JP4845613B2 - Battery charger with power capacitor life diagnosis function - Google Patents

Description

  The present invention relates to a charging device with a power capacitor life diagnosis function 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. .

  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 or an inverter device. Electrolytic capacitors have the characteristic that, since an electrochemical reaction takes place internally, the capacity decreases and the loss increases as the usage time increases. The life of the electrolytic capacitor is specified, and this life is affected by the operating temperature environment, and the life is further shortened when used in a high temperature environment.

  Electrolytic capacitors that have reached the end of their life experience phenomena such as loss of capacity, increased loss, and increased leakage current. However, it is difficult to judge these deteriorations from the appearance. For this reason, various devices for diagnosing capacity loss of electrolytic capacitors have been proposed.

  In Patent Document 1, the charging time until the voltage charged in the power capacitor reaches a predetermined voltage is measured, and the charging time and the reference time until the normal power capacitor reaches the predetermined voltage are measured. A diagnostic device is described that determines the degradation of a power capacitor based on a comparison.

  In Patent Document 2, a discharge characteristic curve at the beginning of operation of a power capacitor is compared with a discharge characteristic curve after use, and the time difference between the initial voltage drop time after operation and the voltage drop time after use is a predetermined allowable value. If it exceeds the limit, it is determined that the power capacitor has a lifetime.

  Further, in Patent Document 3, after the inverter circuit is powered off, the voltage of the electrolytic capacitor is lowered to the first predetermined voltage, and when the preset reference time has elapsed, it is below the life detection voltage level. In some cases, a life detection means for outputting a life detection signal is provided.

  Further, in Patent Document 4, the terminal voltage of the power capacitor after the application of the power supply voltage is stopped is sampled, a time constant is obtained from each sampling voltage and the sampling interval, and the power capacitor is determined from the time constant and a known resistance value. The capacity is calculated, and the capacity is compared with a predetermined capacity to determine whether the capacity is missing. Based on this determination, the arrival of the life of the power capacitor is diagnosed.

  Further, in Patent Document 5, it is detected that the voltage across the input smoothing capacitor has dropped to the reference voltage, and the time until the voltage across the input smoothing capacitor drops from the switch off to the reference voltage is a certain time or longer. Judging whether there is.

Japanese Patent Laid-Open No. 5-215800 (paragraph 0006) JP 7-92212 A (paragraph 0005) JP-A-8-80055 (paragraph 0010) Japanese Patent Laid-Open No. 11-231008 (Summary Solution) JP 2002-281735 A (paragraph 0005)

  The conventional charging device with a power capacitor life diagnosis function is configured as described above, and the devices in Patent Document 2 to Patent Document 5 measure the voltage at the time of discharging the power capacitor after stopping the power supply by sampling or the like. Compared with a predetermined discharge characteristic curve and a predetermined capacity, the power capacitor is diagnosed to have reached the end of its life. Both of them measure the discharge characteristic of the power capacitor after the power is stopped. If the power supply of the CPU drops after the application stops and the measurement continues until the CPU reset voltage is reached, the CPU itself cannot predict the arrival of the reset voltage, so the CPU internal registers and data are saved immediately before the voltage drops to the reset voltage. Since the reset voltage is reached in the middle of measurement without being able to be performed, the measurement is interrupted or data in the middle of calculation is lost. When the power supply of the life diagnosis function configured by PU is backed up by another system power supply or the power supply voltage drop of the CPU is monitored and dropped to a predetermined voltage, the data in the middle of calculation and the data of the register are interrupted There has been a problem that a process of saving to a memory with compensation is required.

  In addition, since the device of Patent Document 1 forcibly applies a voltage to the power capacitor and determines the deterioration of the power capacitor, an extra circuit such as a parallel connection of the second switch and the resistor is not provided. There is a problem that the configuration is complicated and the conventional circuit cannot be used as it is.

  The present invention has been made to solve the above-described problems, and does not require backup power supply or data backup used for diagnosing the life from the measurement of the discharge characteristics of the electrolytic capacitor, and forcing the voltage. The life of a power capacitor can be diagnosed with a simple configuration and the cause of life deterioration can be determined without the need for an extra circuit to be used when judging the deterioration of the power capacitor An object of the present invention is to obtain a charging device with a function for diagnosing power capacitor life.

A charging device with a power capacitor life diagnosis function according to the present invention includes a power capacitor charging circuit for charging a power capacitor, and a power capacitor charging control circuit for generating a control pulse for controlling charging by the power capacitor charging circuit. And the preset charging time and charging voltage characteristics of the power capacitor and the state of the power capacitor corresponding to each characteristic are measured, and the charging time and charging voltage from the start of charging of the power capacitor are measured. Then, by comparing the measured charging time and charging voltage with the characteristics of the stored charging time and charging voltage, from the relationship between the charging time and charging voltage during constant current charging, the capacity of the power capacitor is lost. , normal state, increasing state of the equivalent series resistance, or to determine the increasing state of the leakage current, increasing state or the leakage of the equivalent series resistance A case where it is determined that increasing state of the flow when possible transition to constant voltage charging, and counts the control pulses generated by the power capacitor charging control circuit, based on the counted control pulses, the power The capacitor for use includes a power capacitor life diagnosis circuit for determining whether the equivalent series resistance is increased or the leakage current is increased .

  According to the present invention, it is possible to diagnose the life of the power capacitor and determine the life deterioration factor with a simple configuration.

Embodiment 1 FIG.
1 is a diagram showing a configuration of a charging device with a power capacitor life diagnosis function according to Embodiment 1 of the present invention. The charging device with power capacitor life diagnosis function includes a power capacitor charging circuit 1, a power capacitor charging control circuit 11, and a power capacitor life diagnosis circuit 21.

  Here, the power capacitor charging circuit 1 is a circuit for charging the power capacitor 10, the power capacitor charging control circuit 11 is a circuit for controlling the power capacitor charging circuit 1, and the power capacitor life diagnosis circuit 21 is a power. This is a circuit for diagnosing the life of the capacitor 10 and determining the life deterioration factor and informing the result.

  In FIG. 1, the power capacitor charging circuit 1 includes a power supply circuit 3, a semiconductor switch 4, a diode 5, a resistor 6, a reactor 7, a semiconductor switch 8, and a diode 9.

  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. The semiconductor switch 4 is connected to a high potential line on the output side of the power supply circuit 3, and a resistor 6 connected in series to the anode of the diode 5 and the diode 5 is a high potential line and a low potential line on the output side of the semiconductor switch 4. The resistor 6 detects a charging current charged to the power capacitor 10 as the voltage 102 when the semiconductor switches 4 and 8 are turned off.

  The reactor 7 is connected to the high potential line on the output side of the diode 5, the 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 diode 9 is the high potential on the output side of the semiconductor switch 8. The power capacitor 10 is connected between the high potential line and the low potential line on the output side of the diode 9 and is repeatedly charged.

  In FIG. 1, a power capacitor charge control circuit 11 includes a reference current setting unit 12, a constant current control error amplification circuit 13, a triangular wave generation circuit 14, a comparison circuit 15, a target voltage setting unit 16, and a charge voltage control error amplification circuit. 17 and an OR circuit 18 are provided.

  In the power capacitor charging control circuit 11, the reference current setting unit 12 presets a reference charging current for charging the power capacitor 10 when the semiconductor switches 4 and 8 are turned off, and sets a set voltage 101 corresponding to the reference charging current. Output. The constant current control error amplifying circuit 13 starts its operation in response to a selection signal 112 from a life diagnosis determination unit 25 described later, and applies a set voltage 101 and a resistor 6 corresponding to the reference charging current set by the reference current setting unit 12. The voltage 102 corresponding to the generated charging current is compared, and the signal 103 having a smaller voltage is output as the difference between the set voltage 101 and the voltage 102 increases.

  The target voltage setting unit 16 presets and outputs a target charging voltage 104 for charging the power capacitor 10. The charge voltage control error amplifying circuit 17 starts to operate in response to a selection signal 113 from a life diagnosis determination unit 25 described later, and the target charging voltage 104 set by the target voltage setting unit 16 and the high potential line of the power capacitor 10. When the charging voltage 105 has reached the target charging voltage 104, the peak of the triangular wave 108 from the triangular wave generating circuit 14 is compared. When the signal 106 having a voltage larger than the value is output and the charging voltage 105 is lower than the target charging voltage 104 due to the leakage current of the power capacitor 10 or the like, the voltage is smaller than the peak value of the triangular wave 108 from the triangular wave generating circuit 14. The smaller the voltage, the smaller the signal 106 is output.

  The OR circuit 18 outputs either the signal 103 from the constant current control error amplification circuit 13 or the signal 106 from the charge voltage control error amplification circuit 17 as a signal 107. The triangular wave generation circuit 14 generates and outputs a triangular wave 108 having a constant peak value and width. The comparison circuit 15 inputs the signal 107 from the OR circuit 18 to the negative input terminal, inputs the triangular wave 108 from the triangular wave generation circuit 14 to the positive input terminal, and the voltage of the signal 107 from the OR circuit 18 is small. Outputs a control pulse 109 having a long pulse width, and outputs a control pulse 109 having a short pulse width when the voltage of the signal 107 from the OR circuit 18 is large.

  The control pulse 109 from the comparison circuit 15 is output to the base of the semiconductor switch 4 and the base of the semiconductor switch 8 of the power capacitor charging circuit 1 and to the control pulse counter 27 of the power capacitor life diagnosis circuit 21 described later. Is done. The semiconductor switch 4 and the semiconductor switch 8 of the power capacitor charging circuit 1 have a longer ON period when the control pulse 109 having a long pulse width is input from the comparison circuit 15 to each base, and the charging current of the power capacitor 10 is reduced. When the control pulse 109 having a short pulse width is input from the comparison circuit 15 to each base, the ON period is shortened and the charging current of the power capacitor 10 is decreased.

  In FIG. 1, a power capacitor life diagnosis circuit 21 includes a control circuit power supply circuit 22, a timer circuit 23, a charge time charge voltage storage unit 24, a life diagnosis determination unit 25, a display alarm unit 26, and a control pulse counter 27. Yes.

  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 when the power is turned on into a DC power supply, the power capacitor charging control circuit 11 and the power supply circuit 22. The DC power is supplied to each circuit of the capacitor life diagnosis circuit 21.

  The timer circuit 23 generates a reference clock 110 necessary for measuring the charging time of the power capacitor 10, and the charging time charging voltage storage unit 24 sets characteristics (relationships) of the charging time and charging voltage of the power capacitor 10 that are set in advance. ) And life diagnosis results 111 corresponding to those characteristics are stored.

  Based on the charging voltage 105 of the power capacitor 10 from the charging voltage detection line connected to the high potential line of the power capacitor 10, the life diagnosis determination unit 25 constantly charges the power capacitor 10 in the initial stage of charging. In order to keep the charging voltage constant at the stage of completion of charging, the charging voltage control is performed to output the selection signal 112 to the error amplifier circuit 13 for constant current control. The selection signal 113 is output to the error amplifier circuit 17 to perform constant voltage control.

  The life diagnosis determination unit 25 uses the reference clock 110 generated from the timer circuit 23 as a charge start (trigger) to detect the charge voltage 105 of the power capacitor 10 and measures the charge time from the start of charge. The charging voltage 105 of the power capacitor 10 from the charging voltage detection line is measured, and the characteristics of the charging time and charging voltage of the power capacitor 10 stored in the charging time charging voltage storage unit 24, and the life diagnosis according to these characteristics Based on the comparison of the result 111 with the measured charging time and charging voltage from the charging start of the power capacitor 10, the life diagnosis result 111 of the corresponding power capacitor 10 is extracted from the charging time charging voltage storage unit 24 and displayed. Output to the alarm unit 26.

  The control pulse counter 27 can count when the life diagnosis determination unit 25 selects the constant voltage control by the selection signal 113, counts the control pulse 109 from the comparison circuit 15, and outputs the count value 114. The life diagnosis determination unit 25 determines the life deterioration factor 115 based on the count value 114 within a predetermined time and outputs it to the display alarm unit 26. The display alarm unit 26 notifies the user of the life diagnosis result 111 and the life deterioration factor 115 by a lamp display, an alarm buzzer, or an alarm contact output.

Next, the operation will be described.
In FIG. 1, when AC power is turned on, the power supply circuit 3 of the power capacitor charging circuit 1 rectifies and smoothes the AC power supplied when the power is turned on to generate DC power. When the AC power source is turned on, the control circuit power source circuit 22 of the power capacitor life diagnosis circuit 21 converts the supplied AC power source into a DC power source, and the power capacitor charging control circuit 11 and the power capacitor life time. The DC power is supplied to each circuit of the diagnostic circuit 21.

  In the power capacitor charging control circuit 11, the reference current setting unit 12 is preset with a reference charging current for charging the power capacitor 10 when the semiconductor switches 4 and 8 are turned off, and the reference current setting unit 12 sets the set reference. A set voltage 101 corresponding to the charging current is generated. The constant current control error amplifying circuit 13 starts operating in response to the selection signal 112 from the life diagnosis determination unit 25, and is generated in the set voltage 101 and the resistor 6 corresponding to the reference charging current set by the reference current setting unit 12. The voltage 102 corresponding to the charging current is compared, and the signal 103 having a smaller voltage is output as the difference between the set voltage 101 and the voltage 102 increases.

  The comparison circuit 15 compares the triangular wave 108 from the triangular wave generation circuit 14 with the signal 107 via the OR circuit 18 from the constant current control error amplification circuit 13, and responds to a period in which the triangular wave 108 is equal to or higher than the voltage of the signal 107. A control pulse 109 having a pulse width is output. Immediately after the power supply of this circuit is turned on, only the triangular wave 108 from the triangular wave generation circuit 14 is input to the comparison circuit 15, and the control pulse 109 having the maximum pulse width is output in the period of the triangular wave 108.

FIG. 2 is a diagram showing the input / output timing of the comparison circuit 15. Here, the signal 103 (signal 107) from the constant current control error amplification circuit 13, the triangular wave 108 from the triangular wave generation circuit 14, and the comparison circuit 15 are shown. The timing of the control pulse 109 is shown.
The pulse width of the control pulse 109 is wide when the power is turned on, narrows with time, and finally the pulse width becomes constant. Based on the control pulse 109, the operation of the semiconductor switches 4 and 8 is controlled. That is, the semiconductor switches 4 and 8 are turned on when the control pulse 109 is at a high level, and the semiconductor switches 4 and 8 are turned off when the control pulse 109 is at a low level. Make it work.

In the power capacitor charging circuit 1, when the semiconductor switches 4 and 8 are turned on, a current flows from the power supply circuit 3 through the paths of the semiconductor switch 4, the reactor 7, and the semiconductor switch 8, and electromagnetic energy is accumulated in the reactor 7.
In addition, the electromagnetic energy accumulated in the reactor 7 is circulated through the path of the reactor 7, the diode 9, the power capacitor 10, the resistor 6, and the diode 5 by turning off the semiconductor switches 4 and 8, and the power capacitor 10 is charged. The

  In the power capacitor life diagnosis circuit 21, the life diagnosis determination unit 25 outputs a selection signal 112 to the constant current control error amplifier circuit 13 in the initial stage of charging based on the charging voltage 105 of the power capacitor 10, and the constant current The control error amplifier circuit 13 is caused to carry out constant current control so that the charging current to the power capacitor 10 becomes the reference charging current (set voltage 101).

  First, in the case of the constant current control, the power capacitor charging control circuit 11 has a configuration including the resistor 6, the reference current setting unit 12, and the constant current control error amplification circuit 13, and the comparison circuit 15 via the OR circuit 18. From this time, when the power is turned on, the on-time width of the semiconductor switches 4 and 8 is long, the on-time width gradually decreases with time, and finally a control pulse 109 is generated which becomes constant. It is possible to control the charging current of the power capacitor 10 to become the reference charging current by the control pulse 109 so that the on-time width becomes constant.

  Next, in the power capacitor life diagnosis circuit 21, the life diagnosis determination unit 25 is based on the charging voltage 105 of the power capacitor 10, and the charging completion stage, for example, the charging voltage 105 is changed to a charging voltage V 4 in FIG. When the life diagnosis result 111 is reached, the output of the selection signal 112 to the constant current control error amplification circuit 13 is stopped, and the selection signal 113 is output to the charge voltage control error amplification circuit 17, The charge voltage control error amplification circuit 17 is caused to perform constant voltage control so that the charge voltage of the power capacitor 10 is held at the target charge voltage 104.

  In the power capacitor charging control circuit 11, the target charging voltage 104 of the power capacitor 10 is preset in the target voltage setting unit 16, and the set target charging voltage 104 is output from the target voltage setting unit 16. .

  The charge voltage control error amplification circuit 17 starts operating in response to the selection signal 113 from the life diagnosis determination unit 25 and is connected to the target charging voltage 104 set by the target voltage setting unit 16 and the high potential line of the power capacitor 10. The charging voltage 105 of the power capacitor 10 from the charged charging voltage detection line is compared, and when the charging voltage 105 has reached the target charging voltage 104, the peak value of the triangular wave 108 from the triangular wave generation circuit 14 is obtained. When a large voltage signal 106 is output and the charging voltage 105 is lower than the target charging voltage 104 due to a leakage current of the power capacitor 10 or the like, the voltage is lower than the peak value of the triangular wave 108 from the triangular wave generation circuit 14. The larger the applied voltage is, the smaller the signal 106 is output.

  The comparison circuit 15 compares the triangular wave 108 from the triangular wave generation circuit 14 with the signal 107 via the OR circuit 18 from the charge voltage control error amplification circuit 17, and the triangular wave 108 corresponds to a period of time equal to or higher than the voltage of the signal 107. A control pulse 109 having a pulse width is output. That is, when the charging voltage 105 of the power capacitor 10 reaches the target charging voltage 104, the comparison circuit 15 outputs a signal larger than the peak value of the triangular wave 108 from the charging voltage control error amplification circuit 17 via the OR circuit 18. 107, the generation of the control pulse 109 is stopped, and when the charging voltage 105 of the power capacitor 10 is lower than the target charging voltage 104 due to the leakage current of the power capacitor 10, an error amplification for charging voltage control A signal 107 having a voltage smaller than the peak value of the triangular wave 108 from the circuit 17 via the OR circuit 18 and a smaller voltage is inputted as the voltage decreases, and a pulse width corresponding to a period in which the triangular wave 108 is equal to or longer than the voltage of the signal 107. The control pulse 109 is output.

  When the charging voltage 105 of the power capacitor 10 reaches the preset target charging voltage 104 by the control pulse 109, the operation of the semiconductor switches 4 and 8 is stopped, and the power is increased by the leakage current of the power capacitor 10 and the like. When the charging voltage 105 of the capacitor for electric power 10 is lower than the target charging voltage 104, the charging voltage 105 of the electric capacitor 10 is set to the target charging voltage by operating the semiconductor switches 4 and 8 according to the period of the control pulse 109. 104 can be held.

FIG. 3 is a circuit diagram showing an equivalent circuit of the power capacitor 10. As shown in FIG. 3, the power capacitor 10 is not generally composed of only the capacitance component 10a, but is equivalent to the capacitance component 10a. There is an ESR (Equivalent Series Resistance) 10b. When the power capacitor 10 further deteriorates, the forward insulation of the oxide film of the anode and cathode foil deteriorates, the internal resistance 10c decreases, and the leakage current increases. Therefore, the power capacitor 10 is equivalent to that shown in FIG.
In the actual equivalent circuit, inductive reactance exists in series with the equivalent series resistance 10b, but this is not greatly affected by the present invention, and is omitted in FIG. 3 for convenience.

  In the process of failure and deterioration of the power capacitor 10, first, an increase in the induction 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 induction tangent tan δ, it is considered that the equivalent series resistance 10b is increased. When the equivalent series resistance 10b of the power capacitor 10 increases, it takes time to charge the power capacitor. Similarly, when the internal resistance 10c of the oxide film of the anode and cathode foil of the power capacitor 10 is reduced and the leakage current is increased, it takes time to charge the power capacitor 10. On the other hand, when the capacity of the power capacitor 10 decreases and the capacity is lost, the charging of the power capacitor 10 is completed quickly.

FIG. 4 is a characteristic diagram showing characteristics of the charging time and charging voltage of the power capacitor 10, and is an image of data that is preset and stored in the charging time charging voltage storage unit 24.
In FIG. 4, the horizontal axis indicates the charging time of the power capacitor 10, and the vertical axis indicates the charging voltage of the power capacitor 10. Charging voltages V1, V2, V3, and V4 on the vertical axis are checkpoint charging voltages necessary for life diagnosis of the power capacitor 10. For example, in a high-pressure vacuum electromagnetic contactor, V1 is an operating limit voltage, V2 Is a cut-off limit voltage, V3 is a charge threshold value, V4 is a charge regulation voltage, and the like. T1, T2, and T3 on the horizontal axis are target values for the charging time corresponding to the charging voltages V1, V2, V3, and V4 on the vertical axis.

  In FIG. 4, the power capacitor 10 is normal when reaching the region A, the capacity is lost when reaching the region B, and the equivalent series resistance 10b is increased or the leakage current is increased when reaching the region C. When it reaches the region D, the equivalent series resistance 10b is extremely increased or the leakage current is increased. When it reaches the region E, the equivalent series resistance 10b and the leakage current are extremely increased. State.

  Note that the data preset in the charging time charging voltage storage unit 24 is not a characteristic diagram as shown in FIG. 4, but charging voltages V1, V2, V3, V4 at check points necessary for the life diagnosis of the power capacitor 10. Only the charging times T1, T2, T3 and the life diagnosis result 111 may be stored.

  The life diagnosis determination unit 25 uses the charging time and charging voltage measured in response to the start of charging of the power capacitor 10 as charging voltages V1, V2, V3, V4 at check points preset in the charging time charging voltage storage unit 24. Compared with the charging times T1, T2, and T3, the life diagnosis result 111 of the power capacitor 10 is extracted from the charging time charging voltage storage unit 24 and output to the display alarm unit 26. Here, the life diagnosis determination unit 25 determines to which region in FIG. 4 the transition of the charging voltage 105 of the power capacitor 10 corresponding to the transition of the charging time from the start of charging of the power capacitor 10 corresponds.

Specifically, the life diagnosis determination unit 25 determines as follows.
(Area A) When the charging voltage V4 is reached within the charging time T1 to T2 from the start of charging, the power capacitor 10 obtains a normal life diagnosis result 111 that is normal.
(Area B) When the charging voltage V4 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. A diagnosis result 111 is obtained.
(Area C) When the charging voltage V4 is reached within the charging time T2 to T3 from the start of charging, the charging is not completed within a predetermined time, and therefore the equivalent series resistance 10b increases in the power capacitor 10. The life diagnosis result 111 is obtained that the leakage current is increased.
(Region D) If the charging voltage is V2 to V3 even after the charging start time T3 from the start of charging, the equivalent series resistance 10b of the power capacitor 10 is extremely increased or the leakage current is increased. A life diagnosis result 111 is obtained.
(Area E) If the charging voltage is V1 to V2 even after the charging time T3 from the start of charging, the life diagnosis that the equivalent series resistance 10b and the leakage current are extremely increased in the power capacitor 10 A result 111 is obtained.
(Area F) If the charging voltage is less than V1 even after the charging time T3 from the start of charging, the life diagnosis result 111 is obtained that the power capacitor 10 is significantly deteriorated and cannot be used.

When the charging voltage of the power capacitor 10 reaches V4 after passing through the region F from the region C, the life diagnosis determination unit 25 selects the constant voltage control. As described above, the charge voltage control error amplification circuit 17 performs constant voltage control so that the charge voltage 105 of the power capacitor 10 becomes the target charge voltage 104. When the voltage drops below the voltage 104, the comparison circuit 15 outputs a control pulse 109. The control pulse counter 27 can count when the life diagnosis determination unit 25 selects the constant voltage control, and counts the control pulse 109 from the comparison circuit 15.

  Note that the control pulse counter 27 outputs a narrow control pulse 109 even when charging is completed when the control pulse 109 is miscounted when noise is superimposed or the charge control method is so-called pulse width modulation. Therefore, it is assumed that an input filter function is provided so as not to count control pulses 109 having a predetermined pulse width or less.

The life diagnosis determination unit 25 reads the count value 114 of the control pulse counter 27 every predetermined time. If the count value 114 exceeds the predetermined count target value, it means that the semiconductor switches 4 and 8 have been driven a lot. Therefore, it is determined that the leakage current of the power capacitor 10 is large. If the predetermined count target value is not exceeded, the leakage current is within a specified range, and therefore it is determined that the equivalent series resistance 10b of the power capacitor 10 is large. Of course, in this case, the display alarm unit 26 has already displayed the life diagnosis result 111 corresponding to any of the region C to the region F. In addition to this display, the leakage current is large or the equivalent series resistance 10b is The life deterioration factor 115 indicating that it is large is displayed.

  As described above, according to the first embodiment, the charging time charging voltage storage unit 24 stores the preset charging time and charging voltage characteristics of the power capacitor 10 and the life diagnosis result 111 corresponding to each characteristic. Then, the life diagnosis determination unit 25 measures the charging time and charging voltage 105 from the start of charging of the power capacitor 10, and the charging time and charging voltage 105 measured and the charging time stored in the charging time charging voltage storage unit 24. The life diagnosis result 111 is extracted by collating the characteristics of time and charging voltage, the control pulse counter 27 counts the control pulse 109 for controlling the charging of the power capacitor 10, and the life diagnosis determining unit 25 is controlled by the control pulse counter 27. The discharge characteristic of the power capacitor 10 is measured by determining the life deterioration factor 115 based on the count value 114 counted by This eliminates the need for backup power supply and data backup required for diagnosing the service life, and does not require an extra circuit for forcibly applying voltage. It is possible to obtain an effect that it is possible to determine the life deterioration factor.

  Further, according to the first embodiment, in the initial stage of charging, the life diagnosis determining unit 25 controls the constant current control error amplifying circuit 13 so that the charging current to the power capacitor 10 becomes the reference charging current. , The electric charge is linearly accumulated in the power capacitor 10, and the linearity of the relationship between the measured charging time from the start of charging of the power capacitor 10 and the measured charging voltage is further improved, and the electric charge is As shown in FIG. 4, since the error in reaching the lifetime region is reduced linearly in the capacitor 10 for power use, the life diagnosis performance of the power capacitor 10 can be further improved.

  Furthermore, according to the first embodiment, at the completion stage of charging, the life diagnosis determination unit 25 causes the charging voltage control error amplification circuit 17 to hold the charging voltage of the power capacitor 10 at the target charging voltage 104. By performing the constant voltage control, an effect that the charging voltage of the power capacitor 10 can be held at the target charging voltage is obtained.

  In the first embodiment, a predetermined time for the life diagnosis determination unit 25 to read the count value 114 of the control pulse counter 27 and a predetermined count target value for determining that the leakage current of the power capacitor 10 is large are fixed. Although it may be a value, an optimum value can be selected according to the capacity, type, etc. of the power capacitor 10 to be charged by setting the setting means to an arbitrary value.

Embodiment 2. FIG.
FIG. 5 is a diagram showing a configuration of a charging device with a power capacitor life diagnosis function according to Embodiment 2 of the present invention. The configuration shown in FIG. 5 differs from that in FIG. 1 of the first embodiment in that the control pulse counter 27 is deleted and the charging current measuring unit 28 is added in the power capacitor life diagnosis circuit 21. Other configurations are the same as those in FIG.

When charging of power capacitor 10 passes from region C to region F and the charging voltage reaches V4, life diagnosis determination unit 25 outputs selection signal 113 to charging voltage control error amplification circuit 17 to perform constant voltage control. select. As described above, the charge voltage control error amplification circuit 17 performs constant voltage control so that the charge voltage 105 of the power capacitor 10 becomes the target charge voltage 104. A control pulse 109 is output. The semiconductor switches 4 and 8 are turned on by the control pulse 109, a charging current flows, and a voltage 102 corresponding to the charging current generated in the resistor 6 is generated. The charging current measuring unit 28 measures the voltage 102 corresponding to the charging current generated in the resistor 6 and outputs the voltage 102 to the life diagnosis determining unit 25.

The life diagnosis determination unit 25 inputs a voltage 102 corresponding to the charging current measured by the charging current measurement unit 28, and when the charging current corresponding to the voltage 102 exceeds a predetermined target charging current, the charging current Therefore, it is determined that the leakage current of the power capacitor 10 is large. When the predetermined target charging current is not exceeded, the leakage current is within a specified range, and therefore it is determined that the equivalent series resistance 10b of the power capacitor 10 is large. Of course, in this case, since the life diagnosis result 111 corresponding to any of the areas C to F is already displayed on the display alarm unit 26, in addition to this display, the leakage current is large or equivalent. The life deterioration factor 115 indicating whether the series resistance is large is displayed.

The power capacitor charging control circuit 11 performs power supply control so that the target charging voltage 104 becomes constant when the charging voltage 105 of the power capacitor 10 falls below the target charging voltage 104 due to leakage current or the like. The charging operation of the power capacitor 10 by the capacitor charging circuit 1 is intermittent. Since it is difficult for the life diagnosis determination unit 25 to determine the voltage 102 based on the instantaneous value of the charging current that flows intermittently, the charging current measurement unit 28 measures the integral value or the average value of the voltage 102 based on the instantaneous value of the charging current. Output to the life diagnosis determination unit 25.
The processing of the other components in FIG. 5 is the same as the processing of the first embodiment.

  As described above, according to the second embodiment, the charging time charging voltage storage unit 24 stores the preset charging time and charging voltage characteristics of the power capacitor 10 and the life diagnosis result 111 corresponding to each characteristic. Then, the life diagnosis determination unit 25 measures the charging time and charging voltage 105 from the start of charging of the power capacitor 10, and the charging time and charging voltage 105 measured and the charging time stored in the charging time charging voltage storage unit 24. The life diagnosis result 111 is extracted by collating the characteristics of the time and the charging voltage, the charging current measuring unit 28 measures the voltage 102 according to the charging current of the power capacitor 10, and the life diagnosis determining unit 25 measures the charging current. By determining the life deterioration factor 115 based on the voltage 102 corresponding to the charging current measured by the unit 28, the life can be calculated from the measurement of the discharge characteristics of the power capacitor 10. It does not require backup power supply or data backup required for disconnection, and does not require an extra circuit for forcibly applying voltage, and diagnoses the life of power capacitors with a simple configuration. The effect that the lifetime deterioration factor can be determined is obtained.

  Further, according to the second embodiment, in the initial stage of charging, the life diagnosis determination unit 25 controls the constant current control error amplifier circuit 13 so that the charging current to the power capacitor 10 becomes the reference charging current. , The electric charge is linearly accumulated in the power capacitor 10, and the linearity of the relationship between the measured charging time from the start of charging of the power capacitor 10 and the measured charging voltage is further improved, and the electric charge is As shown in FIG. 4, since the error in reaching the lifetime region is reduced linearly in the capacitor 10 for power use, the life diagnosis performance of the power capacitor 10 can be further improved.

  Furthermore, according to the second embodiment, at the completion stage of charging, the life diagnosis determination unit 25 causes the charging voltage control error amplification circuit 17 to hold the charging voltage of the power capacitor 10 at the target charging voltage 104. By performing the constant voltage control, an effect that the charging voltage of the power capacitor 10 can be held at the target charging voltage is obtained.

Embodiment 3 FIG.
FIG. 6 is a diagram showing the configuration of a charging device with a power capacitor life diagnosis function according to Embodiment 3 of the present invention. The configuration shown in FIG. 6 differs from FIG. 1 of the first embodiment in that the control pulse counter 27 is deleted and the control pulse width measurement unit 29 is added in the power capacitor life diagnosis circuit 21. Other configurations are the same as those in FIG.

When charging of power capacitor 10 passes from region C to region F and the charging voltage reaches V4, life diagnosis determination unit 25 outputs selection signal 113 to charging voltage control error amplification circuit 17 to perform constant voltage control. Let it be implemented. As described above, the charge voltage control error amplification circuit 17 performs constant voltage control so that the charge voltage 105 of the power capacitor 10 is held at the target charge voltage 104, so that the comparison circuit 15 decreases when the charge voltage 105 decreases. Outputs a control pulse 109. The semiconductor switches 4 and 8 are turned on by the control pulse 109 and a charging current to the power capacitor 10 flows, and the charging voltage 105 of the power capacitor 10 increases.

  The control pulse width measurement unit 29 measures the pulse width 116 of the control pulse 109 output from the comparison circuit 15 and outputs the measured pulse width 116 to the life diagnosis determination unit 25.

The life diagnosis determination unit 25 receives the pulse width 116, and determines that the leakage current of the power capacitor 10 is large when the pulse width 116 exceeds a predetermined target pulse width. Is not exceeding the predetermined target pulse width, the leakage current is within the specified range, and therefore it is determined that the equivalent series resistance 10b of the power capacitor 10 is large. Of course, in this case, the display alarm unit 26 has already displayed the life diagnosis result 111 indicating that it corresponds to one of the regions C to F. In addition to this display, the leakage current is large or the equivalent series resistance The life deterioration factor 115 indicating whether 10b is large is displayed.
The processing of each other configuration in FIG. 6 is the same as the processing of the first embodiment.

  In the life diagnosis method according to the third embodiment, the pulse width 116 is widened when the control pulse 109 output from the comparison circuit 15 increases the charging current, and the pulse width 116 is narrowed when the charging current is decreased. This is effective when controlling by the pulse width modulation method.

  As described above, according to the third embodiment, the charging time charging voltage storage unit 24 stores the preset charging time and charging voltage characteristics of the power capacitor 10 and the life diagnosis result 111 corresponding to each characteristic. Then, the life diagnosis determination unit 25 measures the charging time and charging voltage 105 from the start of charging of the power capacitor 10, and the charging time and charging voltage 105 measured and the charging time stored in the charging time charging voltage storage unit 24. The life diagnosis result 111 is extracted by collating the characteristics of the time and the charging voltage, and the control pulse width measuring unit 29 measures the pulse width 116 of the control pulse 109 for controlling the charging of the power capacitor 10, and the life diagnosis determining unit 25 determines the life deterioration factor 115 based on the pulse width 116 measured by the control pulse width measuring unit 29, so that the discharge characteristics of the power capacitor 10 are discharged. There is no need for backup power supply or data saving required for diagnosing life from measurement, and no extra circuit for forcibly applying voltage is required. The effect that the lifetime can be diagnosed and the lifetime deterioration factor can be determined is obtained.

  Further, according to the third embodiment, in the initial stage of charging, the life diagnosis determination unit 25 controls the constant current control error amplifier circuit 13 so that the charging current to the power capacitor 10 becomes the reference charging current. , The electric charge is linearly accumulated in the power capacitor 10, and the linearity of the relationship between the measured charging time from the start of charging of the power capacitor 10 and the measured charging voltage is further improved, and the electric charge is As shown in FIG. 4, since the error in reaching the lifetime region is reduced linearly in the capacitor 10 for power use, the life diagnosis performance of the power capacitor 10 can be further improved.

  Further, according to the third embodiment, at the completion stage of charging, the life diagnosis determination unit 25 keeps the charging voltage of the power capacitor 10 at the target charging voltage 104 in the charging voltage control error amplification circuit 17. By performing the constant voltage control, an effect that the charging voltage of the power capacitor 10 can be held at the target charging voltage is obtained.

  In the first to third embodiments described above, 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 necessary or configured by a DC / DC converter. good.

  In FIG. 4, the life diagnosis result 111 of the power capacitor 10 is divided into six regions, region A to region F, but is not limited to these six regions, and may be divided into regions as necessary. .

  Furthermore, the life diagnosis determination unit 25 may determine the charging time based on the charging time when the charging voltage 105 reaches the target charging voltage 104 or the value of the charging voltage 105 that reaches the predetermined charging time. The data stored in the time charging voltage storage 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 first to third embodiments, the semiconductor switches 4 and 8 are turned on and off at the same time. However, as shown in Patent Document 5, the first and second semiconductor switches are turned on. DC power is applied to the reactor during the period and electromagnetic energy is stored in the reactor. When the second semiconductor switch is turned off, in addition to the electromagnetic energy stored in the reactor, the AC power source energy is converted into a rectifier, smoothing capacitor, and reactor. If the power capacitor is configured to be circulated through the diode and power capacitor paths, the power capacitor can be charged including the energy of the AC power supply.

  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 104 for charging the power capacitor 10 can be seen by the operator and the operation can be performed. Possible forms. Furthermore, when the reference charging current and the target charging voltage 104 are determined in advance by the charging device, they may be fixed.

  Furthermore, the charging time charging voltage storage unit 24 can similarly be configured to use a variable resistor, a digital switch, etc., so that the set charging voltage and power receiving time can be seen by the operator and can be operated. . Furthermore, when the reference charging current and the target charging voltage are determined in advance by the charging device, they may be fixed.

It is a figure which shows the structure of the charging device with a capacitor | condenser life diagnosis function for electric power by Embodiment 1 of this invention. It is a figure which shows the input / output timing of the comparison circuit in the charging device with a capacitor life diagnosis function for electric power by Embodiment 1 of this 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 charge time of a capacitor | condenser for electric power, and the characteristic of a charge voltage. It is a figure which shows the structure of the charging device with a capacitor | condenser life diagnosis function for electric power by Embodiment 2 of this invention. It is a figure which shows the structure of the charging device with a capacitor | condenser life diagnosis function 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 semiconductor switch, 5 diode, 6 resistor, 7 reactor, 8 semiconductor switch, 9 diode, 10 power capacitor, 10a capacitive component, 10b equivalent series resistance, 10c internal 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 charge voltage control error amplification circuit , 18 OR circuit, 21 power capacitor life diagnosis circuit, 22 control circuit power supply circuit, 23 timer circuit, 24 charge time charge voltage storage unit, 25 life diagnosis determination unit, 26 display alarm unit, 27 control pulse counter, 28 charge Current measurement unit, 29 control pulse width measurement unit, 101 set voltage, 102 voltage, 103 signal, 04 Target charge voltage, 105 Charge voltage, 106 signal, 107 signal, 108 Triangular wave, 109 Control pulse, 110 Reference clock, 111 Life diagnosis result, 112 Selection signal, 113 Selection signal, 114 Count value, 115 Life deterioration factor, 116 pulse width.

Claims (7)

A power capacitor charging circuit for charging the power capacitor;
A power capacitor charging control circuit for generating a control pulse for controlling charging by the power capacitor charging circuit;
Store the characteristics of the charging time and charging voltage of the power capacitor set in advance and the state of the power capacitor corresponding to each characteristic, measure the charging time and charging voltage from the start of charging of the power capacitor, From the relationship between the charging time and charging voltage during constant current charging by comparing the measured charging time and charging voltage with the stored charging time and charging voltage characteristics, the capacity loss state of the power capacitor, When the normal state, the increase state of the equivalent series resistance, or the increase state of the leakage current is determined, and it is determined that the increase state of the equivalent series resistance or the increase state of the leakage current, and when it can shift to the constant voltage charging , counting the control pulses generated by the power capacitor charging control circuit, based on the counted control pulses, the above power capacitors, equivalent Power capacitors life diagnosis function charging device including a power capacitor life diagnosis circuit that determines an increase state of the increasing state or the leakage current of the series resistance. The power capacitor life diagnosis circuit determines that the power capacitor is in a leakage current increasing state when the count value of the control pulse every predetermined time exceeds the predetermined count target value, and the count value is 2. The charging device with a power capacitor life diagnosis function according to claim 1, wherein when the predetermined count target value is not exceeded, it is determined that the power capacitor is in an equivalent series resistance increasing state . A power capacitor charging circuit for charging the power capacitor;
A power capacitor charging control circuit for generating a control pulse for controlling charging by the power capacitor charging circuit;
Store the characteristics of the charging time and charging voltage of the power capacitor set in advance and the state of the power capacitor corresponding to each characteristic, measure the charging time and charging voltage from the start of charging of the power capacitor, From the relationship between the charging time and charging voltage during constant current charging by comparing the measured charging time and charging voltage with the stored charging time and charging voltage characteristics, the capacity loss state of the power capacitor, When the normal state, the increase state of the equivalent series resistance, or the increase state of the leakage current is determined, and it is determined that the increase state of the equivalent series resistance or the increase state of the leakage current, and when it can shift to the constant voltage charging , the charging current of the power capacitor is measured, based on the measured charge voltage, the power capacitors are increasing the increasing state or the leakage current of the equivalent series resistance Power capacitors life diagnosis function charging device including a power capacitor life diagnosis circuit that determines a state. The power capacitor life diagnosis circuit determines that the power capacitor is in a leakage current increasing state when the charging current of the power capacitor exceeds a predetermined target charging current, and the charging current is determined to be the predetermined target charging current. 4. The charging device with a power capacitor life diagnosis function according to claim 3, wherein when the current does not exceed, the power capacitor is determined to be in an equivalent series resistance increasing state . A power capacitor charging circuit for charging the power capacitor;
A power capacitor charging control circuit for generating a control pulse for controlling charging by the power capacitor charging circuit;
Store the characteristics of the charging time and charging voltage of the power capacitor set in advance and the state of the power capacitor corresponding to each characteristic, measure the charging time and charging voltage from the start of charging of the power capacitor, From the relationship between the charging time and charging voltage during constant current charging by comparing the measured charging time and charging voltage with the stored charging time and charging voltage characteristics, the capacity loss state of the power capacitor, When the normal state, the increase state of the equivalent series resistance, or the increase state of the leakage current is determined, and it is determined that the increase state of the equivalent series resistance or the increase state of the leakage current, and when it can shift to the constant voltage charging , the pulse width of the control pulses generated by the power capacitor charging control circuit is measured, based on the measured pulse width, it is the power capacitors, equivalent Power capacitors life diagnosis function charging device including a power capacitor life diagnosis circuit that determines an increase state of the increasing state or the leakage current of the series resistance. When the pulse width exceeds a predetermined target pulse width, the power capacitor life diagnosis circuit determines that the power capacitor is in a leakage current increasing state, and the pulse width exceeds the predetermined target pulse width. 6. The charging device with a power capacitor life diagnosis function according to claim 5, wherein if it does not exceed, the power capacitor is determined to be in an equivalent series resistance increasing state .   The power capacitor charging control circuit performs constant current control so that the charging current to the power capacitor becomes a preset reference charging current in the initial stage of charging, and the charging voltage of the power capacitor is set in the charging completion stage. 6. The power capacitor life diagnosis function according to claim 1, wherein constant voltage control is performed so as to be maintained at a preset target charging voltage. Charging device.

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