase determination signal (waveform W10), the V-phase inversion signal (waveform W11), and the W-phase inversion signal (waveform W12). The smoothing unit 40 outputs a U-phase smoothed signal with a voltage around (2 / 3VDD), as shown in waveform W13. The smoothing unit 40 also outputs a V-phase smoothed signal with a voltage around (2 / 3VDD), as shown in waveform W14. The smoothing unit 40 also outputs a W-phase smoothed signal with a voltage around (2 / 3VDD), as shown in waveform W15.

[0091] Thus, when the three-phase AC signal is normal, the smoothing unit 40 outputs a smoothing signal with a voltage of approximately (2 / 3VDD) for all of the smoothing signals of each phase. In this case, the detection control unit 52 determines that the three-phase AC signal is normal when the voltage range VR1 of (2 / 3VDD ± 10%) is set as the first voltage range and the U-phase determination signal, V-phase inversion signal, and W-phase inversion signal are all within the voltage range VR1.

[0092] Next, with reference to Figure 3, the smoothed signal of the fault condition of the abnormality detection device 1 according to this embodiment will be described. Figure 3 is a timing chart showing an example of the operation of the fault detection device 1 according to this embodiment when it is in a junction state.

[0093] In Figure 3, waveforms W21 to W23 show the waveforms of a three-phase AC signal with a V-phase AC signal in a short circuit, and from top to bottom they show the U-phase AC signal (voltage at node N1), the V-phase AC signal (voltage at node N2), and the W-phase AC signal (voltage at node N2). Waveforms W24 to W26 show the waveforms of the square wave signals of each phase, which are the output of the square wave conversion unit 20, and from top to bottom they show the U-phase square wave signal (voltage at node N5), the V-phase square wave signal (voltage at node N9), and the W-phase square wave signal (voltage at node N13).

[0094] Waveforms W27 to W29 show the waveforms of the interference signals for each phase, which are the output of the interference unit 30. From top to bottom, they show the U-phase interference signal (voltage at node N6), the V-phase interference signal (voltage at node N10), and the W-phase interference signal (voltage at node N14). Waveforms W30 to W32 show the waveforms of the inverted signals for each phase, which are the output of the inverter circuit 41. From top to bottom, they show the U-phase inverted signal, the V-phase inverted signal, and the W-phase inverted signal.

[0095] Furthermore, waveforms W33 to W35 show the waveforms of the smoothing signals for each phase, which are the output of the smoothing unit 40. From top to bottom, they show the U-phase smoothing signal (voltage at node N7), the V-phase smoothing signal (voltage at node N11), and the W-phase smoothing signal (voltage at node N15). In each graph, the vertical axis represents voltage, and the horizontal axis represents time.

[0096] As shown in waveform W22 of Figure 3, the V-phase AC signal is fixed at a predetermined voltage in a faulty state. Waveforms W21 and W23 are the same as waveforms W1 and W3 in Figure 2 described above.

[0097] Furthermore, if the signal line of the V-phase AC signal is short-circuited, the square wave conversion unit 20 generates a V-phase square wave signal fixed to the L state based on the V-phase AC signal (waveform W22) (waveform W25). The square wave conversion unit 20 also generates a U-phase square wave signal based on the U-phase AC signal (waveform W21) that falls at times T11 and T15 and rises at time T13 (waveform W24). The square wave conversion unit 20 also generates a V-phase square wave signal based on the W-phase AC signal (waveform W23) that rises at times T12 and T16 and falls at time T14 (waveform W26).

[0098] Next, the interference unit 30 generates a U-phase interference signal (waveform W27) by changing the period during which the W-phase square wave signal (waveform W26) is in the H state of the U-phase square wave signal (waveform W24) to the L state. For example, since the W-phase square wave signal is in the H state from time T13 to time T14, the interference unit 30 converts the H state of the U-phase square wave signal to the L state during this period from time T13 to time T14 to generate a U-phase interference signal.

[0099] Furthermore, the interference unit 30 generates a V-phase interference signal (waveform W28) by changing the period during which the U-phase square wave signal (waveform W24) is in the H state of the V-phase square wave signal (waveform W25) to the L state. Here, since the V-phase square wave signal (waveform W25) is fixed in the L state, the interference unit 30 generates a V-phase interference signal that is fixed in the L state, as shown in waveform W28.

[0100] Furthermore, the interference unit 30 generates a W-phase interference signal (waveform W29) by changing the period during which the V-phase square wave signal (waveform W25) is in the H state of the W-phase square wave signal (waveform W26) to the L state. Here, since the V-phase square wave signal (waveform W25) is fixed in the L state, the interference unit 30 generates the W-phase square wave signal as is, as shown in waveform W29.

[0101] Next, the inverter circuits 41 (41-1 to 41-3) of the smoothing unit 40 logically invert the U-phase interference signal, V-phase interference signal, and W-phase interference signal, respectively, to generate inverted signals (U-phase determination signal, V-phase inversion signal, and W-phase inversion signal) as shown in waveforms W30 to W32. Here, the U-phase determination signal (waveform W30) is a square wave with a high-state ratio of approximately 2:1 (duty cycle of approximately 66%) between the high-state and low-state periods. The V-phase inversion signal (waveform W31) is fixed in the high-state. The W-phase determination signal (waveform W32) is a square wave with a high-state ratio of approximately 1:1 (duty cycle of approximately 50%) between the high-state and low-state periods.

[0102] Next, the smoothing unit 40 outputs signals (U-phase smoothed signal, V-phase smoothed signal, and W-phase smoothed signal) obtained by integrating the U-phase determination signal (waveform W30), the V-phase inversion signal (waveform W31), and the W-phase inversion signal (waveform W32). The smoothing unit 40 outputs a U-phase smoothed signal with a voltage around (2 / 3VDD), as shown in waveform W33. The smoothing unit 40 also outputs a V-phase smoothed signal with a voltage around VDD, as shown in waveform W34. The smoothing unit 40 also outputs a W-phase smoothed signal with a voltage around (1 / 2VDD), as shown in waveform W35.

[0103] Thus, when one of the three-phase AC signals is short-circuited, the smoothing unit 40 outputs a smoothing signal with a voltage of approximately VDD to one of the smoothing signals of each phase, and outputs a smoothing signal with a voltage lower than the voltage range VR1 (1 / 2VDD) to the remaining one. In this case, the detection control unit 52 sets the voltage range VR2 of (1 / 2VDD ± 10%) as the second voltage range.

[0104] Next, with reference to Figure 4, the ground fault condition smoothing signal of the abnormality detection device 1 according to this embodiment will be described. Figure 4 is a timing chart showing an example of the operation of the abnormality detection device 1 according to this embodiment in the event of a ground fault.

[0105] In Figure 4, waveforms W41 to W43 show the waveforms of a three-phase AC signal when the V-phase AC signal is grounded, and from top to bottom they show the U-phase AC signal (voltage at node N1), the V-phase AC signal (voltage at node N2), and the W-phase AC signal (voltage at node N2). Waveforms W44 to W46 show the waveforms of the square wave signals of each phase, which are the output of the square wave conversion unit 20, and from top to bottom they show the U-phase square wave signal (voltage at node N5), the V-phase square wave signal (voltage at node N9), and the W-phase square wave signal (voltage at node N13).

[0106] Waveforms W47 to W49 show the waveforms of the interference signals for each phase, which are the output of the interference unit 30. From top to bottom, they show the U-phase interference signal (voltage at node N6), the V-phase interference signal (voltage at node N10), and the W-phase interference signal (voltage at node N14). Waveforms W50 to W52 show the waveforms of the inverted signals for each phase, which are the output of the inverter circuit 41. From top to bottom, they show the U-phase inverted signal, the V-phase inverted signal, and the W-phase inverted signal.

[0107] Waveforms W53 to W55 show the waveforms of the smoothing signals for each phase, which are the output of the smoothing unit 40. From top to bottom, they show the U-phase smoothing signal (voltage at node N7), the V-phase smoothing signal (voltage at node N11), and the W-phase smoothing signal (voltage at node N15). In each graph, the vertical axis represents voltage, and the horizontal axis represents time.

[0108] As shown in waveform W42 of Figure 4, the V-phase AC signal is fixed at the L state voltage (ground voltage) when there is a ground fault. Waveforms W41 and W43 are the same as waveforms W1 and W3 in Figure 2 described above.

[0109] Furthermore, if the signal line of the V-phase AC signal is grounded, the square wave conversion unit 20 generates a V-phase square wave signal that is fixed in the H state (waveform W45) based on the V-phase AC signal (waveform W42). The square wave conversion unit 20 also generates a U-phase square wave signal that falls at times T21 and T25 and rises at time T23 (waveform W44) based on the U-phase AC signal (waveform W41). In addition, the square wave conversion unit 20 generates a W-phase square wave signal that rises at times T22 and T26 and falls at time T24 (waveform W46) based on the W-phase AC signal (waveform W43).

[0110] Next, the interference unit 30 generates a U-phase interference signal (waveform W47) by changing the period during which the W-phase square wave signal (waveform W46) is in the H state of the U-phase square wave signal (waveform W44) to the L state. For example, since the W-phase square wave signal is in the H state from time T23 to time T24, the interference unit 30 converts the H state of the U-phase square wave signal to the L state during this period from time T23 to time T24 to generate a U-phase interference signal.

[0111] Furthermore, the interference unit 30 generates a V-phase interference signal (waveform W48) by changing the period during which the U-phase square wave signal (waveform W44) is in the H state of the V-phase square wave signal (waveform W45) to the L state. Here, since the V-phase square wave signal (waveform W45) is fixed in the H state, the interference unit 30 generates a logical inverted signal of the U-phase square wave signal (waveform W44) as the V-phase interference signal, as shown in waveform W48.

[0112] Furthermore, the interference unit 30 generates a W-phase interference signal (waveform W29) by changing the period during which the V-phase square wave signal (waveform W45) is in the H state of the W-phase square wave signal (waveform W46) to the L state. Here, since the V-phase square wave signal (waveform W45) is fixed in the H state, the interference unit 30 generates a W-phase interference signal that is fixed in the L state, as shown in waveform W49.

[0113] Next, the inverter circuits 41 (41-1 to 41-3) of the smoothing unit 40 logically invert the U-phase interference signal, V-phase interference signal, and W-phase interference signal, respectively, to generate inverted signals (U-phase determination signal, V-phase inversion signal, and W-phase inversion signal) as shown in waveforms W50 to W52. Here, the U-phase determination signal (waveform W50) is a square wave with a high-state ratio of approximately 2:1 (duty cycle of approximately 66%) between the high-state and low-state periods. The V-phase inversion signal (waveform W51) is a square wave with a high-state ratio of approximately 1:1 (duty cycle of approximately 50%) between the high-state and low-state periods. The W-phase determination signal (waveform W52) is fixed in the high-state.

[0114] Next, the smoothing unit 40 outputs smoothed signals (U-phase smoothed signal, V-phase smoothed signal, and W-phase smoothed signal) obtained by integrating the U-phase determination signal (waveform W50), the V-phase inversion signal (waveform W51), and the W-phase inversion signal (waveform W52). The smoothing unit 40 outputs a U-phase smoothed signal with a voltage around (2 / 3VDD), as shown in waveform W53. The smoothing unit 40 also outputs a W-phase smoothed signal with a voltage around (1 / 2VDD), as shown in waveform W54. The smoothing unit 40 also outputs a V-phase smoothed signal with a voltage around VDD, as shown in waveform W55.

[0115] Thus, when one of the three-phase AC signals is grounded, the smoothing unit 40 outputs a smoothing signal with a voltage of approximately VDD to one of the smoothing signals of each phase, and outputs a smoothing signal with a voltage lower than the voltage range VR1 (1 / 2VDD) to the remaining one. In this case, the detection control unit 52 sets the voltage range VR2 of (1 / 2VDD ± 10%) as the second voltage range.

[0116] Next, with reference to Figure 5, the smoothing signal of the phase-to-phase short-circuit state of the abnormality detection device 1 according to this embodiment will be described. Figure 5 is a timing chart showing an example of the operation of the abnormality detection device 1 according to this embodiment when it is in a phase-to-phase short-circuit state.

[0117] In Figure 5, waveforms W61 to W63 show the waveforms of a three-phase AC signal in which the AC signal is short-circuited between the V-phase and W-phase, and from top to bottom they show the U-phase AC signal (voltage at node N1), the V-phase AC signal (voltage at node N2), and the W-phase AC signal (voltage at node N2). Waveforms W64 to W66 show the waveforms of the square wave signals of each phase, which are the output of the square wave conversion unit 20, and from top to bottom they show the U-phase square wave signal (voltage at node N5), the V-phase square wave signal (voltage at node N9), and the W-phase square wave signal (voltage at node N13).

[0118] Waveforms W67 to W69 show the waveforms of the interference signals for each phase, which are the output of the interference unit 30. From top to bottom, they show the U-phase interference signal (voltage at node N6), the V-phase interference signal (voltage at node N10), and the W-phase interference signal (voltage at node N14). Waveforms W70 to W72 show the waveforms of the inverted signals for each phase, which are the output of the inverter circuit 41. From top to bottom, they show the U-phase inverted signal, the V-phase inverted signal, and the W-phase inverted signal.

[0119] Waveforms W73 to W75 show the waveforms of the smoothing signals for each phase, which are the output of the smoothing unit 40. From top to bottom, they show the U-phase smoothing signal (voltage at node N7), the V-phase smoothing signal (voltage at node N11), and the W-phase smoothing signal (voltage at node N15). In each graph, the vertical axis represents voltage, and the horizontal axis represents time.

[0120] As shown in waveforms W62 and W63 of Figure 5, the V-phase AC signal and the W-phase AC signal are short-circuited, resulting in an AC signal that is the inverted version of the U-phase AC signal. Waveform W61 is the same as waveform W1 in Figure 2 described above.

[0121] Furthermore, if the signal line for the V-phase AC signal and the signal line for the W-phase AC signal are short-circuited, the square wave conversion unit 20 generates a U-phase square wave signal (waveform W64) based on the U-phase AC signal (waveform W61) that falls at times T31 and T33 and rises at time T32. Also, the square wave conversion unit 20 generates a V-phase square wave signal (waveform W62) and a W-phase square wave signal (waveform W63), respectively, that rise at times T31 and T33 and fall at time T32 (waveforms W65 and W66).

[0122] Next, the interference unit 30 generates a U-phase interference signal (waveform W67) by changing the period during which the W-phase square wave signal (waveform W66) is in the H state of the U-phase square wave signal (waveform W64) to the L state. Here, the interference unit 30 outputs the U-phase square wave signal as is, as the U-phase interference signal.

[0123] Furthermore, the interference unit 30 generates a V-phase interference signal (waveform W68) by changing the period during which the U-phase square wave signal (waveform W64) is in the H state of the V-phase square wave signal (waveform W65) to the L state. Here, the interference unit 30 outputs the V-phase square wave signal as is, as the V-phase interference signal.

[0124] Furthermore, the interference unit 30 generates a W-phase interference signal (waveform W69) by changing the period during which the V-phase square wave signal (waveform W65) is in the H state of the W-phase square wave signal (waveform W66) to the L state. Here, since the V-phase square wave signal and the W-phase square wave signal are similar signals, the interference unit 30 generates it as a W-phase interference signal fixed in the L state, as shown in waveform W69.

[0125] Next, the inverter circuits 41 (41-1 to 41-3) of the smoothing unit 40 logically invert the U-phase interference signal, V-phase interference signal, and W-phase interference signal, respectively, to generate inverted signals (U-phase determination signal, V-phase inversion signal, and W-phase inversion signal) as shown in waveforms W70 to W72. Here, the U-phase determination signal (waveform W70) and the V-phase inversion signal (waveform W71) are square waves with a ratio of approximately 1:1 (duty cycle of about 50%) between the H state and the L state. The W-phase determination signal (waveform W72) is fixed in the H state.

[0126] Next, the smoothing unit 40 outputs signals (U-phase smoothed signal, V-phase smoothed signal, and W-phase smoothed signal) obtained by integrating the U-phase determination signal (waveform W70), the V-phase inversion signal (waveform W71), and the W-phase inversion signal (waveform W72). The smoothing unit 40 outputs a U-phase smoothed signal with a voltage around (1 / 2VDD), as shown in waveform W73. The smoothing unit 40 also outputs a W-phase smoothed signal with a voltage around (1 / 2VDD), as shown in waveform W74. The smoothing unit 40 also outputs a V-phase smoothed signal with a voltage around VDD, as shown in waveform W75.

[0127] Thus, when two of the three phases of the AC signal are short-circuited, the smoothing unit 40 outputs a smoothing signal with a voltage of approximately VDD to one of the smoothing signals of each phase, and outputs smoothing signals with a voltage lower than the voltage range VR1 (1 / 2VDD) to the remaining two phases. In this case, the detection control unit 52 sets the voltage range VR2 of (1 / 2VDD ± 10%) as the third voltage range.

[0128] Furthermore, even if one of the AC signals in each phase is disconnected, the smoothing unit 40 outputs a smoothed signal similar to the waveforms W73 to W75 shown above, in the case of a short circuit between two phases. In this embodiment, the three-phase neutral point from the generator 2 is floating, and there is no grounding such as earth. Therefore, in the case of a disconnection in one phase, the waveform is the same as in the case of a short-circuit between two phases.

[0129] Next, with reference to Figure 6, the abnormality determination process of the abnormality detection device 1 according to this embodiment will be described. Figure 6 is a flowchart showing an example of the operation of the abnormality determination process of the abnormality detection device 1 according to this embodiment.

[0130] As shown in Figure 6, the detection control unit 52 of the abnormality detection device 1 first acquires the voltage value of the smoothing signal for each phase (step S101). The detection control unit 52 acquires the voltage value of the smoothing signal for each phase detected by the ADC unit 51.

[0131] Next, the detection control unit 52 determines whether the voltage values ​​of all three phases are within the voltage range VR1 (first voltage range) (step S102). Here, the voltage range VR1 is, for example, within the range of (2 / 3VDD ± 10%). If the voltage values ​​of all three phases are within the voltage range VR1, as shown in waveforms W13 to W15 in Figure 2 above (step S102: YES), the detection control unit 52 proceeds to step S103. If at least one of the voltage values ​​of the three phases is not within the voltage range VR1 (step S102: NO), the detection control unit 52 proceeds to step S104.

[0132] In step S103, the detection control unit 52 determines that the three-phase AC signal is normal. After processing in step S103, the detection control unit 52 returns to processing in step S101.

[0133] In step S104, the detection control unit 52 determines whether the voltage value of one phase is greater than or equal to the threshold Vth1 (greater than or equal to the first threshold voltage) and whether the voltage value of the remaining one phase is within the voltage range VR2. Here, the threshold Vth1 is, for example, (VDD-10%). The voltage range VR2 is, for example, within the range of (1 / 2VDD±10%). If the voltage value of one phase is greater than or equal to the threshold Vth1 (greater than or equal to the first threshold voltage) and the voltage value of the remaining one phase is within the voltage range VR2 (step S104:YES), as shown in the waveforms W33 to W35 in Figure 3 (or the waveforms W53 to W55 in Figure 4), the detection control unit 52 proceeds to step S105. If the voltage value of one phase is less than the threshold Vth1, or the voltage value of the remaining one phase is not within the voltage range VR2 (step S104:NO), the detection control unit 52 proceeds to step S106.

[0134] In step S105, the detection control unit 52 determines that a ceiling fault or ground fault has occurred in the three-phase AC signal. After processing in step S104, the detection control unit 52 returns to step S101.

[0135] In step S106, the detection control unit 52 determines whether the voltage value of one phase is greater than or equal to Vth1 (greater than or equal to the second threshold voltage) and whether the voltage values ​​of the remaining two phases are within the voltage range VR2 (within the third voltage range). If the voltage value of one phase is greater than or equal to the threshold Vth1 and the voltage values ​​of the remaining two phases are within the voltage range VR2 (step S106: YES), as shown in waveforms W73 to W75 in Figure 5 above, the detection control unit 52 proceeds to step S107. If the voltage value of one phase is less than the threshold Vth1, or the voltage values ​​of the remaining two phases are not within the voltage range VR2 (step S106: NO), the detection control unit 52 proceeds to step S108.

[0136] In step S107, the detection control unit 52 determines that a wire break or a phase short circuit has occurred. After processing in step S107, the detection control unit 52 returns to step S101.

[0137] In step S108, the detection control unit 52 determines that another abnormality has occurred. After processing in step S108, the detection control unit 52 returns to step S101.

[0138] As described above, the abnormality detection device 1 according to this embodiment comprises a square wave conversion unit 20, an interference unit 30, and a smoothing unit 40. The square wave conversion unit 20 converts the AC signals of each phase of a three-phase AC signal into binarized square wave signals. The interference unit 30 outputs an interference signal obtained by interfering the square wave signal of each phase of the three phases with one square wave signal of a different phase. The smoothing unit 40 generates smoothed signals for each phase by integrating and smoothing the interference signals of each phase output by the interference unit 30.

[0139] As a result, the anomaly detection device 1 according to this embodiment can detect anomalies in the three-phase AC signal by detecting the voltage of the smoothed signal of each smoothed phase. Therefore, the anomaly detection device 1 according to this embodiment can detect anomalies in the three-phase AC signal with a simple configuration without requiring an ADC capable of high-speed sampling or software design that supports high-speed sampling.

[0140] Furthermore, the abnormality detection device 1 according to this embodiment includes a detection control unit 52 that detects abnormalities in the three-phase AC signal based on the voltage values ​​of the smoothed signals of each phase smoothed by the smoothing unit 40. As a result, the abnormality detection device 1 according to this embodiment can appropriately detect abnormalities in a three-phase AC signal from the voltage values ​​of the smoothing signals of each phase with a simple configuration.

[0141] Furthermore, in this embodiment, the detection control unit 52 determines that the three-phase AC signal is normal when the voltage value of the smoothing signal for each phase is within a first voltage range which is the intermediate voltage of the power supply voltage of the smoothing unit 40 (for example, within the voltage range VR1 of (2 / 3VDD ± 10%)). As a result, the abnormality detection device 1 according to this embodiment can appropriately detect whether the three-phase AC signal is normal with a simple configuration.

[0142] Furthermore, in this embodiment, the detection control unit 52 determines that one of the AC signals of each phase is experiencing a ceiling fault or ground fault if one of the voltage values ​​of the smoothed signals of each phase is above a first threshold higher than the voltage range VR1 (for example, above threshold Vth1), and one of the remaining voltage values ​​of the smoothed signals is within a second voltage range lower than the voltage range VR1 (for example, within the voltage range VR2 of (1 / 2VDD ± 10%)). As a result, the abnormality detection device 1 according to this embodiment can appropriately detect when a ceiling fault or ground fault occurs in a three-phase AC signal with a simple configuration.

[0143] Furthermore, in this embodiment, the detection control unit 52 determines that a disconnection abnormality has occurred, where one of the AC signals of each phase is disconnected, or a short-circuit abnormality has occurred, where the remaining two phases are short-circuited, if one of the voltage values ​​of the smoothing signals of each phase is above a second threshold higher than the voltage range VR1 (for example, above threshold Vth1), and the voltage values ​​of the smoothing signals of the remaining two phases are both within a third voltage range lower than the voltage range VR1 (for example, within the voltage range VR2 of (1 / 2VDD ± 10%)). As a result, the abnormality detection device 1 according to this embodiment can appropriately detect when a disconnection or inter-phase short-circuit abnormality occurs in a three-phase AC signal with a simple configuration.

[0144] Furthermore, in this embodiment, the square wave conversion unit 20 converts the AC signals of each phase into square wave signals of each phase obtained by logically inverting the AC signals of each phase. The interference unit 30 comprises a first interference unit (resistor 31-1 and switch unit 32-1), a second interference unit (resistor 31-2 and switch unit 32-2), and a third interference unit (resistor 31-3 and switch unit 32-3). The first interference unit has a switch unit 32-1 (first switch) which is connected between the signal line of the first phase square wave signal (U-phase square wave signal) of the three phases and the ground line (GND terminal), and the signal line of the third phase square wave signal (W-phase square wave signal) is connected to the control terminal (base), and the conduction state is controlled according to the third phase square wave signal, and is interfered with by the third phase square wave signal (W-phase square wave signal). The It outputs a one-phase interference signal (U-phase interference signal). The second interference section has a switch section 32-2 (second switch) which is connected between the signal line of the second phase of the three-phase rectangular wave signal (V-phase rectangular wave signal) and the ground line (GND terminal), and the signal line of the first phase rectangular wave signal (U-phase rectangular wave signal) is connected to the control terminal (base terminal), and the conduction state is controlled according to the first phase rectangular wave signal (U-phase rectangular wave signal), and is interfered with by the first phase rectangular wave signal (U-phase rectangular wave signal). TheIt outputs a two-phase interference signal (V-phase interference signal). The third interference section has a switch section 32-3 (third switch) whose conduction state is controlled according to the second-phase square wave signal (V-phase square wave signal), connected between the signal line of the third-phase square wave signal (W-phase square wave signal) and the ground line (GND terminal), and the signal line of the second-phase square wave signal (V-phase square wave signal) is connected to the control terminal (base terminal), and is interfered with by the second-phase square wave signal (V-phase square wave signal). The The device outputs a three-phase interference signal (W-phase interference signal). The smoothing unit 40 generates smoothed signals for each phase by integrating the logic inverted signals of each phase of the first-phase interference signal (U-phase interference signal), the second-phase interference signal (V-phase interference signal), and the third-phase interference signal (W-phase interference signal).

[0145] As a result, the abnormality detection device 1 according to this embodiment can easily generate interference signals with a simple configuration of switch units 32-1 to 32-3, and can detect abnormalities in three-phase AC signals with an even simpler configuration.

[0146] Furthermore, in this embodiment, the square wave conversion unit 20 has a Zener diode 22 that clamps the AC signal of each phase to a voltage below the input breakdown voltage of the square wave conversion unit 20, and converts the AC signal of each phase, which has been clamped to a voltage below the input breakdown voltage, into a square wave signal for each phase.

[0147] As a result, the abnormality detection device 1 according to this embodiment can easily reduce the voltage to below the input withstand voltage even when the AC voltage value changes significantly depending on the rotational speed, such as in the case of a three-phase AC signal generated by a generator 2, and can therefore safely detect abnormalities in the three-phase AC signal.

[0148] Furthermore, the battery charging device 100 according to this embodiment includes the abnormality detection device 1 described above, a rectifier unit 10, and a control unit 50. The rectifier unit 10 supplies DC power, which is obtained by rectifying the three-phase AC signal, to the battery 3 as charging power by conducting switch elements (thyristors (11, 12)) connected to each signal line of the three-phase AC signal output by the generator 2, in accordance with the rotation of the rotor. The control unit 50 controls the conduction of the switch elements (thyristors (11, 12)) so that the voltage of the DC power output by the rectifier unit 10 becomes a predetermined voltage. The abnormality detection device 1 then detects an abnormality in the three-phase AC signal. As a result, the battery charging device 100 according to this embodiment has the same effect as the abnormality detection device 1 described above, and can detect abnormalities in the three-phase AC signal with a simple configuration.

[0149] Furthermore, the abnormality detection method according to this embodiment includes a square wave conversion step, an interference step, and a smoothing step. In the square wave conversion step, the square wave conversion unit 20 converts the AC signals of each phase of the three-phase AC signal into binarized square wave signals. In the interference step, the interference unit 30 outputs an interference signal obtained by interfering the square wave signal of each phase of the three-phase signal with one square wave signal of another phase different from that phase. In the smoothing step, the smoothing unit 40 generates smoothed signals for each phase by integrating and smoothing the interference signals of each phase output in the interference step. As a result, the abnormality detection method according to this embodiment has the same effect as the abnormality detection device 1 described above, and can detect abnormalities in three-phase AC signals with a simple configuration.

[0150] It should be noted that the present invention is not limited to the embodiments described above, and can be modified without departing from the spirit of the invention. For example, in the above embodiment, an example of using the abnormality detection device 1 in a battery charging device 100 was described, but the invention is not limited to this, and the abnormality detection device 1 may be applied to other devices (other uses).

[0151] Furthermore, although the above embodiment describes an example in which the same threshold Vtjh1 is used for both the first and second thresholds, the invention is not limited to this, and different values ​​may be used for the first and second thresholds.

[0152] Furthermore, although the above embodiment describes an example in which the same voltage range VR2 is used for the second voltage range and the third voltage range, the invention is not limited to this, and different voltage ranges may be used for the second voltage range and the third voltage range.

[0153] Furthermore, although the above embodiment describes an example in which a Zener diode 22 is used in the square wave conversion unit 20, the invention is not limited to this. For example, if the AC voltage of the three-phase AC signal is fixed, the resistively divided three-phase AC signal may be binarized.

[0154] Furthermore, although the above embodiment describes an example in which the abnormality detection device 1 detects abnormalities in a three-phase AC signal, it is not limited to this and may be applied to the detection of abnormalities in four-phase or more AC signals.

[0155] Furthermore, although the above embodiment describes an example in which the abnormality detection device 1 detects abnormalities in a three-phase AC signal, it is not limited to this and may be applied to the detection of abnormalities in four-phase or more AC signals.

[0156] Furthermore, although the above embodiment describes an example in which a perpolar transistor is used in the switch portion 32 of the interference portion 30, it is not limited to this, and other switching elements such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) may be used.

[0157] Furthermore, the aforementioned abnormality detection device 1 and battery charging device 100 have an internal computer system. The processing steps for detecting abnormalities in the three-phase AC signal are stored in program form on a computer-readable recording medium, and the above processing is performed when the computer reads and executes this program. Here, a computer-readable recording medium refers to a magnetic disk, magneto-optical disk, CD-ROM, DVD-ROM, semiconductor memory, etc. Alternatively, this computer program may be distributed to a computer via a communication line, and the computer that receives this distribution may execute the program.

[0158] Furthermore, some or all of the functions of the abnormality detection device 1 and the battery charging device 100 described above may be implemented as integrated circuits such as LSIs (Large Scale Integration). Each of the above functions may be individually implemented as a processor, or some or all of them may be integrated into a single processor. In addition, the method of implementing the integrated circuit is not limited to LSIs; it may also be implemented using dedicated circuits or general-purpose processors. Furthermore, if an integrated circuit technology that can replace LSIs emerges due to advances in semiconductor technology, an integrated circuit using that technology may be used. [Explanation of symbols]

[0159] 1. Anomaly detection device 2 generators 3 Batteries 10 Rectifier 11, 11-1~11-3, 12, 12-1~12-3 Thyristor 13 U-phase driver 14V phase driver 15W phase driver 20 Square wave conversion section 21, 21-1~21-3, 31, 31-1~31-3, 42, 42-1~42-3 Resistors 22, 22-1~22-3 Zener diodes 23, 23-1~23-3, 41, 41-1~41-3 Inverter Circuits 30 Interference section 32, 32-1~32-3 Switch section 40 Smoothing section 43, 43-1~43-3 Capacitors 50 Control Unit 51 ADC section 52 Detection Control Unit 100 Battery Charging Device

Claims

1. A rectangular wave conversion unit converts the AC signals of each phase of a three-phase AC signal into a binarized rectangular wave signal based on whether the AC signals of each phase are above a predetermined threshold, An interference unit outputs an interference signal in which a rectangular wave signal of one other phase different from the current phase is interfered with the rectangular wave signal of each of the three phases, A smoothing unit generates smoothed signals for each phase by integrating and smoothing the interference signals for each phase output by the interference unit, A detection control unit detects an abnormality in the three-phase AC signal based on the voltage value of the smoothed signal of each phase smoothed by the smoothing unit. An anomaly detection device characterized by comprising:

2. The detection control unit determines that the three-phase AC signal is normal if the voltage value of the smoothing signal for each phase is within a predetermined first voltage range. An anomaly detection device according to claim 1.

3. The detection control unit determines that a short circuit to a power line has occurred in one of the AC signals of each phase if one of the voltage values ​​of the smoothing signals of each phase is above a first threshold, which is higher than the first voltage range, and one of the remaining voltage values ​​of the smoothing signals is within a second voltage range, which is lower than the first voltage range. The abnormality detection device according to claim 2.

4. The detection and control unit determines that a disconnection abnormality has occurred, where one of the AC signals of each phase is disconnected, or a short-circuit abnormality has occurred, where the remaining two phases are short-circuited, if one of the voltage values ​​of the smoothing signals of each phase is above a second threshold, which is higher than the first voltage range, and the voltage values ​​of the smoothing signals of the remaining two phases are both within a third voltage range, which is lower than the first voltage range. An anomaly detection device as described in claim 3 or the claim 3.

5. The square wave conversion unit converts the AC signal of each phase into a square wave signal of each phase obtained by logically inverting the logical state of whether or not the AC signal of each phase is above a predetermined threshold, The aforementioned interfering portion is The system includes a first switch connected between the signal line of the first phase of the three-phase rectangular wave signal and the ground line, the signal line of the third phase of the rectangular wave signal connected to a control terminal, and the conduction state of the first switch being controlled according to the third phase rectangular wave signal, and a first interference unit that outputs an interference signal of the first phase that has been interfered with by the third phase rectangular wave signal, A second interference unit has a second switch connected between the signal line of the second phase of the three-phase rectangular wave signal and the ground line, the signal line of the first phase of the rectangular wave signal is connected to a control terminal, and the conduction state is controlled according to the first phase of the rectangular wave signal, and outputs an interference signal of the second phase that is interfered with by the first phase of the rectangular wave signal, A third interference unit is provided, which is connected between the signal line of the third-phase rectangular wave signal and the ground line, the signal line of the second-phase rectangular wave signal is connected to a control terminal, and the conduction state is controlled according to the second-phase rectangular wave signal, and outputs a third-phase interference signal that is interfered with by the second-phase rectangular wave signal. Equipped with, The smoothing section is, The smoothed signals for each phase are generated by integrating and smoothing the logic inverted signals of each phase of the interference signal of the first phase, the interference signal of the second phase, and the interference signal of the third phase. An anomaly detection device according to any one of claims 1 to 4, characterized by the above.

6. The rectangular wave conversion unit has a Zener diode that clamps the AC signal of each phase to a voltage below the input breakdown voltage, which is the breakdown voltage of the input terminal of the rectangular wave conversion unit, and converts the AC signal of each phase, which has been clamped to a voltage below the input breakdown voltage, into the rectangular wave signal of each phase. An anomaly detection device according to any one of claims 1 to 5, characterized in that

7. An abnormality detection device according to any one of claims 1 to 6, A rectifier unit supplies DC power, obtained by rectifying the three-phase AC signal output by the generator, to the battery as charging power, by conducting switch elements connected to each signal line of the three-phase AC signal output by the generator in accordance with the rotation of the rotor. A control unit controls the conduction of the switch element so that the voltage of the DC power output by the rectifier unit becomes a predetermined voltage. Equipped with, The abnormality detection device detects abnormalities in the three-phase AC signal. A battery charging device characterized by the following features.

8. The rectangular wave conversion unit performs a rectangular wave conversion step in which it converts the AC signals of each phase of a three-phase AC signal into a binarized rectangular wave signal based on whether or not the AC signals of each phase are above a predetermined threshold, The interference unit outputs an interference signal in which the rectangular wave signal of each of the three phases is interfered with by one rectangular wave signal of another phase that is different from the current phase. The smoothing unit performs a smoothing step in which it integrates the interference signals of each phase output by the interference step to generate smoothed signals for each phase, A detection control step in which the detection control unit detects an abnormality in the three-phase AC signal based on the voltage value of the smoothed signal of each phase that has been smoothed by the smoothing step. An anomaly detection method characterized by including

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