JP2007306651A - Power generation control device of ac generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely conduct an abnormality diagnosis of an AC generator when controlling power generation by arranging the AC generator which can freely change a power generation amount by using an ECM control signal of a control means, and by arranging a current detection means which can detect a load current value of an electric load, in a power generation control device of the AC generator. <P>SOLUTION: In this power generation control device, a control means comprises: a warm-up state estimation part which estimates the warm-up state of the AC generator; a magnetic field current control part which controls a magnetic field current of the AC generator by using an external input signal value which is set according to the warm-up state of the AC generator estimated by the warm-up state estimation means when a load current value detected by the current detection means is larger than a load current set value; and a failure diagnosis mode part which compares a battery voltage value and a set voltage value (S8), and determines whether the AC generator is failed or not. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power generation control device for an AC generator, and more particularly, to provide an AC generator that can freely change the amount of power generation according to a control signal of a control means and to detect current detection means for detecting a load current value of an electric load. The present invention relates to a power generation control device for an alternating current generator that diagnoses an abnormality of the alternating current generator in a system that controls power generation.

The vehicle is provided with an AC generator (generator) that is driven by the mounted engine to charge the battery, and at least the vehicle running state or the engine running state is determined by an ECM control signal that is a control signal of the control means (ECM). What provided the power generation control device which controls the field current of an alternator by the external input signal value (duty signal) which changes according to the battery voltage value, and controls the power generation amount which is the output of this alternator. is there.
In this power generation control, an AC generator that can freely change the power generation amount by the ECM control signal of the control means is used, and the fuel consumption is improved by reducing the power generation amount by the ECM control signal of the control means. . For this reason, when the alternator fails, the fuel consumption deteriorates, so the fault diagnosis of the alternator is performed.
In this fault diagnosis of the AC generator, as shown in FIG. 7, the power generation amount is reduced by a predetermined power generation cut ratio (%) from the ECM control signal, and the battery voltage value (VB) at that time decreases, Diagnosing faults in the alternator.

Conventionally, in a vehicle alternator abnormality determination method related to battery charging control, a limit value of a correction amount is set in a control signal correction addition means, and the comparison of the correction amount and the limit value is performed. Some control systems determine abnormalities in the control system, monitor the correction amount of the generated voltage command value, and integrate the fault diagnosis of the AC generator into the diagnosis of the conventional internal combustion engine to accurately determine the abnormalities in the control system.
In addition, the voltage control device for a vehicle generator adjusts the output voltage of the generator into a plurality of types according to an external control signal, and the generator is used when the potential of the input portion is within a specific potential range. The field current is adjusted so that the output voltage of the generator becomes the specific output voltage, and the output voltage of the generator is the specific output regardless of whether the potential of the input section is higher or lower than the specific potential range. Some control the field current so that it is other than voltage, and prevent high voltage from being applied to the electrical load when an abnormality occurs.
JP-A-8-79981 Japanese Patent Laid-Open No. 9-19080

However, in the conventional alternator power generation control device, as shown in FIG. 8, since there is a temperature characteristic of the alternator, the same ECM is used when the temperature of the alternator itself is cold and warm. Even if the power generation cut ratio (%) from the control signal is used, the drop width of the battery voltage value (VB) is different for cold, medium warm and warm. Further, as shown in FIG. 9, even in the load current value from the current sensor which is a current detecting means simulating the electric load, the drop width of the battery voltage value (VB) is based on the presence / absence of the electric load (ON / OFF). Wrong.
As described above, since the AC generator has temperature characteristics, the battery voltage may not drop when the AC generator is cold even if the power generation amount is reduced at a predetermined power generation cut rate. There was a problem that failure diagnosis could not be performed accurately.

  Therefore, an object of the present invention is to provide an AC generator that can freely change the amount of power generation according to a control signal of the control means, and to provide power generation by providing current detection means that can detect the load current value of the electric load. An object of the present invention is to provide an alternator power generation control device capable of accurately performing abnormality diagnosis of an alternator in a system to be controlled.

  The present invention provides an AC generator that is driven by an engine mounted on a vehicle to charge a battery, and is based on at least an external input signal value and a battery voltage value that change according to the traveling state of the vehicle or the operating state of the engine. In a generator control device for an AC generator provided with a control means for controlling a field current of the AC generator to control an output of the AC generator, a load current value used in an electric load of the vehicle is detected. Current detection means is provided, and the control means is configured to estimate a warm-up state of the AC generator, and when a load current value detected by the current detection means is greater than a load current set value. A field current control for controlling the field current of the AC generator using an external input signal value set according to the warm-up state of the AC generator estimated by the warm-up state estimating means. And parts, characterized in that by comparing the battery voltage value and the set voltage value and a determining fault diagnosis mode unit whether the alternator is faulty.

  The alternator generator control device according to the present invention can accurately perform abnormality diagnosis of an alternator by changing the value of an input parameter used at the time of failure diagnosis according to the warm-up state of the alternator. .

The purpose of this invention is to accurately perform abnormality diagnosis of an alternator when an external input set according to the estimated warm-up state of the alternator when the load current value is larger than the load current set value. The signal current is used to control the field current of the AC generator, and the battery voltage is compared with the set voltage value to determine whether the AC generator has failed.
Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

1 to 6 show an embodiment of the present invention. In FIG. 6, reference numeral 1 denotes an in-vehicle engine, 2 a battery, and 3 a power generation control device. The power generation control device 3 includes an AC generator (generator) 4 and a control means (ECM) 5. A control means 5 is connected to the AC generator 4 via a first signal line 6, and a plus (+) terminal 2 </ b> A of the battery 2 is connected via a second signal line 7.
The AC generator 4 is driven by the engine 1 to charge the battery 2.
The control means 5 controls the field current of the AC generator 4 based on the external input signal value and the battery voltage value that change according to at least the running state of the vehicle or the operating state of the engine 1, and the output of the AC generator 4. A certain amount of power generation is controlled. For this reason, the control means 5 outputs an ECM control signal, which is a control signal, to the AC generator 4 and controls the power generation amount of the AC generator 4 based on a predetermined power generation cut ratio (DTY) from the ECM control signal. .
In the middle of the second signal line 7, a third signal line 8 connected to the control means 5 is connected. The fourth signal line 9 connected to the control means 5 is connected to the minus (−) terminal 2B of the battery 2. Thereby, the control means 7 can recognize a battery voltage value. A ground wire 10 is connected to the middle of the fourth electric wire 9.
The engine 1 is provided with an intake air temperature sensor 11 that detects an intake air temperature that is the temperature of intake air, and a water temperature sensor 12 that detects a water temperature that is a cooling water temperature. The intake air temperature sensor 11 is connected to the control means 5 via the fifth signal line 13. The water temperature sensor 12 is connected to the control means 5 via the sixth electric wire 14.
An electric load 16 of the vehicle is connected to the plus (+) terminal 2 </ b> A of the battery 2 via an electric wire 15. In the middle of the electric wire 15, a current sensor 17 is provided as a current detecting means for detecting a load current value (A) used in the electric load 16 of the vehicle. The current sensor 17 is connected to the control means 5 via the seventh signal line 18.
Further, a vehicle speed sensor 19 that can detect the stop state of the vehicle and an idle switch 20 that can detect the idling operation state of the engine 1 are in communication with the control means 5.

As shown in FIG. 1, the control means 5 includes a control start condition for fault diagnosis of the alternator 4, a condition that the alternator 4 is under power generation control, a condition that the vehicle is stopped, and an engine 1. All conditions are satisfied: when the engine is idling, when the water temperature is equal to or higher than the set temperature (80 ° C), and when the load current value exceeds the load current set value (current1) set at the intake air temperature When you are.
Further, as shown in the target power generation cut ratio table of FIG. 5, the control means 5 sets a target power generation cut ratio (target1) (%) according to the intake air temperature.

Further, as shown in FIG. 6, the control means 5 includes a warm-up state estimation unit 5A that estimates the warm-up state of the AC generator 4, and the load current value detected by the current sensor 17 is a load current set value (current1). ), The field current for controlling the field current of the AC generator 4 using the external input signal value set according to the warm-up state of the AC generator 4 estimated by the warm-up state estimating means 5A. A current control unit 5B, a failure diagnosis mode unit 5C for comparing the battery voltage value and the set voltage value (13.5 V) to determine whether or not the AC generator 4 has failed, and the battery voltage value And a battery voltage calculation unit 5D for calculation.
The load current set value (current1) is a value that changes in accordance with the intake air temperature state detected by the intake air temperature sensor 11, as shown in the load current table of FIG.
Further, the warm-up state estimation unit 5A estimates the warm-up state of the AC generator 4 from the intake air temperature detected by the intake air temperature sensor 11.
Further, failure diagnosis mode unit 5C determines that AC generator 4 is in failure when the battery voltage value does not become less than the set voltage value within a set time (for example, 60 sec).
That is, in this embodiment, the value of the input parameter used at the time of failure diagnosis is changed according to the warm-up state of the AC generator 4.

Next, the operation of this embodiment will be described based on the flowchart of FIG. 1 and the time charts of FIGS.
As shown in FIG. 1, when the program of the control means 5 is started (step S1), first, in order to determine whether or not the control start condition for failure diagnosis of the AC generator 4 is satisfied, whether or not the power generation control is in progress is determined. If this step S2 is NO, this determination is continued. If this step S2 is YES, it is determined whether or not the vehicle is stopped (step S3). If S3 is NO, the process returns to step S2. If this step S3 is YES, it is determined whether the engine 1 is idling (step S4). If this step S4 is NO, Returning to step S2, if this step S4 is YES, it is determined whether or not the water temperature exceeds the set water temperature (80 ° C.) (step S5), and if this step S5 is NO Returns to step S2, and if this step S5 is YES, it is determined whether or not the load current value exceeds the load current set value (current1) (step S6), and if this step S6 is NO Return to step S2.
When this step S6 is YES, it determines with the failure diagnosis conditions of the AC generator 4 having been satisfied, and starts control (step S7) (it shows by time t1 of FIG. 2, FIG. 3).
In this step S7, the power generation cut ratio (DTY) from the ECM control signal is gradually increased from zero (0) by a predetermined amplitude ratio (gain (%)) to the target power generation cut ratio (target1) set at the intake air temperature. (Indicated by times t1 to t2 in FIGS. 2 and 3).
Then, the power generation cut ratio (DTY) is maintained for a predetermined time (10 seconds) in the state of the target power generation cut ratio (target 1) (indicated by times t2 to t3 in FIGS. 2 and 3), and then power generation from the ECM control signal is performed. The cut ratio (DTY) is gradually increased by a predetermined amplitude ratio (gain (%)) to a value obtained by adding the target power generation cut ratio (target 1) and the feed amount (shift (%)) (FIGS. 2 and 2). 3 indicated by time t3 to t4). Then, this control is repeated.
Thereafter, during this control, it is determined whether or not the battery voltage value is less than the set voltage value (13.5 V) (step S8). If this step S8 is YES, the battery voltage value is set to the set voltage value (13 .5V) (shown at time t5 in FIGS. 2 and 3), it is determined that the AC generator 4 is normal (OK determination) (step S9).
On the other hand, when the step S8 is NO, the battery voltage value is not less than the set voltage value (13.5V), and whether or not a set time (for example, 60 sec) has elapsed from the start of control (time t1). If this step S10 is NO, the process returns to step S7. If this step S10 is YES, that is, during the set time, the power generation from the ECM control signal is further performed. The cut rate (DTY) is gradually increased by a predetermined amplitude ratio (gain (%)) to a value obtained by adding the feed amount (shift (%)) to the target power generation cut rate (target 1) (FIG. 3). When the battery voltage value does not become less than the set voltage value (indicated by time t8 in FIG. 3), it is determined that the AC generator 4 has failed (NG determination). (Step S11).
Then, after the processing of step S9 and step S11, the program is ended (step S12).

That is, in this embodiment, an ECM control signal is sent from the control means 5 to the AC generator 4 and the AC generator 4 is controlled to generate power according to the power generation cut ratio (%) from the ECM control signal. However, when the AC generator 4 cannot execute the power generation cut control, that is, when the battery voltage (VB) does not decrease, it is determined that the AC generator 4 is abnormal. In this case, as shown in FIG. 8, since there is a temperature characteristic of the AC generator 4, the power generation cut ratio (%) from the same ECM control signal is used in the case where the temperature of the AC generator 4 itself is cold and warm. ), However, there is a characteristic that the drop width of the battery voltage value (VB) is different, and, as shown in FIG. 9, even the load current value from the current sensor 15 which is a current detecting means simulating an electric load. The battery voltage value (VB) has a different drop width.
Therefore, the present invention diagnoses the fault of the AC generator 4 taking all these characteristics into consideration, and by adding the condition of the load current value (A) to the control start condition of the fault diagnosis of the AC generator 4. The battery voltage (VB) can be surely lowered, and the load current set value can be set in the intake air temperature table to cope with the temperature characteristics of the AC generator 4. By setting another target power generation cut ratio (%), the temperature characteristics of the AC generator 4 can be handled.

Although the embodiments of the present invention have been described above, the configuration of the above-described embodiments will be described for each claim.
First, in the first aspect of the invention, the control means 5 includes a warm-up state estimation unit 5A that estimates the warm-up state of the AC generator 4, and the load current value detected by the current sensor 17 is a load current set value. Field current for controlling the field current of the AC generator 4 using the external input signal value set according to the warm-up state of the AC generator 4 estimated by the warm-up state estimation means 5A when A control unit 5B and a failure diagnosis mode unit 5C that compares the battery voltage value with the set voltage value to determine whether or not the AC generator 4 has failed are provided. Thereby, according to the warming-up state of the AC generator 4, the value of the input parameter used at the time of failure diagnosis can be changed, and an accurate failure diagnosis of the AC generator 4 can be performed.

  Next, in the invention according to claim 2, the failure diagnosis mode unit 5C determines that the AC generator 4 is in failure when the battery voltage value does not become less than the set voltage value within the set time. Thereby, since the battery voltage value is used as the determination value for the failure determination of the AC generator 4, it is not necessary to provide a dedicated measuring device, and the configuration is simple and inexpensive.

  Furthermore, in the invention described in claim 3, the warm-up state estimation unit 5 </ b> A estimates the warm-up state of the AC generator 4 from the temperature of the intake air supplied to the engine 1. Thereby, the warm-up state of the AC generator 4 can be estimated without directly measuring the temperature of the AC generator 4.

  According to a fourth aspect of the present invention, the load current set value is a value that changes according to the temperature state of the intake air supplied to the engine 1. Thereby, the precision of the value of the input parameter used for the failure diagnosis of the AC generator 4 can be increased.

  When the load current value is larger than the load current set value, the field current of the AC generator is controlled using the external input signal value set according to the estimated warm-up state of the AC generator, and the battery Comparing the voltage and the set voltage value to determine whether or not the AC generator has failed can be applied to other controls.

It is a flowchart of the failure determination of an AC generator. It is a time chart when an alternator is normal. It is a time chart when an alternating current generator is abnormal. It is a figure of the table which sets the electric current value (A) according to intake air temperature. It is a figure of the table which sets the target electric power generation cut ratio (%) according to intake air temperature. It is a system block diagram of the electric power generation control apparatus of an alternating current generator. It is a figure which shows the change (warm-up) of the battery voltage (VB) at the time of power generation cut. It is a figure which shows the change (a cold machine, a middle warm-up, a warm-up) of the battery voltage (VB) at the time of a power generation cut. It is a figure which shows the change (effect of an electric load) of the battery voltage (VB) at the time of power generation cut.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Battery 3 Power generation control apparatus 4 AC generator 5 Control means 5A Warm-up state estimation part 5B Field current control part 5C Failure diagnosis mode part 11 Intake temperature sensor 12 Water temperature sensor 16 Electric load 17 Current sensor 19 Vehicle speed sensor 20 Idle switch

Claims (4)

  An alternator that is driven by an engine mounted on a vehicle to charge a battery is provided, and the alternator is at least based on an external input signal value and a battery voltage value that change in accordance with a traveling state of the vehicle or an operating state of the engine. In the generator control device for an alternator provided with a control means for controlling the field current of the alternator to control the output of the alternator, current detection means for detecting a load current value used in the electric load of the vehicle The control means includes a warm-up state estimation unit that estimates a warm-up state of the AC generator, and the warm-up state when the load current value detected by the current detection means is larger than a load current set value. A field current control unit for controlling the field current of the AC generator using an external input signal value set according to the warm-up state of the AC generator estimated by the estimation means; Power generation control apparatus for an AC generator, characterized in that by comparing the re voltage value and the set voltage value and a determining fault diagnosis mode unit whether the alternator is faulty.   2. The AC power generation according to claim 1, wherein the fault diagnosis mode unit determines that the AC generator is faulty when a battery voltage value does not become less than the set voltage value within a set time. Power generation control device.   The power generation control device for an AC generator according to claim 1, wherein the warm-up state estimation unit estimates a warm-up state of the AC generator from a temperature of intake air supplied to the engine.   The power generation control device for an AC generator according to claim 1, wherein the load current set value is a value that changes in accordance with a temperature state of intake air supplied to the engine.

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