KR101610906B1 - Apparatus for measuring isolation resistance using capacitor and method thereof - Google Patents

Abstract

According to an embodiment of the present specification, an insulation resistance estimation device and a method thereof include: a first resistor, a measurement resistor, and a second resistor which are serially connected to a battery; a first capacitor and a second capacitor of which each of one end is connected between the first resistor and the measurement resistor and between the measurement resistor and the second resistor, and the each of the other end is commonly connected to the chassis ground of a vehicle; a first switch and a second switch which connect or block the lines between the battery and the first and the second resistors; a third switch having one end which is connected between the first resistor and the measurement resistor and to the first capacitor and the other end which is connected to the chassis ground of the vehicle; a fourth switch having one end which is connected between the measurement resistor and the second resistor and to the second capacitor and the other end which is connected to the third switch and the ground; one and the other common resistors connected to the first and the second resistors in parallel, respectively; a voltage measurement circuit of which both ends are connected to the measurement resistor and which measures the battery voltage from the battery voltage; and a control unit which estimates the insulation resistance before the voltage is stabilized by turning on the third or the fourth switch and then calculating the battery voltage measured by the voltage measurement circuit and the voltage variation at the time of the measurement of the battery voltage and controls the first and the second switches according to the breakdown status by the estimated insulation resistance.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an insulation resistance estimating apparatus using capacitors,

The present invention relates to an apparatus and method for estimating an insulation resistance using a capacitor, and more particularly, to an apparatus and method for estimating an insulation resistance using a capacitor, which can prevent a peak voltage generated when a switch for estimating an insulation resistance is closed by measuring a voltage using a capacitor The present invention relates to an apparatus for estimating insulation resistance and a method thereof.

In recent years, various devices such as industrial devices, home appliances and automobiles using high-voltage batteries have appeared, and especially in the field of automobile technology, the use of high-voltage batteries is becoming more active.

Automobiles that use internal combustion engines that use fossil fuels such as gasoline or heavy oil as the main fuel have a serious impact on pollution such as air pollution. Therefore, in recent years, efforts have been made to develop electric vehicles or hybrid electric vehicles (HEVs) to reduce pollution.

Electric vehicles (EVs) are vehicles that do not use petroleum fuels and engines but use electric batteries and electric motors. In other words, although an electric vehicle that drives a car by rotating an electric motor that is stored in a battery has been developed before a gasoline car, it has not been put into practical use due to problems such as a heavy weight of a battery and a time required for charging. Recently, And research for commercialization began in the 1990s.

On the other hand, hybrid technology (HEV) that uses electric vehicles, fossil fuels and electric energy adaptively is being commercialized as battery technology has been developed remarkably.

Since HEV uses both gasoline and electricity as power sources, it is receiving positive reviews in terms of fuel efficiency improvement and emission reduction. It is expected that HEV will play an intermediate role in evolving into a full electric vehicle because it is important to overcome the price difference with gasoline automobile by reducing the amount of secondary battery to one third of that of electric cars.

Since HEV and EV vehicles using such electric energy use a battery in which a plurality of rechargeable secondary cells are packed as a main power source, there is no exhaust gas and noise is small. have.

Since the performance of a battery using the electric energy directly affects the performance of the vehicle, it is necessary to measure the voltage of each battery cell, the voltage and current of the entire battery, and to efficiently manage charge and discharge of each battery cell However, a battery management system (BMS: Battery Management System) is required to monitor the state of a cell sensing IC that senses each battery cell and to control the corresponding cell stably.

Generally, a method for detecting a battery voltage in a battery management system (BMS) includes a method using an operational amplifier (OP Amp.) And a method using a relay and a condenser. Among them, a relay and a capacitor use a relay to charge a capacitor of a battery and convert the charging voltage into an analog / digital converter (A / D converter).

On the other hand, hybrid cars and electric vehicles using high voltage batteries have a system that automatically turns off the main high voltage battery in the event of an emergency. In this case, emergency refers to excessive short circuit or insulation breakdown due to short circuit caused by excessive short circuit or insulation break due to aging of the related parts, or component breakage due to external impact.

When an emergency occurs in the vehicle, a command to cut off the main power from the higher-level parts for controlling the high-voltage parts such as the BMS (Battery Management System) and the HCU (Hybrid Control Unit) is issued and the power is interrupted. In this case, the high voltage related parts are monitored by voltage or current of the line connecting the power supply through a series of programs or sensors, so that when voltage or current outside the normal range is detected, or leakage current is over the allowable value, The main power is cut off through CAN communication or signal transmission.

Thus, measurement of insulation resistance is very important in a hybrid vehicle using a high-voltage battery.

Here, there is a method of measuring the leakage current between a high-voltage battery and a hybrid vehicle to destroy the insulation and force the direct current to flow. This method has a disadvantage in that the insulation breaks down while measuring the insulation resistance.

To solve this problem, there is a method of connecting a coupling capacitor between a high voltage battery and a hybrid vehicle, and applying an AC signal to the coupling capacitor to measure an insulation resistance component. However, this method has a disadvantage in that it requires a circuit to pass through the same circuit for charging and discharging the coupling capacitor. Therefore, the conventional dielectric breakdown measuring circuit has a small voltage fluctuation range There is a problem that accurate judgment is difficult.

In addition, the conventional dielectric breakdown measuring circuit can measure the dielectric breakdown of each of the positive electrode and the negative electrode of the high voltage line connected to the battery, but can not measure the dielectric breakdown when the dielectric breakdown occurs simultaneously in the positive electrode and the negative electrode have.

In addition, the conventional dielectric breakdown measuring circuit may cause a peak voltage due to the switching of the switch for estimating the insulation resistance using the capacitor. Because of this peak-to-peak voltage, the variation in the voltage across the measurement resistance can be large. As a result, errors in the measurement of the insulation resistance for the insulation breakdown measurement may occur.

Embodiments of the present invention include a method of calculating a peak voltage generated when a switch for estimating an insulation resistance is closed by calculating a battery voltage from a voltage applied to a measurement resistor connected to a capacitor and measuring an insulation resistance based on the calculated battery voltage, And a method for estimating an insulation resistance using a capacitor.

In the embodiments of the present invention, the insulation resistance can be estimated in advance by using the battery voltage measured at the measurement time and the voltage change amount at the measurement time, so that the insulation resistance can be estimated quickly before the stabilization time generated by the capacitor And a method for estimating an insulation resistance using a capacitor.

In the embodiments of the present invention, the measured battery voltage is integrated during the integration period to calculate the battery integrated voltage, and the calculated battery integrated voltage is used as the insulation resistance to estimate the variation of the battery voltage The present invention also provides an apparatus for estimating an insulation resistance using a capacitor and a method for estimating an insulation resistance by reducing an influence of an introduced noise.

In addition, embodiments of the present invention can correct an estimated insulation resistance accurately by comparing an estimated insulation resistance and a correction resistance by generating a fault that is arbitrarily set by connecting a correction resistor connected to the positive and negative terminals of the battery voltage, And an object thereof is to provide an apparatus and method for estimating an insulation resistance using a capacitor.

According to a first aspect of the present disclosure there is provided a battery comprising a first resistor, a measurement resistor and a second resistor serially connected to the battery; First and second capacitors each having one side connected between the first resistor and the measurement resistor, the measurement resistor and the second resistor, and each of the other sides being commonly connected to the chassis ground of the vehicle; First and second switches connecting or disconnecting the line between the battery and the first resistor and the second resistor; A third switch connected between the first resistor and the measurement resistor and one end connected to the first capacitor and the other end connected to the chassis ground of the vehicle; A fourth switch having one end connected to the measuring resistor and the second resistor and the other end connected to the third switch and the ground; One and the other common resistors connected in parallel with the first and second resistors, respectively; A voltage measuring circuit connected at both ends to the measuring resistor to measure a battery voltage from the battery voltage; And estimating an insulation resistance before voltage stabilization by calculating a voltage change amount at a measurement time point of the battery voltage and the battery voltage measured through the voltage measurement circuit after turning on the third or fourth switch, And a controller for controlling the first and second switches according to whether or not the insulation breakdown is caused by the estimated insulation resistance.

Wherein the control unit calculates a voltage change amount at a measurement time point after a predetermined time from a maximum time point at which the battery voltage rises and decreases at a maximum value after the third or fourth switch is turned on, It is possible to estimate the insulation resistance at a predetermined stabilization time point by using the calculated battery voltage and the calculated voltage change amount.

Wherein the control unit calculates at least one voltage measurement sampling value by calculating voltage variation amounts at measurement points corresponding to at least one battery voltage measured through the voltage measurement circuit after turning on the third or fourth switch, The insulation resistance can be estimated before the voltage stabilization.

The apparatus comprising: one side and the other of the correction resistors having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance; And one side and the other side correction switches for connecting or disconnecting the lines between the one side and the other side correction resistor and the line between the one side and the other side common resistance, wherein the controller turns on one side or the other side correction switch, And the estimated insulation resistance can be corrected by comparing the insulation resistance with the preset correction resistance.

The controller may correct the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the predetermined correction resistance.

On the other hand, according to the second aspect of the present invention, a first resistance, a measurement resistance and a second resistance, which are connected in series to a battery, First and second capacitors each having one side connected between the first resistor and the measurement resistor, the measurement resistor and the second resistor, and each of the other sides being commonly connected to the chassis ground of the vehicle; First and second switches connecting or disconnecting the line between the battery and the first resistor and the second resistor; A third switch connected between the first resistor and the measurement resistor and one end connected to the first capacitor and the other end connected to the chassis ground of the vehicle; A fourth switch having one end connected to the measuring resistor and the second resistor and the other end connected to the third switch and the ground; One and the other common resistors connected in parallel with the first and second resistors, respectively; A voltage measuring circuit connected at both ends to the measuring resistor to measure a battery voltage from the battery voltage; An integrating circuit for integrating the measured battery voltage; And calculating a battery integrated voltage during a predetermined integration period from the battery voltage integrated in the integration circuit after the third or fourth switch is turned on and estimating an insulation resistance using the calculated battery integrated voltage An insulation resistance estimating apparatus using a capacitor including a control unit for controlling the insulation resistance of the capacitor can be provided.

Wherein the control unit sets an integration start and completion time for integrating the measured battery voltage in advance and calculates a battery integrated voltage calculated from the predetermined integration start time to an integral completion time for each start of the vehicle, The calculated battery integrated voltage can be corrected using an error.

The controller may analyze the waveform of the battery voltage measured for each of the detailed time units during a predetermined initial period and change a predetermined integration period according to the waveform of the analyzed battery voltage.

The apparatus comprising: one side and the other of the correction resistors having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance; And one side and the other side correction switches for connecting or disconnecting the lines between the one side and the other side correction resistor and the line between the one side and the other side common resistance, wherein the controller turns on one side or the other side correction switch, And the estimated insulation resistance can be corrected by comparing the insulation resistance with the preset correction resistance.

The controller may correct the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the predetermined correction resistance.

According to a third aspect of the present invention, there is provided a method of driving a vehicle, comprising: a first resistor and a second resistor, one of which is connected between a first resistor and a second resistor, and the other of which is commonly connected to a chassis ground of the vehicle; The method comprising: connecting a first resistor, a measurement resistor, and a second resistor in series to a battery; A third switch having one side connected between the first resistor and the measuring resistor and the other side connected to the chassis ground of the vehicle; and a second switch having one side connected between the measuring resistor and the second resistor and the other side connected to the third switch and the ground Measuring a battery voltage from a resistance voltage by alternately turning on and off a fourth switch to be connected; Calculating a voltage change amount at the time of measuring the battery voltage and the battery voltage measured through the voltage measuring circuit after turning on the third or fourth switch; And estimating the measured battery voltage and the calculated voltage change amount before the voltage stabilization of the insulation resistance.

The step of calculating the voltage change amount may include calculating a voltage change amount from a maximum time point at which the battery voltage increases and decreases at a maximum value so as to estimate the insulation resistance at a predetermined stabilization time point after the third or fourth switch is turned ON, The voltage change at this last measurement point can be calculated.

Wherein the step of estimating the insulation resistance before the voltage stabilization step comprises: after turning on the third or fourth switch in the step of calculating the amount of voltage change, calculating at least one of the at least one battery voltage measured through the voltage measurement circuit, Once the voltage variations at the corresponding measurement points are calculated, the insulation resistance can be estimated prior to voltage stabilization through at least one voltage measurement sampling.

The method includes the steps of: connecting one side and the other of the correction resistors having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance, and the one side and the other side common resistance, And correcting the estimated insulation resistance in comparison with the correction resistance value.

The step of correcting the estimated insulation resistance may correct the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the predetermined correction resistance.

On the other hand, according to the fourth aspect of the present invention, the first and second capacitors each having one side connected between the first resistor and the measuring resistor, the measuring resistor and the second resistor and each of the other side being commonly connected to the chassis ground of the vehicle, The method comprising: connecting a first resistor, a measurement resistor, and a second resistor in series to a battery; A third switch having one side connected between the first resistor and the measuring resistor and the other side connected to the chassis ground of the vehicle; and a second switch having one side connected between the measuring resistor and the second resistor and the other side connected to the third switch and the ground Measuring a battery voltage from a resistance voltage by alternately turning on and off a fourth switch to be connected; Integrating the measured battery voltage after turning on the third or fourth switch, and calculating a battery integrated voltage for a predetermined integration period from the integrated battery voltage; And estimating an insulation resistance using the calculated battery integrated voltage. The method for estimating an insulation resistance using a capacitor may be provided.

The method may further include setting an integration start and completion time for integrating the measured battery voltage in advance, and the step of calculating the battery integrated voltage may include calculating the battery integrated voltage from the predetermined integration start time to the integration completion time The battery integrated voltage may be calculated each time the vehicle is started and the calculated battery integrated voltage may be corrected using an error between the respective battery integrated voltages.

The method includes analyzing a waveform of a battery voltage measured for each unit of detail in a predetermined initial period; And changing a predefined integration period according to the waveform of the analyzed battery voltage.

The method includes the steps of: connecting one side and the other of the correction resistors having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance, and the one side and the other side common resistance, And correcting the estimated insulation resistance in comparison with the correction resistance value.

The step of correcting the estimated insulation resistance may correct the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the predetermined correction resistance.

Embodiments of the present invention include a method of calculating a peak voltage generated when a switch for estimating an insulation resistance is closed by calculating a battery voltage from a voltage applied to a measurement resistor connected to a capacitor and measuring an insulation resistance based on the calculated battery voltage, . ≪ / RTI >

In the embodiments of the present invention, the insulation resistance can be estimated in advance by using the battery voltage measured at the measurement time and the voltage change amount at the measurement time, so that the insulation resistance can be estimated quickly before the stabilization time generated by the capacitor have.

In the embodiments of the present invention, the measured battery voltage is integrated during the integration period to calculate the battery integrated voltage, and the calculated battery integrated voltage is used as the insulation resistance to estimate the variation of the battery voltage Or the influence due to the introduced noise can be reduced to accurately estimate the insulation resistance.

In addition, embodiments of the present invention can correct an estimated insulation resistance accurately by comparing an estimated insulation resistance and a correction resistance by generating a fault that is arbitrarily set by connecting a correction resistor connected to the positive and negative terminals of the battery voltage, can do.

1 is a configuration diagram of an insulation resistance estimation apparatus using a capacitor according to a first embodiment of the present invention.
2 is an explanatory diagram of a switching operation for measuring an anode insulation resistance according to the first embodiment of the present invention.
3 is an explanatory diagram of a switching operation for measuring a negative electrode insulation resistance according to the first embodiment of the present invention.
4 is a configuration diagram of an insulation resistance estimation apparatus using a capacitor according to a second embodiment of the present invention.
5 is an explanatory diagram of a switching operation for measuring an anode insulation resistance according to a second embodiment of the present invention.
6 is an explanatory diagram of a switching operation for measuring a negative electrode insulation resistance according to the second embodiment of the present invention.
7 is a flowchart illustrating a method of estimating an insulation resistance using a capacitor according to the first embodiment of the present invention.
8 is a flowchart illustrating a method of estimating an insulation resistance using a capacitor according to a second embodiment of the present invention.
9 is a flowchart of a method for correcting an estimated insulation resistance according to the first embodiment of the present invention.
10 is a flowchart of a method for correcting an estimated insulation resistance according to a second embodiment of the present invention.
11 is an explanatory diagram of a process of stabilizing the measured battery voltage according to the first embodiment of the present invention.
12 is an explanatory diagram illustrating an integration process of a measured battery voltage according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of techniques which are well known in the technical field to which this specification belongs and which are not directly related to this specification are not described. This is for the sake of clarity without omitting the unnecessary explanation and without giving the gist of the present invention.

For the same reason, some of the components in the drawings are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In the drawings, the same or corresponding components are denoted by the same reference numerals.

1 is a configuration diagram of an insulation resistance estimation apparatus using a capacitor according to a first embodiment of the present invention.

1, an insulation resistance estimation apparatus 100 using a capacitor according to a first embodiment of the present invention includes a first resistor R1, a second resistor R2, a measurement resistor Rm, And first and second switches SW1 and SW2, third and fourth switches SW3 and SW4, a voltage measuring circuit 110 and a control unit 120. The first and second switches SW1 and SW2 are connected to the first and second capacitors C1 and C2. Here, the insulation resistance estimation apparatus 100 may further include positive and negative correction resistors Rx + and Rx-, and positive and negative correction switches SWx + and SWx-.

Unlike FIG. 1 of this specification, when the insulation resistance is measured using only the measurement resistance Rm, the peak voltage generated when the switch for estimating the insulation resistance is closed can not be prevented. That is, an actual system including the battery Vb or the fuel cell may be configured such that the voltage level applied to the measurement resistor varies depending on the state of charge of the battery Vb, the power generation state of the fuel cell, Lt; / RTI > Such high voltage fluctuation may cause a large measurement error when measuring the insulation resistance using the voltage across the measurement resistance.

1, the insulation resistance estimation apparatus 100 includes first and second capacitors C1 and C2 capable of preventing a peak voltage, a measurement resistor Rm connected to both ends of the first and second capacitors C1 and C2, The measurement error of the peak voltage generated when the third switch SW3 or the fourth switch SW4 is closed is reduced to estimate the insulation resistance by measuring the battery voltage and the voltage change amount from the voltage applied to the battery Vb, And the chassis ground can be measured more quickly and accurately.

The specific configuration and operation of each component of the insulation resistance estimation apparatus 100 using the capacitor of FIG. 1 will be described below.

First, the battery Vb may be a hybrid battery or a high voltage battery mounted in an electric vehicle. The battery Vb may be a high-voltage battery, or may be implemented as a single battery, or a battery pack in which a plurality of batteries are connected in series. This is because, in order to generate a high voltage, it is more efficient to generate a high voltage by serially connecting a plurality of batteries generating a low voltage rather than directly generating a high voltage with a single battery in a method commonly used in electric vehicles. The fuel cell may be replaced by a battery. The battery Vb may include various kinds of batteries requiring measurement of insulation resistance. At this time, the high voltage lines connected to the positive terminal (+) and the negative terminal (-) of the battery (Vb) are electrically insulated.

As shown in FIG. 1, a positive common resistance Ry + and a negative common resistance Ry- are formed in series, and a chassis ground (GND) grounded to the chassis of the vehicle is connected between these common resistors. The chassis ground is an object to be insulated from the battery (Vb) and the fuel cell system and the battery and the fuel cell. When the system using the battery and the fuel cell is an automobile, the vehicle body may become chassis ground.

The insulation resistance estimation apparatus 100 using a capacitor is connected to the battery Vb through first and second switches SW1 and SW2.

The first resistor R1, the measurement resistor Rm and the second resistor R2 are connected in series to the battery Vb. Here, the first resistor R1 and the second resistor R2 may be formed of a plurality of resistors, respectively. When the first resistor R1 is composed of a plurality of resistors, one side of the third switch SW3 may be connected between the plurality of resistors. When the second resistor R2 is composed of a plurality of resistors, one side of the fourth switch SW4 may be connected between the plurality of resistors.

The first switch SW1 connects or disconnects the line between the battery Vb and the first resistor R1. Further, the second switch SW2 connects or disconnects the line between the battery Vb and the second resistor R2. The first and second switches SW1 and SW2 are provided on the circuit connected in series to open and close the circuit. The first and second switches SW1 and SW2 may be provided on a line connecting the positive terminal of the battery Vb and the first resistor R1 or may be connected to the negative terminal of the battery Vb and the second resistor R2, And the like. Thus, by operating the first and second switches SW1 and SW2, the resistance and the measurement resistance Rm can be turned on or off.

The first and second switches SW1 and SW2 are connected to a line connecting the positive terminal of the battery Vb and the first resistor R1 and a line connecting the negative terminal of the battery Vb and the second resistor R2 Respectively. That is, the first resistor R1, the measurement resistor Rm, the second resistor R2, and the voltage measurement circuit 110 are provided by opening and closing the circuit by providing two first and second switches SW1 and SW2, And the like can be protected.

The first and second switches SW1 and SW2 and the third and fourth switches SW3 and SW4 may be photo-MOS relays.

PhotomOS relay is a type of photocoupler that is combined with light using LED and closes when receiving light. PhotoMOS relays have a faster response time and higher sensitivity than general mechanical relays, have a long lifetime and do not have chattering phenomena (for example, repeated on and off several times in a very short time without turning on and off at once) More accurate measurement results can be obtained.

The third switch SW3 is connected between the first resistor R1 and the measurement resistor Rm and one side to the first capacitor C1 and the other side to the chassis ground of the vehicle.

The fourth switch SW4 is connected between the measuring resistor Rm and the second resistor R2 and one end connected to the second capacitor C2 and the other end connected to the third switch SW3 and the chassis ground.

That is, a branch is formed between the first resistor R1 and the measurement resistor Rm and between the measurement resistor Rm and the second resistor R2. The third and fourth switches SW3 and SW4 and the measuring resistor Rm are connected in parallel. The line connecting the third switch SW3 and the fourth switch SW4 is grounded to form a chassis ground.

The first capacitor C1 is connected at one side between the first resistor R1 and the measurement resistor Rm and the other end is connected in common with the second capacitor C2 at the chassis ground of the vehicle.

The second capacitor C2 is connected at one side between the measurement resistor Rm and the second resistor R2 and the other end is connected in common with the first capacitor C1 to the chassis ground of the vehicle.

One side common resistance Ry + or Ry- is connected in parallel with the first resistor R1. The other common resistance Ry- or Ry + is connected in parallel with the second resistor R2. Here, one side common resistance (Ry + or Ry-) may have tens to several hundreds of M [Omega].

The voltage measuring circuit 110 is connected at both ends to the measuring resistor Rm and the first and second capacitors C1 and C2 to measure the resistance voltage Vrm. The voltage measuring circuit 110 may include an operational amplifier (Op Amp) to measure the resistance voltage Vrm.

The control unit 120 controls the overall operation of the insulation resistance estimation apparatus 100. [ The control unit 120 controls the switching of the first to fourth switches SW1 to SW4 and the positive and negative correction switches SWx + and SWx-, or the switching of the measurement resistance Rm through the voltage measurement circuit 110. [ (Vrm), which is measured at a predetermined time.

On the other hand, a failure may occur between the battery Vb and the chassis of the vehicle. Then, one side fault resistance (Rf + or Rf-) can be generated by being connected in parallel with the one side common resistance (Ry + or Ry-) and the first resistor (R1). In Fig. 1, the one-side fault resistance (Rf + or Rf-) is shown by a dotted line. For example, the one-side fault resistance (Rf + or Rf-) may be several to several tens of kilohms. The anode breakdown resistor Rf + connected between the anode of the battery Vb and the chassis ground may be represented by an equivalent resistance of the insulation resistance that may occur between the anode of the battery Vb and the chassis ground. Similarly, the cathode fault resistance Rf- connected between the cathode of the battery Vb and the chassis ground may represent an equivalent resistance of the insulation resistance that may occur between the cathode of the battery Vb and the chassis ground.

The insulation resistance estimation apparatus 100 divides the breakdown resistance between the battery Vb and the chassis ground into an anode and a cathode so that the breakdown resistance across the battery Vb can be distinguished to measure the insulation resistance. This is to make it easy to understand the safety problem and the location of the insulation breakdown when the breakdown resistance occurs.

The voltage measuring circuit 110 turns on the third switch SW3 or the fourth switch SW4 when one side fault resistor Rf + or Rf- connected in parallel with the one common resistor Ry + or Ry- ) To measure the resistance voltage Vrm and measure the battery voltage from the measured resistance voltage Vrm. At this time, the control unit 120 calculates the amount of voltage change at the measurement time. Here, the voltage change amount means a voltage change amount at the time of measuring the battery voltage.

The control unit 120 estimates the insulation resistance before the voltage stabilization by using the measured battery voltage and the calculated voltage change amount. The controller 120 may control the first and second switches SW1 and SW2 according to the insulation breakdown due to the estimated insulation resistance.

At this time, the resistance voltage Vrm applied to the measuring resistor Rm may vary depending on opening and closing of the third switch SW3 and the fourth switch SW4. It can also be influenced by the anode common resistance Ry + and the cathode common resistance Ry-. That is, the resistance voltage Vrm applied to the measuring resistor Rm measured through the voltage measuring circuit 110 when only the third switch SW3 is closed and the resistance voltage Vrm applied to the voltage measuring circuit The resistance voltage Vrm applied to the measurement resistor Rm measured through the resistor Rm110 may be correlated with the anode common resistance Ry + and the cathode common resistance Ry-. The control unit 120 uses the resistance voltage Vrm measured when only the third switch SW3 is closed and the resistance voltage Vrm measured when only the fourth switch SW4 is closed so that the insulation breakdown of the high- Can be measured.

Here, one side in FIG. 1 represents the polarity of either the positive (+) or negative (-) side, and the other side shows the opposite polarity to any one of the polarities, but can be represented by the opposite polarity. As described above, the insulation resistance estimation apparatus 100 using a capacitor according to the present invention can measure the insulation resistance when one of the positive electrode and the negative electrode of the high voltage line connected to the battery Vb is insulated, and at the same time, The insulation resistance can be measured even when the insulation is broken.

Hereinafter, for explanation of this specification, one side common resistance Ry + or Ry- is defined as the anode common resistance Ry + and the other side common resistance Ry- or Ry + is defined as the cathode common resistance Ry- do.

Thus, the control unit 120 can control the first and second switches SW1 and SW2 according to the insulation breakdown due to the estimated insulation resistance.

2 is an explanatory diagram of a switching operation for measuring an anode insulation resistance according to the first embodiment of the present invention.

The operation of estimating the anode insulation resistance when the anode breakdown resistance Rf + connected in parallel to the anode common resistance Ry + is generated will be described in detail.

2, when the positive polarity resistance Rf + connected in parallel with the positive common resistance Ry + is generated between the positive terminal of the battery Vb and the first resistor R1, 3 and the fourth switches SW3 and SW4 are respectively turned ON and OFF and then the voltage variation at the time of measurement of the battery voltage and the battery voltage measured through the voltage measuring circuit 110 is calculated, The resistance is estimated before voltage stabilization.

At this time, the control unit 120 turns on and off the third and fourth switches SW3 and SW4, respectively. Thereafter, the control unit 120 determines whether the battery voltage has increased It is possible to calculate the voltage change amount at the time point. Then, the controller 120 can estimate the insulation resistance at a predetermined stabilization time using the measured battery voltage and the calculated voltage change amount at the measurement time.

Here, the controller 120 can accurately estimate the insulation resistance through at least one voltage measurement sampling instead of estimating the insulation resistance only once. That is, the controller 120 can estimate the insulation resistance before the voltage stabilization by calculating the voltage variation amounts at the measurement time corresponding to the at least one battery voltage measured through the voltage measurement circuit 110, respectively. That is, the insulation resistance can be more accurately estimated through at least one voltage measurement sampling.

On the other hand, the insulation resistance estimation apparatus 100 may further include an anode correction resistor Rx + and a cathode correction switch SWx-.

The anode correction resistance Rx + has a predetermined correction resistance value (for example, 1 M OMEGA or the like) and is connected in parallel with the anode common resistance Ry +.

The positive polarity correction switch SWx + can connect or disconnect the line between the positive polarity correction resistor Rx + and the positive common resistance Ry +, respectively.

The control unit 120 can correct the insulation resistance estimated by comparing the estimated insulation resistance with the predetermined correction resistance after turning on the anode correction switch SWx +. Here, the controller 120 may correct the insulation resistance estimated according to the resistance difference between the estimated insulation resistance and the preset correction resistance.

3 is an explanatory diagram of a switching operation for measuring a negative electrode insulation resistance according to the first embodiment of the present invention.

Next, an operation of estimating the negative electrode insulation resistance when the negative electrode common resistance Ry- and the negative electrode breakdown resistance Rf- connected in parallel is generated will be described in detail.

3, when the negative terminal resistance Rf- connected in parallel with the negative common resistance Ry- is generated between the negative terminal of the battery Vb and the second resistor R2, After the fourth and third switches SW4 and SW3 are turned ON and OFF respectively and then the voltage change amount at the time of measuring the battery voltage and the battery voltage measured through the voltage measuring circuit 110 is calculated And the insulation resistance is estimated before the voltage stabilization.

At this time, the controller 120 turns on and off the fourth and the third switches SW4 and SW3, respectively. Then, the controller 120 measures the battery voltage It is possible to calculate the voltage change amount at the time point. Then, the controller 120 can estimate the insulation resistance at a predetermined stabilization time using the measured battery voltage and the calculated voltage change amount at the measurement time.

Here, the controller 120 can accurately estimate the insulation resistance through at least one voltage measurement sampling instead of estimating the insulation resistance only once. That is, the controller 120 can estimate the insulation resistance before the voltage stabilization by calculating the voltage variation amounts at the measurement time corresponding to the at least one battery voltage measured through the voltage measurement circuit 110, respectively. That is, the insulation resistance can be more accurately estimated through at least one voltage measurement sampling.

Meanwhile, the insulation resistance estimation apparatus 100 may further include a negative-pole correction resistor Rx- and a negative-pole correction switch SWx-.

The cathode correction resistor Rx- has a predetermined correction resistance value (e.g., 1 M OMEGA or the like) and is connected in parallel with the cathode common resistance Ry-.

The cathode correction switch SWx- can connect or disconnect the line between the cathode correction resistor Rx- and the cathode common resistance Ry-, respectively.

Here, the controller 120 may correct the insulation resistance estimated by comparing the estimated insulation resistance with the predetermined correction resistance after turning on the cathode correction switch SWx-. The controller 120 may correct the insulation resistance estimated according to the resistance difference between the estimated insulation resistance and the preset correction resistance.

Hereinafter, an insulation resistance estimation apparatus using a capacitor according to a second embodiment of the present invention will be described. In order to more clearly communicate the gist of the second embodiment of the present invention, description of the technical contents overlapping with the first embodiment of the present specification will be omitted.

4 is a configuration diagram of an insulation resistance estimation apparatus using a capacitor according to a second embodiment of the present invention.

4, the insulation resistance estimation apparatus 100 according to the second embodiment of the present invention includes a first resistor R1, a second resistor R2, a measurement resistor Rm, first and second The first and second switches SW1 and SW2, the third and fourth switches SW3 and SW4, the voltage measuring circuit 110, the integrating circuit 130 and the control unit 120 do. Here, the insulation resistance estimation apparatus 100 may further include positive and negative correction resistors Rx + and Rx-, and positive and negative correction switches SWx + and SWx-.

Unlike FIG. 4 of this specification, when the insulation resistance is measured using only the measurement resistance Rm, the peak voltage generated when the switch for estimating the insulation resistance is closed can not be prevented. In addition, not only when the switch is closed but also a large amount of noise may occur in the high voltage motor and the inverter of the vehicle. For example, during measurement of the voltage for insulation resistance estimation (for example, 5 seconds, etc.), the voltage measured from time to time fluctuates and an error occurs. This noise can affect the measured value of the battery voltage. Such real time fluctuating noise may cause a large measurement error when the insulation resistance is measured using the voltage applied to the measurement resistance.

The specific configuration and operation of each component of the insulation resistance estimation apparatus 100 of FIG. 4 according to the second embodiment of the present invention will now be described with reference to portions different from those of the first embodiment.

The insulation resistance estimation apparatus 100 according to the second embodiment of the present invention estimates the insulation resistance using the battery integrated voltage while measuring the voltage rather than estimating the insulation resistance by measuring the battery voltage only once. Using the accumulated battery voltage can be more efficient in estimating the insulation resistance.

In addition, the insulation resistance estimation apparatus 100 according to the second embodiment of the present invention includes a first and a second capacitors C1 and C2 capable of preventing a peak voltage, and a voltage It is possible to estimate the insulation resistance by measuring the battery voltage and the voltage change amount from the battery voltage Vb and the battery voltage Vb to reduce the measurement error caused by the peak voltage generated when the third switch SW3 or the fourth switch SW4 is closed, It is possible to more quickly and accurately measure the dielectric breakdown between the electrodes.

To this end, the third switch SW3 is connected between the first resistor R1 and the measuring resistor Rm and one side to the first capacitor C1 and the other side to the chassis ground of the vehicle.

The fourth switch SW4 is connected between the measuring resistor Rm and the second resistor R2 and one end connected to the second capacitor C2 and the other end connected to the third switch SW3 and the chassis ground.

That is, a branch is formed between the first resistor R1 and the measurement resistor Rm and between the measurement resistor Rm and the second resistor R2. The third and fourth switches SW3 and SW4 and the measuring resistor Rm are connected in parallel. The line connecting the third switch SW3 and the fourth switch SW4 is grounded to form a chassis ground.

The first capacitor C1 is connected at one side between the first resistor R1 and the measurement resistor Rm and the other end is connected in common with the second capacitor C2 at the chassis ground of the vehicle.

The second capacitor C2 is connected at one side between the measurement resistor Rm and the second resistor R2 and the other end is connected in common with the first capacitor C1 to the chassis ground of the vehicle.

One side common resistance Ry + or Ry- is connected in parallel with the first resistor R1. The other common resistance Ry- or Ry + is connected in parallel with the second resistor R2. Here, one side common resistance (Ry + or Ry-) may have tens to several hundreds of M [Omega].

The voltage measuring circuit 110 is connected at both ends to the measuring resistor Rm and the first and second capacitors C1 and C2 to measure the resistance voltage Vrm. The voltage measuring circuit 110 may include an operational amplifier (Op Amp) to measure the resistance voltage Vrm.

The integration circuit 130 integrates the battery voltage measured by the voltage measurement circuit 110.

The control unit 120 controls the overall operation of the insulation resistance estimation apparatus 100. [ For this purpose, the control unit 120 controls switching of the first to fourth switches SW1 to SW4 and the positive and negative correction switches SWx + and SWx-, or transmits the integrated battery integrated voltage in the integrating circuit 130 Receive. Next, the controller 120 calculates a battery integrated voltage for a predetermined integration period from the battery voltage integrated in the integration circuit 130, and estimates the insulation resistance using the calculated battery integrated voltage.

On the other hand, a failure may occur between the battery Vb and the chassis of the vehicle. Then, one side fault resistance (Rf + or Rf-) can be generated by being connected in parallel with the one side common resistance (Ry + or Ry-) and the first resistor (R1). In Fig. 1, the one-side fault resistance (Rf + or Rf-) is shown by a dotted line. For example, the one-side fault resistance (Rf + or Rf-) may be several to several tens of kilohms. The anode breakdown resistor Rf + connected between the anode of the battery Vb and the chassis ground may be represented by an equivalent resistance of the insulation resistance that may occur between the anode of the battery Vb and the chassis ground. Similarly, the cathode fault resistance Rf- connected between the cathode of the battery Vb and the chassis ground may represent an equivalent resistance of the insulation resistance that may occur between the cathode of the battery Vb and the chassis ground.

The insulation resistance estimation apparatus 100 divides the breakdown resistance between the battery Vb and the chassis ground into an anode and a cathode so that the breakdown resistance across the battery Vb can be distinguished to measure the insulation resistance. This is to make it easy to understand the safety problem and the location of the insulation breakdown when the breakdown resistance occurs.

The voltage measuring circuit 110 turns on the third switch SW3 or the fourth switch SW4 when one side fault resistor Rf + or Rf- connected in parallel with the one common resistor Ry + or Ry- ) To measure the resistance voltage Vrm and measure the battery voltage from the measured resistance voltage Vrm.

The integration circuit 130 integrates the battery voltage measured by the voltage measurement circuit 110.

Next, the controller 120 calculates a battery integrated voltage for a predetermined integration period from the battery voltage integrated in the integration circuit 130, and estimates the insulation resistance using the calculated battery integrated voltage.

Then, the controller 120 can control the first and second switches SW1 and SW2 according to the insulation breakdown due to the estimated insulation resistance.

At this time, the resistance voltage Vrm applied to the measuring resistor Rm may vary depending on opening and closing of the third switch SW3 and the fourth switch SW4. It can also be influenced by the anode common resistance Ry + and the cathode common resistance Ry-. That is, the resistance voltage Vrm applied to the measuring resistor Rm measured through the voltage measuring circuit 110 when only the third switch SW3 is closed and the resistance voltage Vrm applied to the voltage measuring circuit The resistance voltage Vrm applied to the measurement resistor Rm measured through the resistor Rm110 may be correlated with the anode common resistance Ry + and the cathode common resistance Ry-. The control unit 120 uses the resistance voltage Vrm measured when only the third switch SW3 is closed and the resistance voltage Vrm measured when only the fourth switch SW4 is closed so that the insulation breakdown of the high- Can be measured.

Here, one side in FIG. 4 indicates a polarity of either the positive (+) or negative (-) side, and the other side shows a polarity opposite to any one of the polarities, but can be represented with opposite polarities. As described above, the insulation resistance estimation apparatus 100 of the present invention can measure the insulation resistance when one of the anode and the cathode of the high voltage line connected to the battery Vb is insulated, and at the same time, The insulation resistance can be measured.

Hereinafter, for explanation of this specification, one side common resistance Ry + or Ry- is defined as the anode common resistance Ry + and the other side common resistance Ry- or Ry + is defined as the cathode common resistance Ry- do.

Thus, the control unit 120 can control the first and second switches SW1 and SW2 according to the insulation breakdown due to the estimated insulation resistance.

5 is an explanatory diagram of a switching operation for measuring an anode insulation resistance according to a second embodiment of the present invention.

The operation of estimating the anode insulation resistance when the anode breakdown resistance Rf + connected in parallel to the anode common resistance Ry + is generated will be described in detail.

5, when an anode fault resistance Rf + connected in parallel with the anode common resistance Ry + is generated between the anode terminal of the battery Vb and the first resistor R1, 3 and the fourth switches SW3 and SW4 are respectively turned ON and OFF and then the integrated voltage of the battery for a predetermined integration period is calculated from the battery voltage integrated by the integrating circuit 130, The insulation resistance is estimated using the battery integrated voltage.

Here, the control unit 120 may set the integration start and completion time for integrating the battery voltage measured by the voltage measurement circuit 110 in advance. Then, the control unit 120 calculates the battery integrated voltage calculated from the predetermined integration start time to the integration completion time through the integration circuit 130 at the start of the vehicle. Then, the control unit 120 may correct the battery integrated voltage calculated by using the error between the respective battery integrated voltages.

In addition, the controller 120 may analyze the waveform of the battery voltage measured for each of the detailed time units during a predetermined initial period. The control unit 120 may change the predetermined integration period according to the waveform of the analyzed battery voltage.

In addition, the controller 120 can accurately estimate the insulation resistance through at least one voltage measurement sampling instead of only estimating the insulation resistance once. That is, the control unit 120 calculates at least one battery integrated voltage for a predetermined integration period from the battery voltage integrated by the integration circuit 130. [ The control unit 120 may estimate the insulation resistance using the calculated at least one battery integrated voltage. That is, the insulation resistance can be more accurately estimated through at least one voltage measurement sampling.

On the other hand, the insulation resistance estimation apparatus 100 may further include an anode correction resistor Rx + and a cathode correction switch SWx-.

The anode correction resistance Rx + has a predetermined correction resistance value (for example, 1 M OMEGA or the like) and is connected in parallel with the anode common resistance Ry +.

The positive polarity correction switch SWx + can connect or disconnect the line between the positive polarity correction resistor Rx + and the positive common resistance Ry +, respectively.

The control unit 120 can correct the insulation resistance estimated by comparing the estimated insulation resistance with the predetermined correction resistance after turning on the anode correction switch SWx +. Here, the controller 120 may correct the insulation resistance estimated according to the resistance difference between the estimated insulation resistance and the preset correction resistance.

6 is an explanatory diagram of a switching operation for measuring a negative electrode insulation resistance according to the second embodiment of the present invention.

Next, an operation of estimating the negative electrode insulation resistance when the negative electrode common resistance Ry- and the negative electrode breakdown resistance Rf- connected in parallel is generated will be described in detail.

6, when the negative terminal resistance Rf- connected in parallel with the negative common resistance Ry- is generated between the negative terminal of the battery Vb and the second resistor R2, After the fourth and third switches SW4 and SW3 are turned on and off respectively, a battery integrated voltage for a predetermined integration period is calculated from the battery voltage integrated by the integrating circuit 130, The insulation resistance is estimated using the calculated battery integrated voltage.

Here, the control unit 120 may set the integration start and completion time for integrating the battery voltage measured by the voltage measurement circuit 110 in advance. Then, the control unit 120 calculates the battery integrated voltage calculated from the predetermined integration start time to the integration completion time through the integration circuit 130 at the start of the vehicle. Then, the control unit 120 may correct the battery integrated voltage calculated by using the error between the respective battery integrated voltages.

In addition, the controller 120 may analyze the waveform of the battery voltage measured for each of the detailed time units during a predetermined initial period. The control unit 120 may change the predetermined integration period according to the waveform of the analyzed battery voltage.

Meanwhile, the insulation resistance estimation apparatus 100 may further include a negative-pole correction resistor Rx- and a negative-pole correction switch SWx-.

The cathode correction resistor Rx- has a predetermined correction resistance value (e.g., 1 M OMEGA or the like) and is connected in parallel with the cathode common resistance Ry-.

The cathode correction switch SWx- can connect or disconnect the line between the cathode correction resistor Rx- and the cathode common resistance Ry-, respectively.

Here, the controller 120 may correct the insulation resistance estimated by comparing the estimated insulation resistance with the predetermined correction resistance after turning on the cathode correction switch SWx-. The controller 120 may correct the insulation resistance estimated according to the resistance difference between the estimated insulation resistance and the preset correction resistance.

7 is a flowchart illustrating a method of estimating an insulation resistance using a capacitor according to the first embodiment of the present invention.

A method of calculating the anode insulation resistance in the insulation resistance estimation apparatus 100 according to the first embodiment of the present invention will be described first, and a method of calculating the anode insulation resistance will be described.

First, the steps S702 to S716 for calculating the anode insulation resistance will be described as follows.

The insulation resistance estimation apparatus 100 turns on the first and second switches SW1 and SW2 (S702).

The first and second switches SW1 and SW2 are closed to measure the insulation breakdown of the high voltage line connected to the positive terminal and the negative terminal of the battery Vb so that the battery Vb and the first resistor R1, The measuring resistor Rm and the second resistor R2 are connected to each other so that the voltage is applied to the resistors and the measuring resistor Rm.

Then, the insulation resistance estimation apparatus 100 turns on the third switch SW3 (S704).

Thereafter, the insulation resistance estimation apparatus 100 measures the resistance voltage Vrm caught by the measurement resistance Rm (S706).

That is, the insulation resistance estimation apparatus 100 using a capacitor measures a voltage applied to the measurement resistor Rm through the voltage measurement circuit 110 in a state in which the third switch SW3 is closed and the fourth switch SW4 is opened do.

Next, the insulation resistance estimation apparatus 100 measures the battery voltage Vb from the resistance voltage Vrm measured through the voltage measurement circuit 110 (S708).

Then, the insulation resistance estimation apparatus 100 turns on and off the third and fourth switches SW3 and SW4, respectively. Then, the insulation resistance estimation apparatus 100 estimates the battery voltage and the battery voltage measured through the voltage measurement circuit 110 The voltage variation at the measurement time is calculated (S710). At this time, the control unit 120 turns on and off the third and fourth switches SW3 and SW4, respectively. Thereafter, the control unit 120 determines whether the battery voltage has increased It is possible to calculate the voltage change amount at the time point.

Thereafter, the insulation resistance estimation apparatus 100 estimates the anode insulation resistance before voltage stabilization (S712). That is, the controller 120 can estimate the insulation resistance at a predetermined stabilization time using the measured battery voltage and the calculated voltage change amount at the measurement time.

Then, the insulation resistance estimation apparatus 100 confirms whether the insulation between the battery Vb and the chassis ground is insulation breakdown (S714).

If the check result (S714) is an insulation breakdown, the insulation resistance estimation apparatus 100 turns off the first and second switches SW1 and SW2 (S716).

On the other hand, if the check result (S714) is NO, the insulation resistance estimation apparatus 100 turns off the third switch SW3 and turns on the fourth switch SW4 (S718).

Then, the insulation resistance estimation apparatus 100 using a capacitor measures a resistance voltage Vrm applied to the measurement resistor Rm (S720).

Next, the insulation resistance estimation apparatus 100 measures the battery voltage Vb from the resistance voltage Vrm measured through the voltage measurement circuit 110 (S722).

Then, the insulation resistance estimation apparatus 100 turns on and off the third and fourth switches SW3 and SW4, respectively. Then, the insulation resistance estimation apparatus 100 estimates the battery voltage and the battery voltage measured through the voltage measurement circuit 110 The voltage change amount at the measurement time is calculated (S724). At this time, after the third and fourth switches SW3 and SW4 are turned on and off, the control unit 120 determines that the battery voltage is higher than the maximum value, It is possible to calculate the voltage change amount at the time point.

Thereafter, the insulation resistance estimation apparatus 100 estimates the negative insulation resistance before voltage stabilization (S726). That is, the controller 120 can estimate the insulation resistance at a predetermined stabilization time using the measured battery voltage and the calculated voltage change amount at the measurement time.

Then, the insulation resistance estimation apparatus 100 confirms whether the insulation between the battery Vb and the chassis ground is insulation failure (S728).

In the case of insulation breakdown (S728), the insulation resistance estimation apparatus 100 using a capacitor turns off the first and second switches SW1 and SW2 (S730).

On the other hand, if it is determined that the insulation resistance is not destroyed (S728), the insulation resistance estimation apparatus 100 determines that the insulation resistance of the battery Vb is not insulation insulation, and ends the insulation resistance estimation process.

8 is a flowchart illustrating a method of estimating an insulation resistance using a capacitor according to a second embodiment of the present invention.

A method of calculating the anode insulation resistance in the insulation resistance estimation apparatus 100 according to the second embodiment of the present invention will be described first, and a method of calculating the anode insulation resistance will be described below.

First, the steps S802 to S816 for calculating the anode insulation resistance will be described as follows.

The insulation resistance estimation apparatus 100 turns on the first and second switches SW1 and SW2 (S802).

The first and second switches SW1 and SW2 are closed to measure the insulation breakdown of the high voltage line connected to the positive terminal and the negative terminal of the battery Vb so that the battery Vb and the first resistor R1, The measuring resistor Rm and the second resistor R2 are connected to each other so that the voltage is applied to the resistors and the measuring resistor Rm.

Then, the insulation resistance estimation apparatus 100 turns on the third switch SW3 (S804).

Thereafter, the insulation resistance estimation apparatus 100 measures a resistance voltage Vrm applied to the measurement resistor Rm (S806).

That is, the insulation resistance estimation apparatus 100 using a capacitor measures a voltage applied to the measurement resistor Rm through the voltage measurement circuit 110 in a state in which the third switch SW3 is closed and the fourth switch SW4 is opened do.

Then, the insulation resistance estimation apparatus 100 measures the battery voltage Vb from the measured resistance voltage Vrm through the voltage measurement circuit 110 for each detailed time unit during the initial period (S808).

The insulation resistance estimation apparatus 100 integrates the battery voltage measured by the voltage measurement circuit 110 during a predetermined integration period through the integration circuit 130 (S810).

Next, the insulation resistance estimation apparatus 100 calculates a battery integrated voltage for a predetermined integration period from the battery voltage integrated by the integration circuit 130, and estimates an anode insulation resistance using the calculated battery integrated voltage (S812 ).

Then, the insulation resistance estimation apparatus 100 confirms whether the insulation between the battery Vb and the chassis ground is dielectric breakdown (S814).

If the check result (S814) is an insulation breakdown, the insulation resistance estimation apparatus 100 turns off the first and second switches SW1 and SW2 (S816).

On the other hand, if the check result (S814) is NO, the insulation resistance estimation apparatus 100 turns off the third switch SW3 and turns on the fourth switch SW4 (S818).

Thereafter, the insulation resistance estimation apparatus 100 using a capacitor measures a resistance voltage Vrm applied to the measurement resistor Rm (S820).

Then, the insulation resistance estimation apparatus 100 measures the battery voltage Vb from the resistance voltage Vrm measured through the voltage measurement circuit 110 for each detail time unit during the initial section (S822).

The insulation resistance estimation apparatus 100 integrates the battery voltage measured by the voltage measurement circuit 110 during a predetermined integration period through the integration circuit 130 (S824).

Then, the insulation resistance estimation apparatus 100 calculates a battery integrated voltage for a predetermined integration period from the battery voltage integrated by the integration circuit 130, and estimates a negative insulation resistance using the calculated battery integrated voltage (S826 ).

Subsequently, the insulation resistance estimation apparatus 100 confirms whether the insulation between the battery Vb and the chassis ground is insulation breakdown (S828).

In the case of insulation breakdown (S828), the insulation resistance estimation apparatus 100 using a capacitor turns off the first and second switches SW1 and SW2 (S830).

On the other hand, if the result of the check (S828) is not insulation breakdown, the insulation resistance estimation apparatus 100 determines that the insulation resistance of the battery Vb is not insulation breakdown, and ends the insulation resistance estimation process.

9 is a flowchart of a method of correcting an insulation resistance using a correction resistor according to the first embodiment of the present invention.

The insulation resistance estimation apparatus 100 recognizes the start-on (IG ON) signal of the vehicle (S902).

The insulation resistance estimation apparatus 100 then turns on the correction switch SWx + or SWx- to connect the line between the correction resistor Rx + or Rx- and the common resistance Ry + or Ry- (S904).

Then, the insulation resistance estimation apparatus 100 estimates the insulation resistance at a predetermined stabilization time using the measured battery voltage and the calculated voltage change amount at the measurement time (S906).

The insulation resistance estimation apparatus 100 confirms whether the estimated insulation resistance and the correction resistance value match (S908).

As a result of the check (S908), if the estimated insulation resistance and the correction resistance value coincide with each other, the insulation resistance estimation apparatus 100 ends the insulation resistance correction using the correction resistance.

On the other hand, if the estimated insulation resistance does not match the correction resistance value (S908), the insulation resistance estimation apparatus 100 corrects the insulation resistance estimated by comparing the estimated insulation resistance with a predetermined correction resistance value (S910 ). Here, the insulation resistance estimation apparatus 100 can correct the insulation resistance estimated according to the resistance difference between the estimated insulation resistance and the predetermined correction resistance value.

After correcting the insulation resistance, the insulation resistance estimation apparatus 100 re-measures the insulation resistance (S912).

10 is a flowchart illustrating a method of correcting an insulation resistance using a correction resistor according to a second embodiment of the present invention.

The insulation resistance estimation apparatus 100 recognizes the start-on (IG ON) signal of the vehicle (S1002).

The insulation resistance estimation apparatus 100 then turns on the correction switch SWx + or SWx- to connect the line between the correction resistor Rx + or Rx- and the common resistor Ry + or Ry- (S1004).

Thereafter, the insulation resistance estimation apparatus 100 measures the battery voltage at each detailed time unit during the initial section (S1006).

The insulation resistance estimation apparatus 100 integrates the battery voltage for a preset integration period (S1008).

The insulation resistance estimation apparatus 100 estimates insulation resistance using the calculated battery integrated voltage (S1010).

The insulation resistance estimation apparatus 100 confirms whether the estimated insulation resistance and the correction resistance value match (S1012).

As a result of the check (S1012), if the estimated insulation resistance and the correction resistance value coincide with each other, the insulation resistance estimation apparatus 100 ends the insulation resistance correction using the correction resistance.

On the other hand, if the estimated insulation resistance does not match the correction resistance value (S1012), the insulation resistance estimation apparatus 100 corrects the insulation resistance estimated by comparing the estimated insulation resistance and the preset correction resistance value (S1014 ). Here, the insulation resistance estimation apparatus 100 can correct the insulation resistance estimated according to the resistance difference between the estimated insulation resistance and the predetermined correction resistance value.

After correcting the insulation resistance, the insulation resistance estimation apparatus 100 re-measures the insulation resistance (S1014).

11 is an explanatory diagram of a process of stabilizing the measured battery voltage according to the first embodiment of the present invention.

When the insulation resistance estimation apparatus 100 turns on the third or fourth switch SW3 or SW4 to measure the insulation resistance, it takes a long time to stabilize the voltage as shown in FIG.

Therefore, the insulation resistance estimation apparatus 100 must measure the insulation resistance after the measured battery voltage has stabilized. This not only lengthens the measurement period, but it also exposes the operator to danger during the sensing time, even if the insulation is destroyed.

Referring to the voltage waveform shown in FIG. 11, the shape of a slope that stabilizes the voltage and a voltage that goes up to a peak according to the voltage of the battery are changed. At this time, the insulation resistance estimation apparatus 100 estimates the insulation resistance by calculating the expected voltage with a voltage change amount (for example, a voltage slope) at a specific measurement time before the battery voltage is stabilized.

For example, assuming that the time takes 5 seconds to stabilize the voltage, the insulation resistance estimation apparatus 100 obtains the voltage change amount dv / dt at the 1-second time point (measurement time point). Then, the insulation resistance estimation apparatus 100 can measure the insulation resistance in one second by estimating the battery voltage at 5 seconds (stabilization time) using the voltage change amount.

Here, the insulation resistance estimation apparatus 100 can estimate the voltage after 5 seconds with a slope of (voltage change amount) / 1 ms by measuring the voltage at 1 second and the voltage at 1 ms or later.

The insulation resistance estimation apparatus 100 according to the first embodiment of the present invention can detect not only insulation resistance estimation time but also insulation resistance breakdown in real time. At this time, the insulation resistance estimation apparatus 100 can perform a total of five measurements over the same period (for example, 5 seconds), and can perform sampling several times, thereby improving the measurement accuracy.

In addition, since the operation of turning on the switch to measure the insulation resistance is the same as that of the insulation breakdown, the insulation resistance estimation apparatus 100 according to the first embodiment of the present invention generates the insulation resistance in the high voltage region It is possible to lower the possibility of influx of surge or noise.

12 is an explanatory diagram illustrating an integration process of a measured battery voltage according to a second embodiment of the present invention.

The insulation resistance estimation apparatus 100 determines whether insulation breakdown is based on the total voltage of the battery. However, an error occurs due to the voltage of the battery which fluctuates frequently during the insulation resistance measurement (for example, for 5 seconds).

Also, a large amount of noise is generated in a high voltage motor and an inverter of a vehicle. At this time, such noise may flow into the battery side, which may affect the measured value of the battery voltage. Therefore, the insulation resistance estimation apparatus 100 does not acquire the resultant value of the insulation resistance only once. The insulation resistance estimation apparatus 100 measures a voltage from an integration start time (for example, default 1 second) and uses the integrated voltage value 1201 integrated during the integration period from the integration completion time (for example, the fixed value 5 seconds) And the insulation resistance is estimated. This is to avoid the influence of the measurement performance of the insulation resistance from the voltage of the fluctuating battery and the noise introduced.

12, the insulation resistance estimation apparatus 100 integrates a voltage ranging from a default value (1 second) initially set through the integration circuit 130 to a fixed value (5 seconds) By using the value as a value for resistance measurement, not only is it insensitive to noise, but also the insulation resistance can be accurately estimated by reflecting the voltage of the battery.

At this time, a fixed value is used for 5 seconds in which the voltage measurement is completed, and a default value of 1 second in which the measurement is started can be set. The integration interval may be changed so as to correct the error value at the start of the vehicle.

It will be understood by those skilled in the art that the present specification may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present specification is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the present specification Should be interpreted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is not intended to limit the scope of the specification. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: An insulation resistance estimation device using a capacitor
110: Voltage measurement circuit
120: Integrating circuit
130:
R1 and R2: first and second resistors
Rm: Measuring resistance
SW1 to SW4: First to fourth switches
Ry + And Ry-: anode and cathode common resistance
Rf + And Rf-: anode and cathode fault resistance
SWx + And SWx-: Positive and Negative Correction Switches
Rx + And Rx-: anode and cathode correction resistances

Claims (20)

A first resistor connected in series to the battery, a measurement resistor and a second resistor;
First and second capacitors each having one side connected between the first resistor and the measurement resistor, the measurement resistor and the second resistor, and each of the other sides being commonly connected to the chassis ground of the vehicle;
First and second switches connecting or disconnecting the line between the battery and the first resistor and the second resistor;
A third switch connected between the first resistor and the measurement resistor and one end connected to the first capacitor and the other end connected to the chassis ground of the vehicle;
A fourth switch having one end connected to the measuring resistor and the second resistor and the other end connected to the third switch and the ground;
One and the other common resistors connected in parallel with the first and second resistors, respectively;
A voltage measuring circuit connected at both ends to the measuring resistor to measure a battery voltage from the battery voltage; And
Estimating an insulation resistance before voltage stabilization by calculating a voltage change amount at a measurement time point of the battery voltage and the battery voltage measured through the voltage measurement circuit after turning on the third or fourth switch, And controls the first and second switches in accordance with the insulation breakdown caused by the insulation resistance
And a capacitor connected to the capacitor. The method according to claim 1,
The control unit
Calculating a voltage change amount at a measurement time point after a predetermined time from a maximum time point at which the battery voltage rises and decreases at a maximum value after the third or fourth switch is turned on, And estimating an insulation resistance at a predetermined stabilization time using the calculated voltage change amount. The method according to claim 1,
The control unit
Calculating voltage variation amounts at measurement points respectively corresponding to at least one battery voltage measured through the voltage measurement circuit after turning on the third or fourth switch, A device for estimating insulation resistance using a capacitor that estimates a resistance before voltage stabilization. The method according to claim 1,
One side and the other of the correction resistors having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance; And
Further comprising a one-side and one-side correction switches for connecting or disconnecting the line between the one side and the other side correction resistor and the one side and the other side common resistance,
Wherein the controller corrects the estimated insulation resistance by comparing the estimated insulation resistance with the predetermined correction resistance after turning on one or the other of the correction switches. 5. The method of claim 4,
The control unit
And corrects the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the preset correction resistance. A first resistor connected in series to the battery, a measurement resistor and a second resistor;
First and second capacitors each having one side connected between the first resistor and the measurement resistor, the measurement resistor and the second resistor, and each of the other sides being commonly connected to the chassis ground of the vehicle;
First and second switches connecting or disconnecting the line between the battery and the first resistor and the second resistor;
A third switch connected between the first resistor and the measurement resistor and one end connected to the first capacitor and the other end connected to the chassis ground of the vehicle;
A fourth switch having one end connected to the measuring resistor and the second resistor and the other end connected to the third switch and the ground;
One and the other common resistors connected in parallel with the first and second resistors, respectively;
A voltage measuring circuit connected at both ends to the measuring resistor to measure a battery voltage from the battery voltage;
An integrating circuit for integrating the measured battery voltage; And
After turning on the third or fourth switch, the integrated voltage of the battery for a predetermined integration period is calculated from the integrated battery voltage in the integration circuit, and the insulation resistance is estimated using the calculated battery integrated voltage The control unit
And a capacitor connected to the capacitor. The method according to claim 6,
The control unit
The method includes calculating an integration start and completion time for integrating the measured battery voltage in advance and calculating a battery integrated voltage calculated from the predetermined integration start time to an integration completion time for each starting of the vehicle and using an error between the battery integrated voltages And correcting the calculated battery integrated voltage. The method according to claim 6,
The control unit
Wherein the waveform of the measured battery voltage is analyzed for each of the detailed time units during a predetermined initial period, and the predefined integral period is changed according to the waveform of the analyzed battery voltage. The method according to claim 6,
One side and the other of the correction resistors having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance; And
Further comprising a one-side and one-side correction switches for connecting or disconnecting the line between the one side and the other side correction resistor and the one side and the other side common resistance,
Wherein the controller corrects the estimated insulation resistance by comparing the estimated insulation resistance with the predetermined correction resistance after turning on one or the other of the correction switches. 10. The method of claim 9,
The control unit
And corrects the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the preset correction resistance. A capacitor in the insulation resistance estimating apparatus including first and second capacitors each having one side connected between a first resistor and a measurement resistor, the measurement resistor and a second resistor, and the other side commonly connected to the chassis ground of the vehicle A method for estimating an insulation resistance,
Connecting a first resistor, a measurement resistor and a second resistor in series with the battery;
A third switch having one side connected between the first resistor and the measuring resistor and the other side connected to the chassis ground of the vehicle; and a second switch having one side connected between the measuring resistor and the second resistor and the other side connected to the third switch and the ground Measuring a battery voltage from a resistance voltage by alternately turning on and off a fourth switch to be connected;
Calculating a voltage change amount at the time of measuring the measured battery voltage and the battery voltage after turning on the third or fourth switch; And
Estimating the measured battery voltage and the calculated voltage change amount before the voltage stabilization of the insulation resistance
Wherein the first and second resistors are connected in series. 12. The method of claim 11,
The step of calculating the voltage change amount
A voltage change amount at a measurement time point after a predetermined time from a maximum time point at which the battery voltage rises and decreases at a maximum value so as to estimate the insulation resistance at a predetermined stabilization time point after turning on the third or fourth switch, A method for estimating an insulation resistance using a capacitor. 12. The method of claim 11,
The step of estimating the insulation resistance before voltage stabilization
When the third or fourth switch is turned on in the step of calculating the voltage change amount, when the voltage change amounts at the respective measurement points corresponding to the measured at least one battery voltage are calculated, at least one voltage measurement sampling A method for estimating insulation resistance using a capacitor that estimates the insulation resistance before voltage stabilization. 12. The method of claim 11,
A line between the one side and the other side common resistance having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance and the one side and the other side common resistance are connected to each other and then compared with the estimated insulation resistance and the predetermined correction resistance value And correcting the estimated insulation resistance
Further comprising the steps of: 15. The method of claim 14,
The step of correcting the estimated insulation resistance
And correcting the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the predetermined correction resistance. A capacitor in the insulation resistance estimating apparatus including first and second capacitors each having one side connected between a first resistor and a measurement resistor, the measurement resistor and a second resistor, and the other side commonly connected to the chassis ground of the vehicle A method for estimating an insulation resistance,
Connecting a first resistor, a measurement resistor and a second resistor in series with the battery;
A third switch having one side connected between the first resistor and the measuring resistor and the other side connected to the chassis ground of the vehicle; and a second switch having one side connected between the measuring resistor and the second resistor and the other side connected to the third switch and the ground Measuring a battery voltage from a resistance voltage by alternately turning on and off a fourth switch to be connected;
Integrating the measured battery voltage after turning on the third or fourth switch, and calculating a battery integrated voltage for a predetermined integration period from the integrated battery voltage; And
Estimating an insulation resistance using the calculated battery integrated voltage
Wherein the first and second resistors are connected in series. 17. The method of claim 16,
Further comprising presetting an integration start and completion time for integrating the measured battery voltage,
Wherein the step of calculating the battery integrated voltage includes calculating a battery integrated voltage calculated from the predetermined integration start time to an integral completion time for each starting of the vehicle and correcting the calculated battery integrated voltage using an error between the respective battery integrated voltages (Method of Estimating Insulation Resistance Using a Capacitor). 17. The method of claim 16,
Analyzing a waveform of the battery voltage measured every detail time unit during a predetermined initial period; And
A step of changing a predetermined integration period according to the waveform of the analyzed battery voltage
Further comprising the steps of: 17. The method of claim 16,
A line between the one side and the other side common resistance having a predetermined correction resistance value and connected in parallel with the one side and the other side common resistance and the one side and the other side common resistance are connected to each other and then compared with the estimated insulation resistance and the predetermined correction resistance value And correcting the estimated insulation resistance
Further comprising the steps of: 20. The method of claim 19,
The step of correcting the estimated insulation resistance
And correcting the estimated insulation resistance according to a resistance difference between the estimated insulation resistance and the predetermined correction resistance.

Images