KR102421402B1 - Diagnostic method of smart power relay assembly - Google Patents

Abstract

The present invention relates to a method for diagnosing a smart PRA (Power Relay Assembly). Specifically, when the smart PRA is applied to switching a high voltage battery of an electric vehicle or a hybrid vehicle, it is possible to diagnose the presence of an abnormality and determine the detailed failure type. It relates to a diagnosis method of smart PRA.
The smart PRA diagnosis method according to the present invention includes a first relay having one side connected in series to the (+) terminal of a battery and the other side connected in series with a load, and a first electronic switch connected in parallel with the first relay. and a second relay having one side connected in series to the negative (-) terminal of the battery and the other side being connected in series with a load, a second electronic switch connected in parallel with the second relay, and the first and second electronic switches A smart PRA diagnosis method comprising: and a control unit for controlling the first and second relays, the diagnosis signal input step of the control unit receiving a diagnosis signal; The control unit compares one side voltage value, the other side voltage value, and one side voltage value of the other relay among the first relay or the second relay according to the diagnostic signal input to the first relay or the second relay. a passive diagnosis step of determining any one of normal, battery power failure, load side short circuit, and contact failure; and determining whether the controller performs the operation sequence of the smart PRA if the diagnosis result of the passive diagnosis step is normal, and does not proceed with the operation sequence if it is not normal; includes

Description

Diagnosis method of smart PRA {DIAGNOSTIC METHOD OF SMART POWER RELAY ASSEMBLY}

The present invention relates to a diagnosis method of a smart PRA (Power Relay Assembly). Specifically, when the smart PRA is applied to switching a high voltage battery of an electric vehicle or a hybrid vehicle, it is possible to diagnose the presence of an abnormality and determine the detailed failure type. It relates to a diagnosis method of smart PRA.

Today, due to high oil prices and carbon dioxide regulations, the development of eco-friendly vehicles that can replace the existing internal combustion engine vehicles is actively progressing. Depending on the car manufacturer, hybrid vehicles that do this are already being commercialized and released or are about to be commercialized.

Such electric or hybrid vehicles are equipped with a high-voltage battery as a main power source for supplying power to an electric motor serving as a driving source, and a Power Relay Assembly (PRA) is installed between the high-voltage battery and the electric motor driving device. It is a device that is located and responsible for the connection, and is composed of a plurality of high voltage relays.

When a defect occurs in a switch or a peripheral circuit in controlling the plurality of relays, a problem may occur in supplying or blocking power. In particular, relays may be damaged due to high heat caused by overcurrent, which may cause disruptions in power supply, which is the main power source of electric vehicles. In addition, in order to check whether the relay is damaged, it is inconvenient to remove a part of the component.

Conventionally, a technique for measuring the voltage at each point of the relay of the PRA and comparing it with a normal value has been disclosed to determine the presence or absence of a failure of the PRA. Since it is a method to control the relay, there is a disadvantage that it is impossible to check during relay operation.

Korean Patent Publication No. 10-2015-0047367

Accordingly, the present invention compares the voltage values of each point of the relay of the smart PRA with each other to subdivide and determine the failure type of the smart PRA, and a smart PRA diagnosis method that can determine the failure even during the operation of the high voltage relay of the smart PRA. It is intended to provide

The smart PRA diagnosis method according to the present invention includes a first relay having one side connected in series to the (+) terminal of a battery and the other side connected in series with a load, and a first electronic switch connected in parallel with the first relay. and a second relay having one side connected in series to the negative (-) terminal of the battery and the other side being connected in series with a load, a second electronic switch connected in parallel with the second relay, and the first and second electronic switches A smart PRA diagnosis method comprising: and a control unit for controlling the first and second relays, the diagnosis signal input step of the control unit receiving a diagnosis signal; The control unit compares the voltage value of one side, the voltage value of the other side of any one of the first relay or the second relay, and the voltage value of one side of the other relay according to the received diagnosis signal to the first relay or the second relay. a passive diagnosis step of determining any one of normal, battery power failure, load-side short circuit, and contact failure; and determining whether the control unit performs the operation sequence of the smart PRA if the diagnosis result of the passive diagnosis step is normal, and does not proceed with the operation sequence if it is not normal; includes

In the passive diagnosis step, when the control unit turns off the first and second electronic switches and the first and second relays, voltage values on one side of the first and second relays satisfy a preset battery power standard, respectively a battery power failure determination step of terminating the diagnosis by judging that it is normal, and determining that the battery power is defective if not satisfied; If the determination result of the battery power specification failure step is normal, after turning on the diagnosis target relay among the first relay or the second relay, one side voltage value of the diagnosis target relay and one side voltage value of the other relays are compared. a load-side short-circuit determination step of judging normal if they are the same, otherwise determining as a load-side short circuit and terminating the diagnosis; and if the determination result of the load-side short circuit determination step is normal, compare the voltage value of one side and the voltage value of the other side of the relay to be diagnosed, and if they are the same, it is determined as normal; contact failure determination step; includes

In the smart PRA diagnosis method, after the operation determination step, when the control unit determines that the result of the passive diagnosis is normal and proceeds with the operation sequence, the control unit performs the one-side voltage value of the first relay according to a predetermined cycle and the voltage value of one side of the second relay, and the voltage value of the other side of the first relay and the voltage value of the other side of the second relay are compared to determine one of normal, insulation breakdown, relay or electronic switch failure, and circuit abnormality active diagnosis step; and when the result of the active diagnosis step is not normal, an operation stopping step of stopping the operations of the first and second relays and the first and second electronic switches; further includes

In the active diagnosis step, the controller compares the voltage value of one side of the first relay with the voltage value of one side of the second relay, and compares the voltage value of the other side of the first relay with the voltage value of the other side of the second relay, respectively If they are the same, it is diagnosed as normal, and if any one of the voltage value on one side of the first relay and the voltage value on one side of the second relay is 0V, it is diagnosed as insulation breakdown, and if any one voltage value is low, a low voltage value is measured. It is diagnosed as a failure of one relay or an electronic switch connected in parallel with the relay, and when the voltage value of the other side of the first relay is not the same as the voltage value of the other side of the second relay, it is diagnosed as a circuit abnormality.

The insulation breakdown is a state in which insulation is broken due to a short circuit between the ground of the battery and the ground of the low voltage power supply of the smart PRA, and the circuit abnormality is the first or second relay abnormality, the first or second electronic switch abnormality, and At least one of the circuit abnormalities of the load.

According to the present invention, the smart PRA diagnosis method can subdivide and discriminate the failure type of the smart PRA, so that a quick failure action is possible. It helps to reduce the repair cost of the product by preventing the problem caused by the failure of the smart PRA from having a greater impact on the overall product.

1 is a schematic configuration diagram of a smart PRA according to an embodiment of the present invention.
2 is a flowchart showing the process of the smart PRA diagnosis method according to the present invention.
3 is a flowchart illustrating a detailed process of the passive diagnosis step in the smart PRA diagnosis method according to the present invention.
4 is a table showing detailed conditions of the active diagnosis step in the smart PRA diagnosis method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a schematic configuration diagram of a smart PRA according to an embodiment of the present invention.

Referring to FIG. 1 , a smart PRA 100 according to an embodiment of the present invention has one side connected in series to the (+) terminal of the battery 10 and the other side is a first relay connected in series with the load 20 ( RL1) and a first electronic switch SW1 connected in parallel with the first relay RL1, one end connected in series to the (-) terminal of the battery 10 and the other end connected in series with the load 20 A second relay (RL2) connected to, a second electronic switch (SW2) connected in parallel with the second relay (RL2), the first and second electronic switches (SW1, SW2), and the first and second and a controller (not shown) for controlling the relays RL1 and RL2.

In an embodiment of the present invention, a high voltage battery that outputs a direct voltage of several hundred V is applied to the battery 10, and accordingly, the first and second relays RL1 and RL2 are also high voltage relays for high voltage switching. is composed of

The first and second electronic switches SW1 and SW2 are arcs generated at the contacts of the first and second relays RL1 and RL2 when the first and second relays RL1 and RL2 are opened. The electronic switches SW1 and SW2 are devices that can be controlled in an on/off mode, and may be implemented as, for example, an insulated gate bipolar transistor (IGBT).

Although not shown in the drawing, the control unit not only controls the on/off of the first and second electronic switches SW1 and SW2 and the first and second relays RL1 and RL2, but also one side of the first relay. A role of diagnosing the smart PRA (100) by measuring the voltage (V1) and the voltage of the other side (V2) of the second relay and the voltage (V3) of one side and the voltage (V4) of the other side of the second relay and comparing the values do. As a means for the control unit to measure the voltage, various known voltage measuring means may be applied, and it is not limited to any one measuring means.

2 is a flowchart illustrating a process of a smart PRA diagnosis method according to the present invention.

Referring to FIG. 2 , first, the control unit performs a diagnostic signal input step S10 of receiving a diagnostic signal. The diagnosis signal may be input from an external device controlling the battery 10 and the smart PRA 100 or an external test device for verifying the performance of the smart PRA 100 . As an example, it may be a battery management system (BMS) of a vehicle.

Next, the control unit compares the voltage value of one side of the first relay or the second relay (RL1 or RL2), the voltage value of the other side, and the voltage value of one side of the other relay according to the received diagnosis signal to determine the first A passive diagnosis step (S20) of determining any one of normal, battery power failure, load-side short circuit, and contact failure is performed on the relay RL1 or the second relay RL2. Conditions and detailed processes for determining the diagnosis result in the passive diagnosis step S20 will be described later.

Next, if the result of the passive diagnosis step (S20) is normal, the control unit proceeds with the operation sequence of the smart PRA 100 (S31), and if not normal, determines whether the operation is terminated without proceeding with the operation sequence ( S30) is performed.

Although not shown in the drawings, in an embodiment of the present invention, if the result of the passive diagnosis step S20 is normal, the control unit transmits the result to an external device or an external test device that received the diagnosis signal in the diagnosis signal input step S10. The operation sequence of the smart PRA 100 is performed (S31) by receiving a response of the operation sequence progress accordingly.

The operation sequence is a sequence of operations for turning on the first and second relays RL1 and RL2.

The operation determination step (S30) is a process for limiting the operation by determining that the smart PRA 100 is defective and cannot perform the normal operation if the diagnosis result of the passive diagnosis step (S20) is not normal. .

When the operation of the smart PRA 100 is restricted in the operation determination step S30, the control unit checks what kind of failure has occurred in the smart PRA 100 through the diagnosis result of the passive diagnosis step S20 Thus, it can be configured to transmit it to an external display device or test device, so that an external user or inspector can easily recognize the type of defect and take appropriate action.

Next, after the operation determination step (S30), when the controller determines that the result of the passive diagnosis (S20) is normal and proceeds with the smart PRA operation sequence (S31), the controller performs the operation according to a predetermined cycle A voltage value V1 of one side of the first relay RL1 and a voltage value V3 of one side of the second relay RL2 are compared, and the voltage value V2 of the other side of the first relay RL1 is compared with the second voltage value V2 of the first relay RL1. By comparing the voltage value V4 of the other side of the two relays RL2, an active diagnosis step S40 of determining one of normal, insulation breakdown, each relay or electronic switch failure, and circuit abnormality is performed. While the operation sequence is in progress, the first and second relays RL1 and RL2 and the first and second electronic switches SW1 and SW2 are both on-controlled by the control unit, and the active diagnosis (S40) The predetermined time, which is a period for performing , may be appropriately set to a value greater than the time required for the controller to perform the active diagnosis ( S40 ). Detailed conditions for determining the diagnosis result in the active diagnosis step S40 will be described later.

Finally, when the result of the active diagnosis step (S40) is not normal (S50), the controller controls the first and second relays RL1 and RL2 and the first and second electronic switches SW1 and SW2. An operation stop step of stopping the operation of (S51) is performed. If the result of the active diagnosis step (S40) is normal, the controller performs the active diagnosis (S40) again according to the diagnosis cycle of the active diagnosis (S40).

After the operation stop step, the control unit can check what kind of failure has occurred in the smart PRA 100 in operation through the diagnosis result of the active diagnosis step S40, and transmit it to an external display device or test device. Therefore, it can be configured so that an external user or inspector can easily recognize the type of defect and take appropriate action.

3 is a flowchart showing a detailed process of the passive diagnosis step in the smart PRA diagnosis method according to the present invention.

Referring to FIG. 3 , the passive diagnosis step S20 may be further divided into a battery power failure determination step S110 , a load-side short circuit determination step S120 , and a contact failure determination step S130 . First, the control unit is the first and second electronic switches (SW1, SW2) and the first and second relays (RL1, RL2) in the off state, one side voltage value of the first and second relay (V1, If V3) satisfies the preset battery power standard, it is determined to be normal (S111), and if not satisfied, it is determined as a battery power failure (S112) and a battery power failure determination step (S110) of terminating the diagnosis is performed. The voltage value V1 on one side of the first relay is the voltage value of the (+) terminal of the battery 10, and the voltage value V3 on one side of the second relay is the voltage value of the (-) terminal of the battery 10 equal to the voltage value. The battery power failure determination step (S110) is a process for confirming whether the (+) terminal and (-) terminal power of the battery 10 are normally output, and the battery power standard is the output of the battery applied to each embodiment. It can be appropriately determined by applying the measurement error range of the control unit to the voltage standard. In an embodiment of the present invention, the voltage value of the (+) terminal and the voltage value of the (-) terminal of the battery 10 are set to have the same value while only the direction of the current is opposite.

Next, if the determination result of the battery power standard determination step S110 is normal, the control unit turns on the diagnosis target relay among the first relay RL1 or the second relay RL2 (S119), the By comparing the voltage value of one side of the relay to be diagnosed and the voltage value of one side of the other relays, if they are the same, it is determined as normal (S121). . When the diagnosis target relay is turned on, the load 20 connected to the other side of the diagnosis target relay is electrically connected to one side of the relay, and accordingly, whether the load 20 is abnormal is determined on one side of the diagnosis target relay can affect As described in the battery power failure determination step (S110), the voltage value of the (+) terminal and the voltage value of the (-) terminal of the battery 10 are opposite only in the direction of the current and have the same value. The voltage value and the voltage value of one side of the rest of the relay should be the same if it is normal. However, if a short circuit occurs between the circuit specific point of the load 10 and the ground, the voltage value of one side of the relay to be diagnosed is divided by the short-circuited load 20 and measured to be lower than the normal value, so that one side of the other relay Since it is different from the voltage value, a short circuit on the load side can be judged from this result.

Next, if the determination result of the load-side short circuit determination step (S120) is normal, the controller compares the voltage value of one side and the voltage value of the other side of the relay to be diagnosed and determines that it is normal (S131) if they are the same, and ends the diagnosis. A contact failure determination step (S130) of terminating the diagnosis by determining that the diagnosis target relay has a defective contact (S132) is performed. When the diagnosis target relay is turned on, one side and the other side of the relay are electrically connected through a contact point, so that the voltage value of the one side and the voltage value of the other side must be the same. If the two voltage values are measured differently, since a defect has occurred in the contact point of the diagnosis subject relay connecting one side and the other side of the diagnosis subject relay, it is possible to determine the defective contact point of the diagnosis subject relay.

Finally, when the diagnosis is finished, the process of turning off the on-controlled diagnosis target relay RL1 or RL2 before the load-side short circuit determination step S120 is performed. The control unit first turns on the electronic switch SW1 or SW2 connected in parallel with the diagnosis target relay RL1 or RL2 in order to prevent an arc that may occur when the diagnosis target relay RL1 or RL2 is opened. After controlling (S133), the on-controlled diagnostic target relay RL1 or RL2 is controlled off (S134). After the diagnosis target relay RL1 or RL2 is completely turned off, the controller turns off the on-controlled electronic switch SW1 or SW2 (S135), and ends the manual diagnosis step (S20).

4 is a diagram showing detailed diagnosis conditions of the active diagnosis step in the smart PRA diagnosis method according to the present invention.

Referring to FIG. 4 , in the active diagnosis step S40, the control unit compares a voltage value V1 of one side of the first relay with a voltage value V3 of one side of the second relay, and the other side of the first relay The voltage value V2 and the voltage value V4 of the other side of the second relay are compared and if they are the same, it is diagnosed as normal, and the voltage value of one side of the first relay (V1) and the voltage value of one side of the second relay (V3) When this is not the same, if any one of the voltage value V1 on one side of the first relay and the voltage value V3 on one side of the second relay is 0V, it is diagnosed as insulation breakdown, and if any one voltage value is low, it is low If the voltage value of the one side relay or the electronic switch connected in parallel with the relay is diagnosed as defective, and the voltage value (V2) of the other side of the first relay and the voltage value (V4) of the other side of the second relay are not the same, the circuit is faulty is the stage of diagnosis.

In the active diagnosis step S40, the first and second relays RL1 and RL2 and the first and second electronic switches SW1 and SW2 are in an ON-controlled state, and the first and second relays RL1 , RL2), since the load 20 is connected to the other side, the voltage values V1, V2, V3 and V4 of one side and the other side of the first and second relays are the first and second relays RL1. , RL2), the power supply of the battery 10 connected to one side of the first and second relays RL1 and RL2 is voltage-divided by the circuit on the side of the load 20 connected to the other side of the first and second relays RL1 and RL2. It is measured with a low value, and it is normal that all the values are the same.

If the voltage values of V1, V2, V3 and V4 are not the same, it can be determined that an abnormality has occurred in the smart PRA, and depending on the condition of the measured voltage value, insulation breakdown, relay or electronic switch failure, and circuit abnormality can be distinguished as

When any one of the voltage values V1 and V3 of one side of the first and second relays is 0V, the controller determines that it is insulation breakdown. The insulation breakdown is a state in which insulation is broken due to a short circuit between the ground of the battery 10 and the ground of the low-voltage power supply of the smart PRA 100, and in the case of insulation breakdown, the battery 10 applied to an embodiment of the present invention Due to the internal circuit structure, the voltage value of only the (+) terminal or the negative terminal of the battery 10 becomes 0V. The low voltage power of the smart PRA 100 corresponds to 5V or 12V power used for driving communication or control devices in the control unit of the smart PRA 100 .

When any one of the voltage value V1 of one side of the first relay and the voltage value V3 of one side of the second relay is smaller and not 0V, the control unit is the relay of which the smaller voltage value is measured or It is determined that the electronic switch connected in parallel with the relay is defective. In this case, it is a result of the internal circuit structure of the battery 10 and the circuit of the load 20 applied to an embodiment of the present invention, and in another embodiment, it may be determined by other conditions.

When the voltage value V2 of the other side of the first relay is different from the voltage value V4 of the other side of the second relay, the control unit determines that the circuit is abnormal. The circuit abnormality is at least one of the first or second relay (RL1 or RL2) abnormality, the first or second electronic switch (SW1 or SW2) abnormality, and the circuit abnormality of the load 20. and the second relay (RL1, RL2), the first and second electronic switches (SW1, SW2), and the battery 10 and the load 20 are all connected and operated in a situation where the control unit operates the circuit It is difficult to distinguish any of the above cases, and when it is desired to more precisely classify the circuit abnormality, it is preferable to perform the passive diagnosis ( S20 ) or directly inspect the actual circuit after the diagnosis and operation are finished.

Although the present invention described above has been described in detail through preferred embodiments, it is to be noted that the present invention is not limited to the contents of these embodiments. Those of ordinary skill in the art to which the present invention pertains, although not presented in the examples, various imitations or improvements to the present invention are possible within the scope of the appended claims, all of which fall within the technical scope of the present invention. Belonging is so self-evident. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: smart PRA
10: battery 20: load
RL1: first relay RL2: second relay
SW1: first electronic switch SW2: second electronic switch
V1: Voltage value of one side of the first relay V2: Voltage value of the other side of the first relay
V3: Voltage value of one side of the second relay V4: Voltage value of the other side of the second relay

Claims (5)

A first relay having one end connected in series to the (+) terminal of the battery and the other end connected in series with the load, a first electronic switch connected in parallel with the first relay, and one end connected to the (-) terminal of the battery A second relay connected in series and the other end connected in series with a load, a second electronic switch connected in parallel with the second relay, the first and second electronic switches, and the first and second relays to control In the diagnosis method of smart PRA comprising a control unit,
a diagnostic signal input step in which the controller receives a diagnostic signal;
According to the diagnostic signal received by the control unit, the first relay or the second relay using the voltage value of one side and the voltage value of the other side of the first relay and the second relay is normal, battery power failure, load side short circuit and contact point a passive diagnosis step of determining any one of the defects; and
determining whether the control unit proceeds with the operation sequence of the smart PRA if the diagnosis result of the passive diagnosis step is normal, and does not proceed with the operation sequence if not normal; including,
The passive diagnosis step is
In the state in which the first and second electronic switches and the first and second relays are turned off, the control unit determines that the voltage at one side of the first and second relays respectively satisfies a preset battery power standard and is normal, If not satisfied, the battery power failure determination step of determining the battery power failure; and
If the determination result of the battery power failure determination step is normal, after turning on the diagnosis target relay among the first and second relays, the voltage value of one side of the diagnosis target relay is compared with the voltage value of one side of the other relays. Diagnosis method of smart PRA including; The method of claim 1,
The passive diagnosis step is
If the determination result of the load-side short circuit determination step is normal, compare the voltage value of one side and the voltage value of the other side of the relay to be diagnosed, and if they are the same, it is determined as normal. bad judgment step; A diagnostic method of smart PRA further comprising a. The method of claim 1,
After the operation determination step, when the control unit determines that the result of the passive diagnosis is normal and proceeds with the operation sequence,
The control unit compares the voltage value of one side of the first relay and the voltage value of one side of the second relay according to a period in advance, and compares the voltage value of the other side of the first relay with the voltage value of the other side of the second relay, An active diagnosis step of determining any one of insulation breakdown, relay or electronic switch failure, and circuit abnormality; and
an operation stopping step of stopping operations of the first and second relays and the first and second electronic switches when the result of the active diagnosis step is not normal; A diagnostic method of smart PRA further comprising a. 4. The method of claim 3,
In the active diagnosis step, the controller compares the voltage value of one side of the first relay with the voltage value of one side of the second relay, and compares the voltage value of the other side of the first relay with the voltage value of the other side of the second relay, respectively If it is the same, it is diagnosed as normal, and if any one of the voltage value on one side of the first relay and the voltage value on one side of the second relay is 0V, it is diagnosed as insulation breakdown, and if any one voltage value is low, a low voltage value is measured. A diagnostic method of smart PRA for diagnosing a failure of one relay or an electronic switch connected in parallel with the relay, and diagnosing a circuit abnormality if the voltage value of the other side of the first relay and the voltage value of the other side of the second relay are not the same. 5. The method of claim 4,
The insulation breakdown is a state in which insulation is broken due to a short circuit between the ground of the battery and the ground of the low-voltage power supply of the smart PRA, and the circuit abnormality is the first or second relay abnormality, the first or second electronic switch abnormality, and A diagnostic method of a smart PRA that is at least one of the circuit abnormalities of the load.

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