JP5172720B2 - Relay inspection device and drive device - Google Patents

Description

  The present invention relates to a relay inspection device and a drive device, and more particularly to an inspection of a relay unit that interrupts current of an assembled battery mounted on an electric vehicle such as an electric vehicle or a hybrid vehicle.

  Conventionally, battery packs for storing electric power supplied to a drive motor are mounted on electric vehicles such as hybrid vehicles and electric vehicles. The battery pack includes an assembled battery in which a plurality of battery modules are combined, various devices for controlling the assembled battery, and an upper case and a lower case for protecting the assembled battery and various devices. An example of various devices is a relay unit (contact switching device, hereinafter referred to as a relay) that cuts off the electric power supplied from the assembled battery to the drive motor as necessary.

  Between the terminals on the input side of the inverter of the electric vehicle, a large-capacity electrolytic capacitor is provided for smoothing fluctuations in voltage and stabilizing the operation of the inverter. When driving an electric vehicle, the operation of the main switch that starts the electric vehicle or the detection of the driver by the keyless entry device closes the relay to start the inverter operation and charges the electrolytic capacitor. Direct charging can cause large currents that can damage contactor contacts. Therefore, first, the precharge relay is closed, the capacitor is precharged while limiting the current with a precharge resistor or the like, and the contactor is prevented from being damaged by closing the main contactor after the precharge is completed.

  If the contact operation (ON operation) and separation operation (OFF operation) of the contact of the main relay are not performed normally, the predetermined precharge operation will not be performed and the contact may be damaged, or the main switch of the electric vehicle Even when the operation is turned off, the high voltage of the battery pack remains applied to the inverter, which impairs safety during inspection and maintenance of the wires from the inverter and the charge / discharge output terminal of the battery pack to the inverter. There is a fear. Therefore, it is necessary to accurately determine the state of the relay, and it is necessary to reliably determine whether precharge is performed normally, that is, whether the circuit is intermittently connected by the relay.

  Patent Document 1 below describes that precharge is determined to have ended when the capacitor voltage becomes equal to or higher than a reference value after the start of precharge.

  Patent Document 2 describes that an assembled battery voltage and an inverter voltage are compared to detect that there is no welding of a relay contact.

  Further, Patent Document 3 describes that it is determined from a cumulative amount of electricity flowing from the assembled battery to the inverter for a predetermined time that the precharge is correctly performed due to a failure of the relay.

US Pat. No. 5,369,540 Japanese Patent Laid-Open No. 11-341821 JP-A-10-304501

  However, in the configuration in which the operation of the relay is determined based on the voltage or energization on the inverter side, both the positive side relay and the negative side relay need to be turned on. Therefore, even if there is a problem in the operating state by measuring the voltage on the inverter side, it can be determined whether the operating state of either the positive side relay or the negative side relay is a problem, but either the positive side relay or the negative side relay Cannot determine if it is a problem.

  In addition, in order to determine the relay operation during traveling, it is necessary to discharge the inverter charge and then charge it by turning on the relay. It is difficult.

  Further, when the operation state is determined by checking the time transition of the voltage or current of the inverter, it takes time for the determination, and the user cannot start the engine during that time.

The present invention is a relay inspection apparatus for determining an abnormality of a relay that intermittently supplies a current supplied to a drive motor from an assembled battery serving as a power source of a hybrid electric vehicle via an inverter. The relay provided in between is composed of a positive side relay, a negative side relay, and a precharge relay connected in parallel to the positive side relay, and detects an operation sound caused by contact or separation of the contact of the relay. detection means for, determining the synchronization of the operation signal for driving the signal and the relay of the operation sound, have a judging means for judging abnormality of the relay when not synchronized, the operation signal Is a signal that causes the relay to operate according to a predetermined procedure, and the determination means is configured such that the signal of the operation sound is the same as the operation signal according to the predetermined procedure. Characterized in that when not determining an abnormality of the relay.

  In one embodiment of the present invention, the determination unit determines abnormality of the relay when the electric vehicle is started.

  In another embodiment of the present invention, the determination unit determines abnormality of the relay by determining synchronization between the operation sound signal and the operation signal when the relay is operated a plurality of times. To do.

Further, the present invention is a drive device that supplies drive power to a drive motor of a hybrid electric vehicle, and includes an assembled battery, an inverter that converts current from the assembled battery into alternating current and supplies the alternating current to the drive motor, A relay composed of a positive side relay, a negative side relay, and a precharge relay connected in parallel to the positive side relay, which controls electrical connection and disconnection between the assembled battery and the inverter, and the relay A relay driving means for supplying an operation signal for operating the relay to the relay, a detection means for detecting an operation sound caused by contact or separation of the contact of the relay, and synchronization between the operation sound signal and the operation signal. determined, and a determination means for determining abnormality of the relay when not synchronized, the operation signal is a signal for operating in a predetermined procedure the relay Ri, the determining means, the signal of the operation sound is characterized by determining an abnormality of the relay when the not previously operating signal corresponding to established procedures and synchronization.

  According to the present invention, it is possible to quickly and reliably determine a relay abnormality. Further, according to the present invention, it is possible to determine a relay abnormality regardless of the traveling state of the electric vehicle.

It is an external appearance expanded view of the battery pack in an embodiment. It is a block diagram of the drive system in an embodiment. It is operation | movement explanatory drawing of a relay. It is operation | movement explanatory drawing of a relay. It is operation | movement explanatory drawing of a relay. It is a sound pressure waveform figure of a relay operation sound. It is a frequency characteristic figure of a sound pressure waveform. It is a sound pressure waveform diagram at the time of a plurality of ON / OFF operations of the relay. It is a frequency characteristic figure at the time of the on / off operation of the relay several times. It is an operation signal timing chart of each of the positive electrode side, the negative electrode side, and the precharge relay.

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

In FIG. 1, the external appearance expanded view of the battery pack 10 in this embodiment is shown. The battery pack 10 may be installed in an electric vehicle of a hybrid automobile, to accumulate electric power to be supplied to the drive motor.

  In FIG. 1, a battery case that is a casing of the battery pack 10 includes an upper case 12 that covers the upper part of the assembled battery 16 configured by combining a plurality of battery modules, and a lower case 14 that covers the lower part of the assembled battery 16. Have The assembled battery 16 is configured by arranging a plurality of battery modules in a row. In addition to the assembled battery 16, various devices such as a battery ECU (electronic control unit) 28, a positive side relay, a negative side relay, a precharge relay, and a precharge resistor are incorporated in the battery pack 10. A charge / discharge output terminal 30 is attached to the outer wall surface of the lower case 14. The assembled battery 16 is connected to the charge / discharge output terminal 30 via a positive electrode side relay and a negative electrode side relay. Each relay in the present embodiment is a mechanical relay.

  FIG. 2 is a block diagram of a drive system for an electric vehicle in which the drive motor 42 is driven by the power supplied from the battery pack 10.

  In FIG. 2, the direct current output from the assembled battery 16 is converted into alternating current by a signal from the vehicle ECU 29 via the inverter 40 and supplied to the drive motor 42. Between the assembled battery 16 and the inverter 40, a positive side relay 20, a negative side relay 22, and a precharge relay 24 are provided. That is, one end of the positive electrode side relay 20 is connected to the positive electrode side of the assembled battery 16, and the other end of the positive electrode side relay 20 is connected to the positive electrode side of the charge / discharge output terminal 30. One end of the negative electrode side relay 22 is connected to the negative electrode side of the assembled battery 16, and the other end of the negative electrode side relay 22 is connected to the negative electrode side of the charge / discharge output terminal 30. A precharge relay 24 and a precharge resistor 26 are connected between the positive electrode side of the assembled battery 16 and the positive electrode side of the charge / discharge output terminal 30 so as to be in parallel with the positive electrode relay 20. The precharge relay 24 and the precharge resistor 26 are connected in series with each other. The capacitor 44 is a large-capacity electrolytic capacitor for smoothing voltage fluctuations and stabilizing the operation of the inverter 40.

  The positive side relay 20, the negative side relay 22, and the precharge relay 24 individually perform an on operation and an off operation according to an operation signal from the vehicle ECU 29. The vehicle ECU 29 supplies a current to the excitation coil of each relay by turning on a semiconductor switch inside the vehicle ECU and controls opening and closing of the contact of each relay. For example, the excitation coil 24 a of the precharge relay 24 is connected to the vehicle ECU 29, and the excitation coil 24 a is excited by an operation signal from the vehicle ECU 29 to open and close the contacts of the precharge relay 24.

  The battery ECU 28 detects the voltage and temperature of the assembled battery 16 and monitors the storage state of the assembled battery 16 and the presence or absence of a failure. A vibration detection unit 28 a is provided inside the battery ECU 28. The vibration detection means 28a is composed of a vibration sensor and a microcomputer. The vibration sensor is composed of a semiconductor sensor or a piezoelectric element mounted on a printed wiring board inside the battery ECU. The microcomputer performs robust processing against noise such as matching processing of signal outputs from the vibration sensor.

  The vehicle ECU 29 and the battery ECU 28 are connected by a CAN (controller area network) which is a kind of in-vehicle LAN, and the vehicle ECU 29 outputs a signal indicating which relay is to be turned on or off to the battery ECU 28, and at the same time, An operation signal is output. When the battery ECU 28 receives the relay operation signal from the CAN, the battery ECU 28 confirms the synchronization with the signal output from the vibration detection means 28a. That is, the battery ECU 28 confirms the synchronization between the vibration signal detected by the built-in vibration detection means 28a and the operation signal received from the vehicle ECU 29.

  The vibration signal detected by the vibration detecting means 28a is an operation sound (contact opening / closing sound) signal of each relay. Also, the confirmation of synchronization is executed by the determination means 28b in the battery ECU 28. The determination means 28b is constituted by a microcomputer. If the synchronized signal, that is, the operation signal of the relay and the operation sound signal of the relay are synchronized, the battery ECU 28 determines that the relay is normally on or off. Further, if the synchronized signal cannot be detected, it is determined that the contact ON / OFF operation is hindered due to a failure such as welding of the relay contact. The determination result is transmitted to the vehicle ECU 29. When the vehicle ECU 29 receives the abnormality determination from the battery ECU 28, the vehicle ECU 29 notifies the vehicle occupant and the like of the abnormality.

  When the ignition key of the electric vehicle is turned on, power is supplied from an auxiliary battery provided in the vehicle ECU 29 separately from the assembled battery 16 and having a voltage lower than that of the assembled battery 16 to start up. The vehicle ECU 29 first turns on the negative relay 22 and then turns on the precharge relay 24 to charge the capacitor 44. At this time, a large inrush current is restricted by the current limiting precharge resistor 26. After the smoothing capacitor 44 is charged, the vehicle ECU 29 turns on the positive side relay 20 to start supplying power to the drive circuit of the drive motor 42 and simultaneously turns off the precharge relay 24.

  When the ignition key of the electric vehicle is turned off, the vehicle ECU 29 turns off the positive side relay 20 and the negative side relay 22 and opens the electrical connection between the assembled battery 16 and the inverter 40.

  3A, 3B, and 3C show the basic operation principle of each relay. Each of the relays 20, 22, and 24 is collectively shown as a relay 1. The relay 1 is attached to the upper part 14a of the lower case 14 with a fixing screw 2a via a fixing tool 2, for example. The relay 1 is a so-called mechanical relay, and includes an excitation coil 1a, a movable iron core (drive shaft) 1b driven by the electromagnetic force of the excitation coil 1a, and a case 1d that houses the excitation coil 1a, the movable iron core 1b, and the like.

  In FIG. 3A, when the relay 1 is turned on, the exciting coil 1a is excited and an electromagnetic force is generated. As a result, as shown in FIG. 3B, the movable iron core 1b rises, the return spring 1e contracts, and the internal contact terminal 1c provided on the upper part of the movable iron core 1b contacts the external input terminal 3a and the external output terminal 3b. And energize. At this time, a sound is generated in which the internal contact terminal 1c contacts the external input terminal 3a and the external output terminal 3b. Further, when the relay 1 is turned off, the electromagnetic force of the exciting coil 1a is lost, and as shown in FIG. 3C, the movable iron core 1b is lowered by the restoring force of the contracted return spring 1e, and the internal contact terminal 1c is an external input terminal. 3a and the external output terminal 3b. At this time, when the movable iron core 1b is lowered, it comes into contact with the relay bottom surface 1f and generates a sound. Note that the sound at the time of relay separation is not limited to the contact between the movable iron core and the bottom surface of the relay, but may be the sound that the movable contact including the movable iron core and the internal contact terminal contacts the relay components.

  As described above, since the internal contact terminal is in contact with or separated from the external input terminal and the external output terminal during the ON / OFF operation of the relay (the movable iron core is in contact with or separated from the bottom surface of the relay), sound is generated along with the contact / disengagement operation. . In the present embodiment, it is determined whether or not the relay is operating normally by detecting this sound by the vibration detecting means 28a. In particular, since the energization current of an electric vehicle is large and the vibration of the vehicle is large, it is necessary to set a large pressing force for the relay contact and the spring constant of the return spring. Sound is likely to occur.

  FIG. 4 shows the measurement result of the sound pressure (Pa) when the relay is turned on / off as a sound pressure waveform. The vibration detection means 28a of the battery ECU 28 detects such a sound pressure waveform accompanying the opening / closing of the relay.

  FIG. 5 shows a general frequency characteristic of the sound pressure level in the case of the relay on / off operation as a reference diagram. FIG. 6 shows the relationship between the sound pressure level and time when the relay is turned on and off a plurality of times. In addition, FIG. 7 shows a sound pressure level and frequency characteristics as a reference diagram when the relay is turned on and off a plurality of times. Further, FIG. 8 shows an operation signal of each relay corresponding to a plurality of ON / OFF operations of the relay. 8A shows an operation signal of the positive side relay 20, FIG. 8B shows an operation signal of the negative side relay 22, and FIG. 8C shows an operation signal of the precharge relay 24. 5 to 7 are data obtained by arranging the battery pack 10 behind the rear seat of the electric vehicle and the microphone at the position of the driver seat. 6 and FIG. 8 are compared, the peaks P1, P2, P3, P4, P5, P6, and P7 in FIG. Correspond.

  Although it is difficult to predict the disturbance noise mixed in the relay operation, the relay is driven by a predetermined procedure of ON / OFF operation of the relay as shown in FIGS. 6 to 8, and the vibration is detected. If the operation state of the relay is determined, the influence of noise can be effectively removed.

  In the present embodiment, the operation of opening / closing (or advancing / retreating) of the relay contact is detected as a sound. Therefore, the positive-side relay 20, the negative-side relay 22, and the precharge relay 24 are individually turned on and off in a very short time. It is possible to reliably detect contact and separation operations of the contacts.

  In the present embodiment, the precharge relay 24 can confirm the operation regardless of the traveling state. Also, the operation of the main relays (positive side relay 20 and negative side relay 22) is confirmed regardless of the running state when the voltage difference between the assembled battery 16 side and the inverter 40 side is small, that is, the inverter 40 is stopped. can do.

  In addition, although it is difficult to predict the frequency characteristics of noise related to driving while driving, noise such as car audio, car navigation, etc., the relay is operated multiple times, and the operation signal of the relay is synchronized with the sound generated by the relay. It is possible to confirm the operation with high accuracy by, for example, determining that the relay is not operating when the frequency that the sound cannot be detected is high is acquired. Moreover, since the noise level in the passenger compartment is high during traveling, there is no possibility that the passenger will feel uncomfortable even if the relay is operated a plurality of times.

  Further, when the time transition of the voltage or current of the inverter 40 is confirmed, it takes time to make a determination. However, in this embodiment, since an opening / closing (or advance / retreat) sound is detected, it takes only a short time.

  Also, by setting the operation time interval of the relay on / off operation in advance and driving the relay, and determining the state of the relay from the relay vibration time interval, a synchronization signal between the relay drive circuit and the determination means is required And not. For example, the relay is operated by outputting an operation signal from the vehicle ECU 29 in the engine, and the vibration detection means 28 a and the determination means 28 b are built in the battery ECU 28 in the vicinity of the assembled battery 16. The vehicle ECU 29 and the battery ECU 28 are connected via an in-vehicle LAN. If the relay operation interval is set in advance, the relay operation status can be determined regardless of the communication status of the in-vehicle LAN (delay due to congestion).

  The vibration detection means 28a in the present embodiment can also use a G sensor mounted in an airbag ECU or car navigation, a speaker used for audio, and the like. Further, it is apparent from the frequency characteristics of FIG. 5 or 7 that the vibration to be detected is not necessarily limited to an audible sound.

  10 battery pack, 12 upper case, 14 lower case, 16 assembled battery, 20 positive side relay, 22 negative side relay, 24 precharge relay, 26 precharge resistor, 28 battery ECU, 29 vehicle ECU, 40 inverter, 42 drive motor .

Claims (4)

A relay inspection device for determining an abnormality of a relay that intermittently connects a current supplied to a drive motor from an assembled battery serving as a power source of a hybrid electric vehicle,
The relay provided between the assembled battery and the inverter is composed of a positive side relay, a negative side relay, and a precharge relay connected in parallel to the positive side relay ,
Detecting means for detecting an operation sound accompanying contact or separation of the relay contacts;
Determining the synchronization of the signal of the operation sound and the operation signal for driving the relay, and determining means for determining abnormality of the relay when not synchronized,
I have a,
The operation signal is a signal for operating the relay in a predetermined procedure,
The determination means determines an abnormality of the relay when the operation sound signal is not synchronized with an operation signal corresponding to the predetermined procedure . The apparatus of claim 1.
The determination means determines an abnormality of the relay when starting the electric vehicle. The apparatus of claim 1.
The determination means determines an abnormality of the relay by determining the synchronization between the operation sound signal and the operation signal when the relay is operated a plurality of times. A drive device for supplying drive power to a drive motor of a hybrid electric vehicle,
An assembled battery;
An inverter that converts current from the assembled battery into alternating current and supplies the drive motor;
A relay composed of a positive-side relay, a negative-side relay, and a precharge relay connected in parallel to the positive-side relay, which controls electrical connection and disconnection between the assembled battery and the inverter;
Relay drive means for supplying an operation signal for operating the relay to the relay;
Detecting means for detecting an operation sound accompanying contact or separation of the relay contacts;
A determination means for determining the synchronization between the operation sound signal and the operation signal, and determining the abnormality of the relay when not synchronized,
Have
The operation signal is a signal for operating the relay in a predetermined procedure,
The determination unit determines an abnormality of the relay when a signal of the operation sound is not synchronized with an operation signal corresponding to the predetermined procedure .

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