JP2008228370A - Inverter device with fault detection function, inverter device with fault detection function and battery, and fault detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter device with a fault detection function, an inverter device with the fault detection function and a battery, and a fault detection device that can detect a fault of the inverter device with high precision, taking into consideration the fluctuation of resistance with temperature rise of a limiting resistor (the fluctuation of time constant determined by the static capacitance of a smoothing capacitor and the resistance of the limiting resistor arising from it). <P>SOLUTION: The inverter device 21 with the fault detection function includes a rate-of-change-with-passage-of-time calculation means (Step S5), which calculates the rate of capacitance-change γ with passage of time (=Crb/Co) of static capacitance Crb during a first reference period of time tb to the initial reference static capacitance Co of the smoothing capacitor 3 based on a resistor current Irb during the first reference period of time tb and a voltage Vcb across the terminals of the capacitor, and a fault decision means (Steps S6, S7), which decides whether a fault occurs to an inverter device 41 based on the rate of capacitance-change γ with passage of time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inverter device with an abnormality detection function, an inverter device with an abnormality detection function attached to a battery, and an abnormality detection device.

  Various technologies related to an inverter device with an abnormality detection function and an abnormality detection device that detects an abnormality of the inverter device have been proposed (see, for example, Patent Document 1 and Patent Document 2).

Japanese Patent No. 3289743 Japanese Patent No. 3269377

  In Patent Document 1, a filter circuit having the same time constant as the time constant determined by the capacitance of the smoothing capacitor constituting the inverter device and the resistance value of the limiting resistor is used, and the output voltage of the filter circuit and the voltage of the smoothing capacitor are used. And a method for interrupting the current flowing through the limiting resistor is disclosed. Specifically, when the voltage of the smoothing capacitor is lower than the output voltage of the filter circuit, the current flowing through the limiting resistor is cut off because a problem such as a short circuit has occurred in the inverter or the smoothing capacitor.

  In Patent Document 2, when a predetermined time has elapsed from the start of energization, the voltage of the smoothing capacitor is measured, and the measured voltage of the smoothing capacitor and the reference voltage of the smoothing capacitor in the normal state stored in advance are measured. By comparison, a method for interrupting the current flowing through the limiting resistor is disclosed. Specifically, when the measured voltage of the smoothing capacitor is lower than the reference voltage, the current flowing through the limiting resistor is cut off because there is a problem such as a short circuit in the inverter or the smoothing capacitor. Further, a temperature sensor (in the embodiment, a thermistor) for detecting the temperature of the limiting resistor is provided, and it is determined whether or not the temperature of the limiting resistor detected by the temperature sensor exceeds a predetermined temperature, and exceeds the predetermined temperature. In such a case, a technique for cutting off the energization is also disclosed.

  By the way, in general, the resistance value of the limiting resistor varies with temperature (specifically, the resistance value increases as the temperature of the limiting resistor increases). Accordingly, the time constant determined by the capacitance of the smoothing capacitor and the resistance value of the limiting resistor also varies (increases). On the other hand, in the method of Patent Document 1, since a filter circuit in which the resistance value of the limiting resistor is regarded as constant is used as a reference for comparison, whether or not an abnormality such as a short circuit has occurred in the inverter or the smoothing capacitor is appropriately determined. May not be able to judge.

  Specifically, even when the inverter and the smoothing capacitor are normal, the temperature of the limiting resistor increases as the energization time elapses, and the resistance value of the limiting resistor increases. The time constant determined by the capacitance and the resistance value of the limiting resistor is larger than the time constant of the filter circuit. As a result, even when the inverter and the smoothing capacitor are normal, the voltage of the smoothing capacitor is lower than the output voltage of the filter circuit, so it is erroneously determined that an abnormality such as a short circuit has occurred in the inverter or the smoothing capacitor. There was a fear. In particular, when used in an inverter mounted on an automobile, etc., the temperature of the limiting resistor fluctuates greatly depending on the usage environment, season, etc., so it is erroneously determined that an abnormality such as a short circuit has occurred in the inverter or smoothing capacitor. It is easy to cause trouble.

  Furthermore, even in the method disclosed in Patent Document 2 for comparing the measured voltage of the smoothing capacitor with the reference voltage of the smoothing capacitor in a normal state, the capacitance of the smoothing capacitor constituting the inverter device and the resistance value of the limiting resistor It is not taken into consideration that the time constant determined by the above changes due to the temperature change of the limiting resistor. For this reason, it may not be possible to appropriately determine whether an abnormality such as a short circuit has occurred in the inverter or the smoothing capacitor. Specifically, even when the inverter or smoothing capacitor is normal, the measured voltage of the smoothing capacitor may be lower than the reference voltage, and it may be erroneously determined that an abnormality such as a short circuit has occurred in the inverter or smoothing capacitor. was there.

  Also, in the method of determining whether or not to turn off the current with the temperature of the limiting resistance detected by the temperature sensor, it is difficult to accurately detect the temperature of the limiting resistance with the temperature sensor. It is doubtful whether it can be detected properly. Furthermore, by separately providing a temperature sensor, a temperature detection circuit, or the like to detect the temperature of the limiting resistor, the number of parts increases, so the entire apparatus (circuit) becomes expensive and the arrangement space also increases. It was not preferable.

  The present invention has been made in view of such a current situation, and is a change in resistance value accompanying a rise in temperature of the limiting resistor (a change in time constant determined by the capacitance of the smoothing capacitor and the resistance value of the limiting resistor). The present invention has an object to provide an inverter device with an abnormality detection function, an inverter device with an abnormality detection function attached to a battery, and an abnormality detection device that can accurately detect an abnormality of the inverter device.

  The means for solving the problem is an inverter circuit, a smoothing capacitor that is arranged on the DC power supply side of the inverter circuit, connected in parallel with the inverter circuit, and connected in series with the inverter circuit and the smoothing capacitor, An inverter device comprising: a limiting resistor for limiting an inrush current from a power source to the inverter circuit and the smoothing capacitor; and a switch means for intermittently connecting a resistance current flowing through the limiting resistor, wherein the magnitude of the resistance current is measured. A current sensor for measuring, a capacitor voltage sensor for measuring the magnitude of the voltage across the capacitor terminals of the smoothing capacitor, and a predetermined first from the start of energization in energization via a resistor from the DC power source through the switch means and the limiting resistor. The first time measured by the current sensor at the first reference time tb after the reference time has elapsed. The time course of the capacitance Crb at the first reference time tb with respect to the initial reference capacitance Co of the smoothing capacitor based on the magnitude of the coercive current and the magnitude of the voltage across the capacitor terminals measured by the capacitor voltage sensor. A rate-of-change calculating unit that calculates a capacity change rate γ (= Crb / Co); and an abnormality determining unit that determines whether an abnormality has occurred in the inverter device based on the time-dependent capacity change rate γ. This is an inverter device with an abnormality detection function.

  Another solution is an inverter circuit, a smoothing capacitor that is arranged on the DC power supply side of the inverter circuit and connected in parallel with the inverter circuit, and is connected in series with the inverter circuit and the smoothing capacitor. A limiting resistor for limiting inrush current from the DC power source to the inverter circuit and the smoothing capacitor, switch means for interrupting the resistance current flowing through the limiting resistor, a current sensor for measuring the magnitude of the resistance current, An abnormality detection device for determining whether an abnormality has occurred in an inverter device comprising a capacitor voltage sensor for measuring the magnitude of the voltage across the capacitor terminals of the smoothing capacitor, wherein the abnormality detection device is configured to pass through the switch means and the limiting resistor. In addition, in the energization via the resistor from the DC power source, a predetermined first reference time has elapsed from the start of energization. The initial reference electrostatic capacitance of the smoothing capacitor is determined based on the magnitude of the resistance current measured by the current sensor and the magnitude of the voltage across the capacitor terminals measured by the capacitor voltage sensor at the first reference time tb. A time-dependent change rate calculating means for calculating a time-dependent capacity change rate γ (= Crb / Co) of the capacitance Crb at the first reference time tb with respect to the capacity Co, and an abnormality in the inverter device based on the time-dependent capacity change rate γ. And an abnormality determination unit that determines whether or not an error has occurred.

  The inverter device with an abnormality detection function of the present invention and the abnormality determination means of the present invention both have the magnitude of the resistance current measured by the current sensor at the first reference time tb and the capacitor at the first reference time tb. Based on the magnitude of the voltage across the capacitor terminals measured by the voltage sensor, the time-dependent capacitance change rate γ (= Crb / Co) of the capacitance Crb at the first reference time tb with respect to the initial reference capacitance Co of the smoothing capacitor. Is provided with a time-dependent change rate calculating means for calculating. That is, based on the resistance current corresponding to the resistance value of the limiting resistor at the first reference time tb (resistance value reflecting the temperature of the limiting resistor) and the voltage between the capacitor terminals, the time-dependent capacitance change rate γ is calculated. calculate. Compared to the case of calculating without considering the fluctuation of the resistance value due to the temperature rise of the limiting resistance (the fluctuation of the time constant determined by the capacitance of the smoothing capacitor and the resistance value of the limiting resistance) due to this, A highly reliable capacity change rate with time γ can be obtained.

  Then, in the inverter device with an abnormality detection function of the present invention and the abnormality determination means of the present invention, it is determined whether or not an abnormality has occurred in the inverter device based on the highly reliable temporal capacity change rate γ. To do. For this reason, the abnormality of the inverter device can be detected with high accuracy.

  As the initial reference capacitance Co of the smoothing capacitor, for example, the nominal capacitance Ck of the smoothing capacitor can be used. Further, as the reference capacitance Co, the corrected nominal capacitance β · Ck (β is the actual initial capacitance Crc with respect to the nominal capacitance Ck) obtained by correcting the variation in the nominal capacitance Ck (the manufacturing variation in the capacitance of the smoothing capacitor). In other words, the actual initial capacitance Crc may be used. This is preferable because the error of the reference capacitance Co due to the manufacturing variation of the capacitance of the smoothing capacitor can be reduced and the reference capacitance Co becomes accurate.

Further, the abnormality of the inverter device includes, for example, an abnormality in which the smoothing capacitor is deteriorated with time and the capacitance Cr of the smoothing capacitor is the lifetime capacitance Cx considered to have reached the end of the life of the smoothing capacitor. Can do.
This abnormality can be detected as follows, for example. That is, the time-dependent change rate calculation means calculates the time-dependent capacity change rate γ based on the resistance current and the voltage between the capacitor terminals at the first reference time tb every time the current is passed through the resistance or every predetermined number of times of current supply. Then, in the abnormality determination means, it is determined whether or not the calculated temporal capacity change rate γ is below a predetermined first reference value γ1. That is, when the time-dependent capacitance change rate γ is lower than the first reference value γ1, it is possible to determine that the smoothing capacitor has deteriorated with time, and the capacitance of the smoothing capacitor has reached the lifetime capacitance Cx.

  In addition, an abnormality in which the resistance value of the limiting resistor is greatly reduced due to a short circuit or the like can be given. Even if the smoothing capacitor is normal, if there is an abnormality in which the resistance value of the limiting resistor is greatly reduced due to a short circuit or the like, the capacitance change rate with time is as if the capacitance Cr of the smoothing capacitor is greatly reduced. This is because γ is a small value.

  Moreover, the abnormality which the smoothing capacitor short-circuited and the abnormality which the inverter circuit short-circuited can also be mentioned. This abnormality can be detected, for example, by determining whether or not the time-dependent capacity change rate γ exceeds a predetermined second reference value γ2 (γ2> 1) in the abnormality determination unit. That is, when the time-dependent capacity change rate γ exceeds the second reference value γ2, it can be determined that a smoothing capacitor short circuit or an inverter circuit short circuit has occurred.

  Furthermore, in the above inverter device with an abnormality detection function, the abnormality determination means determines that the inverter device is abnormal when the time-dependent capacity change rate γ falls below a predetermined first reference value γ1. An inverter device with an abnormality detection function is preferable.

  Furthermore, in the above abnormality detection device, the abnormality determination means determines that the inverter device is abnormal when the time-dependent capacity change rate γ is lower than a predetermined first reference value γ1. It is better to use a device.

  In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, when the time-dependent capacity change rate γ falls below a predetermined first reference value γ1 (for example, γ1 <1), the inverter device malfunctions. It is determined that Thereby, abnormality of an inverter apparatus can be detected appropriately.

  In the abnormality determining means of the present invention, the smoothing capacitor is deteriorated with time, and the resistance value of the limiting resistor is greatly reduced due to an abnormality in which the capacitance of the smoothing capacitor reaches the lifetime capacitance Cx or a short circuit. Abnormalities can be detected.

  Furthermore, in any one of the above-described inverter devices with an abnormality detection function, the abnormality determination means determines that the inverter device is abnormal when the time-dependent capacity change rate γ exceeds a predetermined second reference value γ2. It is preferable to use an inverter device with an abnormality detection function for determination.

  Furthermore, in any one of the abnormality detection devices described above, the abnormality determination unit determines that the inverter device is abnormal when the time-dependent capacity change rate γ exceeds a predetermined second reference value γ2. An anomaly detection device is preferable.

In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, when the time-dependent capacity change rate γ exceeds a predetermined second reference value γ2 (for example, γ2> 1), the inverter device is abnormal. It is determined that Thereby, abnormality of an inverter apparatus can be detected appropriately.
The abnormality determination means of the present invention can detect an abnormality in which the smoothing capacitor is short-circuited or an abnormality in which the inverter circuit is short-circuited.

  Furthermore, in any one of the above inverter devices with an abnormality detection function, an abnormality detection function comprising an opening instruction means for opening the switch means when the abnormality determination means determines that an abnormality has occurred in the inverter device. It is good to use an inverter device with.

  Furthermore, when any of the above-described abnormality detection devices is provided, the abnormality detection device includes an opening instruction unit that opens the switch unit when the abnormality determination unit determines that an abnormality has occurred in the inverter device. good.

  In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, when it is determined that an abnormality has occurred in the inverter device, the switch means is opened. Thereby, the resistance current flowing through the limiting resistor can be cut off, and abnormal temperature rise (burnout) of the limiting resistor can be prevented.

  Furthermore, in any one of the above-described inverter devices with an abnormality detection function, when the smoothing capacitor has a nominal capacity of Ck and the energization frequency N through the resistor is a predetermined initial energization frequency Nd, The nominal value of the smoothing capacitor is based on the magnitude of the resistance current and the magnitude of the voltage across the capacitor terminals measured at a second reference time tc when a predetermined second reference time has elapsed since the start of energization via resistance. An initial capacity ratio calculating means for calculating an initial capacity ratio β (= Crc / Ck) of the electrostatic capacity Crc of the smoothing capacitor at the second reference time tc of the initial energization number Nd with respect to the capacity Ck; The rate-of-change calculation means is a corrected nominal capacity β obtained by multiplying the nominal capacity Ck by the initial capacity ratio β as the reference capacitance Co of the smoothing capacitor. May the abnormality detection function inverter using ck.

  Furthermore, in any one of the abnormality detection devices described above, when the smoothing capacitor has a nominal capacity of Ck and the energization number N of the energization via the resistor is a predetermined initial energization number Nd, Based on the magnitude of the resistance current and the magnitude of the voltage across the capacitor terminals measured at a second reference time tc when a predetermined second reference time has elapsed since the start of energization in the energization, the nominal capacity Ck of the smoothing capacitor Initial capacitance ratio calculating means for calculating an initial capacitance ratio β (= Crc / Ck) of the electrostatic capacity Crc of the smoothing capacitor at the second reference time tc of the initial energization frequency Nd. The calculation means uses a corrected nominal capacitance β · Ck obtained by multiplying the nominal capacitance Ck by the initial capacitance ratio β as the reference capacitance Co of the smoothing capacitor. It may be an ordinary detector.

  The smoothing capacitors that are actually used may vary in a range of about −20% to + 20% with respect to the nominal capacitance Ck even at the initial initial capacitance. For this reason, when the time-dependent capacity change rate γ is calculated using the nominal capacity Ck as a reference, the time-dependent capacity change rate γ may be a value greatly deviating from the actual time-dependent capacity change rate.

  On the other hand, in the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, as the reference capacitance Co of the smoothing capacitor, the corrected nominal capacity β · Using Ck, the capacity change rate γ with time is calculated. Thereby, since the reliable time-dependent capacity | capacitance change rate (gamma) can be obtained appropriately, abnormality of an inverter apparatus can be detected with a sufficient precision by determining abnormality based on this.

Furthermore, the inverter device with an abnormality detection function includes a power supply voltage sensor that measures a power supply voltage on the DC power supply side with respect to the limiting resistor, and the initial capacity ratio calculating means is configured to output the initial capacity ratio at the second reference time tc. When the magnitude of the power supply voltage measured by the power supply voltage sensor is Vbc, the magnitude of the resistance current is Irc, and the magnitude of the voltage between the capacitor terminals is Vcc, the initial capacitance ratio β is expressed by the following equation: An inverter device with an abnormality detection function obtained using (1) is preferable.

β = −tc / [Ck × (Vbc−Vcc) / Irc] × ln [1− (Vcc / Vbc)] (1)

Furthermore, in the above abnormality detection device, the inverter device is an inverter device that includes a power supply voltage sensor that measures a power supply voltage on the DC power supply side with respect to the limiting resistor, and the initial capacity ratio calculating unit includes: , When the magnitude of the power supply voltage measured by the power supply voltage sensor at the second reference time tc is Vbc, the magnitude of the resistance current is Irc, and the magnitude of the voltage between the capacitor terminals is Vcc, It is preferable that the initial capacity ratio β be an abnormality detection device that is acquired using the following formula (1).

β = −tc / [Ck × (Vbc−Vcc) / Irc] × ln [1− (Vcc / Vbc)] (1)

  As described above, the resistance value of the limiting resistor varies with temperature. Specifically, the resistance value increases as the temperature of the limiting resistor increases. Accordingly, since the resistance value of the limiting resistor gradually increases as time passes after the start of energization, the time constant τ (τ = Ck × Rr) determined by the capacitance C of the smoothing capacitor and the resistance value Rr of the limiting resistor. Gradually increases.

On the other hand, in the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, based on the power supply voltage Vbc, resistance current Irc, and capacitor terminal voltage Vcc measured at the second reference time tc. Then, the initial capacity ratio β is calculated by the equation (1). This expression (1) is charged according to the actual capacitor terminal voltage Vcc and the time constant τc at the second reference time tc (τc = β · Ck × Rrc = β · Ck × (Vbc−Vcc) / Irc). The voltage between the terminals of the smoothing capacitor Vbc × {1-exp (−tc / τc)} is assumed to be equal to the following expression (1-1).

Vcc = Vbc × {1-exp (−tc / (β · Ck × (Vbc−Vcc) / Irc)}} (1-1)

  Here, the power supply voltage Vbc, the resistance current Irc, and the voltage Vcc between the capacitor terminals are all values corresponding to the resistance value Rrc of the limiting resistor at the second reference time tc (Rrc = (Vbc−Vcc) / Irc). It is. Therefore, by calculating the initial capacitance ratio β using Equation (1), it is possible to appropriately obtain a highly reliable initial capacitance ratio β that takes into account fluctuations in the resistance value of the limiting resistor due to the temperature change of the limiting resistor. Can do.

Alternatively, in the inverter device with an abnormality detection function, the initial capacity ratio calculating means flows from the start of energization to the second reference time tc in the N energization of the initial energization number Nd. Further, when the integral value of the resistance current Ir is expressed by the following formula (2) and the voltage between the capacitor terminals at the second reference time tc is Vcc, the initial capacitance ratio β is expressed by the following formula (3). It is preferable to use an inverter device with an abnormality detection function that is obtained and used.

  Alternatively, in the abnormality detection device, the initial capacity ratio calculation unit may be configured to apply the resistance that has flowed from the start of energization to the second reference time tc in the energization via the resistance at the initial energization count Nd. When the integrated value of the current Ir is the above equation (2) and the voltage between the capacitor terminals at the second reference time tc is Vcc, the initial capacitance ratio β is obtained using the above equation (3). It is preferable to obtain an abnormality detection device to be acquired.

In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, the integrated value of the resistance current Ir from the start of energization to the second reference time tc (see equation (2)), and the second Based on the capacitor terminal voltage Vcc at the time when the reference time tc has elapsed, the initial capacitance ratio β is calculated by Equation (3). This equation (3) is the integrated value of the resistance current Ir from the start of energization to the second reference time tc (see equation (2)) and the smoothing capacitor is charged from the start of energization to the second reference time tc. The obtained charge amount Qc = β · Ck × Vcc is obtained from the following formula (3-1), which is assumed to be equal.

  Here, the integral value of the resistance current Ir (refer to the equation (2)) and the voltage Vcc between the capacitor terminals are both limited resistances that vary with the temperature change from the start of energization to the second reference time tc. The value corresponds to the resistance value. Therefore, by calculating the initial capacitance ratio β using Equation (3), it is possible to appropriately obtain a highly reliable initial capacitance ratio β that takes into account the variation of the resistance value of the limiting resistor accompanying the temperature change of the limiting resistor. Can do.

Further, any one of the above inverter devices with an abnormality detection function, further comprising a power supply voltage sensor that measures a power supply voltage on the DC power supply side with respect to the limiting resistor, and the temporal change rate calculating means includes the first reference time At tb, when the magnitude of the power supply voltage measured by the power supply voltage sensor is Vbb, the magnitude of the resistance current is Irb, and the magnitude of the voltage between the capacitor terminals is Vcb, at the first reference time tb It is preferable that the capacity change rate γ with time is an inverter device with an abnormality detection function that is obtained by using the following formula (4).

γ = −tb / [Co × (Vbb−Vcb) / Irb] × ln [1− (Vcb / Vbb)] (4)

Furthermore, in any one of the abnormality detection devices described above, the inverter device is an inverter device that includes a power supply voltage sensor that measures a power supply voltage on the DC power supply side with respect to the limiting resistor, and calculates the rate of change over time. When the first reference time tb is Vb, the magnitude of the power supply voltage measured by the power supply voltage sensor is Vbb, the magnitude of the resistance current is Irb, and the magnitude of the voltage between the capacitor terminals is Vcb. It is preferable that the abnormality detection device obtains the time-dependent capacity change rate γ at the first reference time tb using the following formula (4).

γ = −tb / [Co × (Vbb−Vcb) / Irb] × ln [1− (Vcb / Vbb)] (4)

In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, based on the power supply voltage Vbb, the resistance current Irb, and the capacitor terminal voltage Vcb at the first reference time tb, The capacity change rate γ with time is calculated. This equation (4) is in accordance with the voltage Vcb between the capacitor terminals measured at the first reference time tb and the time constant τb (τb = Co × Rrb = Co × (Vbb−Vcb) / Irb at the first reference time tb. It is obtained from the following equation (4-1) that assumes that the voltage Vbb between terminals of the charged smoothing capacitor is equal to {1-exp (−tb / τb)}.

Vcb = Vbb × {1-exp (−tb / (Co × (Vbb−Vcb) / Irb)}} (4-1)

  Here, the power supply voltage value Vbb, the resistance current value Irb, and the capacitor terminal voltage value Vcb are all values corresponding to the resistance value Rrb of the limiting resistor at the first reference time tb (Rrb = (Vbb−Vcb) / Irb). Therefore, by calculating the time-dependent capacity change rate γ using the equation (4), a highly reliable time-dependent capacity change rate γ that takes into account the variation of the resistance value of the limiting resistor accompanying the temperature change of the limiting resistor is appropriately obtained. Obtainable.

Furthermore, in any one of the above-described inverter devices with an abnormality detection function, the rate of change with time calculation means the first energization from the start of energization in the energization via the resistance at the Ng energization times exceeding the initial energization frequency Nd. When the integral value of the resistance current Ir that has flowed up to the reference time tb is represented by the following equation (5), and the magnitude of the voltage between the capacitor terminals at the first reference time tb is Vcb, the capacity change rate with time It is preferable that γ be an inverter device with an abnormality detection function that is acquired using the following formula (6).

  Furthermore, in any one of the above-described abnormality detection devices, the rate of change with time calculation means the first reference time from the start of energization in the energization through the resistance Ng times of energization times exceeding the initial energization number Nd. When the integral value of the resistance current Ir that has flowed up to tb is expressed by the above equation (5) and the magnitude of the voltage between the capacitor terminals at the first reference time tb is Vcb, the time-dependent capacitance change rate γ is It is preferable that the abnormality detection device be acquired using the above equation (6).

In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, the integral value of the resistance current Ir from the start of energization to the first reference time tb at the energization frequency Ng (see equation (5)), Based on the capacitor terminal voltage Vbc at the first reference time tb, the time-dependent capacity change rate γ is calculated by Equation (6). This equation (6) shows the integral value of the resistance current Ir from the start of energization to the first reference time tb (see equation (5)) and the charge charged in the smoothing capacitor until the first reference time tb. The quantity Qb is obtained from the following formula (6-1) that is assumed to be equal to γ · Co × Vcb.

  Here, the integrated value of the resistance current Ir (see equation (5)) and the voltage Vcb between the capacitor terminals are both limited resistances that vary with temperature changes from the start of energization to the first reference time tb. The value corresponds to the resistance value. Therefore, by calculating the time-dependent capacity change rate γ according to the equation (6), a highly reliable time-dependent capacity change rate γ that takes into account the variation of the resistance value of the limiting resistor accompanying the temperature change of the limiting resistor is appropriately set. Obtainable.

  The energization count Ng may be a value larger than the initial energization count Nd. For example, the energization count Ng may be larger than the initial energization count Nd. In addition, each of the energization times (for example, Nd + 10, Nd + 20, Nd + 30, etc.) that increases by a predetermined number (for example, 10 times) after exceeding the initial energization number Nd may be set as the energization number Ng. Further, a predetermined number of energizations (for example, 100th) greater than the initial energization number Nd may be set as the energization number Ng (for example, Ng = 100).

  Furthermore, in any one of the above-described inverter devices with an abnormality detection function, the temporal change rate calculation means has a corresponding value corresponding to a predetermined condition of the energization via resistance reaching a reference corresponding value T satisfying a predetermined condition. For each predetermined energization, the time-dependent capacity change rate γ is calculated and stored, and the change rate (Δγ / T) of the time-dependent capacity change rate γ that has fluctuated until the reference corresponding value T is reached for each predetermined energization. It is preferable that the inverter device with an abnormality detection function is provided with a deterioration abnormality detecting means for detecting a deterioration abnormality of the smoothing capacitor when the calculated fluctuation rate (Δγ / T) falls below a predetermined reference fluctuation rate G.

  Still further, in any one of the above-described abnormality detection devices, the temporal change rate calculating means includes a predetermined energization in which a corresponding value corresponding to a predetermined condition among the energization via resistance reaches a reference corresponding value T satisfying a predetermined condition. Each time, the time-dependent capacity change rate γ is calculated and stored, and the change rate (Δγ / T) of the time-dependent capacity change rate γ that has changed until the reference corresponding value T is reached for each predetermined energization. When the fluctuation rate (Δγ / T) falls below a predetermined reference fluctuation rate G, the abnormality detection device may be provided with a deterioration abnormality detection unit that detects a deterioration abnormality of the smoothing capacitor.

  In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, the rate of change of the capacity change rate γ with time (Δγ / T) is calculated. Further, when the variation rate (Δγ / T) falls below a predetermined reference variation rate G, the deterioration abnormality of the smoothing capacitor is detected. Therefore, when the capacity change rate γ with time decreases rapidly (when the deterioration of the smoothing capacitor proceeds abnormally fast), it can be appropriately detected as a deterioration abnormality.

  The “predetermined condition” refers to a condition in which a change in characteristics of the smoothing capacitor is expected to be measurable. Furthermore, examples of the “standard corresponding value T satisfying the predetermined condition” include a predetermined increase amount (for example, T = 1000 times) applied to the number N of energizations from the DC power source through the switch means and the limiting resistor. . In this case, every time the energization number N increases by a predetermined reference number (for example, T = 1000 times), the fluctuation rate (Δγ / T) of the time-dependent capacity change rate γ is calculated.

Further, the predetermined increase amount related to the integrated value of the resistance current may be set as “a reference corresponding value T satisfying a predetermined condition” (for example, T = 1000 A). In this case, every time the integrated value of the resistance current increases by a predetermined reference value (for example, T = 1000 A), the variation rate (Δγ / T) of the capacity change rate γ with time is calculated.
In addition, when the inverter device with an abnormality detection function of the present invention is mounted on an automobile, the predetermined increase amount of the travel distance may be “a reference corresponding value T that satisfies a predetermined condition” (for example, T = 10000 km). In this case, every time the travel distance increases by a predetermined reference distance (for example, T = 10000 km), the variation rate (Δγ / T) of the time-dependent capacity change rate γ is calculated.

  In addition, when a deterioration abnormality of the smoothing capacitor is detected, even if the time-dependent capacity change rate γ is in a normal range (γ1 <γ <γ2), the time-dependent capacity change rate γ is rapidly decreased. It can be estimated that the capacity change rate γ with time is out of the normal range (γ <γ1 is satisfied). Therefore, it is preferable to issue an alarm to the effect that the abnormality of the inverter device is approaching when the deterioration abnormality of the smoothing capacitor is detected. In this way, an appropriate measure (such as replacement of the smoothing capacitor) can be performed before the smoothing capacitor becomes abnormal, and abnormal temperature rise (burnout) of the limiting resistor can be prevented.

Furthermore, in any one of the above inverter devices with an abnormality detection function, the number of energizations through the resistor when the time-dependent capacitance change rate γ is obtained is Nh, and the capacitance of the smoothing capacitor is a lifetime capacitance. It is preferable to use an inverter device with an abnormality detection function including life energization frequency estimation means for estimating the lifetime energization frequency Nx reaching Cx using the following equation (7).

Nx = Nh {1- (Cx / Co)} / (1-γ) (7)

Furthermore, in any one of the abnormality detection devices described above, the number of energizations via the resistor when the time-dependent capacitance change rate γ is obtained is Nh, and the capacitance of the smoothing capacitor becomes the lifetime capacitance Cx. It is preferable to use an abnormality detection apparatus including life energization frequency estimation means for estimating the life energization frequency Nx to be reached using the following formula (7).

Nx = Nh {1- (Cx / Co)} / (1-γ) (7)

In the inverter device with an abnormality detection function of the present invention and the abnormality detection device of the present invention, the number Nx of lifetime energization until the capacitance of the smoothing capacitor reaches the lifetime capacitance Cx is estimated using Equation (7). . This equation (7) is a smoothing capacitor change over time (Co−γ · Co) / Nh = Co (1−γ) / Nh when energized via a resistor Nh times. Assuming that the capacitance change with time (Co-Cx) / Nx of the smoothing capacitor per energization is equal when the energization can be performed Nx times until the capacitance of the capacitor reaches the lifetime capacitance Cx. Obtained from the following formula (7-1).
Co (1-γ) / Nh = (Co-Cx) / Nx (7-1)

Thereby, before the electrostatic capacitance of a smoothing capacitor reaches the lifetime electrostatic capacitance Cx, the lifetime energization frequency Nx can be easily estimated.
It is also possible to estimate the number of energizations (remaining life energization times) that is possible until the capacitance of the smoothing capacitor reaches the life energization number Nx by subtracting the energization number Nh from the life energization number Nx.

  Furthermore, it is good to set it as the inverter apparatus with a battery attached abnormality detection function which has one of the said inverter apparatuses with an abnormality detection function, and the battery as said DC power supply.

  In the inverter device with a battery attached abnormality detection function of the present invention, the battery can appropriately energize the smoothing capacitor and the inverter circuit through the limiting resistor. Examples of the battery include a nickel metal hydride storage battery and a lithium ion secondary battery.

(Example 1)
Next, an inverter device 21 with an abnormality detection function according to Embodiment 1 of the present invention will be described with reference to the drawings. In addition, the inverter apparatus 21 with an abnormality detection function of the first embodiment can be used by being mounted on, for example, a hybrid vehicle.
As shown in FIG. 1, the inverter device 21 with an abnormality detection function includes an inverter device 41 and an ECU 6 (an abnormality detection device).

  Among these, the inverter device 41 includes the inverter circuit 5, the smoothing capacitor 3 that is arranged on the battery 1 (DC power supply) side of the inverter circuit 5 and connected in parallel with the inverter circuit 5, the inverter circuit 5, and the smoothing A limiting resistor 2 that is connected in series with the capacitor 3 and limits the inrush current from the battery 1 (DC power supply) to the inverter circuit 5 and the smoothing capacitor 3, and a switching means 4 that intermittently connects the resistance current Ir flowing through the limiting resistor 2, Main relays 12 and 13 are provided. Further, the inverter device 41 includes a current sensor 7 that measures the magnitude of the resistance current Ir, a power supply voltage sensor 8 that measures the power supply voltage Vb (battery terminal voltage) on the battery 1 side of the limiting resistor 2, and a smoothing. And a capacitor voltage sensor 9 that measures the magnitude of the voltage Vc between the capacitor terminals of the capacitor 3.

  The ECU 6 (abnormality detection device) has a known configuration including a CPU 6b, a ROM 6c, a RAM 6d, and the like, and is measured by the current sensor 7 at a first reference time tb as described later according to a built-in program. Based on the resistance current Irb, the power supply voltage Vbb measured by the power supply voltage sensor 8, and the capacitor terminal voltage Vcb measured by the capacitor voltage sensor 9, the first reference time with respect to the initial reference capacitance Co of the smoothing capacitor 3 The time-dependent capacity change rate γ (= Crb / Co) of the electrostatic capacity Crb of tb is calculated. Further, it is determined whether or not an abnormality has occurred in the inverter device 41 based on the calculated capacity change rate γ over time.

In the first embodiment, an apparatus including the inverter device 21 with abnormality detection function and the battery 1 is referred to as an inverter device 31 with battery abnormality detection function.
In the first embodiment, as the battery 1, an assembled battery formed by connecting a large number of nickel-metal hydride storage batteries in series is used.

Here, the abnormality determination process according to the inverter device 21 with the abnormality detection function of the first embodiment will be described with reference to FIG.
First, in step S1, the switch means 4 is closed (ON) and the main relay 13 is closed (ON) according to a command from the ECU 6. The main relay 12 is opened (OFF) in advance. Thereby, energization from the battery 1 to the smoothing capacitor 3 and the inverter circuit 5 through the limiting resistor 2 is started, and the inverter device 21 with an abnormality detection function is activated. At this time, an inrush current (resistance current Ir) flows from the battery 1 toward the smoothing capacitor 3 and the inverter circuit 5. Furthermore, in step S2, a timer is started and the elapsed time t from the start of energization is measured.

  Next, the process proceeds to step S3, and the ECU 6 determines whether or not the elapsed time t from the start of energization has reached the first reference time tb stored in the ROM 6c in advance (t = tb). If it is determined that the elapsed time t has not reached the first reference time tb (No), the determination in step S3 is repeated. In the first embodiment, the first reference time tb is set to 6 msec, for example.

  Thereafter, when it is determined that the elapsed time t has reached the first reference time tb (Yes), the process proceeds to step S4, the power supply voltage sensor 8 measures the power supply voltage Vbb at the first reference time tb, and this is detected by the ECU 6. Stored in the RAM 6d. Furthermore, the resistance current Irb at the first reference time tb is measured by the current sensor 7 and stored in the RAM 6d of the ECU 6. Further, the capacitor voltage sensor 9 measures the capacitor terminal voltage Vcb at the first reference time tb, and stores it in the RAM 6 d of the ECU 6.

Next, the process proceeds to step S5, and the first reference time tb with respect to the initial reference capacitance Co of the smoothing capacitor 3 based on the power supply voltage Vbb, the resistance current Irb, and the capacitor terminal voltage Vcb measured in step S4. The change rate γ (= Crb / Co) of the capacitance Crb with time is calculated and stored in the RAM 6d of the ECU 6. Specifically, the time-dependent capacity change rate γ at the first reference time tb is calculated using the following formula (4). In the first embodiment, the nominal capacitance Ck of the smoothing capacitor 3 is used as the initial reference capacitance Co of the smoothing capacitor 3.
γ = −tb / [Co × (Vbb−Vcb) / Irb] × ln [1− (Vcb / Vbb)] (4)

For example, when tb = 6 (msec), Co = Ck = 4700 (μF), Vbb = 400 (V), Vcb = 336 (V), Irb = 55 (A), from Equation (4),
γ = −6 × 10 ⁻³ / {4700 × 10 ⁻⁶ × (400-336) / 55} × ln {1- (336/400)} = 0.60.
From this result, it can be seen that the electrostatic capacity Crb of the smoothing capacitor 3 is reduced to 60% of the initial reference electrostatic capacity Co (nominal capacity Ck).

By the way, the equation (4) is obtained by changing the voltage Vcb between the capacitor terminals measured at the first reference time tb and the time constant τb (τb = Co × Rrb = Co × (Vbb−Vcb) / Irb at the first reference time tb. Therefore, the voltage between the terminals of the charged smoothing capacitor Vbb × {1-exp (−tb / τb)} is obtained from the following equation (4-1), which is assumed to be equal.
Vcb = Vbb × {1-exp (−tb / (Co × (Vbb−Vcb) / Irb)}} (4-1)

  Here, the power supply voltage Vbb, the resistance current Irb, and the capacitor terminal voltage Vcb are all values corresponding to the resistance value Rrb of the limiting resistor at the first reference time tb (Rrb = (Vbb−Vcb) / Irb). is there. Therefore, by calculating the time-dependent capacity change rate γ using the equation (4), a highly reliable time-dependent capacity change rate γ that takes into account the variation of the resistance value of the limiting resistor accompanying the temperature change of the limiting resistor is appropriately obtained. Obtainable.

  Next, the process proceeds to step S6, where it is determined whether or not the capacity change rate γ with time falls below a predetermined first reference value γ1 (for example, γ1 = 0.75). If it is determined that the time-dependent capacity change rate γ is lower than the first reference value γ1 (Yes), it is determined that an abnormality has occurred in the inverter device 41, the process proceeds to step S8, and the switch means 4 is opened (OFF). ) Thereby, since electricity supply through the limiting resistor 2 can be interrupted, abnormal temperature rise (burnout) of the limiting resistor 2 can be prevented.

  Then, it progresses to step S9, issues a 1st abnormality alarm, and notifies a driver | operator etc. of the abnormality of the inverter apparatus 41. FIG. In step S6, for example, the smoothing capacitor 3 is deteriorated with time, and the resistance value Rr of the limiting resistor 2 is greatly reduced due to an abnormality in which the capacitance of the smoothing capacitor 3 reaches the lifetime capacitance Cx, a short circuit, or the like. It is possible to detect abnormalities.

  On the other hand, if it is determined in step S6 that the time-dependent capacity change rate γ is not less than the first reference value γ1 (No), the process proceeds to step S7, where the time-dependent capacity change rate γ is a predetermined second reference value. It is determined whether or not γ2 (for example, γ2 = 1.25) is exceeded. If it is determined that the capacity change rate γ with time exceeds the second reference value γ2 (Yes), it is determined that the inverter device 41 is abnormal, and the process proceeds to step S8, where the switch means 4 is opened (OFF). . Thereby, since electricity supply through the limiting resistor 2 can be interrupted, abnormal temperature rise (burnout) of the limiting resistor 2 can be prevented.

  Then, it progresses to step S9, issues a 1st abnormality alarm, and notifies a driver | operator etc. of the abnormality of the inverter apparatus 41. FIG. In step S7, for example, an abnormality in which the smoothing capacitor 3 is short-circuited or an abnormality in which the inverter circuit 41 is short-circuited can be detected.

  On the other hand, if it is determined in step S7 that the time-dependent capacity change rate γ does not exceed the second reference value γ2 (No), the process proceeds to step SA, where the corresponding value corresponding to the predetermined condition satisfies the predetermined condition. It is determined whether or not the corresponding value T has been reached. When it is determined that the reference correspondence value T has been reached (Yes), the process proceeds to step SB, and the fluctuation rate Δγ / T of the time-dependent capacity change rate γ that has changed until the reference correspondence value T is reached is calculated.

  Here, the “predetermined condition” refers to a condition in which the characteristic change of the smoothing capacitor 3 is expected to be measurable. Furthermore, examples of the “standard corresponding value T satisfying the predetermined condition” include a predetermined increase amount (for example, T = 1000 times) applied to the number N of energizations from the battery 1 through the switch unit 4 and the limiting resistor 2. Can do. In this case, every time the energization number N increases by a predetermined reference number (for example, T = 1000 times), the variation rate Δγ / T of the time-dependent capacity change rate γ is calculated. For example, if the reference correspondence value T is 1000 times the increased energization number and the time-dependent capacity change rate γ decreases by 0.02 while the energization number N ranges from 8000 to 9000, the variation rate Δγ / T = −0. .02 / 1000 = −20 (ppm / time).

  In addition, the predetermined increase amount of the travel distance applied to the automobile on which the inverter device 21 with the abnormality detection function is mounted may be “a reference corresponding value T that satisfies a predetermined condition” (for example, T = 10000 km). In this case, every time the travel distance increases by a predetermined value (for example, T = 10000 km), the variation rate Δγ / T of the time-dependent capacity change rate γ is calculated. For example, when the reference correspondence value T is an increased travel distance of 10000 km and the capacity change rate γ decreases by 0.02 while the travel distance is from 80000 km to 90000 km, the change rate Δγ / T = −0.02 / 10000. = -2 (ppm / km).

  After calculating the fluctuation rate Δγ / T in step SB, the process proceeds to step SC, and whether or not the fluctuation rate Δγ / T is below a predetermined reference fluctuation rate G (for example, −30 ppm / time, −3 ppm / km, etc.). Determine whether. When it is determined that the fluctuation rate Δγ / T is lower than the reference fluctuation rate G (Yes), the deterioration abnormality of the smoothing capacitor 3 is detected, the process proceeds to step SD, and the abnormality of the inverter device 41 is approaching. A second abnormality alarm is issued.

  By the way, if it is determined in step SC that the relationship of Δγ / T <G is satisfied (Yes), even if the time-dependent capacity change rate γ is in the normal range (γ1 <γ <γ2), the time-dependent capacity is deteriorated due to the deterioration abnormality. Since the rate of change γ rapidly decreases, it can be estimated that the capacity change rate γ with time will be out of the normal range (satisfy γ <γ1). Therefore, when it is determined that Δγ / T <G, the second abnormality alarm that the inverter device 41 is approaching an abnormality is issued in step SD as in the first embodiment. Is preferred. In this way, before the smoothing capacitor 3 becomes abnormal, it is possible to prompt the driver or the like to take appropriate measures (such as replacement of the smoothing capacitor), and to prevent abnormal temperature rise (burnout) of the limiting resistor 2. You can also.

  After issuing the second abnormality alarm in step SD, the process proceeds to step SG and shifts to normal operation. Specifically, after energization is continued for a predetermined time without opening the switch means 4 and the main relay 13 (while being closed), the main relay 12 is closed (ON), and then the switch circuit 4 is opened (OFF). ) Thus, the battery 1 is energized from the battery 1 to the inverter circuit 5 without going through the limiting resistor 2, and the inverter circuit 5 starts conversion processing to AC power.

On the other hand, if it is determined in step SA that the reference correspondence value T is not satisfied (No), the process proceeds to step SE, and the life energization number Nx at which the capacitance of the smoothing capacitor 3 reaches the life capacitance Cx is determined. Calculate and store. Specifically, the number Nx of lifetime energization is calculated using the following equation (7), where Nh (Nh <Nx) is the number of energizations through the resistance when the capacity change rate γ is obtained.
Nx = Nh {1- (Cx / Co)} / (1-γ) (7)

This equation (7) is expressed as follows: capacitance change with time (Co−γ · Co) / Nh = Co (1−γ) / Nh of the smoothing capacitor 3 when energization via a resistor is performed Nh times, When the energization can be performed Nx times until the capacitance of the smoothing capacitor 3 reaches the lifetime capacitance Cx, the change in capacitance with time (Co-Cx) / Nx of the smoothing capacitor 3 per energization It is obtained from the following formula (7-1) that is assumed to be equal.
Co (1-γ) / Nh = (Co-Cx) / Nx (7-1)

Thereby, before the electrostatic capacitance of the smoothing capacitor 3 reaches the lifetime electrostatic capacitance Cx, the lifetime energization frequency Nx can be easily estimated.
If it is determined in step SC that the relationship Δγ / T <G is not satisfied (No), the process similarly proceeds to step SE and the above-described processing is performed.

Next, the process proceeds to step SF, where the number of energizations (remaining life energization times Nr) that are possible until the capacitance of the smoothing capacitor 3 reaches the life energization times Nx is estimated and displayed. Specifically, the remaining life energization frequency Nr (= Nx−Nh) can be obtained by subtracting the energization frequency Nh from the life energization frequency Nx calculated in step SE. Then, it progresses to step SG and transfers to normal operation as mentioned above.
In the first embodiment, such a process is repeated every time energization from the battery 1 through the switch means 4 and the limiting resistor 2 is performed.

  In the first embodiment, step S5 corresponds to a temporal change rate calculating means. Steps S6 and S7 correspond to abnormality determination means. Steps SB and SC correspond to deterioration abnormality detecting means. Step S8 corresponds to an opening instruction means. Step SE corresponds to life energization frequency estimation means.

(Example 2)
Next, an inverter device 22 with abnormality detection function (abnormality detection device 16) according to a second embodiment of the present invention will be described with reference to the drawings.
The inverter device 22 with the abnormality detection function of the second embodiment is different from the inverter device 21 with the abnormality detection function of the first embodiment only in the ECU (abnormality detection device), and the others are the same. Specifically, the only difference is that an ECU 16 having a different process by a built-in program is arranged instead of the ECU 6 of the first embodiment (see FIG. 1). Therefore, here, an abnormality determination process different from that of the first embodiment will be described, and description of the other will be omitted.
In addition, as shown in FIG. 1, let the apparatus provided with the battery 1 in addition to the inverter apparatus 22 with an abnormality detection function be the inverter apparatus 32 with a battery attached abnormality detection function.

Here, the abnormality determination process according to the inverter device 22 with the abnormality detection function of the second embodiment will be described with reference to FIG.
First, in step T1, the energization count N is integrated. Next, the process proceeds to step T2, and it is determined whether the energization count N exceeds a predetermined initial energization count Nd (for example, Nd = 3). If the energization count N does not exceed the initial energization count Nd, the process proceeds to step T3, and it is determined whether the energization count N has reached the initial energization count Nd (N = Nd).

  If it is determined in step T3 that the energization number N has not reached the initial energization number Nd (No), the process proceeds to step T4, and the switch means 4 is closed (ON) by a command from the ECU 6, and the main relay 13 Is closed (ON). The main relay 12 is opened (OFF) in advance. As a result, energization from the battery 1 to the smoothing capacitor 3 and the inverter circuit 5 through the limiting resistor 2 is started, and the inverter device 22 with an abnormality detection function is activated. At this time, an inrush current (resistance current Ir) flows from the battery 1 toward the smoothing capacitor 3 and the inverter circuit 5.

  Then, it progresses to step TR and transfers to normal operation. Specifically, after energization is continued for a predetermined time without opening the switch means 4 and the main relay 13 (while being closed), the main relay 12 is closed (ON), and then the switch circuit 4 is opened (OFF). ) Thus, the battery 1 is energized from the battery 1 to the inverter circuit 5 without going through the limiting resistor 2, and the inverter circuit 5 starts conversion processing to AC power.

  On the other hand, if it is determined in step T3 that the energization number N has reached the initial energization number Nd (Yes), the process proceeds to step T5, the switch means 4 is closed (ON), and the main relay 13 is closed ( ON). Furthermore, in step T6, a timer is started and the elapsed time t from the start of energization is measured.

  Next, the process proceeds to step T7, where the ECU 6 determines whether or not the elapsed time t from the start of energization has reached the second reference time tc stored in the ROM 6c in advance (t = tc). If it is determined that the elapsed time t has not reached the second reference time tc (No), the determination in step T7 is repeated. In the second embodiment, the second reference time tc is set to 6 msec, for example.

  Thereafter, when it is determined that the elapsed time t has reached the second reference time tc (Yes), the process proceeds to step T8, and the power supply voltage sensor 8 measures the power supply voltage Vbc at the second reference time tc. Stored in the RAM 6d. Furthermore, the resistance current Irc at the second reference time tc is measured by the current sensor 7 and stored in the RAM 6d of the ECU 16. Further, the capacitor voltage sensor 9 measures the capacitor terminal voltage Vcc at the second reference time tc and stores it in the RAM 6d of the ECU 16.

Next, proceeding to step T9, the second energization number Nd of the initial energization number Nd for the nominal capacity Ck of the smoothing capacitor 3 based on the power supply voltage Vbc, the resistance current Irc, and the capacitor terminal voltage Vcc measured in step T8. The initial capacitance ratio β (= Crc / Ck) of the electrostatic capacity Crc of the smoothing capacitor 3 at the reference time tc is calculated. Specifically, the initial capacity ratio β is calculated using the following formula (1).
β = −tc / [Ck × (Vbc−Vcc) / Irc] × ln [1− (Vcc / Vbc)] (1)

For example, when tc = 6 (msec), Ck = 4700 (μF), Vbc = 400 (V), Vcc = 240 (V), Irc = 138 (A), from equation (1),
β = −6 × 10 ⁻³ / {4700 × 10 ⁻⁶ × (400−240) / 138} × ln {1− (240/400)} = 1.2.
In this case, it is determined that the electrostatic capacity Crc of the smoothing capacitor 3 at the second reference time tc of the initial energization number Nd is 20% larger than the nominal capacity Ck.

By the way, the expression (1) is obtained according to the actual capacitor terminal voltage Vcc and the time constant τc at the second reference time tc (τc = β · Ck × Rrc = β · Ck × (Vbc−Vcc) / Irc). It is obtained from the following formula (1-1) that assumes that the terminal voltage Vbc × {1-exp (−tc / τc)} of the charged smoothing capacitor 3 is equal.
Vcc = Vbc × {1-exp (−tc / (β · Ck × (Vbc−Vcc) / Irc)}} (1-1)

  Here, the power supply voltage Vbc, the resistance current Irc, and the capacitor terminal voltage Vcc are all values (Rrc = (Vbc−Vcc) / Irc) corresponding to the resistance value Rrc of the limiting resistor 2 applied at the second reference time tc. ). Therefore, by calculating the initial capacitance ratio β using the equation (1), a highly reliable initial capacitance ratio β that takes into account the variation of the resistance value Rr of the limiting resistor 2 due to the temperature change of the limiting resistor 2 is appropriately obtained. Can get to.

Then, it progresses to step TR and transfers to a normal driving | operation as mentioned above.
Thereafter, when energization via resistance is performed again, as described above, the processing is performed in the order of steps T1 and T2, and in step T2, it is determined that the energization count N exceeds the initial energization count Nd (Yes). In this case, the process proceeds to step TA, and the switch means 4 is closed (ON) and the main relay 13 is closed (ON) according to a command from the ECU 16. Further, in step TB, a timer is started and the elapsed time t from the start of energization is measured. Thereafter, similarly to steps S3 and S4 of the first embodiment, the processes of steps TC and TD are performed, and the power supply voltage Vbb, the resistance current Irb, and the voltage Vcb between the capacitor terminals at the first reference time tb are measured. Stored in the RAM 6d.

Next, the process proceeds to step TE, and the first reference time tb with respect to the initial reference capacitance Co of the smoothing capacitor 3 based on the power supply voltage Vbb, the resistance current Irb, and the capacitor terminal voltage Vcb measured in step TD. The change rate γ (= Crb / Co) of the capacitance Crb with time is calculated and stored in the RAM 6d of the ECU 6. Specifically, the time-dependent capacity change rate γ at the first reference time tb is calculated using the following formula (4).
γ = −tb / [Co × (Vbb−Vcb) / Irb] × ln [1− (Vcb / Vbb)] (4)

  By the way, the smoothing capacitor 3 actually used may vary in a range of about −20% to + 20% with respect to the nominal capacitance Ck even in the initial capacitance. For this reason, when the time-dependent capacity change rate γ is calculated using the nominal capacity Ck as a reference, the time-dependent capacity change rate γ may be a value greatly deviating from the actual time-dependent capacity change rate.

  On the other hand, in Example 2, using the ratio (initial capacity ratio β) of the initial capacitance Crc to the nominal capacitance Ck obtained in the previous step T9, the time-dependent capacitance change in step TE. The rate γ is calculated. Specifically, the capacitance change rate γ over time is calculated using the corrected nominal capacitance β · Ck obtained by multiplying the nominal capacitance Ck by the initial capacitance ratio β (= Crc / Ck) as the reference capacitance Co of the smoothing capacitor 3. To do. Thereby, in the present Example 2, the highly reliable time-dependent capacity | capacitance change rate (gamma) can be obtained appropriately. Therefore, the abnormality of the inverter device 41 can be accurately detected by performing an abnormality determination (steps TF, TG, etc.) described later based on the capacity change rate γ over time.

For example, when tb = 6 (msec), Co = Ck = 4700 (μF), Vbb = 400 (V), Vcb = 336 (V), Irb = 55 (A), the initial value relative to the nominal capacity Ck of the smoothing capacitor 3 In consideration of the variation of the electrostatic capacity Crc (initial capacity ratio β = 1.2), the time-dependent capacity change rate γ is calculated from the equation (4).
γ = −6 × 10 ⁻³ /{1.2×4700×10 ⁻⁶ × (400-336) / 55} × ln {1− (336/400)} = 0.50.
In this case, it is determined that the capacitance Crb of the smoothing capacitor 3 is reduced by 50% with respect to the initial reference capacitance Co (= β · Ck).

In addition, without considering the variation of the initial capacitance Crc (the initial capacitance ratio β = 1.2) with respect to the nominal capacitance Ck of the smoothing capacitor 3, the time-dependent capacitance change rate γ is calculated from the equation (4).
γ = −6 × 10 ⁻³ / {4700 × 10 ⁻⁶ × (400-336) / 55} × ln {1- (336/400)} = 0.60.
In this case, it is determined that the capacitance Crb of the smoothing capacitor 3 is reduced by 40% with respect to the initial reference capacitance Co (= Ck). That is, it can be seen that an error of 10% occurs as compared with the case where the capacity change rate γ with time is calculated in consideration of the initial capacity rate β.

  Thereafter, similarly to Steps S6 to SG of Example 1, the processes of Steps TF to TR are performed. In the second embodiment, as described above, in step TE, the nominal capacitance Ck is multiplied by the initial capacitance ratio β (= Crc / Ck) as the reference capacitance Co of the smoothing capacitor 3. Using Ck, the capacity change rate γ with time is calculated. Therefore, based on the capacity change rate γ over time, the abnormality determination of the inverter device 41 in steps TF and TG, the deterioration abnormality detection of the smoothing capacitor 3 in step TM, and the life energization count Nx in step TP are estimated. These processes can be performed with high accuracy.

  In the second embodiment, step T9 corresponds to the initial capacity ratio calculating means. Step TE corresponds to a temporal change rate calculation means. Steps TF and TG correspond to abnormality determination means. Steps TL and TM correspond to deterioration abnormality detecting means. Step TH corresponds to an opening instruction means. Step TP corresponds to life energization frequency estimation means.

(Example 3)
Next, an inverter device 23 with abnormality detection function (abnormality detection device 26) according to Example 3 of the present invention will be described with reference to the drawings.
As shown in FIG. 4, the inverter device 23 with abnormality detection function of the third embodiment is different from the inverter device 22 with abnormality detection function of the second embodiment in that the ECU (abnormality detection device) is different from the power supply voltage. The difference is that the sensor 8 is not provided, and the other points are the same. Specifically, instead of the ECU 16 of the second embodiment, an ECU 26 having a different process by a built-in program is arranged (see FIG. 4).
In addition, as shown in FIG. 4, let the apparatus provided with the battery 1 in addition to the inverter apparatus 23 with an abnormality detection function be the inverter apparatus 33 with a battery attached abnormality detection function.

  Next, the abnormality determination process according to the inverter device 23 with the abnormality detection function of the third embodiment will be described with reference to FIG. The abnormality determination process according to the third embodiment is different from the abnormality determination process according to the second embodiment in the calculation method of the initial capacity rate β and the time-dependent capacity change rate γ, and the others are the same. Therefore, here, the description will focus on the differences from the abnormality determination process of the second embodiment, and the description of similar points will be omitted or simplified.

  First, in step U1, the number N of energizations is integrated. Next, the process proceeds to step U2, and it is determined whether the energization count N exceeds a predetermined initial energization count Nd (for example, Nd = 3). If the energization count N does not exceed the initial energization count Nd, the process proceeds to step U3, where it is determined whether the energization count N has reached the initial energization count Nd (N = Nd).

  If it is determined in step U3 that the energization number N has not reached the initial energization number Nd (No), the process proceeds to step U4, and the switch means 4 is closed (ON) in response to a command from the ECU 6, and the main relay 13 Is closed (ON). The main relay 12 is opened (OFF) in advance. As a result, energization from the battery 1 to the smoothing capacitor 3 and the inverter circuit 5 through the limiting resistor 2 is started, and the inverter device 23 with an abnormality detection function is activated.

  Then, it progresses to step UT and transfers to normal operation. Specifically, after energization is continued for a predetermined time without opening the switch means 4 and the main relay 13 (while being closed), the main relay 12 is closed (ON), and then the switch circuit 4 is opened (OFF). ) Thus, the battery 1 is energized from the battery 1 to the inverter circuit 5 without going through the limiting resistor 2, and the inverter circuit 5 starts conversion processing to AC power.

  On the other hand, if it is determined in step U3 that the energization count N has reached the initial energization count Nd (Yes), the flow proceeds to step U5, the switch means 4 is closed (ON), and the main relay 13 is closed ( ON). Furthermore, in step U6, a timer is started and the elapsed time t from the start of energization is measured.

  Next, the process proceeds to step U7, and the resistance current Ir is measured by the current sensor 7 every predetermined time, and the measured resistance current Ir is sequentially stored in the RAM 6d of the ECU 6. Next, the process proceeds to step U8, where the ECU 6 determines whether the elapsed time t from the start of energization has reached the second reference time tc stored in the ROM 6c in advance (t = tc). If it is determined that the elapsed time t has not reached the second reference time tc (No), the determination in step T7 is repeated. In addition, until the elapsed time t reaches the second reference time tc, the resistance current Ir is continuously measured by the current sensor 7 every predetermined time.

Thereafter, when it is determined that the elapsed time t has reached the second reference time tc (Yes), the process proceeds to step U9, where the capacitor voltage sensor 9 measures the capacitor terminal voltage Vcc at the second reference time tc. Is stored in the RAM 6d of the ECU 6.
Furthermore, the integral value of the resistance current Ir that flows from the start of energization to the second reference time tc is calculated using the following equation (2). Specifically, based on the resistance current Ir measured every predetermined time until reaching the second reference time tc, an integrated value of the resistance current Ir is obtained using the following formula (2).

Next, the process proceeds to step UA, where the initial capacity ratio is calculated by the following equation (3) based on the integrated value of the resistance current Ir (see equation (2)) and the capacitor terminal voltage Vcc obtained in step U9. β is calculated and stored in the RAM 6d of the ECU 6.
This equation (3) indicates the integral value of the resistance current Ir from the start of energization to the second reference time tc (see equation (2)) and the smoothing capacitor 3 from the start of energization to the second reference time tc. This is obtained from the following equation (3-1), assuming that the charged amount of charge Qc = β · Ck × Vcc is equal.

  Here, the integral value of the resistance current Ir (refer to the equation (2)) and the voltage Vcc between the capacitor terminals are both limited resistances that vary with the temperature change from the start of energization to the second reference time tc. The value corresponds to the resistance value. Therefore, by calculating the initial capacitance ratio β by the equation (3), a highly reliable initial capacitance ratio β that takes into account the variation of the resistance value of the limiting resistor 2 due to the temperature change of the limiting resistor 2 is appropriately obtained. Obtainable.

Thereafter, the process proceeds to Step UT, and the normal operation is performed as described above.
After that, also when energization via resistance is performed again, as described above, the processing is performed in the order of steps U1 and U2, and it is determined in step U2 that the energization count N exceeds the initial energization count Nd (Yes). In this case, the process proceeds to step UB, where the switch means 4 is closed (ON) and the main relay 13 is closed (ON) according to a command from the ECU 6. Further, in step UC, a timer is started and the elapsed time t from the start of energization is measured.

  Thereafter, similarly to step U7, the resistance current Ir is measured by the current sensor 7 every predetermined time, and the measured resistance current Ir is sequentially stored in the RAM 6d of the ECU 6. Next, the process proceeds to step UE, where the ECU 6 determines whether or not the elapsed time t from the start of energization has reached the first reference time tb stored in the ROM 6c in advance (t = tb). If it is determined that the elapsed time t has not reached the first reference time tb (No), the determination in step UE is repeated. In addition, until the elapsed time t reaches the first reference time tb, the resistance current Ir is continuously measured by the current sensor 7 every predetermined time.

  Thereafter, when it is determined that the elapsed time t has reached the first reference time tb (Yes) in the Ng-th resistance energization, the process proceeds to step UF, and the capacitor voltage sensor 9 causes the first reference time tb to be reached. The capacitor terminal voltage Vcb is measured and stored in the RAM 6d of the ECU 6. In the third embodiment, the energization count Ng is set to all energization counts greater than the initial energization count Nd.

Furthermore, the integral value of the resistance current Ir that flows from the start of energization to the first reference time tb is calculated using the following equation (5). Specifically, based on the resistance current Ir measured every predetermined time until reaching the first reference time tb, an integrated value of the resistance current Ir is obtained using the following formula (5).

Next, the process proceeds to step UG, and the capacity change with time is obtained by the following equation (6) based on the integrated value of the resistance current Ir (see equation (5)) and the capacitor terminal voltage Vcb obtained in the previous step UF. The rate γ is calculated and stored in the RAM 6d of the ECU 6. This equation (6) indicates the integral value of the resistance current Ir from the start of energization to the first reference time tb (see equation (5)) and the smoothing capacitor 3 from the start of energization to the first reference time tb. This is obtained from the following equation (6-1), assuming that the charged charge amount Qb = γ · Co × Vcb is equal.

  In the third embodiment, as in the second embodiment, as the reference capacitance Co of the smoothing capacitor 3, the capacitance change with time using the corrected nominal capacitance β · Ck obtained by multiplying the nominal capacitance Ck by the initial capacitance ratio β. The rate γ is calculated. For this reason, a time-dependent capacity change rate γ can be obtained with higher reliability than when the nominal capacitance Ck is used as it is as the reference capacitance Co. Therefore, as will be described later, by performing abnormality determination processing (steps UH, UL) based on such a capacity change rate γ with time, abnormality of the inverter device 42 can be detected with high accuracy.

  In addition, the integrated value of the resistance current Ir (see equation (5)) and the voltage Vcb between the capacitor terminals are both of the limiting resistor 2 that varies with the temperature change from the start of energization to the first reference time tb. This is a value corresponding to the resistance value Rr. Therefore, by calculating the time-dependent capacity change rate γ using the equation (6), a highly reliable time-dependent capacity change rate γ that takes into account the variation of the resistance value Rr of the limiting resistor 2 due to the temperature change of the limiting resistor 2 is obtained. Can be obtained properly.

  Thereafter, similarly to steps TF to TR of the second embodiment, the processes of steps UH to UT are performed. In the third embodiment, as in the second embodiment, in step UG, the nominal capacitance Ck is multiplied by the initial capacitance ratio β (= Crc / Ck) as the reference capacitance Co of the smoothing capacitor 3. Using Ck, the capacity change rate γ with time is calculated. Therefore, based on this time-dependent capacity change rate γ, abnormality determination of the inverter device 42 in steps UH and UL, detection of deterioration abnormality of the smoothing capacitor 3 in step UP, and estimation of the number Nx of life energization in step UR are performed. These processes can be performed with high accuracy.

  In the third embodiment, step UA corresponds to the initial capacity ratio calculating means. Step UG corresponds to a temporal change rate calculation means. Steps UH and UL correspond to abnormality determination means. Steps UN and UP correspond to deterioration abnormality detection means. Step UJ corresponds to an opening instruction means. Step UR corresponds to life energization frequency estimation means.

In the above, the present invention has been described with reference to the first to third embodiments. However, the present invention is not limited to the above-described embodiments, and it can be applied as appropriate without departing from the scope of the present invention. Nor.
For example, in Example 1 or the like, a nickel metal hydride storage battery is used as the DC power supply, but other batteries such as a lithium ion secondary battery may be used.

It is a block diagram of the inverter apparatuses 21 and 22 with an abnormality detection function concerning Example 1,2. 3 is a flowchart illustrating a flow of abnormality determination processing according to the first embodiment. 12 is a flowchart illustrating a flow of abnormality determination processing according to the second embodiment. It is a block diagram of the inverter apparatus 23 with an abnormality detection function concerning Example 3. FIG. 12 is a flowchart illustrating a flow of abnormality determination processing according to the third embodiment.

Explanation of symbols

1 Battery (DC power supply)
2 Limiting resistor 3 Smoothing capacitor 4 Switch means 5 Inverter circuits 6, 16, 26 ECU (abnormality detection device)
7 Current sensor 8 Power supply voltage sensor 9 Capacitor voltage sensor 21, 22, 23 Inverter devices 31, 32, 33 with abnormality detection function Inverter devices 41, 42 with battery attached abnormality detection function Inverter device

Claims (23)

An inverter circuit;
A smoothing capacitor that is disposed on the DC power supply side of the inverter circuit and connected in parallel with the inverter circuit,
A limiting resistor connected in series with the inverter circuit and the smoothing capacitor, and limiting an inrush current from the DC power source to the inverter circuit and the smoothing capacitor;
Switch means for interrupting the resistance current flowing through the limiting resistor;
An inverter device comprising:
A current sensor for measuring the magnitude of the resistance current;
A capacitor voltage sensor for measuring the magnitude of the voltage across the capacitor terminals of the smoothing capacitor;
The magnitude of the resistance current measured by the current sensor at a first reference time tb when a predetermined first reference time has elapsed from the start of energization in the energization via the resistance from the DC power source through the switch means and the limiting resistor. And the capacitance change rate γ with time of the capacitance Crb at the first reference time tb with respect to the initial reference capacitance Co of the smoothing capacitor based on the magnitude of the voltage across the capacitor terminals measured by the capacitor voltage sensor. A rate of change with time for calculating (= Crb / Co);
An inverter device with an abnormality detection function, comprising: an abnormality determination unit that determines whether an abnormality has occurred in the inverter device based on the time-dependent capacity change rate γ. The inverter device with an abnormality detection function according to claim 1,
The abnormality determining means includes
An inverter device with an abnormality detection function that determines that the inverter device is abnormal when the time-dependent capacity change rate γ falls below a predetermined first reference value γ1. An inverter device with an abnormality detection function according to claim 1 or claim 2,
The abnormality determining means includes
An inverter device with an abnormality detection function that determines that the inverter device is abnormal when the time-dependent capacity change rate γ exceeds a predetermined second reference value γ2. An inverter device with an abnormality detection function according to any one of claims 1 to 3,
An inverter device with an abnormality detection function, comprising: an opening instruction means for opening the switch means when the abnormality determining means determines that an abnormality has occurred in the inverter device. An inverter device with an abnormality detection function according to any one of claims 1 to 4,
The nominal capacity of the smoothing capacitor is Ck;
The resistance measured at a second reference time tc when a predetermined second reference time has elapsed from the start of energization via the resistance when the energization frequency N of the energization via the resistance is a predetermined initial energization frequency Nd. Based on the magnitude of the current and the voltage between the capacitor terminals, the capacitance Crc of the smoothing capacitor at the second reference time tc of the initial energization number Nd with respect to the nominal capacity Ck of the smoothing capacitor. An initial capacity ratio calculating means for calculating an initial capacity ratio β (= Crc / Ck);
The rate of change with time calculation means
An inverter device with an abnormality detection function using a corrected nominal capacitance β · Ck obtained by multiplying the nominal capacitance Ck by the initial capacitance ratio β as the reference capacitance Co of the smoothing capacitor. An inverter device with an abnormality detection function according to claim 5,
A power supply voltage sensor for measuring the power supply voltage on the DC power supply side from the limiting resistor,
The initial capacity ratio calculating means includes:
When the magnitude of the power supply voltage measured by the power supply voltage sensor at the second reference time tc is Vbc, the magnitude of the resistance current is Irc, and the magnitude of the voltage between the capacitor terminals is Vcc,
An inverter device with an abnormality detection function that acquires the initial capacity ratio β using the following formula (1).

β = −tc / [Ck × (Vbc−Vcc) / Irc] × ln [1− (Vcc / Vbc)] (1)
An inverter device with an abnormality detection function according to claim 5,
The initial capacity ratio calculating means includes:
In the initial energization number Nd, the integral value of the resistance current Ir flowing from the start of energization to the second reference time tc in the energization via the resistance is represented by the following formula (2):
When the voltage between the capacitor terminals at the second reference time tc is Vcc,
An inverter device with an abnormality detection function that acquires the initial capacity ratio β using the following formula (3).

An inverter device with an abnormality detection function according to any one of claims 1 to 7,
A power supply voltage sensor for measuring the power supply voltage on the DC power supply side from the limiting resistor,
The rate of change with time calculation means
When the magnitude of the power supply voltage measured by the power supply voltage sensor at the first reference time tb is Vbb, the magnitude of the resistance current is Irb, and the magnitude of the voltage between the capacitor terminals is Vcb,
An inverter device with an abnormality detection function that acquires the capacity change rate γ with time at the first reference time tb by using the following equation (4).

γ = −tb / [Co × (Vbb−Vcb) / Irb] × ln [1− (Vcb / Vbb)] (4)
An inverter device with an abnormality detection function according to any one of claims 1 to 7,
The rate of change with time calculation means
The integral value of the resistance current Ir that flows from the start of energization to the first reference time tb in the energization via the resistance at the Ng energization count exceeding the initial energization count Nd is represented by the following formula (5):
When the magnitude of the voltage between the capacitor terminals at the first reference time tb is Vcb,
An inverter device with an abnormality detection function that acquires the capacity change rate γ with time using the following formula (6).

An inverter device with an abnormality detection function according to any one of claims 1 to 9,
The rate of change with time calculation means
For each predetermined energization in which the corresponding value corresponding to the predetermined condition among the energization via the resistance reaches the reference corresponding value T satisfying the predetermined condition, the time-dependent capacity change rate γ is calculated and stored,
For each predetermined energization, the fluctuation rate (Δγ / T) of the time-dependent capacity change rate γ that has fluctuated until the reference corresponding value T is reached is calculated, and the fluctuation rate (Δγ / T) is a predetermined reference fluctuation rate G An inverter device with an abnormality detection function, comprising deterioration abnormality detecting means for detecting a deterioration abnormality of the smoothing capacitor when the value falls below. An inverter device with an abnormality detection function according to any one of claims 1 to 10,
Using Nh as the number of energizations through the resistor when the capacity change rate γ is obtained, the life energization number Nx at which the capacitance of the smoothing capacitor reaches the lifespan capacitance Cx is expressed by the following equation (7). An inverter device with an anomaly detection function comprising means for estimating the number of energization times for life estimation.

Nx = Nh {1- (Cx / Co)} / (1-γ) (7)
An inverter device with an abnormality detection function according to any one of claims 1 to 11,
An inverter device with a battery attached abnormality detection function, comprising: a battery as the DC power source. An inverter circuit, a smoothing capacitor disposed on the DC power supply side of the inverter circuit and connected in parallel to the inverter circuit, the inverter circuit and the smoothing capacitor connected in series, and the inverter circuit from the DC power supply And a limiting resistor for limiting the inrush current to the smoothing capacitor, switch means for interrupting the resistance current flowing through the limiting resistor, a current sensor for measuring the magnitude of the resistance current, and a voltage across the capacitor terminals of the smoothing capacitor Determining whether an abnormality has occurred in an inverter device comprising a capacitor voltage sensor that measures the magnitude of
An anomaly detection device,
The magnitude of the resistance current measured by the current sensor at a first reference time tb when a predetermined first reference time has elapsed from the start of energization in the energization via the resistance from the DC power source through the switch means and the limiting resistor. And the capacitance change rate γ with time of the capacitance Crb at the first reference time tb with respect to the initial reference capacitance Co of the smoothing capacitor based on the magnitude of the voltage across the capacitor terminals measured by the capacitor voltage sensor. A rate of change with time for calculating (= Crb / Co);
An abnormality detection device comprising: an abnormality determination unit that determines whether an abnormality has occurred in the inverter device based on the time-dependent capacity change rate γ. The abnormality detection device according to claim 13,
The abnormality determining means includes
An abnormality detection device that determines that the inverter device is abnormal when the time-dependent capacity change rate γ falls below a predetermined first reference value γ1. The abnormality detection device according to claim 13 or claim 14,
The abnormality determining means includes
An abnormality detection device that determines that the inverter device is abnormal when the time-dependent capacity change rate γ exceeds a predetermined second reference value γ2. The abnormality detection device according to any one of claims 13 to 15,
An abnormality detection apparatus comprising: an opening instruction means for opening the switch means when the abnormality determination means determines that an abnormality has occurred in the inverter device. It is an abnormality detection device according to any one of claims 13 to 16,
The nominal capacity of the smoothing capacitor is Ck;
The resistance measured at a second reference time tc when a predetermined second reference time has elapsed from the start of energization via the resistance when the energization frequency N of the energization via the resistance is a predetermined initial energization frequency Nd. Based on the magnitude of the current and the voltage between the capacitor terminals, the capacitance Crc of the smoothing capacitor at the second reference time tc of the initial energization number Nd with respect to the nominal capacity Ck of the smoothing capacitor. An initial capacity ratio calculating means for calculating an initial capacity ratio β (= Crc / Ck);
The rate of change with time calculation means
An abnormality detection apparatus using a corrected nominal capacitance β · Ck obtained by multiplying the nominal capacitance Ck by the initial capacitance ratio β as the reference capacitance Co of the smoothing capacitor. The abnormality detection device according to claim 17,
The inverter device is an inverter device including a power supply voltage sensor that measures a power supply voltage on the DC power supply side with respect to the limiting resistor,
The initial capacity ratio calculating means includes:
When the magnitude of the power supply voltage measured by the power supply voltage sensor at the second reference time tc is Vbc, the magnitude of the resistance current is Irc, and the magnitude of the voltage between the capacitor terminals is Vcc,
An abnormality detection apparatus that acquires the initial capacity ratio β using the following formula (1).

β = −tc / [Ck × (Vbc−Vcc) / Irc] × ln [1− (Vcc / Vbc)] (1)
The abnormality detection device according to claim 17,
The initial capacity ratio calculating means includes:
In the initial energization number Nd, the integral value of the resistance current Ir flowing from the start of energization to the second reference time tc in the energization via the resistance is represented by the following formula (2):
When the voltage between the capacitor terminals at the second reference time tc is Vcc,
An abnormality detection apparatus that acquires the initial capacity ratio β using the following equation (3).

The abnormality detection device according to any one of claims 13 to 19,
The inverter device is an inverter device including a power supply voltage sensor that measures a power supply voltage on the DC power supply side with respect to the limiting resistor,
The rate of change with time calculation means
When the magnitude of the power supply voltage measured by the power supply voltage sensor at the first reference time tb is Vbb, the magnitude of the resistance current is Irb, and the magnitude of the voltage between the capacitor terminals is Vcb,
An abnormality detection apparatus that acquires the time-dependent capacity change rate γ at the first reference time tb by using the following formula (4).

γ = −tb / [Co × (Vbb−Vcb) / Irb] × ln [1− (Vcb / Vbb)] (4)
The abnormality detection device according to any one of claims 13 to 19,
The rate of change with time calculation means
The integral value of the resistance current Ir that flows from the start of energization to the first reference time tb in the energization via the resistance at the Ng energization count exceeding the initial energization count Nd is represented by the following formula (5):
When the magnitude of the voltage between the capacitor terminals at the first reference time tb is Vcb,
An abnormality detection apparatus that acquires the time-dependent capacity change rate γ using the following equation (6).

The abnormality detection device according to any one of claims 13 to 21,
The rate of change with time calculation means
For each predetermined energization in which the corresponding value corresponding to the predetermined condition among the energization via the resistance reaches the reference corresponding value T satisfying the predetermined condition, the time-dependent capacity change rate γ is calculated and stored,
For each predetermined energization, the fluctuation rate (Δγ / T) of the time-dependent capacity change rate γ that has fluctuated until the reference corresponding value T is reached is calculated, and the fluctuation rate (Δγ / T) is a predetermined reference fluctuation rate G An abnormality detecting device comprising a deterioration abnormality detecting means for detecting a deterioration abnormality of the smoothing capacitor when the value falls below. The abnormality detection device according to any one of claims 13 to 22,
Using Nh as the number of energizations through the resistor when the capacity change rate γ is obtained, the life energization number Nx at which the capacitance of the smoothing capacitor reaches the lifespan capacitance Cx is expressed by the following equation (7). An abnormality detection apparatus comprising life energization frequency estimation means for estimation.

Nx = Nh {1- (Cx / Co)} / (1-γ) (7)

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