JP2002247771A - Voltage sensor of strong electricity battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a voltage of a strong electricity battery for diagnosis of faults in a simplified structure by reducing deterioration due to aging. SOLUTION: A switching unit 10, a bypass filter 20, a protection circuit 30 and a measuring unit 42 of a battery control device 40 are connected to the strong electricity battery 1. A diagnostic unit 50 controls the on/off of the switching unit at a frequency equal to or higher than a cut-off frequency of the high-pass filter to provide an artificial AC of the voltage of the strong electricity battery. The measuring unit measures an output voltage divided with ceramic capacitors 12, 16 of the high-pass filter and the diagnostic unit diagnoses as voltage fault of the strong electricity battery, when the measured voltage goes out of a normal range. Since a ceramic capacitor is used in place of an existing photocoupler, a stabilizing power supply is unnecessary and the deterioration due to aging is also small. Moreover, a fault other than a defective voltage and the location of such fault can be detected from a profile of the measured voltage, when the switching unit is turned to on or to off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage sensor for measuring a voltage of a high-power battery such as a motor for driving an electric vehicle.

[0002]

2. Description of the Related Art In an electric vehicle, a driving power of a motor is supplied from a high-power system battery composed of a plurality of unit batteries, and the vehicle travels. Voltage management is needed. In order to measure the voltage of such a high-current battery, for example,
Japanese Patent Application Laid-Open No. 11-230997 discloses a voltage sensor using a stabilized power supply and a photocoupler.

As shown in FIG. 7, a light emitting diode 6 which emits light at the output of a stabilizing power supply 60 for stabilizing the voltage of a unit battery 2 constituting a high-power battery, as shown in FIG.
4 and a first photodiode 66 for receiving light from the light emitting diode 64, and differentially amplifies the divided voltage value of the unit battery 2 by the resistors 70 and 71 and the feedback voltage from the first photodiode 66. The operational output of the light emitting diode 64 is controlled by the operational amplifier 74. Then, a second photodiode 68 for receiving light from the light emitting diode 64 is provided, and a light receiving output of the second photodiode 68 is integrated by an operational amplifier 76 driven by a weak power supply, and the integrated voltage is stored in a battery. Of the detection voltage. When detecting the total voltage of the high-power system battery, the above configuration is provided for each unit battery 2. The photocoupler 62 including the light-emitting diode 64 and the second photodiode 68 cuts off the high-current system and the low-current system, thereby preventing the direct current of the high-current system from leaking to the low-current system and generating noise or the like.

[0004]

However, in the above-described conventional voltage sensor, the light emitting diode 64 and the second photodiode 6 are used to insulate between the high-current system and the low-current system.
The photocoupler 62 composed of No. 8 is used. Since the photocoupler deteriorates with time, the characteristics of the light-generated voltage change due to the deterioration. Therefore, fluctuation prediction and measures for suppressing the fluctuation are required. Therefore, for example, there is a problem in that the structure is complicated and the cost for man-hours is increased, for example, setting of a cooling structure for reducing the temperature of the surrounding environment, which is an accelerating factor of deterioration, and confirmation by experiments. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a voltage sensor for a high-power battery having a simple configuration without the risk of aging.

[0005]

According to the present invention, there is provided a switching device connected to a high-voltage battery, a high-pass filter connected to the switching device, and a switching device connected to the high-pass filter. The high-pass filter section includes voltage-dividing means for dividing the output of the switching means with a capacitor, and the switching means interrupts the DC voltage of the high-voltage battery at a frequency equal to or higher than the cut-off frequency of the high-pass filter section. The voltage was converted into a voltage, and the measurement unit measured the output voltage divided by the high-pass filter unit, and calculated the voltage of the high-power battery based on the measured voltage.

According to a second aspect of the present invention, a protection circuit having a zener diode is provided between the high-pass filter section and the measuring section.

According to a third aspect of the present invention, the switching means comprises:
A switching unit provided between the high-power battery and the high-pass filter unit; and a control unit for sending an on / off control signal having a cut-off frequency or higher to the switching unit. Abnormality diagnosis is performed by receiving the measurement voltage from the section.

According to a fourth aspect of the present invention, the control means outputs an overvoltage suppression command to the motor controller when the measured voltage exceeds the set value of the voltage higher than the normal range and the motor is regenerating.

According to a fifth aspect of the present invention, in addition to the control signal for turning on / off the switching unit at a frequency equal to or higher than the cutoff frequency as the diagnostic signal, the control unit controls the switching unit to the on state or the off state. The signal is output to the switching unit.

[0010]

According to the first aspect of the present invention, a DC voltage of a high-voltage battery is converted into an intermittent voltage by a switching means and converted into a pseudo AC, and a voltage divided by a voltage dividing means by a capacitor of a high-pass filter is measured. Since the measurement is performed by the unit, the application of the high-voltage direct current to the measurement unit of the weak electric system is cut off without using the photocoupler. Similarly, since no resistor is used for voltage division, dark current is reduced and loss is also reduced. Further, since the processing of the voltage of the high-voltage battery is only interrupted by the switching means, it is easy to increase the withstand voltage, and a stabilized power supply in the high-voltage system is not required. Further, the level adjustment of the input voltage to the measuring section can be easily performed by changing the intermittent duty and the capacitance ratio of the capacitor. As a result, aging does not occur due to the use of the photocoupler, the configuration is simplified, the size is easily reduced, and the cost is reduced.

According to the second aspect of the present invention, since a protection circuit including a zener diode is provided between the high-pass filter and the measuring section, the voltage applied to the measuring section can be maintained even when the capacitor of the high-pass filter short-circuits. Is suppressed by the clamp pressure of the Zener diode, and the influence on the measurement section and other weak electric systems is prevented.

According to a third aspect of the present invention, the switching means comprises a switching section and a control means, and the control means further has a diagnosis function, and performs an abnormality diagnosis based on the measured voltage of the measurement section. When there is an abnormality, it is easy to identify the abnormal part from the aspect of the measured voltage. For example, when the measured voltage deviates from the normal range, it is detected that the high-voltage battery has a low-voltage abnormality or a high-voltage abnormality. In particular, when the waveform of the measured voltage has an impulse shape in the case of a low voltage, the control unit itself or the switching unit is abnormal because the cutoff frequency has not been reached. Also,
When the measured voltage sticks to the clamp pressure of the Zener diode, a short-circuit failure of the capacitor of the high-pass filter is detected.

According to the present invention, when the measured voltage exceeds the upper limit of the normal range and the measured voltage exceeds the set value of the high voltage, the regenerative voltage of the motor is applied to the high-voltage battery. Check if there is any, and if regeneration is in progress, output an overvoltage suppression command to the motor controller.
The cause of the abnormal state can be clarified, and the voltage applied to the high-power battery can be reduced to a normal range.

According to a fifth aspect of the present invention, the control means can output a diagnostic signal for turning the switching section on or off to the switching section. An abnormality can be detected, and the site can be specified. For example, when the measured voltage exceeds a predetermined value in spite of the fact that the measured voltage should be 0 with respect to the output of the diagnostic signal for turning off the switching unit, an abnormality has occurred in the switching unit or the measured unit. You can see that there is. Further, by turning on the switching unit before turning on / off the switching unit at a frequency equal to or higher than the cutoff frequency, the measured voltage can be set to the predetermined value even in this case, regardless of whether the measured voltage should be zero. Is exceeded, it can be detected at an early stage that there is a short-circuit failure in the capacitor of the high-pass filter unit.

[0015]

Embodiments of the present invention will be described below in detail. FIG. 1 is a block diagram showing a configuration of the embodiment. A plurality of unit batteries 2 (2a, 2b,
...) are connected in series to form a battery pack 1
A switching unit 10 is connected between the two terminals of the battery controller 4 having a high-pass filter unit 20, a protection circuit 30, and a CPU.
0 measuring unit 42 is connected. A diagnostic unit 50 having another CPU is connected to the battery controller 40, and the diagnostic unit 50 outputs a diagnostic signal to the switching unit 10. The battery controller 40 and the diagnosis unit 50 operate on a weak power source (not shown). Also,
The battery controller 40 detects the high-current battery 1
Is output to the motor controller 55, and the diagnostic unit 50 is also connected to the motor controller 55.

The switching unit 10 includes a high-power battery 1
And a transistor 16 having a collector connected to the base of the transistor 12 via a resistor 14. A resistor 13 is connected between the emitter and the base of the transistor 12, and the collector serves as an output to the high-pass filter unit 20.

The emitter of the transistor 16 is connected to the ground GN connected to the negative (-) terminal of the high-voltage battery.
D, and the resistor 17 connects between the emitter and the base. The base of the transistor 16 is a resistor 18
Is connected to the diagnostic unit 50 through the CPU and receives a diagnostic signal. The resistors 13 and 17 are for applying a bias to the base when receiving an H (high) signal described later from the diagnostic unit 50.

The high-pass filter section 20 includes a ceramic capacitor 2 connected to the collector of the transistor 12.
2 and a filter circuit 21 including a resistor 26 connected between the capacitor 22 and the ground GND.
Connection point between capacitor 22 and resistor 26 and ground GN
A ceramic capacitor 24 is connected between D. Capacitors 22 and 24 have respective capacities C1 and C2,
Assuming that the resistance value of the resistor 26 is R1, the cutoff frequency fc of the filter circuit 21 is fc = 1 / (C1 · R1) (1) Further, in the high-pass filter section 20, a voltage dividing circuit 28 is formed by the capacitors 22 and 24. This voltage dividing circuit 28 constitutes a voltage dividing means in the present invention.

The protection circuit 30 includes a capacitor 22 and a resistor 2
6 includes a resistor 32 connected to the connection point 6 and a zener diode 34 connected between the resistor 32 and the ground GND. Clamp pressure Vz of Zener diode 34
Is set according to the input withstand voltage of the battery controller 40, and protects the battery controller 40 when the capacitor 22 of the high-pass filter unit 20 is short-circuited. The connection point between the resistor 32 and the Zener diode 34 is connected to the voltage measurement terminal AD of the measurement unit 42 of the battery controller 40.

The diagnostic section 50 normally has a cut-off frequency f
c is output to the switching unit 10. The battery controller 40 calculates the voltage of the high-power battery 1 based on the voltage measurement result of the voltage measurement terminal AD by the measurement unit 42, and outputs the result to the motor controller 55. And output to the high-power system battery 1.

At the time of diagnosis, the battery controller 4
0 sends the voltage measurement result to the diagnostic unit 50 together with the waveform input to the voltage measurement terminal AD. The diagnostic unit 50 compares the voltage measurement result with the output state of the diagnostic signal, determines whether there is an abnormality, and outputs the result to the battery controller 40 as a diagnostic result. The battery controller 40 performs charge / discharge control and the like of the high-voltage battery 1 based on the voltage measurement result in the normal state, while taking measures according to the nature of the abnormality, such as stopping control for system protection in the event of a high voltage abnormality. I do.
In the present embodiment, the diagnosis unit 50 and the switching unit 10 constitute a switching unit in the present invention, and in particular, the diagnosis unit 50 constitutes a control unit.

In the above configuration, when the diagnostic unit 50 outputs a pulse of H (high) and L (low) alternately to the switching unit 10 as a diagnostic signal, the switching unit 10 outputs a transistor when the diagnostic signal is H. When the signals 12 and 16 are ON and the diagnostic signal is L, the transistors 12 and 16 are turned OFF respectively, and a pseudo AC voltage is generated. Although the passage of the DC voltage is blocked by the filter circuit 21 of the high-pass filter section 20, if the diagnostic signal is equal to or higher than the cutoff frequency fc, the pseudo AC voltage passes through the protection circuit 30 and the voltage of the battery controller 40 is measured. Input to terminal AD.

During this time, the pseudo AC voltage is reduced to the measurement range level of the battery controller 40 by the voltage dividing circuit 28 of the high-pass filter section 20. Assuming that the total voltage of the high-power system battery 1 is Vb, the ON time of the transistor 12 of the switching unit 10 is Ton, and the OFF time is Toff, the output voltage Vout of the high-pass filter unit 20
Is represented by the following equation (2). Vout = Vc · (C1 / C2) · Ton / (Ton + Toff) (2) where Vc is the output voltage of the switching unit 10, and Vc = Vb in a normal state.

In this embodiment, the total voltage of the high-power battery 1 is set to Vb = 400 V, and the capacity of the capacitor 22 is set to Cb.
1 = 0.01 μF, the capacitor 24 is set to C2 = 1 μF, and the resistance is set to R1 = 10 KΩ. The clamp pressure of the Zener diode 34 of the protection circuit 30 is set to Vz = 6.2V. The cut-off frequency of the high-pass filter unit 20 is fc = 1 / (0.01 μF × 10 KΩ) = 10 KHz.

The on / off state of the switching unit 10
Assuming that the duty of the off control is 50%, the output voltage Vout of the high-pass filter unit 20 is as follows: Vout = 400 V × (0.01 μF / 1 μF) × 50 μsec / (50 μsec + 50 μsec) = 2.0 V FIG. 2 shows the output (Vc) of the switching unit 10 and the output (Vout) of the high-pass filter unit 20 in a normal state when on / off control is performed at 10 KHz and a duty of 50%.

When the input to the high-pass filter section 20 is lower than the cutoff frequency fc, as shown in FIG. 3, the output (Vout) of the high-pass filter section 20 has an impulse shape only at the rise and fall of the pulse. And the peak voltage is Vc · (C1 /
C2). FIG. 3 shows a case where the frequency of the on / off control is 1 Hz, which is lower than the cutoff frequency.

Hereinafter, the flow of control in this embodiment will be described with reference to the flowcharts of FIGS. In this control, an ignition switch (not shown) of the electric vehicle is turned on.
It is started by being done. First, in step 101, the diagnosis unit 50 sets an initial value of a variable,
In step 102, an L signal is output to the switching unit 10 as a diagnostic signal, and the transistors 12 and 16 are turned off.
Let it. That is, the switching unit 10 is turned off.

In step 103, the battery controller 40 measures the voltage VAD input to the voltage measuring terminal AD, and outputs the measurement result to the diagnosis section 50. The measuring unit 42 from the switching unit 10 via the high-pass filter unit 20
If the system up to is normal, the measured voltage (measurement result) Vs
Is equal to VAD, and the voltage VAD is equal to Vout described above.

In step 104, the diagnosis unit 50 checks whether the measured voltage Vs is equal to or less than a predetermined value V1. When the transistor 12 is OFF, that is, when the switching unit 10 is OFF, the power supply from the high-power battery 1 is cut off, and Vs = 0. Here, the predetermined value is set to, for example, V1 = 0.5 V in consideration of noise and the like. When the measured voltage Vs is equal to or lower than V1, the process proceeds to step 105.

In step 105, H is used as a diagnostic signal.
A signal is output to the switching unit 10 and the transistor 12
Then, in step 106, the battery controller 40 measures the input voltage of the voltage measuring terminal AD, and outputs the measured voltage Vs to the diagnostic unit 50. In step 107, the diagnosis unit 50 checks whether the measured voltage Vs is equal to or lower than a predetermined value V1. Even when the switching unit 10 remains ON, the direct current from the high-power battery 1 is cut off by the high-pass filter unit 20, so that Vs = 0. Therefore, the predetermined value V1 = 0.5 V is used as the reference value here. When the measured voltage Vs is equal to or lower than V1, the process proceeds to step 108.

In step 108, the diagnostic section 50 starts outputting a control pulse having a frequency of 10 KHz and a duty of 50% as a diagnostic signal. Then, the next step 109
Then, the measuring unit 42 is 10 m of the input voltage of the voltage measuring terminal AD.
The measured voltage Vs is obtained as an average value. Note that this 10 msec can be increased or decreased within a range where a pseudo AC input is secured. In step 110, the diagnosis unit 50 determines that the measured voltage Vs is equal to the predetermined value V2 = 1.
Check if it is V or more. V2 = 1 above
V corresponds to Vc = 200 V, and when it is lower than this, the voltage of the high-power battery becomes abnormally low. When the measured voltage Vs is equal to or higher than V2, the process proceeds to step 111.

In step 111, it is checked whether the measured voltage Vs is equal to or less than a predetermined value V3 = 2.1V.
This V3 = 2.1V corresponds to Vc = 420V, and when it is higher than this, the voltage of the high-power battery becomes abnormally high. If the measured voltage Vs is equal to or lower than V3, a normal diagnostic result is sent to the battery controller 40 in step 112. In step 113, the battery controller 40 reversely calculates Vc from the above equation (2) based on the measured voltage Vs, and uses this Vc as a measurement result of the total voltage Vb of the high-power battery 1. This measurement result is output to the motor controller 55 as required. The above is the flow at the time of normal operation.

Next, when the measured voltage Vs exceeds V1 in the check in step 104, the diagnosis section 50
Proceeding to step 114, the value of m is incremented by one, and in step 115, it is checked whether m is 3 or less. The process returns to step 103 while m is 3 or less. This is 3
This is for checking the number of times to confirm that the same state continues. Steps 103, 104, 114, 1
When m is greater than 3 by repeating 15, it can be determined that the switching unit 10 has failed or the measurement unit 42 has failed. Therefore, the process proceeds to step 116, and the battery controller 40 determines that the switching unit 10 or The measurement unit 42 sends out a diagnosis result indicating that the measurement unit 42 is abnormal.

If the measured voltage Vs exceeds V1 in the check in step 107, the diagnosis section 50 proceeds to step 117 and increments the value of n by one. In step 118, n is 3 or less. Check if. The process returns to step 106 while n is 3 or less. Steps 106, 107, 117 and 118 are repeated so that n becomes 3
Is exceeded, it can be determined that a short-circuit fault has occurred in the capacitor 22 of the high-pass filter unit 20. In this case, the process proceeds to step 119, where a diagnosis result indicating that the capacitor 22 is short-circuited is sent to the battery controller 40 as a second type abnormality.

When the capacitor 22 is short-circuited,
When the switching unit 10 repeatedly performs the on / off control, the measured voltage Vs becomes equal to the clamp pressure Vz (= 6.2) of the zener diode 34 like Vout shown in FIG.
V). Therefore, a short-circuit failure of the capacitor 22 can be detected from this phenomenon. FIG. 6 shows 10KH
z, the output (Vc) of the switching unit 10 when on / off control is performed at a duty of 50% and the high-pass filter unit 2
0 (Vout) is shown.

If Vs is lower than V2 in the check in step 110, the diagnostic section 50 proceeds to step 120, increments the value of p by 1, and checks in step 121 whether p is 3 or less. The process returns to step 109 while p is 3 or less. Steps 109, 110, 12
When 0 and 121 are repeated and p exceeds 3, the routine proceeds to step 122, where it is checked whether the input waveform to the voltage measurement terminal AD is not in the form of an impulse. When the input waveform is in the form of an impulse such as Vout shown in FIG.
0 or a diagnosis result indicating that the switching unit 10 is abnormal is sent to the battery controller 40.

If the input waveform is not an impulse in the check in step 122, there is no problem in the function of the switching unit 10. In this case, the process proceeds to step 124, in which a diagnosis result indicating that the voltage of the high-power battery 1 is low or the connection is poor is sent to the battery controller 40 as a fourth type abnormality.

In the check of step 111, the measured voltage Vs
Exceeds the predetermined value V3, the routine proceeds to step 125, where the value of r is incremented by one, and
At 6, check whether r is 3 or less. The process returns to step 109 while r is 3 or less. Steps 109, 111,
When r exceeds 3 by repeating steps 125 and 126, the routine proceeds to step 127, where the measured voltage Vs is set to the predetermined value V4.
Check if this is the case. The predetermined value V4 is set to, for example, V4 = 3.5V in order to confirm whether or not a voltage due to regenerative power generation from the motor is applied. This value corresponds to Vc = 700V.

If the measured voltage Vs is equal to or higher than V4, it is checked in step 128 whether the motor is regenerating. If the motor is regenerating, the process proceeds to step 129, sends an overvoltage suppression command to the battery controller 40, and then returns to step 109. On the other hand, step 12
If the measured voltage Vs is lower than V4 in the check in step 7, or if the motor is not regenerating in the check in step 128, the process proceeds to step 130, and the fifth type abnormality is a voltage abnormality in which the high-voltage battery 1 is at a high voltage. Is transmitted to the battery controller 40. When the battery controller 40 receives the diagnosis results of the first to fifth abnormalities from the diagnostic unit 50 from the diagnostic unit 50, it temporarily terminates the control flow, executes a measure corresponding to each abnormal condition, and Resume accordingly.

The present embodiment is configured as described above. The switching unit 10 converts the voltage of the high-power battery 1 into a pseudo AC voltage, and converts the voltage to a low voltage by the high-pass filter unit 20 including a voltage dividing circuit using a capacitor. Since the measurement is performed by the measurement unit 42 based on the divided voltage, the measurement unit of the weak electric system can be cut off from the DC high voltage with a simple configuration, and the dark current can be reduced.

Further, since no photocoupler or operational amplifier is required, it is easy to increase the breakdown voltage of each component. Further, power loss caused by stepping down a DC high voltage to a differential voltage of a photocoupler or an operational amplifier by using a large resistor as in the related art is also released, and miniaturization and cost reduction can be achieved. Further, there is no need for a costly circuit such as a stabilized power supply for a photocoupler that requires a high-precision operating voltage for a high-voltage battery having a large voltage fluctuation.

Further, in the high-pass filter 20, the voltage is divided by the ratio of the capacitances of the capacitors 12 and 16, and the output voltage of the high-pass filter 20 is determined by the duty. Changing the duty of the switching unit 10 can be easily performed. Also, by using the capacitors 12 and 16 as ceramic capacitors,
Since the deterioration is particularly small over time and the life is hardly changed by the temperature of the surrounding environment, the cooling structure can be simplified and the number of steps for confirming the experiment can be reduced.

As a diagnostic function, in addition to detecting a voltage abnormality exceeding a high voltage or a low voltage of a high-power battery from a measured voltage, the switching unit 10 is turned on at the beginning of turning on an ignition switch by utilizing characteristics of a high-pass filter unit 20 including a capacitor. By switching the operation to the OFF state or the ON state and checking the measurement voltage, it is possible to identify the abnormality of the high-pass filter unit or the measurement unit from the others and detect it in advance. High-pass filter 2
0 based on the cut-off frequency of 0.
Also, an abnormality of the diagnostic unit 50 that controls this can be detected. Therefore, inspection and maintenance work is also simplified.

Although the embodiment has been described with respect to an example in which the total voltage of the high-power battery 1 is detected, the case where the voltage of each unit battery constituting the high-power battery 1 is detected is different only in the detection voltage. Thus, the present invention can be applied as it is. Further, the measurement unit 42 is configured in the battery controller 40, but is not limited thereto, and the measurement unit 42 may be independent of the battery controller.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a waveform diagram showing outputs of a switching unit and a high-pass filter unit in a normal state.

FIG. 3 is a waveform diagram showing outputs of a switching unit and a high-pass filter unit when the frequency is lower than a cutoff frequency fc.

FIG. 4 is a flowchart illustrating a flow of diagnostic control.

FIG. 5 is a flowchart illustrating a flow of diagnostic control.

FIG. 6 is a waveform diagram showing outputs of the switching unit and the high-pass filter unit when the capacitor of the high-pass filter unit is short-circuited.

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Strong battery 2a, 2b Unit battery 10 Switching part 12, 16 Transistor 13, 14, 17, 18 Resistance 20 High-pass filter part 21 Filter circuit 22, 24 Capacitor 26 Resistance 28 Voltage division circuit (voltage division means) 30 Protection circuit 32 Resistance 34 Zener diode 40 Battery controller 42 Measurement unit 50 Diagnosis unit (control means) 55 Motor controller

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 10/48 H01M 10/48 P H02J 7/10 H02J 7/10 BF term (Reference) 2G016 CA03 CB01 CC04 CC07 CC12 CD10 CD18 2G035 AA15 AB03 AC15 AD08 AD13 AD47 AD55 AD57 5G003 BA01 BA03 CA11 FA04 FA06 GB04 GC05 5H030 AA03 AA06 AA09 AS08 AS18 FF43 FF44 5H115 PA08 PA11 PA15 PC06 PG04 PI14 PI16 PI29 PO02 PO06 Q10 SE03 TR19 TU05 TZ03

Claims (5)

[Claims] A switching unit connected to the high-voltage battery; a high-pass filter unit connected to the switching unit; and a measuring unit connected to the high-pass filter unit, wherein the high-pass filter unit includes a switching unit. The switching means converts the DC voltage of the high-voltage battery into an intermittent voltage at a frequency equal to or higher than the cut-off frequency of the high-pass filter, and the measuring section includes a high-pass filter. A voltage sensor for a high-power battery, wherein the output voltage divided by the filter unit is measured, and the voltage of the high-power battery is calculated based on the measured voltage. 2. The voltage sensor for a high-power battery according to claim 1, wherein a protection circuit including a zener diode is provided between the high-pass filter unit and the measurement unit. 3. The switching unit comprises a switching unit provided between the high-power battery and a high-pass filter unit, and a control unit for sending an on / off control signal having a frequency equal to or higher than the cutoff frequency to the switching unit. 3. The voltage sensor for a high-power battery according to claim 1, wherein the control unit has a diagnostic function, and performs abnormality diagnosis by receiving a measurement voltage from the measurement unit. 4. The motor control apparatus according to claim 1, wherein the control unit outputs an overvoltage suppression command to the motor controller when the measured voltage exceeds a set value of a voltage higher than a normal range and the motor is regenerating. 4. The voltage sensor for a high-power battery according to 3. 5. The control means includes, as a diagnostic signal, a control signal for turning on / off the switching unit at a frequency equal to or higher than the cutoff frequency, and a control signal for turning on / off the switching unit. The voltage sensor according to claim 3, wherein the voltage is output to a switching unit.