JP5239831B2 - Abnormality judgment control device - Google Patents

Description

The present invention relates to an abnormality determination control device that is used in an electric vehicle or the like and detects the presence or absence of leakage between a high-voltage circuit and a low-voltage circuit, and particularly relates to an apparatus that can detect a disconnection.

  In an electric vehicle, a hybrid vehicle including an engine and a motor (hereinafter referred to as “electric vehicle”), a high voltage circuit for driving and controlling a motor using a high voltage battery such as a lithium ion secondary battery as a drive source; And a low voltage circuit for driving an electronic device such as an acoustic device using a low voltage battery such as a lead storage battery as a drive source. The high voltage circuit includes an inverter for driving the motor.

In an electric vehicle, in order to ensure safety to the human body, it is necessary to detect a leakage from the high voltage circuit side to the low voltage circuit side and to cut off the power from the high voltage battery when a leakage is detected. Various types of leakage detection devices have been developed (see, for example, Patent Document 1).
Japanese Patent No. 3986823

  The above-described leakage detection device has the following problems. That is, the frequency of the signal output from the signal generator is fixed at a low frequency of 1 Hz, for example. This is because there is switching noise in the order of kHz generated by the inverter as noise superimposed on the signal from the signal generator via the coupling capacitor. In order to sufficiently attenuate this noise with an LPF (low pass filter), This is because the signal generated by the signal generator needs to be set to a low frequency of 1 Hz. For this reason, at the time of starting, there is a problem that it takes a long time to turn on the ignition key switch and detect the presence or absence of leakage.

  On the other hand, in order to solve this, a signal generator having a variable frequency (for example, a range from 1 Hz to 100 kHz) and an LPF (fc variable) having a variable cutoff frequency (for example, a range from 1 Hz to 100 kHz) are provided. Until the point and the switch on the low voltage circuit side are turned on until the leakage detector detects the presence or absence of leakage, turn off the switch on the high voltage circuit side and set the frequency of the signal generator and the cutoff frequency of the LPF. There are some which can detect electric leakage at high speed when starting an electric vehicle by setting it higher than normal operation (1 Hz) (for example, in a range of 10 kHz to 100 kHz).

  All such leakage detection devices send a predetermined signal to the circuit, receive the returned signal, and determine that no leakage has occurred if the signal intensity of the transmission signal and the reception signal substantially match.

  However, even if an abnormality such as a disconnection occurs in the circuit for some reason, the transmission signal and the reception signal have almost the same strength. For this reason, there is a possibility that the high voltage circuit may be determined to be normal as in the case where there is no leakage.

Therefore, an object of the present invention is to provide an abnormality determination control device that can determine whether or not there is a leakage and can also detect an abnormality in a circuit.

In order to solve the problems and achieve the object, the abnormality determination control device of the present invention is configured as follows.

An abnormality determination control device according to a first aspect of the present invention (corresponding to claim 1) that solves the above-described problem is composed of a high-voltage circuit including a high -voltage device and a low-voltage circuit including a low-voltage device lower than the high voltage. in the abnormality determination control apparatus for detecting the presence or absence of abnormality in the electric circuit, a Y capacitor disposed between are disposed in the high voltage circuit side and the high voltage equipment and the ground of the high voltage circuit, the low A signal generator arranged on the voltage circuit side to generate a high-frequency signal and a low-frequency signal, and to superimpose and output, a capacitor connected between the output terminal of the signal generator and the high-voltage circuit, and a high-frequency judging circuit for detecting a high-frequency signal can pass through the Y capacitor and the capacitor, the Y capacitor is and the capacitor impossible passing the low-frequency judging circuit for detecting the low frequency signal can pass, before Is disposed to the low voltage circuit side is connected to the output of the signal generator, a filter for inputting separately high and low frequencies, to each of the high-frequency judging circuit and the low-frequency determination circuit with reference to a predetermined frequency, A contactor disposed on the high-voltage circuit side and capable of supplying power to the high-voltage device, and distinguishing the high-frequency signal and the low-frequency signal according to connection / disconnection of the contactor, An electrical leakage abnormality determination of the electric circuit is performed with a signal, and a disconnection abnormality determination of the electric circuit is performed with the high-frequency signal .
The abnormality determination control device according to a second invention (corresponding to claim 2) that solves the above-described problem prohibits disconnection abnormality determination of the electric circuit by the high-frequency signal when the contactor is closed.

In the leakage detection device according to a third invention for solving the above problems (corresponding to claim 3), the high voltage equipment, AC power and high voltage battery, an AC motor, the DC power from the high voltage battery And an inverter for controlling the drive of the AC motor.

According to the first aspect of the invention, the high-frequency signal and the low-frequency signal are generated and superimposed and output regardless of whether the vehicle is running or stopped. In addition to being able to determine, a disconnection in the high voltage circuit can also be measured by a Y capacitor that is arranged between the terminal of the high voltage device and the ground and allows a high frequency signal to pass through.
According to the second aspect of the present invention, when the contactor is closed, the disconnection abnormality determination of the electric circuit by the high frequency signal is prohibited, so that the erroneous determination due to the switching noise does not occur.

According to the invention described in claim 3 , it is possible to apply even when the high-voltage device includes an inverter that generates switching noise.

  FIG. 1 is an explanatory view schematically showing an electric vehicle 10 in which an electric leakage detection device 100 according to an embodiment of the present invention is incorporated, FIG. 2 is a block diagram showing an essential part of the electric vehicle 10, and FIG. 4 is an explanatory diagram showing a detection pattern in the apparatus 100. FIG.

  The electric vehicle 10 includes a vehicle body 11. The vehicle body 11 is provided with a vehicle compartment 12, a secondary battery 13 provided at a lower portion of the vehicle compartment 12, and a front chamber 14 provided at a front portion of the passenger space 12. The vehicle body 11 is provided with drive wheels 15, to which high voltage devices 16 including an inverter and a drive motor are connected. In FIG. 2, reference numeral 17 denotes a contactor for connecting the secondary battery 13 and the high voltage device 16. These high voltage devices 16 are connected to a control device 20 in the front chamber 14.

  As shown in FIG. 2, the control device 20 includes a leakage detection device 100. The leakage detection device 100 includes a first oscillator (signal generator) 101 that generates a low-frequency signal and a second oscillator (signal generator) 102 that generates a high-frequency signal. The output terminals of the first oscillator 101 and the second oscillator 102 are connected, and a high frequency signal and a low frequency signal are superimposed and output. The output terminals of the first oscillator 101 and the second oscillator 102 are connected to the capacitor 103 connected to the high voltage circuit side and the input terminal of the filter 104.

  The filter 104 separates the high frequency and the low frequency with a predetermined frequency as a reference, and inputs the high frequency and the low frequency to the low frequency determination circuit 105 and the high frequency determination circuit 106. Output terminals of the low-frequency determination circuit 105 and the high-frequency determination circuit 106 include a leakage check control unit 110.

  Furthermore, both terminals of the high voltage device 16 are grounded (GND) via a Y capacitor 120 provided on the high voltage circuit side.

  The low frequency signal output from the first oscillator is set to a frequency that can pass through the capacitor 103 and cannot pass through the Y capacitor 120. The high frequency signal output from the second oscillator is set to a frequency that can pass through the capacitor 103 and the Y capacitor 120.

  In the leakage detection device 100 configured as described above, a leakage check is performed as follows. That is, the leakage check control unit 110 detects the running state or the stopped state of the electric vehicle 10. FIG. 3 summarizes the measurement patterns and determination results in the leakage inspection control unit 110.

  During traveling, the contactor 17 is closed, and power is supplied from the secondary battery 13 to the high voltage device 16. A test signal in which a low-frequency signal and a high-frequency signal are superimposed is output from the first oscillator 101 and the second oscillator 102.

  Since the inspection signal is alternating current, it passes through the capacitor 103 and enters the high voltage side. A switching noise of several kHz generated by the high voltage device 16 is superimposed on the inspection signal returning to the high voltage side or the filter 104. The inspection signal is divided into a low frequency and a high frequency by the filter 104 and input to the low frequency determination circuit 105 and the high frequency determination circuit 106. Since switching noise is superimposed on the high frequency determination circuit 106, the determination is not performed.

  On the other hand, if the low frequency determination circuit 105 detects a signal that substantially matches the low frequency signal output from the first oscillator 101, no leakage has occurred. On the other hand, if a low frequency signal is not detected, it is determined that a leakage has occurred if it is different from the output low frequency signal or if the level is significantly low. The presence / absence of this detection is output to leakage check control unit 110, and “normal” or “abnormal” is determined (see FIG. 3).

  At the time of stop, the contactor 17 is opened, and the connection between the secondary battery 13 and the high voltage device 16 is released. In this state, a test signal in which a low frequency signal and a high frequency signal are superimposed is output from the first oscillator 101 and the second oscillator 102. A disconnection on the high voltage side (for example, point P in FIG. 2) can also be detected simultaneously.

  As in the case of traveling, an inspection signal in which a low-frequency signal and a high-frequency signal are superimposed is output from the first oscillator 101 and the second oscillator 102.

  Since the inspection signal is alternating current, it passes through the capacitor 103 and enters the high voltage side. The inspection signal returning to the high voltage side or the filter 104 is divided into a low frequency and a high frequency by the filter 104 and input to the low frequency determination circuit 105 and the high frequency determination circuit 106. Note that, since the high-voltage device 16 is stopped, switching noise is not superimposed on the inspection signal input to the filter 104.

  If a signal that substantially matches the low-frequency signal output from the first oscillator 101 is detected in the low-frequency determination circuit 105, no leakage has occurred. On the other hand, if a signal that substantially matches the high-frequency signal output from the second oscillator 102 is detected in the high-frequency determination circuit 106, it is determined that a disconnection has occurred, and if a signal that substantially matches the high-frequency signal is not detected, the disconnection occurs. It is determined that there is no.

  This is due to the following reason. That is, the high voltage side is connected via the Y capacitor 120. Since the Y capacitor 120 is set to have a capacity through which the high frequency signal output from the second oscillator 102 can pass, if there is no disconnection on the high voltage side, the high frequency signal is grounded via the Y capacitor 120 and returned to the high frequency determination circuit 106. Absent. On the other hand, if there is a disconnection, the high frequency signal does not reach the Y capacitor 120 in the first place, and thus the high frequency signal returns to the high frequency determination circuit 106. In addition, since the low frequency signal cannot pass through the Y capacitor 120, the disconnection cannot be determined.

  If the low frequency determination circuit 105 does not detect a signal that matches the low frequency signal output from the first oscillator 101, it is determined that a leakage has occurred. On the other hand, if a signal that substantially matches the high-frequency signal output from the second oscillator 102 is detected in the high-frequency determination circuit 106, it is determined that a disconnection has occurred, and if a signal that substantially matches the high-frequency signal is not detected, the disconnection occurs. It is determined that there is no.

  In this way, the presence / absence of detection of the low frequency and the high frequency is output to the leakage inspection control unit 110, and “normal” or “abnormal” is determined (see FIG. 3).

  As described above, according to the leakage detection device 100 according to the present embodiment, the switching is performed by sending the inspection signal on which the low-frequency signal and the high-frequency signal are superimposed to the high voltage side regardless of the running state or the stopped state. It is possible to determine the presence or absence of electric leakage without performing it. Moreover, if it is a stop state, the presence or absence of a disconnection can also be measured simultaneously. Furthermore, since the high voltage side is direct current, it cannot pass through the capacitor 103, and no high voltage is applied to the low voltage side, which is highly safe and advantageous in terms of cost.

  The present invention is not limited to the above embodiment. For example, although the leakage detection device 100 is described as being in the control device 20, the leakage detection device 100 may be provided in the battery pack. Therefore, as long as an electrical separation between the high voltage side and the low voltage side is provided, the location of the leakage detection device 100 is not limited. In addition, various modifications can be made without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows typically the electric vehicle incorporating the earth-leakage detection apparatus which concerns on one embodiment of this invention. The block diagram which shows the principal part of the same electric vehicle. Explanatory drawing which shows the detection pattern in the same leak detection apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Electric vehicle, 13 ... Secondary battery, 16 ... High voltage apparatus, 20 ... Control apparatus, 100 ... Leakage detection apparatus, 101 ... 1st oscillator (signal generator), 102 ... 2nd oscillator (signal generator), DESCRIPTION OF SYMBOLS 103 ... Capacitor 104 ... Filter 105 ... Low frequency determination circuit 106 ... High frequency determination circuit 120 ... Y capacitor

Claims (3)

In an abnormality determination control device for detecting the presence or absence of abnormality in an electric circuit composed of a high voltage circuit including a high voltage device and a low voltage circuit including a low voltage device lower than the high voltage ,
A Y capacitor disposed on the high voltage circuit side and disposed between the high voltage device and the ground of the high voltage circuit;
A signal generator arranged on the low-voltage circuit side to generate a high-frequency signal and a low-frequency signal, and to superimpose and output,
A capacitor connected between the output of the signal generator and the high voltage circuit;
A high-frequency determination circuit that detects the Y capacitor and a high-frequency signal that can pass through the capacitor;
A low-frequency determination circuit that detects a low-frequency signal through which the Y capacitor cannot pass and the capacitor can pass;
A filter disposed on the low voltage circuit side and connected to the output end of the signal generator, separating a high frequency and a low frequency on the basis of a predetermined frequency and respectively inputting the high frequency determination circuit and the low frequency determination circuit; ,
A contactor disposed on the high voltage circuit side to enable power supply to the high voltage device ;
The high frequency signal and the low frequency signal are determined according to the connection / disconnection of the contactor,
An abnormality determination control device that performs a leakage abnormality determination of the electric circuit with the low-frequency signal and performs a disconnection abnormality determination of the electric circuit with the high-frequency signal . When the contactor is closed, the disconnection abnormality judgment of the electric circuit by the high frequency signal is prohibited.
The abnormality determination control apparatus according to claim 1. The high-voltage device includes a high-voltage battery, an AC motor, and an inverter that converts the DC power from the high-voltage battery into AC power and controls the AC motor. Or the abnormality determination control apparatus of 2.

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