KR20130110553A - Capacitor lifetime calculator for electir vehicle and motor controlling apparatus having the same, and monitoring method of the same - Google Patents

Abstract

PURPOSE: A capacitor life calculation unit for an electric car, a motor control including the same, and the monitoring method thereof are provided to predict the life of capacitor, thereby knowing when to exchange a direct current (DC) link capacitor. CONSTITUTION: A DC link capacitor (210) is connected to a battery and stores DC voltage. An inverter (270) contains a plurality of switching elements and converts DC voltage into motor driving voltage according to control signals and provides them for a motor. A remaining capacitor life calculation unit (220) calculates the consumed amount of power of the DC link capacitor and collects them, and estimates the ripple current included in the DC link capacitor using collected consumed amount of power. The remaining capacitor life calculation unit calculates the life of the DC link capacitor based on the estimated temperature differences and calculated consumed amount of power. [Reference numerals] (100) Battery; (110) Converter; (220) Remaining capacitor life calculation unit; (221) Current estimating module; (222) Consumed power calculating module; (230) Display unit; (250) Voltage detecting unit; (270) Inverter

Description

CAPACCITOR LIFETIME CALCULATOR FOR ELECTIR VEHICLE AND MOTOR CONTROLLING APPARATUS HAVING THE SAME, AND MONITORING METHOD OF THE SAME}

The present invention relates to a capacitor lifetime calculator for an electric vehicle, a motor control apparatus including the same, and a method of monitoring the same, which determine a service life and a replacement time of a DC link capacitor using the accumulated power consumption.

An electric vehicle (EV) refers to a vehicle using an electric battery and an electric motor without using petroleum fuel and an engine, and an electric vehicle using only an electric battery, and other power sources such as gasoline and electric. It includes a hybrid electric vehicle that uses a battery together. An electric vehicle that drives an automobile by rotating an electric motor that is stored in a battery was manufactured earlier than a gasoline automobile in 1873, but was not put to practical use due to problems such as a heavy weight of the battery and a time required for charging. Recently, due to the lack of energy resources such as fossil fuels and environmental pollution caused by gasoline cars, it was re-developed from the 1990s.

As an electric motor for an electric vehicle, both a DC motor and an AC motor may be used, but recently, a brushless DC motor or an induction motor is used, or a modified one thereof is mainly used.

Such an electric vehicle requires a DC link capacitor for smoothly storing a DC voltage supplied from an internal battery, and the DC link capacitor must be replaced at an appropriate time.

However, the replacement time of the conventional DC link capacitor has been indirectly performed by checking the amount of heat generated in the capacitor and predicting the life of the capacitor therefrom. Therefore, it was necessary to find a way to more accurately understand the life time of the DC link capacitor and the replacement time.

Exemplary embodiments of the present invention provide a capacitor lifetime calculator for an electric vehicle, a motor control device including the same, and a method for monitoring the same, using the accumulated value of real-time power consumption calculation of the DC link capacitor. The purpose is to provide.

In addition, embodiments of the present invention can estimate the ripple current value from the power consumption of the DC link capacitor, and by using the corresponding temperature change value and the accumulated power consumption of the capacitor to more accurately predict the life time of the DC link capacitor An object of the present invention is to provide an automobile capacitor life calculator, a motor control device including the same, and a method for monitoring the same.

A motor control apparatus according to an embodiment of the present invention includes: a DC link capacitor connected to a battery to smooth and store a DC voltage; An inverter having a plurality of switching elements, converting a DC voltage output from the DC link capacitor into a motor driving voltage according to a control signal and providing the same to a motor; The power consumption of the DC link capacitor is calculated and accumulated in real time, the ripple current included in the DC link capacitor is estimated using the accumulated power consumption, and an internal temperature change value corresponding to the estimated ripple current and the accumulation are calculated. And a capacitor lifetime calculation unit configured to calculate a life time of the DC link capacitor based on the amount of power consumed.

In an embodiment, the capacitor life expectancy calculating unit calculates and accumulates the power consumption of the DC link capacitor in real time based on the torque and the rotor speed of the motor, and averages the power consumption by a predetermined time unit to calculate the average power consumption. A power calculation module; A current estimation module estimating a ripple current of the DC link capacitor using the accumulated power consumption and the DC voltage value of the DC link capacitor; And a memory module for storing a capacitor life time table prepared based on an internal temperature change value of the DC link capacitor corresponding to the ripple current and the accumulated power consumption.

In an embodiment, the motor control apparatus may calculate and accumulate the power consumption by the power consumption calculation module in real time when the starting power of the electric vehicle is on, and start power of the electric vehicle is off. In this case, the power consumption accumulated immediately before is stored in the memory module.

In an embodiment, the current estimating module may estimate the power consumption divided by the DC voltage value as the ripple current value of the DC link capacitor.

In an embodiment, the motor control apparatus may further include a display unit which displays a life time of the DC link capacitor and whether it is replaced.

The motor control apparatus may further include a voltage detector configured to detect a voltage applied to the DC link capacitor.

In an embodiment, the motor control device may include: a converter positioned between the battery and the DC link capacitor to boost or step down the DC voltage of the battery to provide the DC link capacitor; And further comprising:

In an embodiment, the motor control apparatus may further include a controller configured to generate the motor driving voltage by outputting the control signal to the inverter.

In addition, the capacitor lifetime calculator according to an embodiment of the present invention, a DC link capacitor connected to the battery to smooth and store the DC voltage, and provides the stored DC voltage to the inverter for driving the motor; The power consumption of the DC link capacitor is calculated and accumulated in real time, the ripple current included in the DC link capacitor is estimated using the accumulated power consumption, and the internal temperature of the DC link capacitor corresponding to the estimated ripple current is calculated. A capacitor lifetime calculation unit for calculating a lifetime of the DC link capacitor based on a change value and the accumulated power consumption; And a control unit.

In an embodiment, the capacitor lifetime calculation unit may include: a power consumption calculation unit configured to calculate and accumulate power consumption of the DC link capacitor in real time, and average the result by a predetermined time unit to calculate an average power consumption; A current estimating unit estimating a ripple current value of the DC link capacitor by using the average power consumption and a DC voltage value applied to the DC link capacitor; And a memory for storing a life time table of the DC link capacitor and the accumulated average power consumption based on an internal temperature change value of the DC link capacitor corresponding to the ripple current value and the power consumption amount calculated in real time. Is done.

In an embodiment, the capacitor life calculator may further include a display unit that displays the calculated lifetime of the DC link capacitor and whether the DC link capacitor is replaced.

Furthermore, the monitoring method of the motor control apparatus according to an embodiment of the present invention, a DC link capacitor connected to the battery to smooth and store the DC voltage, and a DC voltage output from the DC link capacitor using a plurality of switching elements. A monitoring method for a motor control apparatus including an inverter for converting a motor driving voltage into a motor, the method comprising: real time calculating an amount of power consumption of the DC link capacitor based on a torque and a rotor speed of the motor; Accumulating the amount of power consumed and averaging by a predetermined time unit and storing the value; Detecting a DC voltage applied to the DC link capacitor; Estimating a ripple current value flowing through the DC link capacitor using the stored average power consumption and the detected DC voltage; calculating an internal temperature change value of the DC link capacitor corresponding to the ripple current and the stored average power consumption; Calculating a life time of the DC link capacitor using the;

In an embodiment, the monitoring method may further include displaying a lifetime and whether or not to replace the DC link capacitor.

Embodiments of the present invention can determine the replacement time of the DC link capacitor by predicting the life time of the DC link capacitor using the accumulated value of the power consumption by the DC link capacitor in real time.

In addition, embodiments of the present invention estimates the magnitude of the ripple current from the power consumption of the DC link capacitor and derives the temperature change value of the capacitor corresponding thereto, thereby more accurately notifying the service life and replacement time of the DC link capacitor. It improves the operating efficiency and system stability.

1 is a view schematically showing an electric vehicle according to embodiments of the present invention;
2 is a block diagram schematically illustrating a configuration of a motor control apparatus including a capacitor life calculator according to embodiments of the present disclosure;
3 is a graph showing a relationship between a ripple current value of a DC link capacitor and an internal temperature change value corresponding thereto;
4 is a graph showing the life time of the DC link capacitor corresponding to the cumulative power consumption and the internal temperature change value of the DC link capacitor;
5 is a flowchart illustrating a process of calculating a life time of a capacitor in a monitoring method of a motor control apparatus according to an exemplary embodiment of the present invention.

Hereinafter, a capacitor life calculator for an electric vehicle, a motor control apparatus including the same, and a monitoring method thereof will be described in detail with reference to the accompanying drawings.

First, referring to FIG. 1, an electric vehicle according to an embodiment of the present invention may generate a rotational force by converting a battery 100 supplying DC power and a DC power supplied by the battery 100 to AC power. Power module 150, the front wheel 510 and the rear wheel 520 rotated by the power module 150, the front wheel suspension 610 and rear wheel suspension 620 to block the vibration of the road surface to the vehicle body Include. In addition, the electric vehicle may further include a drive gear (not shown) for converting the rotational speed of the motor 300 according to the gear ratio.

The power module 150 includes a motor control device 200 that receives DC power from the battery 100, and a motor 300 driven by the motor control device 200 to generate rotational force.

The battery 100 supplies DC power to the power module 150. The battery 100 generally forms a set in which a plurality of unit cells are connected in series and / or in parallel. The plurality of unit cells are managed to maintain a constant voltage by a battery management system (BMS). That is, the battery management system causes the battery 100 to emit a constant voltage. The battery 100 is preferably configured as a secondary battery capable of charging and discharging, but is not limited thereto. As the battery 100, a nickel metal hydride (Ni-MH) battery or a lithium ion (Li-ion) battery is generally used.

The motor control apparatus 200 receives a DC power from the battery 100. The motor control apparatus 200 converts the DC power received from the battery 100 into AC power and supplies the same to the motor 300. In general, the motor control device 200 supplies a three-phase AC power to the motor.

The motor 300 is composed of a stator (not shown) that is fixed without rotation and a rotating rotor (not shown), and generates a rotational force by receiving AC power supplied from the motor control apparatus 200. When AC power is applied to the motor 300, the stator of the motor 300 receives AC power to generate a magnetic field. In the case of a motor having a permanent magnet, the rotor rotates due to the repulsion of the magnetic field generated by the stator and the magnetic field of the permanent magnet provided in the rotor. The rotational force is generated by the rotation of the rotor.

One side of the motor 300 may be provided with a drive gear (not shown). The drive gear converts the rotational force of the motor 300 according to the gear ratio. The rotational force output from the drive gear is transmitted to the front wheel 510 and / or the rear wheel 520 to allow the vehicle to move.

The front wheel suspension 610 and the rear wheel suspension 620 support the front wheel 510 and the rear wheel 520 with respect to the vehicle body, respectively. The front wheel suspension 610 and the rear wheel suspension 620 prevent the vibration of the road surface from touching the vehicle body by a spring or a damping mechanism.

The front wheel 510 may be further provided with a steering device (not shown). The steering device is a device for adjusting the direction of the front wheel 510 to drive the vehicle in the direction intended by the driver.

Now, with reference to Figure 2 looks at the configuration of a motor control device including a capacitor life calculator according to an embodiment of the present invention.

Referring to FIG. 2, the motor control apparatus includes a DC link capacitor 210 connected to a battery 100 to smooth and store a DC voltage, and a plurality of switching elements, according to a control signal. An inverter 270 that converts a DC voltage output from the 210 into a motor driving voltage and provides the motor 300 to the motor 300, and further calculates and accumulates power consumption of the DC link capacitor 210 in real time, The ripple current included in the DC link capacitor is estimated using the accumulated power consumption, and the life time of the DC link capacitor 210 is based on an internal temperature change value corresponding to the estimated ripple current and the accumulated power consumption. It includes a capacitor spare life calculation unit 220 for calculating the. In addition, the motor control apparatus further includes a voltage detector 250 for detecting a voltage of the DC link capacitor 210 and a display unit 230 for displaying the calculated capacitor life.

The DC link capacitor 210 is connected between the battery 100 and the inverter 270 or provided between the converter 110 and the inverter 270 when the DC link capacitor 210 includes a converter. do. The DC link capacitor 210 smoothes and stores the output voltage of the battery 100. In addition, the DC link capacitor 210 smoothes the DC voltage boosted and output from the converter 110.

The inverter 270 includes a plurality of switching elements, and applies a motor driving voltage to the motor 300 by using a PWM driving signal according to a predetermined control signal, for example, a control signal output from a controller (not shown). do.

The motor control apparatus may further include a converter 110 for boosting or stepping down the DC voltage supplied from the battery 100. Such a converter includes a switching element, for example, an Insulated Gate Bipolar Transistor (IGBT), and may further include a reactor as necessary.

The converter 110 is connected to the battery 100, a boost converter for boosting the voltage between the ground line and the power line, that is, the DC voltage generated by the battery 100, or may be implemented to step down as necessary. Can be.

Subsequently, referring to FIG. 2, the motor control apparatus includes a capacitor spare life calculation unit 220 for determining a replacement time of the DC link capacitor 210. The capacitor life expectancy calculator 220 calculates and accumulates power consumption of the DC link capacitor 210 in real time. In addition, the capacitor life expectancy calculator 220 estimates the ripple current included in the DC link capacitor using the accumulated power consumption. In addition, the capacitor lifetime calculation unit 220 calculates the life time of the DC link capacitor 210 based on the internal temperature change value and the accumulated power consumption corresponding to the estimated ripple current. The capacitor lifetime calculation unit 220 includes a power consumption calculation module 222, a current estimation module 221, and a memory module (eg, a database) 223.

The power consumption calculation module 222 calculates and accumulates the power consumption of the DC link capacitor 210 in real time based on the torque command of the motor 300 and the rotor speed. In addition, the power consumption calculation module 222 averages the accumulated power consumption in a predetermined time unit, for example, a minute, an hour, or a day, so that the DC link capacitor 210 is averaged. The average power consumption of can be calculated. In addition, the power consumption calculation module 222 calculates the power consumption in real time when the starting power of the electric vehicle is in an ON state, that is, an IGN ON state.

More specifically, the power consumption calculation module 222 includes an algorithm for calculating the power consumption of the DC link capacitor 210 through the following equation (1). Equation 1 below is derived based on the lifespan of the DC link capacitor 210 is proportional to the accumulated power consumption.

Where T is the rotational torque of the motor, W is the rotor speed, ie the angular speed of the motor, and I _s And V _s are the grid current and the grid voltage, i _d and v _d are the current and voltage of the d-axis, respectively, and i _q And w _q represent current and voltage on the q-axis, respectively, and I _dc and V _dc represent DC current and DC voltage, respectively.

The current estimating module 221 estimates a ripple current flowing through the DC link capacitor using the accumulated power consumption amount and the DC voltage value of the DC link capacitor 210. The magnitude of the ripple current A estimated by the current estimation module 221 is proportional to the accumulated power consumption and also proportional to the life of the DC link capacitor. In addition, the current estimation module 221 estimates the ripple current through the following equation derived from Equation (1).

In addition, the current estimation module 221 estimates the power consumption divided by the DC voltage value by the ripple current value of the DC link capacitor 210. To this end, the current estimation module 221 receives a voltage value from the voltage detector 250 for detecting a voltage applied to the DC link.

In this regard, referring to FIG. 3, the relationship between the ripple current value A estimated by the current estimation module 221 and the corresponding capacitor internal temperature change value ΔT is shown. The test conditions of the graph shown in FIG. 6 show that the switching frequency is 16 Hz, the magnitude of the voltage applied to the DC link is 557 V at maximum, and the dry oven temperature is about 85 ° C. In addition, the relationship between the ripple current and the internal temperature change in the circulation and the non-circulation is shown depending on the circulation of about 8 liters per minute (L). In either case, as the ripple current increases, the temperature change in the capacitor increases. For example, in non-circulation, the internal temperature change of the capacitor when the estimated ripple current value is 100A, that is, ΔT ° C may have about 5 values, and the internal temperature change of the capacitor when the estimated ripple current value is 148A. The value, ΔT ° C., may have about 10 values. Further, for example, in the case of circulation, when the estimated ripple current value is 100A, the internal temperature change value of the capacitor, that is, ΔT ° C may have a value of about −5, and in the case of the estimated ripple current value in the circulation, 148A The temperature change value of the capacitor, that is, ΔT ° C., may have about three values. As such, the magnitude of the ripple current and the temperature change in the capacitor have a proportional relationship. As a result, the use time of the DC link capacitor increases proportionally as the magnitude of the ripple current increases.

4 shows the cumulative power consumption of the DC link capacitor and the life time of the DC link capacitor according to an internal temperature change value corresponding to the ripple current. As shown, the x-axis shows that the power consumption of the DC link capacitor gradually decreases, and the y-axis shows the life time of the DC link capacitor. In addition, graphs a, b, c, ..., h represent a case in which the temperature change value of the capacitor increases as the alphabet increases.

According to FIG. 4, the lifetime hr of the DC link capacitor decreases as the power consumption of the capacitor increases. On the other hand, as the power consumption of the capacitor is smaller, the life time time (Hr) of the DC link capacitor increases. In addition, the lifetime Hr of the DC link capacitor increases as the temperature change of the capacitor in proportion to the ripple current decreases. On the other hand, it can be seen that the lifetime Hr of the DC link capacitor decreases as the temperature change value of the capacitor proportional to the ripple current increases. That is, the relationship between the capacitor usage time of the motor control device, the magnitude of the ripple current, and the amount of power consumption can be expressed as follows.

Term of Capacitor ∝ Ripple Current ∝ Power Consumption

The life expectancy of the capacitor is proportional to the sum of the instantaneous power consumption and the driving power consumption.For example, if the life expectancy of the capacitor is 80 KW when 10000h * 3600, the power of the capacitor is 47KW. Life expectancy can be derived from the proportional formula for it. In addition, the temperature change value of the capacitor internal to the ripple current can be experimentally determined in advance. In this way, the integrated life expectancy of the DC link capacitor according to the expected life time of the capacitor proportional to the sum of the power consumption and the expected life time of the capacitor proportional to the temperature change value of the capacitor corresponding to the ripple current is calculated through an internal algorithm. May be implemented.

2, the memory module 223 stores a capacitor life time table prepared based on an internal temperature change value of the capacitor corresponding to the estimated ripple current and the accumulated power consumption. Here, the capacitor life time table shows a capacitor life time value corresponding to the power consumption amount and the internal temperature change value corresponding to FIG. 4 in a table form. The memory module 223 stores the amount of power immediately accumulated when the starting power of the electric vehicle is in an OFF state, that is, an IGN OFF state. In addition, the memory module 223 provides a previously stored cumulative power consumption when the starting power of the electric vehicle is switched to an ON state.

The display unit 230 displays the calculated screen output means and / or sound output means and the like for the calculated lifetime of the DC link capacitor. In addition, the display unit 230 may further display whether to replace the device according to the calculated life time of the DC link capacitor.

In addition, the capacitor life calculator according to an embodiment of the present invention with reference to Figures 2 to 4, the DC link is connected to the battery of the electric vehicle to smooth and store the DC voltage and provide the stored DC voltage to the inverter for driving the motor The power consumption of the capacitor 210 and the DC link capacitor is calculated and accumulated in real time, the ripple current included in the DC link capacitor is estimated using the accumulated power consumption, and the DC corresponding to the estimated ripple current is calculated. And a capacitor spare life calculation unit 220 for calculating a life time of the DC link capacitor based on an internal temperature change value of the link capacitor and the accumulated power consumption amount. According to this, it is possible to determine in advance the replacement time of the DC link capacitor by predicting the life time of the DC link capacitor based on the accumulated value of the power consumption of the DC link capacitor in real time.

Now, with reference to FIG. 5, the life time calculation process of a DC link capacitor is described as a monitoring method of the said motor control apparatus. The motor control apparatus includes a DC link capacitor connected to a battery to smooth and store a DC voltage, and an inverter converting a DC voltage output from the DC link capacitor into a motor driving voltage using a plurality of switching elements and providing the motor to a motor. It includes.

First, the method calculates the power consumption of the DC link capacitor in real time based on the torque and the rotor speed of the motor (S10). Specifically, the amount of power consumption is calculated by the following equation, for example, every second.

Where T is the rotational torque of the motor, W is the rotor speed, angular speed of the motor, Is and Vs are the grid current and grid voltage, id and vd are the d-axis current and voltage, respectively, and iq and wq are Represent the q-axis current and voltage, respectively, and Idc and Vdc represent the dc current and dc voltage, respectively.

Then, the calculated power consumption is accumulated, averaged by a predetermined time unit, and the value is stored (S20). For example, the accumulated power consumption in seconds is averaged and reset after 1 minute, and then the power consumption is accumulated in minutes. After 1 hour, the accumulated power consumption is reset and averaged after 1 hour. Then, the power consumption is accumulated daily. In addition, a DC voltage applied to the DC link capacitor is detected through predetermined detection means (S30).

Then, the ripple current value flowing through the DC link capacitor is estimated using the average power consumption and the detected DC voltage (S40). Estimation of the ripple current is performed by the following equation.

A life time of the DC link capacitor is calculated using an internal temperature change value of the capacitor corresponding to the estimated ripple current and the stored average power consumption at step S50. In addition, in the exemplary embodiment, the calculated lifetime of the DC link capacitor and whether or not the device is replaced is displayed through a predetermined display device.

As described above, according to the capacitor lifetime calculator for an electric vehicle, a motor control apparatus including the same, and a monitoring method thereof, the power consumption by the DC link capacitor is calculated in real time to use the accumulated value. By estimating the life time of the DC link capacitor, estimating the magnitude of the ripple current from the power consumption and deriving a corresponding temperature change value of the capacitor, the life time and replacement time of the DC link capacitor can be calculated more accurately.

100: battery 110: converter
200: motor control device 210: DC link capacitor
220: capacitor lifetime calculation unit 221: current estimation module
222: power consumption calculation module 223: memory module
230: display unit 250: voltage detection unit
270: inverter 300: motor

Claims (13)

A DC link capacitor connected to the battery to smooth and store a DC voltage;
An inverter having a plurality of switching elements, converting a DC voltage output from the DC link capacitor into a motor driving voltage according to a control signal and providing the same to a motor; And
The power consumption of the DC link capacitor is calculated and accumulated in real time, the ripple current included in the DC link capacitor is estimated using the accumulated power consumption, and an internal temperature change value corresponding to the estimated ripple current and the accumulation are calculated. Characterized in that it comprises; a capacitor lifetime calculation unit for calculating the life time of the DC link capacitor based on the amount of power consumption
Motor control device. The method according to claim 1,
The capacitor life expectancy calculator,
A power consumption calculation module configured to calculate and accumulate the power consumption of the DC link capacitor in real time based on the torque and the rotor speed of the motor, and average the result by a predetermined time unit to calculate an average power consumption;
A current estimation module estimating a ripple current of the DC link capacitor using the accumulated power consumption and the DC voltage value of the DC link capacitor;
And a memory module configured to store a capacitor life time table generated based on an internal temperature change value of the DC link capacitor corresponding to the ripple current and the accumulated power consumption.
Motor control device. The method of claim 2,
When the starting power of the electric vehicle is on, the power consumption calculation module calculates and consumes the power consumption in real time.
When the starting power of the electric vehicle is off (off) state, characterized in that for storing the power consumption accumulated immediately before in the memory module,
Motor control device. The method of claim 2,
The current estimation module,
Characterized in that the power consumption divided by the DC voltage value to estimate the ripple current value of the DC link capacitor,
Motor control device. The method according to claim 1,
Characterized in that it further comprises; the display unit for displaying the life time and whether the replacement of the DC link capacitor,
Motor control device. The method according to claim 1,
And a voltage detector detecting a voltage applied to the DC link capacitor.
Motor control device. The method according to claim 1,
A converter positioned between the battery and the DC link capacitor to boost or step down the DC voltage of the battery to provide the DC link capacitor; Lt; RTI ID = 0.0 > 1, < / RTI &
Motor control device. The method according to claim 1,
And a controller configured to generate the motor driving voltage by outputting the control signal to the inverter.
Motor control device. A DC link capacitor connected to a battery of an electric vehicle to smooth and store a DC voltage and provide the stored DC voltage to an inverter for driving a motor;
The power consumption of the DC link capacitor is calculated and accumulated in real time, the ripple current included in the DC link capacitor is estimated using the accumulated power consumption, and the internal temperature of the DC link capacitor corresponding to the estimated ripple current is calculated. A capacitor margin life calculation unit calculating a life time of the DC link capacitor based on a change value and the accumulated power consumption; ≪ / RTI >
Capacitor life calculator for electric vehicles. 10. The method of claim 9,
The capacitor lifetime calculation unit,
A power consumption calculator configured to calculate and accumulate power consumption of the DC link capacitors in real time, and average the power consumptions by a predetermined time unit to calculate an average power consumption;
A current estimating unit estimating a ripple current value of the DC link capacitor by using the average power consumption and a DC voltage value applied to the DC link capacitor;
And a memory configured to store a life time table of the DC link capacitor and the accumulated average power consumption based on an internal temperature change value of the DC link capacitor corresponding to the ripple current value and the power consumption amount calculated in real time. Characterized in that
Capacitor life calculator for electric vehicles. 10. The method of claim 9,
And a display unit for displaying the calculated lifetime of the DC link capacitor and whether the DC link capacitor is replaced.
Capacitor life calculator for electric vehicles. A motor control apparatus including a DC link capacitor connected to a battery to smooth and store a DC voltage, and an inverter converting a DC voltage output from the DC link capacitor into a motor driving voltage using a plurality of switching elements and providing the motor to a motor driving voltage. In the monitoring method of,
Calculating power consumption of the DC link capacitor in real time based on the torque and the rotor speed of the motor;
Accumulating the amount of power consumed and storing the averaged value by a predetermined time unit;
Detecting a DC voltage applied to the DC link capacitor;
Estimating a ripple current value flowing through the DC link capacitor using the stored average power consumption and the detected DC voltage;
Calculating a life time of the DC link capacitor by using an internal temperature change value of the DC link capacitor corresponding to the ripple current and the stored average power consumption.
Monitoring method of motor control device. The method of claim 12,
Characterized in that it further comprises; indicating the life time and whether the replacement of the DC link capacitor;
Monitoring method of motor control device.

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