JP4812368B2 - Charger with life diagnosis function for power capacitors - Google Patents

Description

  The present invention relates to a charging device with a life diagnosis function of a power capacitor for diagnosing the arrival of the life of a power capacitor in a device that repeatedly charges a power capacitor provided in a DC power source or the like incorporated in a device to a target voltage. is there.

Conventionally, an electrolytic capacitor is generally used as a power capacitor for a main circuit that requires a large capacity in a switching power supply device, an inverter device, or the like. Electrolytic capacitors have the characteristic that the capacity decreases and the loss increases as the usage time increases because an electrochemical reaction takes place inside. For this reason, the lifetime of the electrolytic capacitor is specified. Furthermore, this lifetime is affected by the operating temperature environment, and when used in a high temperature environment, the lifetime is further shortened.
Electrolytic capacitors that have reached the end of their life are subject to phenomena such as loss of capacity, increased loss, increased leakage current, and the like, but it is difficult to judge their deterioration from the appearance. For this reason, various devices have been proposed for diagnosing a capacity loss of an electrolytic capacitor.

  Patent Document 1 includes a first switch connected in series to a high potential side of a battery, a parallel connection of a second switch and a resistor, a parallel circuit connected in series to the first switch, a parallel circuit, and a battery. Of the power capacitor connected between the low potential side of the power capacitor and the power capacitor when the second switch is turned off and the first switch is turned on, and the power capacitor is charged from the battery via the resistor. The voltage detector that detects the voltage and the charging time until the voltage of the power capacitor detected by the voltage detector reaches a predetermined voltage is measured. And a diagnostic device that determines the deterioration of the power capacitor based on a comparison with a reference time until it reaches.

  Patent Document 2 discloses a post-use voltage drop for measuring a post-use voltage drop time during which a DC discharge voltage drops to a predetermined voltage level from a discharge characteristic curve after stopping power supply application of a power capacitor measured by a voltage detection circuit. A waveform comparison circuit that compares the time measurement function with the discharge characteristic curve at the beginning of operation and the discharge characteristic curve after use and calculates the time difference between the initial voltage drop time and the voltage drop time after use, and this waveform comparison circuit. And a determination device that determines that the power capacitor has a life when the calculated time difference exceeds a predetermined allowable value.

  Patent Document 3 discloses a discharging unit that discharges the electric charge of the electrolytic capacitor when the inverter main circuit is powered off, a voltage detecting unit that detects a terminal voltage of the electrolytic capacitor, and a storage unit that stores a preset life detection voltage level. The life in which the detection voltage is stored in the storage means when the preset reference time has elapsed after the detection voltage by the voltage detection means has dropped to the preset first voltage after the power supply of the inverter main circuit is shut off And a life detection means for outputting a life detection signal when the voltage is not more than the detection voltage level.

  Patent Document 4 samples a voltage detection unit that detects a terminal voltage of a power capacitor and a terminal voltage of the power capacitor that is detected by the voltage detection unit after the application of power supply voltage is stopped. From each sampling voltage and a sampling interval, Obtain the time constant, calculate the capacity of the power capacitor from this time constant and the known resistance value, compare this capacity with a predetermined capacity, determine the capacity loss, and based on this determination And a CPU for diagnosing the arrival of the lifetime.

  Patent Document 5 is composed of a rectifier circuit that rectifies an AC power supply, an input smoothing capacitor, and a capacitor built-in device having a switching circuit, and a capacitor life diagnosis device that determines whether the input smoothing capacitor has lost capacity. The capacitor life diagnosis device includes a switch for turning off the rectified output of the rectifier circuit. The capacitor life diagnosis device detects that the voltage across the input smoothing capacitor has dropped to the reference voltage, and the voltage across the input smoothing capacitor from the switch off. And a CPU for determining whether the time until the voltage drops to the reference voltage is a certain time or more.

JP-A-5-215800 Japanese Patent Laid-Open No. 7-92212 JP-A-8-80055 Japanese Patent Laid-Open No. 11-231008 JP 2002-281735 A

Since the conventional charging device with a life diagnosis function for a power capacitor is configured as described above, the devices of Patent Document 2 to Patent Document 5 sample the voltage at the time of discharging the power capacitor after the power supply is stopped. Is compared with a predetermined discharge characteristic curve or a predetermined capacity to determine the end of the life of the power capacitor.
All of these devices measure the discharge characteristics of the power capacitor after the application of power is stopped. Therefore, if the power of the CPU drops after the application of power is stopped and the measurement continues until the CPU reset voltage is reached, the CPU itself Since the reset voltage cannot be predicted, the CPU internal registers and data cannot be saved immediately before the voltage drops to the reset voltage, the reset voltage is reached in the middle of measurement, the measurement is interrupted, There is a problem that data is lost. For this reason, there is a problem that it is necessary to back up the power supply of the life diagnosis function constituted by a CPU or the like with a power supply of another system.

  Further, the apparatus of Patent Document 1 employs a technique for forcibly applying a voltage to a power capacitor to determine deterioration of the power capacitor. For this reason, an extra circuit such as a parallel connection of the second switch and the resistor is required, and there is a problem that the configuration becomes complicated and the existing circuit cannot be used as it is.

  The present invention has been made to solve the above-described problems. By diagnosing the life of the power capacitor by measuring the charging characteristics of the power capacitor after voltage application, the backup power source, the second switch, An object of the present invention is to obtain a charging device with a life diagnosis function for a power capacitor having a simple configuration without requiring an extra circuit such as parallel connection of resistors.

The charging device with a life diagnosis function for a power capacitor according to the present invention includes a preset relationship between a charging time and a charging voltage of the power capacitor, and a measured charging time and a measured charging voltage from the start of charging of the power capacitor. compares, by the charging voltage and charging time becomes checkpoint capacity leakage of power capacitors by detecting whether leads to which area of the area to be subdivided into multiple locations, the equivalent series resistance of increase large, the leakage current It is provided with a power capacitor life diagnosis circuit for diagnosing the life by detecting that the increase exceeds a specified value and notifying the diagnosis result.

According to the present invention, the relationship between the charging time and charging voltage of the power capacitor set in advance and the measured charging time and measured charging voltage from the start of charging of the power capacitor are compared , and the charging voltage serving as a checkpoint detecting that the capacity leakage of power capacitors by detecting whether leads to which area of the region is subdivided into a plurality of locations, the equivalent series resistance of increase large, an increase in leakage current exceeds the specified value by the charge time Because the life is diagnosed by doing so, it does not require the backup power supply that was necessary when diagnosing the life from the measurement of the discharge characteristics of the power capacitor as in the background technology, and as in the background technology, There is an effect that a second switch for forcibly applying a voltage and a parallel connection of resistors do not require an extra circuit and can be simply configured.

Embodiment 1 FIG.
FIG. 1 shows a charging device with a life diagnosis function for a power capacitor according to Embodiment 1 of the present invention. In FIG. 1, a power capacitor charging circuit 1 is a circuit for charging a power capacitor 10 and is charged with a power capacitor. The control circuit 11 is a circuit that controls the power capacitor charging circuit 1, and the power capacitor life diagnosis circuit 21 is a circuit that diagnoses the life of the power capacitor 10 and notifies the diagnosis result.

In the power capacitor charging circuit 1, the power supply circuit 3 is connected to the AC power supply line 2, and rectifies and smoothes the AC power supplied when the power is turned on to generate a DC power supply.
The first semiconductor switch (semiconductor switch) 4 is connected to the high potential line on the output side of the power supply circuit 3. The first diode 5 and the resistor 6 connected in series to the anode of the first diode 5 are connected in reverse polarity between the high potential line and the low potential line on the output side of the first semiconductor switch 4, and the resistor 6 Is to detect a charging current charged in the power capacitor 10 as a voltage signal when the first and second semiconductor switches 4 and 8 are turned off. The reactor 7 is connected to the high potential line on the output side of the first diode 5. The second semiconductor switch (semiconductor switch) 8 is connected between the high potential line and the low potential line on the output side of the reactor 7, and the second diode 9 is the high potential line on the output side of the second semiconductor switch 8. Are connected to the forward polarity. The power capacitor 10 is connected between the high potential line and the low potential line on the output side of the second diode 9 and is repeatedly charged.

  In the power capacitor charging control circuit 11, the reference current setting unit 12 sets a reference charging current for charging the power capacitor 10 when the first and second semiconductor switches 4 and 8 are turned off. The constant current control error amplifying circuit 13 compares a set voltage corresponding to the reference charging current set in the reference current setting unit 12 with a voltage signal corresponding to the charging current by the resistor 6, and the voltage signal is equal to or lower than the set voltage. In this case, a signal is output. The triangular wave generation circuit 14 generates a triangular wave, the comparison circuit 15 inputs the triangular wave from the triangular wave generation circuit 14 from the + terminal, and inputs the signal output from the constant current control error amplification circuit 13 from the − terminal. A control pulse corresponding to the comparison of both waveforms is generated.

  In the power capacitor life diagnosis circuit 21, the control circuit power supply circuit 22 is connected to the AC power supply line 2, converts the AC power supplied in response to power-on to a DC power supply, and the power capacitor charging control circuit 11 and The DC power supply is supplied to each circuit of the power capacitor life diagnosis circuit 21. The timer circuit 23 generates a reference clock necessary for measuring the charging time of the power capacitor 10. The charging time charging voltage storage unit 24 is configured to store the characteristics (relationships) of the charging time and charging voltage of the power capacitor 10 and the life diagnosis result corresponding to these characteristics in advance.

  The life diagnosis determination unit 25 uses the charging voltage detection line (charging voltage detection circuit) connected to the high potential line of the power capacitor 10 to detect the charging voltage of the power capacitor 10 as a charge start (trigger), and starts the timer circuit 23. The charging time from the start of charging by the reference clock generated from the charging capacitor 10 is measured, the charging voltage of the power capacitor 10 by the charging voltage detection line is measured, and the power capacitor 10 stored in the charging time charging voltage storage unit 24 is measured. Characteristics of the power capacitor 10, the life diagnosis result according to the characteristics, and the comparison of the measured charging time and measured charging voltage from the start of charging of the power capacitor 10, The life diagnosis result is extracted from the charging time charging voltage storage unit 24 and generated. The display alarm unit 26 notifies the user of the life diagnosis result by lamp display, alarm buzzer or alarm contact output.

Next, the operation will be described.
In FIG. 1, when AC power is turned on, the power supply circuit 3 rectifies and smoothes the AC power supplied in response to power-on, and generates DC power. When the AC power source is turned on, the control circuit power source circuit 22 converts the supplied AC power source into a DC power source, and the power source capacitor charging control circuit 11 and the power capacitor life diagnosis circuit 21 are connected to each circuit. Supply DC power.

  In the power capacitor charging control circuit 11, a reference charging current for charging the power capacitor 10 when the first and second semiconductor switches 4 and 8 are turned off is set in the reference current setting unit 12 in advance. A setting voltage (1) corresponding to the set reference charging current is generated from the setting unit 12. The constant current control error amplifying circuit 13 compares the set voltage (1) corresponding to the reference charging current set in the reference current setting unit 12 with the voltage signal (2) corresponding to the charging current by the resistor 6, When the voltage signal exceeds the set voltage, no signal is output, and when the voltage signal is equal to or lower than the set voltage, a signal is output (3). This signal output (3) increases in height over time, and finally becomes constant in height.

  The comparison circuit 15 compares the triangular wave (8) from the triangular wave generation circuit 14 with the signal output (3) from the constant current control error amplifying circuit 13, and a control pulse (9) corresponding to a period in which the triangular wave is equal to or longer than the signal output. ). The control pulse (9) has a wide pulse width when the power is turned on, narrows with time, and finally has a constant width. Based on the control pulse (9), the operation of the first and second semiconductor switches 4 and 8 is controlled. That is, the first and second semiconductor switches 4 and 8 are turned on when the control pulse is at a high level, and are turned off when the control pulse is at a low level.

In the power capacitor charging circuit 1, when the first and second semiconductor switches 4 and 8 are turned on, a current flows from the power supply circuit 3 through the path of the first semiconductor switch 4 → the reactor 7 → the second semiconductor switch 8. Thus, electromagnetic energy is accumulated in the reactor 7.
In addition, the electromagnetic energy accumulated in the reactor 7 is changed from the reactor 7 → the second diode 9 → the power capacitor 10 → the resistor 6 → the first diode 5 by the off operation of the first and second semiconductor switches 4 and 8. The power capacitor 10 is charged by circulating through the path.
At this time, by the constant current control by the reference current setting unit 12 and the constant current control error amplifier circuit 13, the ON time width of the first and second semiconductor switches 4 and 8 is long when the power is turned on, and the ON time width is gradually turned on over time. A control pulse (9) is generated in which the time width is shortened and finally becomes constant. With this control pulse having a constant on-time width, the charging current of the power capacitor 10 can be made the reference charging current.

  In the power capacitor life diagnosis circuit 21, the life diagnosis determination unit 25 uses the reference clock (10) generated from the timer circuit 23 as a trigger when charging starts based on detection of the charging voltage (5) of the power capacitor 10. The charging time from the start is measured, and the charging voltage of the power capacitor 10 is measured. In addition, the charging time charging voltage storage unit 24 stores in advance the characteristics of the charging time and charging voltage of the power capacitor 10 and the life diagnosis result corresponding to these characteristics.

  FIG. 2 is a circuit diagram showing an equivalent circuit of the power capacitor. In the figure, the power capacitor 10 is not generally composed of only the capacitive component 10a, but in addition to the capacitive component 10a, an equivalent series resistance (ESR) is shown. : Equivalent Series Resistance) 10b exists. Therefore, the power capacitor 10 is equivalent to that shown in FIG.

  In the failure and deterioration of the power capacitor 10, first, the increase in the dielectric loss tangent tan δ appears more significantly than the change in capacitance. That is, when the degradation of the power capacitor 10 is an increase in the dielectric loss tangent tan δ, it is considered that the equivalent series resistance 10b is increased. For this reason, when the equivalent series resistance 10b of the power capacitor 10 increases, it takes time to charge the power capacitor 10. Similarly, when the leakage current increases, it takes time to charge the power capacitor 10. When the capacity of the power capacitor 10 decreases (so-called capacity loss), the charging of the power capacitor 10 is completed quickly.

FIG. 3 is a characteristic diagram showing characteristics of the charging time and charging voltage of the power capacitor, and is an image of data set and stored in the charging time charging voltage storage unit 24 in advance.
In the figure, the horizontal axis represents the charging time of the power capacitor 10, and the vertical axis represents the charging voltage of the power capacitor 10. The charging voltages V1, V2, V3, and V4 on the vertical axis are checkpoint charging voltages necessary for the life diagnosis of the power capacitor 10. For example, in a vacuum circuit breaker, V1 is an operation limit voltage and V2 is a cutoff limit. Voltage, V3 defines a charging threshold voltage, and V4 defines a charging regulation voltage and the like. The charging times T1, T2, and T3 on the horizontal axis are charging time target values corresponding to the charging voltages V1, V2, V3, and V4 on the vertical axis.

Further, when reaching the region A, it is normal, when reaching the region B, the capacity is lost, when reaching the region C, the equivalent series resistance 10b is increased, and when reaching the region D, the equivalent series resistance 10b is extremely increased or leaked. When the current reaches the region E, the equivalent series resistance 10b and the leakage current are extremely increased. When the region F is reached, the deterioration is remarkable and the state cannot be used.
The data set and stored in the charging time charging voltage storage unit 24 in advance is not a characteristic diagram as shown in FIG. 3, but charging voltages V1, V2, and V2 at checkpoints necessary for life diagnosis of the power capacitor 10. Only V3, V4, charging time T1, T2, T3 and the life diagnosis result are sufficient.

In the life diagnosis determination unit 25, the measured charging time and the measured charging voltage measured in accordance with the start of charging of the power capacitor 10 are the checkpoint charging voltages V1, V2, V3 stored in the charging time charging voltage storage unit 24. Compared with V4 and charging time T1, T2, T3, the life diagnosis result (11) of the power capacitor 10 is extracted from the charging time charging voltage storage unit 24 and generated.
That is, it is determined to which region in FIG. 3 the transition of the increase in the charging voltage of the power capacitor 10 corresponding to the transition of the charging time from the start of charging of the power capacitor 10 corresponds.

In FIG. 3, more specifically,
(Area A) When the charging voltage V3 is reached within the charging time T1 to T2 from the start of charging, the power capacitor 10 obtains a normal life diagnosis result.
(Area B) When the charging voltage V3 is reached within the charging time T1 from the start of charging, the battery is charged earlier than the normal area, and the life of the capacitor 10 is assumed to have lost its capacity. Obtain diagnostic results.
(Area C) When the charging voltage V3 is reached within the charging time T2 to T3 from the start of charging, the life diagnosis that the equivalent series resistance 10b is increased because the charging has not ended within a predetermined time. Get results.
(Area D) Obtaining a life diagnosis result that the equivalent series resistance 10b is extremely increased or the leakage current is increased when the charging voltage is V2 to V3 even after the charging time T3 from the start of charging. .
(Area E) A life diagnosis result is obtained that the equivalent series resistance 10b and the leakage current are extremely increased when the charging voltage is V1 to V2 even when the charging time T3 comes from the start of charging.
(Area F) When the charging voltage is less than V1 even after the charging time T3 from the start of charging, a life diagnosis result indicating that the power capacitor 10 is in a state where it cannot be used due to significant deterioration of the power capacitor 10 is obtained.

  The display alarm unit 26 notifies the user of the life diagnosis result divided from the region A to the region F by the life diagnosis determination unit 25 by a lamp display, an alarm buzzer, or an alarm contact output.

As described above, according to the first embodiment, the life diagnosis determination unit 25 determines the characteristics of the charging time and charging voltage of the power capacitor 10 preset in the charging time charging voltage storage unit 24 and the characteristics. Since the lifetime of the power capacitor 10 is diagnosed based on the comparison of the corresponding life diagnosis result with the measured charging time and measured charging voltage from the start of charging of the power capacitor 10, the measurement of the discharge characteristics of the power capacitor 10 is performed. No need for a backup power supply, which is necessary when diagnosing the life from the power supply, and no need for extra circuits such as a parallel connection of a second switch and a resistor for forcibly applying a voltage. Can be configured.
Further, since the charging current charged in the power capacitor 10 is set to a preset reference charging current, the linearity of the relationship between the measured charging time and the measured charging voltage from the start of charging of the power capacitor 10 is further improved. Further, the linearity of the relationship between the charging time and the charging voltage of the power capacitor 10 preset in the charging time charging voltage storage unit 24 can be further improved, and as a result, the life diagnosis performance of the power capacitor 10 can be further improved. .

Embodiment 2. FIG.
FIG. 4 shows a charging device with a life diagnosis function for a power capacitor according to Embodiment 2 of the present invention. In the power capacitor charging control circuit 11, the target voltage setting unit 16 sets a target charging voltage for charging the power capacitor 10. Is set. The charge voltage control error amplifying circuit 17 uses the target charge voltage set in the target voltage setting unit 16 and the power from the charge voltage detection line (charge voltage detection circuit) connected to the high potential line of the power capacitor 10. Compared with the charging voltage of the capacitor 10, a signal is output when the charging voltage is equal to or higher than the target charging voltage, and the signal output is stopped when the charging voltage is lower than the target charging voltage. The OR circuit 18 takes the sum of the signal output from the constant current control error amplifying circuit 13 and the signal output from the charging voltage control error amplifying circuit 17 and outputs the sum to the-terminal of the comparison circuit 15. It is.

  In the power capacitor life diagnosis circuit 21, the life diagnosis determination unit 25 is based on the charging voltage of the power capacitor 10 by the charging voltage detection line (charging voltage detection circuit) connected to the high potential line of the power capacitor 10. The constant current control by the constant current control error amplifying circuit 13 is selected in the initial stage of charging, and the target charging voltage control by the charging voltage control error amplifying circuit 17 is selected in the charging completion stage. Other configurations are the same as those in FIG.

Next, the operation will be described.
In the power capacitor life diagnosis circuit 21, the life diagnosis determination unit 25 sends a selection signal (12) to the constant current control error amplification circuit 13 in the initial stage of charging based on the charging voltage (5) of the power capacitor 10. The constant current control by the constant current control error amplification circuit 13 is selected.

  In the power capacitor charging control circuit 11, an OR circuit as shown in the first embodiment has a configuration including the resistor (charging current detection circuit) 6, the reference current setting unit 12, and the constant current control error amplification circuit 13. From the comparison circuit 15 through 18, a control pulse (the ON time width of the first and second semiconductor switches 4, 8 is long when the power is turned on and gradually decreases with time and becomes constant at the end. 9) can be generated, and the charging current of the power capacitor 10 can be made the reference charging current by the control pulse having a constant on-time width.

  Further, in the power capacitor life diagnosis circuit 21, the life diagnosis determination unit 25 determines the charge completion stage (for example, the measured charge voltage (5) is charged in FIG. 3 based on the charge voltage (5) of the power capacitor 10. When the voltage V3 is reached and the life diagnosis result is obtained), a selection signal (13) is output to the charge voltage control error amplification circuit 17, and the charge voltage of the power capacitor 10 by the charge voltage control error amplification circuit 17 is output. Select the control so that becomes the target charging voltage.

  In the power capacitor charging control circuit 11, a target charging voltage of the power capacitor 10 is preset in the target voltage setting unit 16, and the set target charging voltage (4) is generated from the target voltage setting unit 16. Is done. The charge voltage control error amplifying circuit 17 includes the target charge voltage (4) set in the target voltage setting unit 16 and the power capacitor 10 from the charge voltage detection line connected to the high potential line of the power capacitor 10. Compared with the charging voltage (5), no signal is output while the charging voltage does not reach the target charging voltage, and a signal is output (6) when the charging voltage reaches the target charging voltage. The comparison circuit 15 compares the triangular wave (8) from the triangular wave generation circuit 14 with the signal output (7) from the charge voltage control error amplification circuit 17 through the OR circuit 18, and according to a period when the triangular wave is longer than the signal output. Control pulse (9) is generated.

  The control pulse is stopped when the charging voltage of the power capacitor 10 reaches a preset target charging voltage. By controlling the operation of the first and second semiconductor switches 4 and 8 based on the control pulse (9), the first charging voltage when the charging voltage of the power capacitor 10 reaches a preset target charging voltage is set. In addition, the operation of the second semiconductor switches 4 and 8 can be stopped, and the charging voltage of the power capacitor 10 can be matched with the target charging voltage.

As described above, according to the second embodiment, the charging current charged in the power capacitor 10 is set in advance until the initial stage of charging, that is, until the life diagnosis result of the power capacitor 10 is obtained. Therefore, the linearity of the relationship between the measured charging time and the measured charging voltage from the start of charging of the power capacitor 10 is further increased, and the power capacitor preset in the charging time charging voltage storage unit 24 is used. The linearity of the relationship between the charging time and the charging voltage of 10 can be further increased, and as a result, the diagnostic performance of the life of the power capacitor 10 can be further improved.
Further, at the stage of completion of charging, the charging voltage of the power capacitor 10 can be matched with a preset target charging voltage.

Embodiment 3 FIG.
FIG. 5 shows a charging device with a life diagnosis function for a power capacitor according to a third embodiment of the present invention. In the power capacitor life diagnosis circuit 21, the start switch 27 is turned on in conjunction with the complete discharge of the power capacitor 10. It operates and outputs a rediagnosis signal to the life diagnosis determination unit 25. Other configurations are the same as those in FIG.

Next, the operation will be described.
In the power capacitor life diagnosis circuit 21, the start switch 27 switches the charging device with a power capacitor life diagnosis function according to the third embodiment into, for example, a vacuum circuit breaker used for short circuit protection and switching of the high voltage circuit. When used as a power supply device for driving a coil or a breaker coil, if a closing coil or a breaker coil is used, the power capacitor 10 is discharged and the charging voltage becomes 0 V. Therefore, the power capacitor 10 is charged again. Need arises.

  At this time, the life diagnosis determination unit 25 is re-diagnosed by turning on the start switch 27 by a signal linked to the completion of the discharge of the power capacitor 10, such as a signal at the time of driving the closing coil or the breaking coil of the vacuum circuit breaker. Output a signal. In response to the input of the re-diagnosis signal, the life diagnosis determination unit 25 has characteristics of the charging time and charging voltage of the power capacitor 10 preset in the charging time charging voltage storage unit 24, and a life diagnosis according to these characteristics. The life of the power capacitor 10 is re-diagnosed based on a comparison between the result and the measured charging time and measured charging voltage from the start of charging of the power capacitor 10. In addition, the display alarm unit 26 notifies the life diagnosis result by the life diagnosis determination unit 25.

  As described above, according to the third embodiment, the life diagnosis determination unit 25 determines whether the power capacitor 10 is in response to the rediagnosis signal from the start switch 27 that is turned on in conjunction with the complete discharge of the power capacitor 10. The life is re-diagnosed, and the display alarm unit 26 can notify the life diagnosis result by the life diagnosis determination unit 25.

  The start switch 27 in the third embodiment may be applied to the charging device with the life diagnosis function of the power capacitor according to the second embodiment, and the start switch 27 is limited to a mechanical contact. A semiconductor switch may be used instead.

  In the first to third embodiments, when the AC power supply line 2 is a DC power supply line, the power supply circuit 3 and the control circuit power supply circuit 22 are not required or are configured by a DC / DC converter. Just do it.

  Further, in FIG. 3, the life diagnosis result of the power capacitor 10 is divided into six regions A to F, but is not limited to these six regions, and may be divided into regions as necessary. .

  Further, the life diagnosis determination unit 25 may determine the charging time based on the charging time when the charging voltage reaches the target voltage or the value of the charging voltage that reaches the predetermined charging time. The data stored in the unit 24 and the configuration of the life diagnosis determination unit 25 can be simplified.

  Further, the charging voltages V1 to V4 and the charging times T1 to T3 stored in the charging time charging voltage storage unit 24 may be fixed values, but are provided with setting means that can be easily set to various devices and various ratings. It may be possible to set the charging voltage and charging time.

  Further, in the charging device with the life diagnosis function of the power capacitor in the first to third embodiments, the first and second semiconductor switches 4 and 8 are simultaneously turned on / off. As shown in Japanese Patent No. 218743, the DC power is applied to the reactor during the ON period of the first and second semiconductor switches, electromagnetic energy is accumulated in the reactor, and the reactor is turned off by turning off the second semiconductor switch. If the AC power supply is configured to circulate through the rectifier, smoothing capacitor, reactor, diode, and power capacitor path in addition to the electromagnetic energy stored in the The power capacitor can be charged including energy.

  Furthermore, the reference current setting unit 12 and the target voltage setting unit 16 use a variable resistor, a digital switch, or the like, so that the reference charging current and the target charging voltage for charging the power capacitor 10 can be seen by the operator and can be operated. Can be made into various forms. Further, when the reference charging current and the target charging voltage are determined in advance by the charging device, they may be fixed.

  Further, similarly, the charging time charging voltage storage unit 24 can also be configured to use a variable resistor, a digital switch, or the like so that the set charging voltage and charging time are visible to the operator and can be operated. . Further, when the charging voltage or charging time is determined in advance by the charging device, it may be fixed.

1 is a charging device with a life diagnosis function for a power capacitor according to Embodiment 1 of the present invention; It is a circuit diagram which shows the equivalent circuit of the capacitor | condenser for electric power. It is a characteristic view which shows the characteristic of charge time and charge voltage of a capacitor for electric power. It is a charging device with the lifetime diagnosis function of the capacitor | condenser for electric power by Embodiment 2 of this invention. It is a charging device with the lifetime diagnosis function of the capacitor | condenser for electric power by Embodiment 3 of this invention.

Explanation of symbols

1 power capacitor charging circuit, 2 AC power line, 3 power circuit, 4 first semiconductor switch (semiconductor switch), 5 first diode, 6 resistor, 7 reactor, 8 second semiconductor switch (semiconductor switch), 9 Second diode, 10 Power capacitor, 10a Capacitance component, 10b Equivalent series resistance, 11 Power capacitor charging control circuit, 12 Reference current setting unit, 13 Constant current control error amplification circuit, 14 Triangular wave generation circuit, 15 Comparison Circuit, 16 Target voltage setting unit, 17 Charging voltage control error amplification circuit, 18 OR circuit, 21 Power capacitor life diagnosis circuit, 22 Control circuit power supply circuit, 23 Timer circuit, 24 Charging time charging voltage storage unit, 25 Life Diagnosis determination unit, 26 display alarm unit, 27 start switch.

Claims (4)

Connected to the power supply circuit, the DC power generated from the power supply circuit is stored as electromagnetic energy in the reactor by turning on the semiconductor switch, and the electromagnetic energy stored in the reactor is stored in the reactor by turning off the semiconductor switch. A power capacitor charging circuit for charging the power capacitor;
A power capacitor charging control circuit for generating a control pulse for turning on and off the semiconductor switch;
Compare the relationship between the charging time and charging voltage of the power capacitor set in advance with the measured charging time and measured charging voltage from the start of charging of the power capacitor , and check the charging voltage and charging time as a checkpoint. life by detecting that the capacity leakage of power capacitors by detecting whether leads to which area of the region is subdivided into a plurality of locations, the equivalent series resistance of increase large, an increase in leakage current exceeds a predetermined value A charging device with a life diagnosis function for a power capacitor, comprising a power capacitor life diagnosis circuit for diagnosing the power and reporting the diagnosis result. Power capacitor charge control circuit
2. A power capacitor life diagnosis function according to claim 1, wherein a control pulse is generated so that a charging current charged in the power capacitor becomes a preset reference charging current when the semiconductor switch is turned off. Charging device. Power capacitor charge control circuit
3. The power capacitor according to claim 1, wherein a control pulse for stopping the operation of the semiconductor switch is generated when the charging voltage of the power capacitor reaches a preset target charging voltage. Battery charger with life diagnosis function. Power capacitor life diagnosis circuit is
In conjunction with the complete discharge of the power capacitor, the relationship between the preset charging time and charging voltage of the power capacitor is compared with the measured charging time and measured charging voltage from the start of charging of the power capacitor. , capacity leakage of power capacitors by detecting whether leads to which area of the region is subdivided into a plurality of locations by the charging voltage and charging time becomes checkpoint, increase the equivalent series resistance is large, an increase in leakage current prescribed The life diagnosis function for a power capacitor according to any one of claims 1 to 3, wherein the life is diagnosed by detecting that the value is exceeded , and the diagnosis result is reported. Charging device.

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