KR102042831B1 - Apparatus and method for measuring isolation resistance using oscillator - Google Patents

Abstract

An objective of the present invention is to provide an apparatus and a method for measuring insulation resistance which can measure precise insulation resistance. According to embodiments of the present invention, the apparatus for measuring insulation resistance comprises: a high side switching unit including a high side switch connected to a first high side node between a high side and a ground unit of a power supply unit, and a high side resistor to limit a current of the power supply unit; a low side switching unit including a low side switch connected to a first low side node between a low side and the ground unit of the power supply unit, and a low side resistor to limit a current of the power supply unit; a high side diagnosis unit which is connected to a second high side node between the high side switching unit and the ground unit, and includes a high side voltage measurement unit to measure a voltage of the second high side node; a low side diagnosis unit which is connected to a second low side node between the low side switching unit and the ground unit, and includes a low side voltage measurement unit to measure a voltage of the second low side node; a power voltage measurement unit to measure a high side voltage of the power supply unit and a lower side voltage of the power supply unit; and a control unit to control the high side switch, the low side switch, the high side diagnosis unit, the low side diagnosis unit, and the power voltage measurement unit.

Description

Insulation resistance measuring apparatus and method {APPARATUS AND METHOD FOR MEASURING ISOLATION RESISTANCE USING OSCILLATOR}

The present invention relates to an insulation resistance measuring apparatus, and more particularly to an insulation resistance measuring apparatus and method for measuring the insulation resistance.

Recently, various devices such as industrial devices, home appliances, and automobiles using high voltage batteries are used, and in particular, the use of high voltage batteries in automobiles is becoming more active.

In this case, automobiles using high voltage batteries and systems using high voltage must maintain the insulation state and maintain the state of infinite insulation resistance. However, when the insulation resistance value is low, leakage current may occur, which may cause problems. .

For this reason, automobiles and systems using high voltage batteries are continuously monitoring the insulation resistance to cut off the high voltage. Thus, insulation resistance measurement is very important in increasing the safety and reliability of the vehicle.

On the other hand, conventionally, the high side (HS) switch and the low side (LS) switch were operated once per cycle and the battery voltage was measured once when the insulation resistance was measured. Because of instantaneous fluctuation according to driving, an error may occur when measuring insulation resistance by measuring battery voltage once.

In addition, the error generated when measuring the insulation resistance could have a big impact on the safety and reliability of a vehicle using a high voltage battery.

SUMMARY OF THE INVENTION The present invention has been made to meet the above-described needs, and an object thereof is to provide an insulation resistance measuring apparatus and method capable of precise insulation resistance measurement.

An insulation resistance measuring apparatus according to an exemplary embodiment of the present invention includes a high side switch connected to a first high side node between a high side and a ground of a power supply unit, and a high side switching unit including a high side resistor to limit a current of the power supply unit. ; A low side switch including a low side switch connected to a first low side node between the low side of the power supply and the ground and a low side resistor for limiting a current of the power supply; A high side diagnosis unit connected to a second high side node between the high side switching unit and the ground unit and including a high side voltage measuring unit measuring a voltage of the second high side node; A low side diagnosis unit connected to a second low side node between the low side switching unit and the ground unit and including a low side voltage measuring unit measuring a voltage of the second low side node; A power supply voltage measuring unit for measuring a high side voltage of the power supply unit and a low side voltage of the power supply unit; And a controller configured to control the high side switch, the low side switch, the high side diagnosis unit, the low side diagnosis unit, and the power supply voltage measuring unit.

In this case, the controller performs a first measurement in a state in which one of the high side switch and the low side switch is turned on and the other switch is turned off, and vice versa A second measurement is performed by turning on and off one of the switches to obtain a high side insulation resistance between the high side switch and the ground portion and a low side insulation resistance between the low side switch and the ground portion. The measurement may be performed by separately measuring the high side voltage of the power supply unit and the low side voltage of the power supply unit through the power supply voltage measuring unit during the first measurement and the second measurement.

The high side diagnosis unit may include a first switch connected to a voltage applying terminal VDD, a second switch connected to the ground unit, and a high side diagnostic resistor connected to the first switch and the second switch. The low side diagnosis unit may include a third switch connected to the voltage applying terminal VDD, a fourth switch connected to the ground unit, and a low side diagnosis resistor connected to the third switch and the fourth switch. .

The high side voltage measuring unit and the low side voltage measuring unit may measure voltages of both sides of the high side diagnostic resistor and the low side diagnostic resistor, respectively.

The power supply voltage measurer may be configured to be connected to the first high side node and the first low side node.

In addition, the controller does not turn on or turn off a plurality of switches included in the high side diagnosis unit and the low side diagnosis unit simultaneously, and when the first switch is turned on, the third switch is turned on. Off, control the third switch to turn on when the first switch is turned off, turn on the second switch when the second switch is turned on, turn off the second switch, and turn off the second switch. 4 The switch can be controlled to turn on.

The control unit may be configured to control the high side diagnosis unit and the low side diagnosis unit to measure the high side insulation resistance and the low side insulation resistance even when the voltage of the power supply unit is a reverse voltage.

Meanwhile, the insulation resistance measuring method according to the embodiment of the present invention includes an insulation including a high side switching unit, a low side switching unit, a high side diagnosis unit, a low side diagnosis unit, a power supply voltage measuring unit, and a control unit to measure the insulation resistance. A method for measuring insulation resistance of a resistance measuring device, the method comprising: a high side switch included in the high side switching unit, a low side switch included in the low side switching unit, and a plurality of high side switches included in the high side diagnosis unit and the low side diagnosis unit; Applying a control signal to a switch of; Comparing a duration of the control signal with a preset time; When the duration of the control signal reaches the preset time, the first measurement is performed while turning on one of the high side switch and the low side switch and turning off the other switch. Performing; Storing a first measured value in the control unit; When the control signal applying step and the comparing step are performed again and the duration of the control signal reaches the preset time, the other switch is turned on and the other switch is turned on as opposed to the first measurement. Performing a second measurement in the off state; Storing a second measurement value in the control unit; And measuring a high side insulation resistance between the high side switch and the ground portion and a low side insulation resistance between the low side switch and the ground portion based on the first measurement value and the second measurement value. The control unit may separately measure the high side voltage of the power supply unit and the low side voltage of the power supply unit through the power supply voltage measuring unit during the first measurement and the second measurement.

In this case, the method may further include determining a failure based on the measured values of the high side insulation resistance and the low side insulation resistance.

In addition, the failure determination step may compare the calculated value of the high side insulation resistance and the low side insulation resistance with a predetermined value.

The error counter may be increased when the measured value of the high side insulation resistance and the low side insulation resistance is equal to or less than a predetermined value in the fault determination step.

The error counter may be reduced when the measured value of the high side insulation resistance and the low side insulation resistance is greater than a predetermined value in the fault determination step.

The error counter may further include initializing the error counter to '0' when the measured values of the high side insulation resistance and the low side insulation resistance are greater than a predetermined value.

The controller may output a failure occurrence signal when the error counter reaches a preset value.

The controller may control the plurality of switches included in the high side diagnosis unit and the low side diagnosis unit not to be turned on or off at the same time.

The control unit may be configured to control the high side diagnosis unit and the low side diagnosis unit to measure the high side insulation resistance and the low side insulation resistance even when the voltage of the power supply unit is a reverse voltage.

Insulation resistance measuring apparatus according to an embodiment of the present invention made as described above measures the battery voltage twice per cycle for measuring the insulation resistance when measuring the insulation resistance, high side (HS) insulation resistance and low side (LS) Since the insulation resistance is calculated, the error factor can be reduced compared to calculating the insulation resistance by measuring the battery voltage once in the existing circuit, thus enabling accurate measurement of the insulation resistance.

In addition, the configuration of the two amplifiers in the insulation resistance measurement unit when using the existing circuit, but the present invention can be reduced compared to the conventional circuit because the precise insulation resistance can be measured without including the configuration of the amplifier. Of course, the scope of the present invention is not limited by these effects.

1 is a circuit diagram of an insulation resistance measuring apparatus according to an embodiment of the present invention.
2 to 4 are circuit diagrams of an insulation resistance measuring apparatus according to still another embodiment of the present invention.
5A to 8B are circuit diagrams for explaining the insulation resistance measurement mode of the insulation resistance measurement apparatus of the present invention.
9 is a timing diagram of an insulation resistance measuring apparatus according to an embodiment of the present invention.
10 is a flowchart illustrating an insulation resistance measurement mode of an insulation resistance measurement apparatus according to an exemplary embodiment of the present invention.
11 is a flowchart illustrating a failure determination mode of an insulation resistance measuring apparatus according to an exemplary embodiment of the present invention.
12 is a circuit diagram for explaining the effect of the insulation resistance measuring apparatus of the present invention compared to the prior art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms, and the following embodiments are intended to complete the disclosure of the present invention, the scope of the invention to those skilled in the art It is provided to inform you completely. In addition, for convenience of description, the components may be exaggerated or reduced in size.

In addition, the following embodiments are provided to those skilled in the art to fully understand the present invention can be modified in various forms, the scope of the present invention is limited to the embodiments described below It doesn't happen.

In addition, the terms including or having in the following embodiments means that there is a feature or component described in the specification, and does not preclude the possibility of adding one or more other features or components. .

Hereinafter, an insulation resistance device according to an exemplary embodiment of the present invention will be described with reference to FIG. 1.

Referring to FIG. 1, the insulation resistance measuring apparatus 100 according to the present invention includes a high side switching unit 120, a low side switching unit 130, a high side diagnosis unit 140, a low side diagnosis unit 150, and a power supply. The voltage measuring unit 170 and the controller 160 may be included.

In more detail, the insulation resistance measuring apparatus 100 of the present invention may be connected to the power supply unit 110 and may receive a voltage from the power supply unit 110. In this case, the power supply unit 110 may be used as a battery or a fuel cell applied to a system requiring a high voltage. For example, the power supply unit 110 may be connected to the load resistor 107.

Meanwhile, the high side switching unit 120 may be connected to both sides (+) of the power supply unit 110, that is, the high side of the power supply unit 110, and the low side switching unit 130 may be connected to the negative side of the power supply unit 110. That is, it may be connected to the low side of the power supply unit 110.

The high side switching unit 120 may include the high side switches SW_S_H and 125 and the high side resistors R_S_H and 123, and the high side switches SW_S_H and 125 and the high side resistors R_S_H and 123 may be removed. One high side node 104 may be connected. At this time, the first high side node 104 is a node connected between the high side of the power supply unit 110 and the ground.

In this case, the high side resistors R_S_H and 123 may not be applied with the high side switches SW_S_H and 125 so that a high current is not applied to the high side switches SW_S_H and 125 before the current is applied to the high side switches SW_S_H and 125. Limit the high side current.

The low side switching unit 130 may include low side switches SW_S_L and 135 and low side resistors R_S_L and 133, and the low side switches SW_S_L and 135 and the low side resistors R_S_L and 133 may be removed. One low side node 106 may be connected. In this case, the first low side node 106 is a node connected between the low side of the power supply unit 110 and the ground.

In this case, the low-side resistors R_S_L and 133 may be applied to the power supply unit 110 before the current of the power supply unit 110 is applied to the low-side switches SW_S_L and 135 so that a high current is not applied to the low-side switches SW_S_L and 135. It is possible to limit the low side current of.

The high side diagnosis unit 140 may be connected to the second high side nodes V_H and 127, and may include a high side voltage measuring unit 143 to measure voltages of the second high side nodes V_H and 127. . In this case, the second high side node V_H 127 is a node connected between the high side switching unit 120 and the ground unit.

The low side diagnosis unit 150 may be connected to the second low side nodes V_L and 137, and may include a low side voltage measuring unit 153 to measure voltages of the second low side nodes V_L and 137. . In this case, the second low side nodes V_L and 137 are nodes connected between the low side switching unit 130 and the ground unit.

The power supply voltage measuring unit 170 may measure the high side voltage V_BAT_1 of the power supply unit 110 and the low side voltage V_BAT_2 of the power supply unit 110 under the control of the controller. In this case, the power supply voltage measuring unit 170 may be connected to the first high side node 104 and the first low side node 106, respectively. Meanwhile, a detailed description of the voltage measurement of the power supply voltage measuring unit 170 will be described later with reference to FIG. 2.

For example, the power supply voltage measuring unit 170 measures the high side voltage V_BAT_1 and the low side voltage V_BAT_2 of the power supply unit 110, measures the high side voltage V_BAT_1 of the power supply unit 110, and then the power supply unit. The high side voltage value V_BAT_1 of 110 is input to the controller 160, the low side voltage V_BAT_2 of the power source 110 is measured, and the low side voltage value V_BAT_2 of the power source 110 is controlled. It can be entered at 160.

In addition, the high side voltage measuring unit 143, the low side voltage measuring unit 153, and the power supply voltage measuring unit 170 operate under the control of the control unit, and in this case, the voltages of the second high side node 127, respectively. The voltage of the second low side node 137, the high side voltage of the power supply unit 110, and the low side voltage of the power supply unit 110 may be measured, and the measured voltage value may be input to the controller 160.

The controller 160 is connected to the high side switching unit 120, the low side switching unit 130, the high side diagnosis unit 140, and the low side diagnosis unit 150, and the high side insulation resistors R_INS_H and 103. The insulation resistance measurement mode for measuring the low side insulation resistance R_INS_L 105 may be operated.

More specifically, the controller 160 controls signals to the high side switch (SW_S_H, 125), the low side switch (SW_S_L, 135), the high side diagnosis unit 140, the low side diagnosis unit 150 in the insulation resistance measurement mode. Can be entered.

In this case, the controller performs a first measurement while turning on one of the high side switches SW_S_H and 125 and the low side switches SW_S_L and 135 and turning off the other switch. On the contrary, the high side insulation resistance (R_INS_H, 103) and the low side insulation resistance (R_INS_L, 105) can be measured by turning on the other switch and turning off one switch to perform the second measurement. .

More specifically, the controller 160 receives the voltage of the second high side node V_H and 127 and the high side voltage V_BAT_1 of the power supply unit 110 through the first measurement, and the second low through the second measurement. The voltages of the side nodes V_L and 137 and the low side voltage V_BAT_2 of the power supply unit 110 may be input. In addition, the controller 160 receives the input voltage value (voltages V_H and 127 of the second high side node, voltages V_L and 137 of the second low side node, high side voltage V_BAT_1 of the power supply unit 110, The high side insulation resistances R_INS_H and 103 and the low side insulation resistances R_INS_L and 105 may be calculated by calculating the low side voltages V_BAT_2 of the power supply 110.

In addition, the controller 160 measures the high side insulation resistances R_INS_H and 103 and the low side insulation resistances R_INS_L and 105, and the high side voltage V_BAT_1 of the power supply 110 and the low side of the power supply 110. The voltage V_BAT_2 can be measured separately.

For example, the high side insulation resistors R_INS_H and 103 are connected between the high side switch SW_S_H and 125 and the ground portion, and the low side insulation resistors R_INS_L and 105 are connected between the low side switch SW_S_L and 135 and the ground portion. Can be connected to.

On the other hand, the insulation resistance measuring apparatus 100 of the present invention may further include a diagnostic switch (SW_DIAG, 139), the diagnostic switch (SW_DIAG, 139) is a second high side node (V_H, 127), the second low side It is connected between the node (V_L, 137) and the input terminal of the analog-to-digital converter can be used for diagnosing the fault location, it can be switched by receiving the control signal of the controller 160.

In this case, the control unit 160 may operate a failure diagnosis mode for diagnosing a location of a failure, and input a control signal to the diagnosis switch SW_DIAG, 139. In this case, the control unit 160 may perform a failure diagnosis mode. The voltage of the power supply unit 110 may be verified.

For example, the controller 160 controls the high side diagnosis unit 140 and the low side diagnosis unit 150 even when the voltage of the power supply unit 110 is the reverse voltage (−) to increase the high side insulation resistances R_INS_H and 103. The low side insulation resistance R_INS_L 105 may be measured.

In addition, the controller 160 may measure the insulation resistance by controlling the switch even when the motor is driven when the insulation resistance is measured.

Meanwhile, details of operating the insulation resistance measurement mode in the controller will be described later with reference to FIGS. 5A to 8B.

2, in the insulation resistance measuring apparatus according to another embodiment of the present invention, the high side diagnosis unit 140 and the low side diagnosis unit 150 may include first to fourth switches SW_H_REV 141 and SW_L ( 142, SW_H 151, SW_L_REV 152, high side diagnostic resistors R_M_H 144, and low side diagnostic resistor 154.

In more detail, the high side diagnosis unit 140 may include a first switch 141, a second switch 142, and a high side diagnosis resistor 144, and the first switch SW_H_REV and 141 may be a voltage. It is connected to the terminal (VDD), the second switch (SW_L, 142) is connected to the ground, the high side diagnostic resistor (R_M_H, 144) is the first switch (SW_H_REV, 141) and the second switch (SW_L, 142) Can be connected to.

The low side diagnosis unit 150 may include a third switch SW_H and 151, a fourth switch SW_L_REV and 152, and a low side diagnostic resistor R_M_L and 154. The fourth switch SW_L_REV and 152 are connected to the ground, and the low side diagnosis resistors R_M_L and 154 are connected to the third switch SW_H and 151 and the fourth switch SW_L_REV. 152 may be connected.

Meanwhile, the first to fourth switches SW_H_REV 141, SW_L 142, SW_H 151, and SW_L_REV 152 may be switched to the voltage applying terminal VDD or the ground, and the first to fourth switches. A current flowing through the SW_H_REV 141, SW_L 142, SW_H 151, and SW_L_REV 152 may flow to the ground portion or the voltage applying terminal VDD.

At this time, the high side voltage measurement unit 143 included in the high side diagnosis unit 140 measures voltages on both sides of the high side diagnosis resistors R_M_H and 144 to measure the voltages of the second high side nodes V_H and 127. The low side voltage measurement unit 153 included in the low side diagnosis unit 150 may measure voltages on both sides of the low side diagnosis resistors R_M_L and 154 to measure the second low side nodes V_L and 137. The voltage of can be measured.

3 and 4 is a circuit diagram showing another connection structure for the insulating device of the present invention.

Referring to FIG. 3, the first to fourth switches SW_H_REV 141, SW_L 142, SW_H 151, and SW_L_REV 152 may be connected to digital outputs. Referring to FIG. 4, FIG. Likewise, the first to fourth switches SW_H_REV 141, SW_L 142, SW_H 151, and SW_L_REV 152 are connected to digital outputs, and the high side voltage measuring unit 143 and the low side voltage measuring unit ( 153) can be combined into one.

In this case, the high side voltage measuring unit 143 and the low side voltage measuring unit 153 may be connected to the analog-digital converter 400, and the capacitor C_LPF may be additionally connected to the analog-digital converter 400. .

More specifically, when the high side switch (SW_S_H, 125) is turned on, the third switch (SW_H, 151) is turned on and the analog-to-digital converter 400 of the second high side node (V_H, 127) When the voltage is input and conversely, when the low side switches SW_S_L and 135 are turned on, the second switches SW_L and 142 are turned on and the second low side node V_L and 137 is connected to the analog-to-digital converter 400. ) May be input.

In this case, even if the circuit is changed as shown in FIGS. 3 and 4 instead of the insulation resistance measuring device circuit of the present invention as shown in FIG. 1, the same effect as the insulation resistance measuring device circuit of the present invention can be obtained.

Meanwhile, the operation of the insulation resistance measurement mode will be described later in detail with reference to FIGS. 5A and 8B.

Referring to FIG. 5A, in the insulation resistance measurement mode, the control unit 160 first measures (first measure) the voltage of the high side voltage V_BAT_1 and the second high side node V_H, 127 of the power supply unit 110. ), A control signal may be applied to the high side switch SW_S_H and 125, the low side switch SW_S_L and 135 to the high side diagnosis unit 140 and the low side diagnosis unit 150.

More specifically, the controller 160 turns on the high side switches SW_S_H and 125, turns off the low side switches SW_S_L and 135, and turns on the first switch SW_H_REV of the high side diagnosis unit 140. , 141 may be turned off, and the second switches SW_L and 142 may be turned on. In this case, the third switch SW_H 151 and the fourth switch SW_L_REV 152 may be controlled to be turned off or turned on in some cases.

In this case, as shown in FIG. 5B, a circuit of the insulation resistance measuring apparatus may be configured. In the controller 160, the high side switches SW_S_H and 125 are turned on, and the low side switches SW_S_L and 135 are turned off. Since the current applied to the insulation resistance measuring apparatus 100 by the power supply unit 110 flows only to the high side of the power supply unit 110.

In this case, the high side voltage measuring unit 120 may measure voltages of the second high side nodes V_H and 127, and the high side current I_R_M_H and the second high side node V_H and 127 of the power supply unit 110. ) May be multiplied by the high side diagnostic resistors R_M_H and 144 to calculate the voltage of the second high side node V_H and 127. In this case, the power supply voltage measuring unit 170 may measure the high side voltage V_BAT_1 of the power supply unit 110.

In addition, the high side voltage measuring unit 143 and the power supply voltage measuring unit 170 may control the control unit 160 to control the voltage value of the second high side node 127 and the high side voltage value of the power supply unit 110. Can be delivered to.

Meanwhile, the controller 160 controls the voltage value of the second high side node V_H and 127 from the high side voltage measuring unit 143 and the power supply voltage measuring unit 170 and the high side voltage value V_BAT_1 of the power supply unit 110. In response to the input, the control unit 160 may again transmit control signals to the high side switches SW_S_H and 125, the low side switches SW_S_L and 135, the high side diagnosis unit 140, and the low side diagnosis unit 150. .

At this time, the controller 160 again controls the high side switch (the second side) in order to measure (second measurement) the low side voltage V_BAT_2 of the power supply unit 110 and the voltages of the second low side nodes V_L and 137. Control signals may be applied to the high side diagnosis unit 140 and the low side diagnosis unit 150 in the SW_S_H 125 and the low side switches SW_S_L 135.

More specifically, referring to FIG. 6A, the controller 160 turns off the high side switches SW_S_H and 125, turns on the low side switches SW_S_L and 135, and turns on the low side diagnosis unit 150. The third switch SW_H 151 may be turned on and the fourth switch SW_L_REV 152 may be turned off. In this case, the first switch SW_H_REV 141 and the second switch SW_L 142 may be controlled to be turned off or turned on in some cases.

In this case, as shown in FIG. 6B, a circuit of the insulation resistance measuring apparatus may be configured. In the controller 160, the high side switches SW_S_H and 125 are turned off, and the low side switches SW_S_L and 135 are turned on. In contrast to FIG. 5B, the current applied to the insulation resistance measuring apparatus 100 by the power supply unit 110 flows only to the low side of the power supply unit 110.

In this case, the low side voltage measuring unit 153 may measure the voltages 137 of the second low side nodes V_L and 137, and the low side current I_R_M_L of the power supply unit 110 and the second low side node ( The voltages of the second low side nodes V_L and 137 may be calculated by multiplying the low side diagnostic resistors R_M_L and 154 connected to the V_L and 137. In this case, the power supply voltage measuring unit 170 may measure the low side voltage V_BAT_2 of the power supply unit 110.

In addition, the low side voltage measuring unit 153 and the power supply voltage measuring unit 170 may control the voltage value of the second low side nodes V_L and 137 and the low side voltage value V_BAT_2 of the power supply unit 110. It may be delivered to the controller 160.

For example, the controller 160 inputs a control signal to the high side switch SW_S_H 125 and the low side switch SW_S_L 135 to the high side diagnosis unit 140 and the low side diagnosis unit 150 to supply the second high side. The voltages of the nodes V_H and 127, the voltages of the second low side nodes V_L and 137, the high side voltage V_BAT_1 of the power supply unit 110 and the low side voltage V_BAT_2 of the power supply unit 110 are received simultaneously. The high side voltage V_BAT_1 of the power supply unit 110 and the voltage values of the second high side nodes V_H and 127 are first inputted without being input, and the low side voltage V_BAT_2 of the power supply unit 110 and the first voltage are received. The voltage values of the two low side nodes V_L and 137 may be input.

Meanwhile, the controller 160 controls the voltages of the second high side nodes V_H and 127, the voltages of the second low side nodes V_L and 137, the high side voltage V_BAT_1 of the power source 110 and the power source 110. The high side insulation resistances R_INS_H and 103 and the low side insulation resistances R_INS_L and 105 may be calculated by inputting the low side voltage V_BAT_2 into Equations 1 and 2 below.

Meanwhile, referring to FIG. 7A, the switching of the high side switches SW_S_H and 125 and the low side switches SW_S_L and 135 are the same, but the first switch SW_H_REV and 141 and the second switch SW_L and 142 are the same. The circuit which operated by switching operation | movement of () reversely is shown.

In this case, in FIG. 7B, similar to FIG. 5B, the current of the power supply unit 110 flows only to the high side of the power supply unit 110, and the high side power measurement unit 143 of the second high side node V_H and 127 is performed. The voltage may be measured, and the high voltage V_BAT_1 of the power source 110 may be measured by the power voltage measurer 170.

Referring to FIG. 8A, the switching of the high side switches SW_S_H and 125 and the low side switches SW_S_L and 135 are the same, but the third switch SW_H and 151 and the fourth switch SW_L_REV and 152 are the same. The circuit which operated by switching operation | movement of () reversely is shown.

In this case, as shown in FIG. 8B, the current of the power supply unit 110 flows only to the low side of the power supply unit 110, and the low side power supply measurement unit 153 of the second low side nodes V_L and 137 is performed. The voltage may be measured and the low side voltage V_BAT_2 of the power source 110 may be measured by the power source voltage measurer 170.

9 is a timing diagram for the operation of the insulation resistance measuring apparatus of the present invention.

Referring to FIG. 9, the control unit 160 may include a switching operation time of a control switch (high side switch 125, low side switch 135, and first to fourth switches 141, 142, 151, and 152). You can compare the predetermined time.

For example, when the controller 160 turns on the high side switches SW_S_H and 125, the controller 110 may compare the turn-on times of the predetermined time t_H_ON and the high side switches SW_S_H and 125. Can be.

In this case, the controller 160 receives the voltages of the second high side nodes V_H and 127, the voltages of the second low side nodes V_L and 137 and the high voltage of the power supply 110. A switch (high side switch 125, low side switch 135, and first to fourth switches 141) controlled by the controller 160 in the sampling signal obtained by sampling the side voltage V_BAT_1 or the low side voltage V_BAT_2. 142, 151, and 152) may receive the sampling voltage value 900 immediately before the turn-on.

For example, when the high side switch SW_S_H 125 is turned on by the controller 160 and the low side switch SW_S_L 135 is turned off, the high side switch SW_S_H 125 is turned on again. The sampling voltage value 900 immediately before the low side switch SW_S_L 135 is turned on again may be stored in the controller 160.

10 is a flowchart illustrating the insulation resistance measuring apparatus of the present invention.

Referring to FIG. 11, when the insulation resistance measurement mode of the controller 160 starts, the controller 160 may initialize the error count. (Step S100)

In this case, the controller 160 may input a control signal to the high side switches SW_S_H and 125, the low side switches SW_S_L and 135, the high side diagnosis unit 140, and the low side diagnosis unit 150. (Step S110)

In this case, the control unit 160 applies a control signal in step S110 and the high side switch (SW_S_H, 125), the low side switch (SW_S_L, 135), the high side diagnosis unit 140 and the low side diagnosis unit 150 The time at which the switch is switched and the predetermined time t_H_ON may be compared.

Meanwhile, when the switching time and the predetermined time t_H_ON are reached in step S100, the voltage and power supply units of the second high side nodes V_H and 127 are high in the high side voltage measuring unit 143 and the power supply voltage measuring unit 170. The high side voltage V_BAT_1 of 110 is measured, and the controller 160 receives the measured voltage values of the second high side nodes V_H and 127 and the high side voltage value V_BAT_1 of the power supply 110. Can be. (Step S120)

The control unit 160 receives the voltage values V_H and V_BAT_1, and again the high side switches SW_S_H and 125, the low side switches SW_S_L and 135, the high side diagnosis unit 140, and the low side diagnosis unit 150. The control signal can be input to. (Step S130)

In this case, the control unit 160 applies a control signal in step S130 and the high side switch (SW_S_H, 125), the low side switch (SW_S_L, 135), the high side diagnosis unit 140 and the low side diagnosis unit 150 The time at which the switch is switched and the predetermined time t_OFF_1 may be compared.

For example, when the controller 160 turns on the high side switches SW_S_H and 125 and turns off the low side switches SW_S_L and 135, the voltage value of the second high side node V_H and 127 and The high side voltage V_BAT_1 of the power supply unit 110 is stored, the high side switches SW_S_H and 125 and the low side switches SW_S_L and 135 are turned off, and then the second low side node V_L and 137 voltage and In order to measure the low side voltage V_BAT_2 of the power supply unit 110, the high side switches SW_S_H and 125 may be turned off, and only the low side switches SW_S_L and 135 may be turned on.

In addition, the controller 160 may again input control signals to the high side switches SW_S_H and 125, the low side switches SW_S_L and 135, the high side diagnosis unit 140, and the low side diagnosis unit 150. . (Step S140)

In this case, the controller 160 may turn off the high side switches SW_S_H and 125, and turn off the low side switches SW_S_L and 135. In step S140, the controller 160 applies a control signal. The time at which the switches of the high side switch (SW_S_H, 125), the low side switch (SW_S_L, 135), the high side diagnosis unit 140, and the low side diagnosis unit 150 are switched can be compared with a predetermined time (t_L_ON). have.

Meanwhile, when the time controlled by the switch controlled in step S140 reaches a predetermined time t_L_ON, the voltage of the second low side node 137 is determined by the low side voltage measuring unit 153 and the power supply voltage measuring unit 170. And measure the low side voltage of the power supply unit 110, and the controller 160 may receive the measured voltage values of the second low side nodes V_L and 137 and the low side voltage value V_BAT_2 of the power supply unit 110. have. (Step S150)

In addition, the controller 160 may again input control signals to the high side switches SW_S_H and 125, the low side switches SW_S_L and 135, the high side diagnosis unit 140, and the low side diagnosis unit 150. . (Step S160)

In this case, the controller 160 may turn off both the high side switches SW_S_H and 125 and the low side switches SW_S_L and 135. In step S160, the controller 160 applies a control signal and the high side switch. (SW_S_H, 125), the time at which the switches of the low side switches SW_S_L and 135, the high side diagnosis unit 140, and the low side diagnosis unit 150 are switched may be compared with a predetermined time t_OFF_2.

The controller 160 receives the input voltage of the second high side node V_H and 127, the voltage of the second low side node V_L and 137, the high side voltage V_BAT_1 of the power source 110 and the power source 110. The high side insulation resistances R_INS_H and 103 and the low side insulation resistances R_INS_L and 105 may be calculated by substituting the low side voltage V_BAT_2 into the equation. (Step S170)

In addition, the controller 160 may determine a failure based on the calculated high side insulation resistances R_INS_H and 103 and the low side insulation resistances R_INS_L and 105. (Step S180)

11 is a flowchart illustrating a failure determination of the insulation resistance measuring apparatus of the present invention.

Referring to FIG. 11, when the failure determination mode is started in the controller 160, it is possible to compare whether the values of the high side insulation resistances R_INS_H and 103 and the low side insulation resistances R_INS_L and 105 are smaller than or equal to a predetermined value. have. (Step S200)

If the values of the high side insulation resistors R_INS_H and 103 and the low side insulation resistors R_INS_L and 105 are smaller than or equal to a predetermined value, the error count may be increased. (Step S210)

However, if the values of the high side insulation resistors R_INS_H and 103 and the low side insulation resistors R_INS_L and 105 are not less than or equal to a predetermined value, the error count may be reduced. (Step S220)

On the other hand, it is possible to compare whether the error count is equal to a predetermined count value. (Step S230)

In this case, when the error count is equal to a predetermined count value, the controller 160 may output a failure occurrence signal. (Step S240)

However, if the error count is not equal to the predetermined count value, the failure determination mode may be terminated. (Step S250)

12 is a circuit diagram for explaining the precise insulation resistance measurement of the insulation resistance device of the present invention.

Referring to FIG. 12, the insulation resistance device of the present invention measures the battery voltage a total of two times. When the battery voltage is measured 1000 as shown in FIG. 12, 300 V may be measured. Because of the instantaneous fluctuation, the battery voltage could be measured at 330V when the second measurement (1100) was performed.

In this case, when the insulation resistance is calculated by measuring the battery voltage at 300 V, the high side insulation resistance 103 is measured at 89.857 kohm, and the low side insulation resistance 105 is measured at 9.861 Mohm. The error could fly badly.

However, in the present invention, since the battery voltage is measured twice, when the first measurement (1000) is measured at 300V and the second battery voltage is measured at 330V when measured (1100), the high side insulation resistance is 99.99kohm. Since the low side insulation resistance is 9.990Mohm, it can be seen that the error is significantly reduced compared to the conventional method.

In addition, the error that occurs when measuring the insulation resistance can greatly affect the safety and reliability of a vehicle using a high voltage battery, so the technology that can accurately measure the insulation resistance can be very important.

Meanwhile, although two amplifiers are required in the insulation resistance measuring unit when using a conventional circuit, the present invention can reduce the cost compared to the conventional circuit because the precise insulation resistance can be measured without including the amplifier configuration.

In the detailed description and the accompanying drawings of the present invention, specific embodiments have been described, but the present invention is not limited to the disclosed embodiments and does not depart from the technical spirit of the present invention for those skilled in the art. Various substitutions, modifications and variations are possible within the scope. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be construed as including not only the claims below but also equivalents thereof.

110: power supply
103: high side insulation resistance
105: low side insulation resistance
120: high side switching unit
125: high side switch
127: second high side node
130: low side switching unit
135: low side switch
137: second low side node
140: high side diagnosis unit
143: high side voltage measurement unit
150: low side diagnosis unit
153: low side voltage measurement unit
160: control unit
170: power supply voltage measuring unit

Claims (16)

A high side switch including a high side switch connected to a first high side node between a high side of the power supply and a ground and a high side resistor for limiting a current of the power supply;
A low side switch including a low side switch connected to a first low side node between the low side of the power supply and the ground and a low side resistor for limiting a current of the power supply;
A high side diagnosis unit connected to a second high side node between the high side switching unit and the ground unit and including a high side voltage measuring unit measuring a voltage of the second high side node;
A low side diagnosis unit connected to a second low side node between the low side switching unit and the ground unit and including a low side voltage measuring unit measuring a voltage of the second low side node;
A power supply voltage measuring unit for measuring a high side voltage of the power supply unit and a low side voltage of the power supply unit; And
And a control unit for controlling the high side switch, the low side switch, the high side diagnosis unit, the low side diagnosis unit, and the power supply voltage measuring unit.
The controller performs a first measurement in a state in which one of the high side switch and the low side switch is turned on and the other one is turned off, and conversely, the other switch is turned on. And performing a second measurement by turning off one of the switches to measure a high side insulation resistance between the high side switch and the ground portion and a low side insulation resistance between the low side switch and the ground portion, The high side voltage of the power supply unit and the low side voltage of the power supply unit are separately measured through the power supply voltage measuring unit during the first measurement and the second measurement.
The high side diagnosis unit includes a first switch connected to a voltage applying terminal (VDD), a second switch connected to the ground unit, and a high side diagnosis resistor connected to the first switch and the second switch,
The low side diagnosis unit includes a third switch connected to the voltage applying terminal VDD, a fourth switch connected to the ground unit, and a low side diagnosis resistor connected to the third switch and the fourth switch.
Insulation resistance measuring device.
delete delete The method of claim 1,
The high side voltage measuring unit and the low side voltage measuring unit respectively measure the voltages of both sides of the high side diagnostic resistor and the low side diagnostic resistor,
Insulation resistance measuring device.
The method of claim 1,
The power supply voltage measurer is configured to be connected to the first high side node and the first low side node.
Insulation resistance measuring device.
The method of claim 1,
The controller does not turn on or off a plurality of switches simultaneously included in the high side diagnosis unit and the low side diagnosis unit.
When the first switch is turned on, the third switch is turned off, and when the first switch is turned off, the third switch is controlled to be turned on,
When the second switch is turned on, the fourth switch is turned off, and when the second switch is turned off, the fourth switch is controlled to be turned on.
Insulation resistance measuring device.
The method of claim 1,
The control unit is configured to measure the high side insulation resistance and the low side insulation resistance by controlling the high side diagnosis unit and the low side diagnosis unit even when the voltage of the power supply unit is reverse voltage.
Insulation resistance measuring device.
In the insulation resistance measurement method of the insulation resistance measurement apparatus comprising a high side switching unit, a low side switching unit, a high side diagnosis unit, a low side diagnosis unit, a power supply voltage measuring unit and a control unit for measuring the insulation resistance,
Applying a control signal to a high side switch included in the high side switching unit, a low side switch included in the low side switching unit, a plurality of switches included in the high side diagnosis unit and the low side diagnosis unit;
Comparing a duration of the control signal with a preset time;
When the duration of the control signal reaches the preset time, the first measurement is performed while turning on one of the high side switch and the low side switch and turning off the other switch. Performing;
Storing a first measured value in the control unit;
When the control signal applying step and the comparing step are performed again and the duration of the control signal reaches the preset time, the other switch is turned on and the other switch is turned on as opposed to the first measurement. Performing a second measurement in the off state;
Storing a second measurement value in the control unit; And
Measuring a high side insulation resistance between the high side switch and the ground portion and a low side insulation resistance between the low side switch and the ground portion based on the first measurement value and the second measurement value; ,
The control unit separately measures the high side voltage of the power supply unit and the low side voltage of the power supply unit through the power supply voltage measuring unit during the first measurement and the second measurement, respectively,
Determining a failure based on the measured value of the high side insulation resistance and the low side insulation resistance;
In the fault determination step, the operation value of the high side insulation resistance and the low side insulation resistance is compared with a predetermined value,
In the fault determination step, if the measured value of the high side insulation resistance and the low side insulation resistance is equal to or less than a predetermined value, the error counter is increased.
How to measure insulation resistance.
delete delete delete The method of claim 8,
If the measured value of the high side insulation resistance and the low side insulation resistance is greater than a predetermined value in the fault determination step, reducing the error counter,
How to measure insulation resistance.
The method of claim 8,
The method may further include initializing the error counter to '0' when the measured value of the high side insulation resistance and the low side insulation resistance is greater than a predetermined value in the fault determination step.
How to measure insulation resistance.
The method of claim 8,
The control unit outputs a failure occurrence signal when the error counter reaches a preset value.
How to measure insulation resistance.
The method of claim 8,
The control unit controls not to turn on or turn off a plurality of switches included in the high side diagnosis unit and the low side diagnosis unit at the same time.
Insulation resistance measurement method.
The method of claim 8,
The control unit is configured to measure the high side insulation resistance and the low side insulation resistance by controlling the high side diagnosis unit and the low side diagnosis unit even when the voltage of the power supply unit is reverse voltage.
How to measure insulation resistance.

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