Discharge detection circuit

Abstract

To detect partial discharge generated in an electronic component at low cost.SOLUTION: A discharge detection circuit comprises first and second booster circuits. The first booster circuit includes: a first capacitative element connected to an input terminal; a first rectifier with which an anode is connected to the first capacitative element and in which first reference voltage is applied to a cathode; a second capacitative element connected to the cathode of the first rectifier; and a second rectifier with which an anode is connected to the second capacitative element and a cathode is connected to the first capacitative element. The second booster circuit includes: a third capacitative element connected to the input terminal; a third rectifier in which second reference voltage is applied to an anode and with which a cathode is connected to the third capacitative element; a fourth capacitative element connected to the anode of the third rectifier; and a fourth rectifier with which an anode is connected to the third capacitative element and a cathode is connected to the fourth capacitative element.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a discharge detection circuit. [Background technology]

[0002] As the recycling-oriented society is promoted, there is an increasing demand for the reuse of electronic parts used in electronic devices. However, until now, manufacturers set the service life of electronic parts and used them within that service life, with no consideration given to the reuse of electronic parts.

[0003] When electronic components are used over a long period of time, the insulators in the electronic components will eventually break down and reach the end of their life. If the remaining life of the insulators can be predicted, the remaining useful life of the electronic components can be estimated, and the electronic components can be reused in other electronic devices within the range of their useful life.

[0004] Before an insulator reaches a dielectric breakdown, a minute discharge called a partial discharge occurs. If the amount of charge released by the partial discharge can be calculated, the remaining life of the insulator can be estimated based on the amount of charge. For example, in Patent Document 1, a discrete Fourier transform is performed on the signal of an electronic component, and partial discharge is detected based on the Fourier coefficients. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. WO2016 / 094344 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technique of Patent Document 1 requires a monitor circuit for acquiring signals from electronic components, and furthermore, the monitor circuit performs a discrete Fourier transform, which increases the circuit cost and makes the technique unrealistic.

[0007] The present invention has been made in view of the above circumstances, and has an object to detect partial discharge occurring in electronic components at low cost. [Means for solving the problem]

[0008] In order to solve the above problem, a discharge detection circuit according to one aspect of the present invention includes an input terminal to which a voltage of an electronic component constituting an electronic device is input, a first boost circuit that outputs a first boosted voltage obtained by boosting the voltage, and a second boost circuit that outputs a second boosted voltage obtained by boosting the voltage, the first boost circuit including a first capacitance element having one end electrically connected to the input terminal, a first rectifying element having an anode electrically connected to the other end of the first capacitance element and having a cathode to which a first reference voltage is applied, a second capacitance element having one end electrically connected to the cathode of the first rectifying element, and a second capacitance element having an anode electrically connected to the other end of the second capacitance element and a cathode to which a first reference voltage is applied. the second boost circuit comprises a third capacitive element having one end electrically connected to the input terminal, a third rectifying element having an anode to which a second reference voltage is applied and a cathode electrically connected to the other end of the third capacitive element, a fourth capacitive element having one end electrically connected to the anode of the third rectifying element, and a fourth rectifying element having an anode electrically connected to the other end of the third capacitive element and a cathode electrically connected to the other end of the fourth capacitive element, the voltage of the cathode being the second boosted voltage. Effect of the Invention

[0009] According to the present invention, partial discharge occurring in electronic components can be detected at low cost.

[0010] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a schematic diagram showing an example of an electronic device that is a target for partial discharge detection in the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the configuration of the discharge detection circuit according to the first embodiment. [Diagram 3] FIG. 3 is an example of a circuit diagram of the DC removal filter and the boost circuit according to the first embodiment. [Figure 4A] FIG. 4A is a timing chart showing an example of a waveform of an input voltage superimposed with a positive pulse voltage caused by partial discharge. [Figure 4B] FIG. 4B is a timing chart showing an example of the waveform of the first boosted voltage when the input voltage shown in FIG. 4A is input. [Figure 5A] FIG. 5A is a timing chart showing an example of a waveform of an input voltage on which a negative pulse voltage caused by partial discharge is superimposed. [Figure 5B] FIG. 5B is a timing chart showing an example of a waveform of the second boosted voltage when the input voltage shown in FIG. 5A is input. [Figure 6] FIG. 6 is an example of a circuit diagram of a boost circuit and a determination circuit according to the second embodiment. [Figure 7] FIG. 7 is an example of a circuit diagram of a boost circuit and a determination circuit according to the third embodiment. [Figure 8] FIG. 8 is an example of a circuit diagram of a boost circuit and a determination circuit according to the fourth embodiment. [Figure 9] FIG. 9 is a schematic diagram illustrating a configuration example of a discharge detection circuit according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings for describing the embodiment, the same members are generally given the same reference numerals, and the repeated description thereof will be omitted as appropriate. In the following embodiment, the components (including element steps, etc.) are not necessarily essential, unless otherwise specified or considered to be obviously essential in principle. In addition, when "consisting of A", "consisting of A", "having A", or "including A" is used, it is understood that other elements are not excluded, except when it is specifically specified that only the element is included. Similarly, in the following embodiment, when referring to the shape, positional relationship, etc. of the components, etc., it includes those that are substantially similar to or similar to the shape, etc., except when it is specifically specified or considered to be obviously not essential in principle.

[0013] First Embodiment FIG. 1 is a schematic diagram showing an example of an electronic device that is a target for partial discharge detection in this embodiment.

[0014] In this example, the electronic device 2 includes a high-voltage DC source 3, a cable 4, and a load 5. The load 5 is, for example, a motor, and is driven by a DC voltage supplied from the high-voltage DC source 3 via the cable 4.

[0015] The cable 4 is an example of an electronic component, and is, for example, a copper wire coated with insulating resin (not shown). Before the insulating resin reaches the end of its life due to dielectric breakdown, pulse-like partial discharges occur repeatedly from the insulating resin. By detecting the partial discharges, it is possible to determine whether the cable 4 has reached the end of its life.

[0016] In this example, a discharge detection circuit 1 for detecting partial discharge is connected to the copper wire of a cable 4, and partial discharge is detected by the discharge detection circuit 1. Note that the object of partial discharge detection is not limited to the cable 4, and partial discharge occurring in, for example, an interlayer insulating layer of a circuit board may be detected.

[0017] 2 is a schematic diagram showing a configuration example of the discharge detection circuit 1 according to this embodiment. The discharge detection circuit 1 is a circuit that receives as an input voltage a pulse-like voltage generated in a detection target such as insulating resin, and includes a DC removal filter 11, a boost circuit 12, an ADC (Analog Digital Converter) 13, and a determination circuit 14.

[0018] The DC removal filter 11 is a high-pass filter that cuts out the DC component from the input voltage.

[0019] The boost circuit 12 is a circuit that boosts an input voltage from which a DC component has been removed, and outputs the boosted voltage.

[0020] The ADC 13 is an analog-to-digital converter that converts the boosted voltage output from the boost circuit 12 into a digital value.

[0021] The determination circuit 14 is a digital circuit that estimates the remaining life of the cable 4 based on the digital value of the boosted voltage.

[0022] FIG. 3 is an example of a circuit diagram of the DC removal filter 11 and the boost circuit 12 according to this embodiment.

[0023] As shown in FIG. 3, the DC removal filter 11 includes a capacitor C H and the resistive element R H The HPF is a high-pass filter (HPF) equipped with a capacitor C H One end of the input voltage V in is applied to the other end, and a resistive element R H is connected. Input voltage V in is the voltage of the electronic components, and in the case of cable 4, is the voltage of the copper wire. When the insulation resin is broken down, a partial discharge occurs as a precursor, and the pulse voltage associated with the partial discharge is equal to the input voltage V in Also, the resistive element R H One end of the H This causes the input voltage V inThe DC component is removed from the input voltage V, which includes the pulse voltage due to partial discharge. in is applied to the input terminal 16 of the boost circuit 12.

[0024] The boost circuit 12 includes a first boost circuit 17, a second boost circuit 18, an intermediate voltage generating circuit 19, and a smoothing circuit 20.

[0025] The first boost circuit 17 is a circuit that boosts a positive pulse voltage, among the pulse voltages applied to the input terminal 16, to a negative first boosted voltage V1. In this example, the first boost circuit 17 includes a first boost block 17a and a second boost block 17b.

[0026] The first booster block 17a includes a first capacitive element C1, a second capacitive element C2, a first rectifying element D1, and a second rectifying element D2.

[0027] One end of the first capacitance element C1 is electrically connected to the input terminal 16, and the other end of the first capacitance element C1 is electrically connected to the anode of the first rectifier element D1. A first reference voltage G1, such as a ground voltage, is applied to the cathode of the first rectifier element D1.

[0028] One end of the second capacitance element C2 is electrically connected to the cathode of the first rectifying element D1, and the other end of the second capacitance element C2 is electrically connected to the anode of the second rectifying element D2. The cathode of the second rectifying element D2 is electrically connected to the other end of the first capacitance element C1.

[0029] The second boost block 17b has a circuit configuration similar to that of the first boost block 17a. However, one end of the first capacitance element C1 in the second boost block 17b is electrically connected to the other end of the first capacitance element C1 in the first boost block 17a. In addition, the cathode of the first rectification element D1 in the second boost block 17b is electrically connected to the anode of the second rectification element D2 in the first boost block 17a.

[0030] According to such a circuit configuration, the first boost circuit 17 performs boosting in units of the boosting blocks 17a and 17b, and the voltage of the anode of the second rectifier element D2 in the final-stage boosting block becomes the first boosted voltage V1.

[0031] Next, the operation of the first boost circuit 17 will be described with reference to FIGS. 4A and 4B.

[0032] FIG. 4A shows an input voltage V in FIG. 4B is a timing chart showing an example of the waveform of the input voltage V in 10 is a timing chart showing an example of a waveform of a first boosted voltage V1 when a first boost voltage V1 is input.

[0033] In general, it is known that the pulse voltage 41 caused by partial discharge has the opposite polarity to the applied voltage, and appears only in either positive or negative polarity. In the example of FIG. 4A, it is assumed that a negative voltage is applied to an electronic component such as a cable 4, and in that case, the positive pulse voltage 41 is the same as the input voltage V in The magnitude of the pulse voltage depends on the voltage applied to the electronic component. For example, when a DC voltage of several kV is applied to the electronic component, the magnitude of the pulse voltage is about several hundred mV. However, the magnitude of the voltage applied to the electronic component is not limited to this, and a voltage of any magnitude may be applied to the electronic component.

[0034] 4A is applied to the input terminal 16, the plate connected to the input terminal 16 of the first capacitance element C1 of the first boost block 17a is momentarily positively charged. As a result, the positive charge of the other plate of the first capacitance element C1 flows through the first rectifier element D1 to the first reference voltage G1 side.

[0035] After that, the plate of the first capacitance element C1 connected to the input terminal 16 immediately returns to a steady voltage, but the movement of positive charges to the other plate is blocked by the first rectifier element D1, so that the other plate becomes negatively charged. Then, in order to return from this negatively charged state to an uncharged state, positive charges move from the plate connected to the anode of the second rectifier element D2 to the first capacitance element C1 via the second rectifier element D2, among both plates of the second capacitance element C2. As a result, the potential at the connection point between the second capacitance element C2 and the second rectifier element D2 becomes negative. This is also propagated to the second boost block 17b, and the first boost voltage V1 also becomes negative.

[0036] Furthermore, as shown in waveform 42 of FIG. 4B, a charge transfer occurs every time a positive pulse voltage 41 occurs, so that the first boosted voltage V1 becomes a negative integrated voltage according to the magnitude and frequency of the positive pulse voltage 41.

[0037] Referring again to Fig. 3, in this example, the first boost circuit 17 is configured with two stages of boost blocks 17a and 17b, but the first boost circuit 17 may be configured with only the first boost block 17a, or may be configured with three or more stages of boost blocks. The first boost voltage V1 can be adjusted by the number of stages of the boost blocks 17a and 17b, and the greater the number of stages, the greater the magnitude of the first boost voltage V1.

[0038] On the other hand, the second boost circuit 18 is a circuit that boosts a negative pulse voltage, among the pulse voltages applied to the input terminal 16, to a positive second boosted voltage V2. In this example, the second boost circuit 18 includes a first boost block 18a and a second boost block 18b.

[0039] The first boosting block 18a includes a third capacitive element C3, a fourth capacitive element C4, a third rectifying element D3, and a fourth rectifying element D4.

[0040] One end of the third capacitance element C3 is electrically connected to the input terminal 16, and the other end of the third capacitance element C3 is electrically connected to the cathode of the third rectifier element D3. A second reference voltage G2, such as a ground voltage, is applied to the anode of the third rectifier element D3.

[0041] One end of the fourth capacitance element C4 is electrically connected to the anode of the third rectifier element D3, and the other end of the fourth capacitance element C4 is electrically connected to the cathode of the fourth rectifier element D4. The anode of the fourth rectifier element D4 is electrically connected to the other end of the third capacitance element C3.

[0042] The second boost block 18b has a circuit configuration similar to that of the first boost block 18a. However, one end of the third capacitive element C3 in the second boost block 18b is electrically connected to the other end of the third capacitive element C3 in the first boost block 18a. In addition, the anode of the third rectifier element D3 in the second boost block 18b is electrically connected to the cathode of the fourth rectifier element D4 in the first boost block 18a.

[0043] According to such a circuit configuration, the second boost circuit 18 performs boosting in units of the boosting blocks 18a and 18b, and the voltage at the cathode of the fourth rectifier element D4 in the final-stage boosting block becomes the second boosted voltage V2.

[0044] Next, the operation of the second boost circuit 18 will be described with reference to FIGS. 5A and 5B.

[0045] FIG. 5A shows an input voltage V in FIG. 5B is a timing chart showing an example of the waveform of the input voltage V in 1 is a timing chart showing an example of the waveform of the second boost voltage V2 when a positive voltage is applied to an electronic component such as a cable 4, and a negative pulse voltage 43 is generated in response to the input voltage V in This assumes that the signal is superimposed on the

[0046] 5A is applied to the input terminal 16, the plate connected to the input terminal 16 of the third capacitance element C3 of the first boost block 18a is momentarily negatively charged. As a result, a positive charge is supplied to the other plate of the third capacitance element C3 from the second reference voltage G2 side via the third rectifier element D3.

[0047] After that, the plate of the third capacitance element C3 connected to the input terminal 16 immediately returns to a steady voltage, but the other plate is prevented from flowing out of positive charge to the second reference voltage G2 side by the third rectifier element D3, so that the other plate becomes positively charged. Then, in order to return from this positively charged state to an uncharged state, a positive charge is transferred from the third capacitance element C3 to the plate connected to the cathode of the fourth rectifier element D4 through the fourth rectifier element D4. As a result, the potential at the connection point between the fourth capacitance element C4 and the fourth rectifier element D4 becomes positive. This is also propagated to the second boost block 18b, and the second boost voltage V2 also becomes positive.

[0048] Furthermore, as shown in waveform 44 in FIG. 5B, a charge transfer occurs every time a negative pulse voltage 43 occurs, so that the second boost voltage V2 becomes a positive integrated voltage according to the magnitude and frequency of the negative pulse voltage 43.

[0049] Referring again to Fig. 3, in this example, the second boost circuit 18 is configured with two stages of boost blocks 18a and 18b, but the second boost circuit 18 may be configured with only the first boost block 18a, or may be configured with three or more stages of boost blocks. The second boost voltage V2 can be adjusted by the number of stages of the boost blocks 18a and 18b, and the greater the number of stages, the greater the magnitude of the second boost voltage V2.

[0050] The capacitance elements C1 to C4 constituting each of the boost circuits 17 and 18 may be capacitors or may be parasitic capacitances occurring in electronic components. An example of parasitic capacitance is capacitance occurring between two copper wires (not shown) running parallel to each other in the cable 4. In addition, when the electronic component is a wiring board, the parasitic capacitance occurring between two wires (not shown) in the wiring board may be used as the capacitance elements C1 to C4.

[0051] Furthermore, in this example, the DC removal filter 11 reduces the input voltage V in Since the DC component has been removed from the input voltage V in The DC component of the input voltage V is not applied to the capacitance elements C1 to C4, and the possibility that the DC component will damage the capacitance elements C1 to C4 can be reduced. in In the case where the withstand voltage of each of the capacitance elements C1 to C4 is sufficiently high compared to that of the capacitance elements C2 to C4, the DC removal filter 11 may be omitted.

[0052] Moreover, the rectifying elements D1 to D4 constituting each of the boost circuits 17 and 18 may be diodes or vacuum tubes.

[0053] The intermediate voltage generating circuit 19 is connected to each of the first boost circuit 17 and the second boost circuit 18, and generates an intermediate voltage V between the first boost voltage V1 and the second boost voltage V2. m As an example, the intermediate voltage generating circuit 19 includes a first resistor element R1 and a second resistor element R2 connected in series. A first boost voltage V1 and a second boost voltage V2 are input to one end of each of the resistor elements R1 and R2. The voltage at a connection point 28 of the resistor elements R1 and R2 is the intermediate voltage V m The intermediate voltage V m The magnitude of can be adjusted by the resistance value of each resistor element R1, R2. In this example, by making the resistance values ​​of each resistor element R1 and R2 the same, V m = (V1+ V2) / 2.

[0054] As shown in Figures 4A and 5A, the pulse voltage caused by partial discharge appears only in either positive or negative polarity, which is opposite to the applied voltage. Therefore, when partial discharge occurs, one of the first boost voltage V1 and the second boost voltage V2 becomes 0V, and the magnitude of the other becomes finite.

[0055] In contrast, the input voltage V in The noise components superimposed on the intermediate voltage V m Therefore, the noise components are cancelled out at the intermediate voltage V m is a value that reflects the frequency and magnitude of partial discharges in electronic components such as cable 4, and its intermediate voltage V m The remaining life of the electronic component can be estimated based on the above.

[0056] In particular, in this example, V m = (V1+ V2) / 2, the intermediate voltage V m When the intermediate voltage V is 0V, it can be determined that no partial discharge is occurring. m When the intermediate voltage V is positive or negative, it can be determined that a partial discharge has occurred. m Since it is the integrated voltage of either positive or negative pulse voltage, the intermediate voltage V m Based on this, the frequency and magnitude of partial discharges can be grasped.

[0057] In this embodiment, an intermediate voltage V m Therefore, a simple circuit configuration can be used to obtain the intermediate voltage V m can be obtained.

[0058] The smoothing circuit 20 outputs an intermediate voltage V m The smoothing circuit 20 is a low-pass filter (LPF) that cuts off high-frequency components so that the band is below the Nyquist frequency of the ADC 13. L and capacitor C L Resistor R L One end of the intermediate voltage V mis applied, and the capacitor C L One end of the resistor is connected to a reference voltage G, such as ground voltage. L According to this, the intermediate voltage V with the AC component cut off is m But resistance R L and capacitor C L Output voltage V out If the band of the ADC 13 (see FIG. 2) is sufficiently wide, the smoothing circuit 20 may be omitted.

[0059] Output voltage V out is converted to a digital value by the ADC 13 (see FIG. 2), and a determination circuit 14 (see FIG. 2) estimates the remaining life of electronic components such as the cable 4 based on the digital value. For example, the determination circuit 14 out by a predetermined coefficient to calculate the cumulative amount of charge discharged by partial discharge. Then, the determination circuit 14 refers to a table (not shown) that shows the relationship between the cumulative amount of charge and the remaining life, which is created in advance for each electronic component, for example, and estimates the remaining life of the electronic component. The determination circuit 14 may display the estimated remaining life on a display (not shown) or the like. This allows the user to check the remaining life of the electronic component, and if the electronic component has not yet reached the end of its life, the electronic component can be reused.

[0060] In addition, the determination circuit 14 determines the output voltage V out The magnitude of |V out When | exceeds a predetermined threshold, it may be determined that the life of an electronic component such as the cable 4 has come to an end. This eliminates the need for the determination circuit 14 to further calculate the accumulated charge amount, thereby reducing the load on the determination circuit 14.

[0061] According to the present embodiment described above, the first boost circuit 17 boosts the positive pulse voltage 41 to output the first boosted voltage V1, and the second boost circuit 18 boosts the negative pulse voltage 43 to output the second boosted voltage V2. Each of the boosted voltages V1 and V2 is a voltage obtained by integrating the frequency and magnitude of partial discharges in electronic components such as the cable 4, and the greater the magnitude of each of the boosted voltages V1 and V2, the closer the insulation of the electronic components will be to dielectric breakdown. For this reason, the determination circuit 14 determines the intermediate voltage V obtained from each of the boosted voltages V1 and V2. m Based on this, the remaining life of the electronic components can be estimated. Moreover, since each of the boost circuits 17 and 18 is composed of only a capacitance element and a rectifier element, it can be manufactured at low cost. As a result, in this embodiment, partial discharge can be detected at low cost.

[0062] <Second embodiment> 6 is an example of a circuit diagram of the boost circuit 12 and the determination circuit 14 according to this embodiment. As shown in FIG. 6, the boost circuit 12 according to this embodiment includes a first boost circuit 17, a second boost circuit 18, a first ADC 31, a second ADC 32, and an arithmetic circuit 33.

[0063] The circuit configurations and operations of the first boost circuit 17 and the second boost circuit 18 are similar to those in the first embodiment.

[0064] The first ADC 31 is an analog-to-digital converter that outputs a first digital value S1 obtained by digitizing the first boosted voltage V1, and the second ADC 32 is an analog-to-digital converter that outputs a second digital value S2 obtained by digitizing the second boosted voltage V2.

[0065] The arithmetic circuit 33 calculates an intermediate voltage V between the first boosted voltage V1 and the second boosted voltage S2 based on the first digital value S1 and the second digital value S2. m Calculate the intermediate voltage V m Output signal S, a digital value indicating out This is a circuit that outputs the intermediate voltage V m is not particularly limited, and may be, for example, V m = (V1+ V2) / 2.

[0066] And the output signal S out Based on this, the determination circuit 14 estimates the remaining life of the electronic components such as the cable 4. As an example, the determination circuit 14 outputs a signal S out The accumulated charge amount discharged by partial discharge is calculated by multiplying by a predetermined coefficient. Then, the determination circuit 14 refers to a table (not shown) indicating the relationship between the accumulated charge amount and the remaining life, which is created in advance for each electronic component as in the first embodiment, and estimates the remaining life of the electronic component.

[0067] According to this embodiment, the arithmetic circuit 33 calculates the intermediate voltage V based on the first digital value S1 and the second digital value S2. m In order to calculate the intermediate voltage V m can be obtained.

[0068] <Third embodiment> 7 is an example of a circuit diagram of the boost circuit 12 and the determination circuit 14 according to this embodiment. As shown in FIG 7, in this embodiment, the intermediate voltage generating circuit 19 and the smoothing circuit 20 in the first embodiment are omitted, and each of the boost circuits 17 and 18 is connected to the determination circuit 14.

[0069] The determination circuit 14 estimates the remaining life of electronic components such as the cable 4 based on the first boosted voltage V1 and the second boosted voltage V2. For example, the determination circuit 14 calculates the cumulative amount of charge discharged by partial discharge by applying a predetermined coefficient to the first boosted voltage V1 or the second boosted voltage V2, whichever voltage deviates more from 0V. The determination circuit 14 then refers to the table (not shown) described in the first embodiment and estimates the remaining life from the amount of charge.

[0070] In addition, for example, the determination circuit 14 determines whether the magnitude |V1| of the first boosted voltage V1 is equal to or smaller than the first threshold voltage V ref_1 or when the magnitude |V2| of the second boost voltage V2 exceeds the second threshold voltage V ref_2In this way, it is possible to determine whether the electronic component has reached the end of its life with a simple circuit configuration that does not use the intermediate voltage generating circuit 19 or the smoothing circuit 20.

[0071] According to this embodiment, the intermediate voltage generation circuit 19 and the smoothing circuit 20 are omitted, and the judgment circuit 14 estimates the remaining life of the electronic component based on each of the boosted voltages V1 and V2, thereby simplifying the circuit configuration of the discharge detection circuit 1 and achieving further cost reduction.

[0072] <Fourth embodiment> 8 is an example of a circuit diagram of the boost circuit 12 and the determination circuit 14 according to this embodiment. As shown in FIG. 8, in this embodiment, the boost circuit 12 is provided with a first comparator 51 and a second comparator 52.

[0073] The first comparator 51 detects the magnitude |V1| of the first boosted voltage V1 and the first threshold voltage V ref_1 A first comparison signal S indicating the result of the comparison with out_1 The first comparison signal S out_1 , |V1|≦V ref_1 When |V1|>V ref_1 This signal is at a high level when

[0074] The second comparator 52 detects the magnitude |V2| of the second boosted voltage V2 and the second threshold voltage V ref_2 A second comparison signal S indicating the result of the comparison with out_2 The second comparison signal S out_2 , |V2|≦V ref_2 When |V2|>V ref_2 This signal is at a high level when

[0075] The decision circuit 14 outputs a first comparison signal S out_1 and the second comparison signal S out_2 Based on the first comparison signal S, the determination circuit 14 determines whether the life of the electronic components such as the cable 4 has expired. out_1 and the second comparison signal S out_2When any one of these signals reaches a high level, it is determined that the electronic component has reached the end of its life.

[0076] According to this embodiment, the determination circuit 14 determines the magnitudes |V1| and |V2| of the boosted voltages and the threshold voltages V ref_1 , V ref_2 Each comparison signal S out_1 , S out_2 Whether the life of the electronic component has expired is determined based on the signal level of the signal . Therefore, it is possible to determine whether the life of the electronic component has expired while simplifying the circuit configuration of the determination circuit 14.

[0077] <Fifth embodiment> 9 is a schematic diagram showing a configuration example of a discharge detection circuit 1 according to this embodiment. In this embodiment, a plurality of discharge detection circuits 1 are used to detect partial discharges in a plurality of electronic components. As an example, in this embodiment, each discharge detection circuit 1 is made up of a DC removal filter 11 and a boost circuit 12, and the ADC 13 and the determination circuit 14 are common to each discharge detection circuit 1. In this case, the ADC 13 and the determination circuit 14 are used to detect the output voltage V out The output voltage V out Based on this, the remaining lives of the electronic components are estimated in a time-division manner.

[0078] This simplifies the circuit configuration compared to a case where each discharge detection circuit 1 is provided with an ADC 13 and a determination circuit 14, and reduces costs.

[0079] Alternatively, the ADC 13 may be provided in each boost circuit 12, and only the determination circuit 14 may be common to each discharge detection circuit 1.

[0080] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0081] The present invention is not limited to the above-described embodiments, and various modifications are included. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the components described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

[0082] In addition, each of the above configurations, functions, processing units, processing means, etc. may be realized in hardware by designing a part or all of them as an integrated circuit, for example. In addition, each of the above configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. Information such as a program, a judgment table, and a file that realizes each function can be placed in a memory, a storage device such as an HDD or SSD, or a recording medium such as an IC (Integrated Circuit) card, an SD (Secure Digital) card, or a DVD (Digital Versatile Disc). In addition, the control lines and information lines are shown as those considered necessary for explanation, and not all control lines and information lines are necessarily shown in the product. In reality, it may be considered that almost all configurations are connected to each other. [Explanation of symbols]

[0083] 1...discharge detection circuit, 2...electronic device, 3...DC high voltage source, 4...cable, 5...load, 11...DC removal filter, 12...boost circuit, 13...ADC, 14...judgment circuit, 16...input terminal, 17...first boost circuit, 17a...first boost block, 17b...second boost block, 18...second boost circuit, 18a...first boost block, 18b...second boost block, 19...intermediate voltage generation circuit, 20...smoothing circuit, 28...connection point, 31...first ADC, 32...second ADC, 33...arithmetic circuit, 41, 43...pulse voltage, 42, 44...waveform, 51...first comparator, 52...second comparator.

Claims

1. an input terminal to which a voltage of an electronic component constituting an electronic device is input, a first boost circuit that outputs a first boosted voltage obtained by boosting the voltage, and a second boost circuit that outputs a second boosted voltage obtained by boosting the voltage, The first boost circuit includes: a first capacitance element having one end electrically connected to the input terminal; a first rectifying element having an anode electrically connected to the other end of the first capacitive element and a cathode to which a first reference voltage is applied; a second capacitive element, one end of which is electrically connected to the cathode of the first rectifying element; a second rectifier element having an anode electrically connected to the other end of the second capacitive element and a cathode electrically connected to the other end of the first capacitive element, such that a voltage of the anode becomes the first boosted voltage; The second boost circuit includes: a third capacitive element having one end electrically connected to the input terminal; a third rectifying element having an anode to which a second reference voltage is applied and a cathode electrically connected to the other end of the third capacitive element; a fourth capacitive element, one end of which is electrically connected to the anode of the third rectifying element; a fourth rectifier element having an anode electrically connected to the other end of the third capacitive element and a cathode electrically connected to the other end of the fourth capacitive element, the voltage of the cathode being the second boosted voltage; Discharge detection circuit.

2. 2. The discharge detection circuit according to claim 1, an intermediate voltage generating circuit connected to each of the first boost circuit and the second boost circuit, for outputting an intermediate voltage between the first boosted voltage and the second boosted voltage as an output voltage; Discharge detection circuit.

3. 3. The discharge detection circuit according to claim 2, The intermediate voltage generating circuit includes: a first resistor element having one end to which the first boosted voltage is input; a second resistor element having one end to which the second boosted voltage is input and the other end electrically connected to the other end of the first resistor element; the intermediate voltage is a voltage at a connection point between the first resistive element and the second resistive element; Discharge detection circuit.

4. 3. The discharge detection circuit according to claim 2, a determination circuit for estimating a remaining life of the electronic component based on the output voltage; Discharge detection circuit.

5. 2. The discharge detection circuit according to claim 1, a first analog-to-digital converter that outputs a first digital value obtained by digitizing the first boosted voltage; a second analog-to-digital converter that outputs a second digital value obtained by digitizing the second boosted voltage; a calculation circuit that calculates an intermediate voltage between the first boosted voltage and the second boosted voltage based on the first digital value and the second digital value, and outputs an output signal indicating the intermediate voltage. Discharge detection circuit.

6. 2. The discharge detection circuit according to claim 1, a determination circuit for estimating a remaining life of the electronic component based on the first boosted voltage and the second boosted voltage. Discharge detection circuit.

7. 7. The discharge detection circuit according to claim 6, the determination circuit determines that the electronic component has reached the end of its life when the magnitude of the first boosted voltage exceeds a first threshold voltage or when the magnitude of the second boosted voltage exceeds a second threshold voltage. Discharge detection circuit.

8. 8. The discharge detection circuit according to claim 7, a first comparator that outputs a first comparison signal indicating a result of comparing the magnitude of the first boosted voltage with a first threshold voltage; a second comparator that outputs a second comparison signal indicating a result of comparing the magnitude of the second boosted voltage with a second threshold voltage, the determination circuit determines whether the electronic component has reached the end of its life based on the first comparison signal and the second comparison signal. Discharge detection circuit.

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