JP4239402B2 - Vehicle power generation control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle power generation control device that controls an output voltage by controlling an excitation current of a vehicle generator.
[0002]
[Prior art]
The vehicular generator performs auxiliary battery charging while the vehicle is running and covers the power for engine ignition, lighting, and other various electrical components. Even when the load condition changes, the output voltage A power generation control device is connected to keep the power supply constant. Particularly recently, the driving torque of the vehicular generator tends to increase as the electric load increases. If the driving torque of the vehicular generator becomes excessive when the electrical load is connected, the engine rotation becomes unstable. Therefore, this situation can be avoided by performing the slow excitation control that gradually increases the excitation current by the power generation control device. Technology is known.
[0003]
For example, Japanese Patent Laid-Open No. 7-177678 discloses a “vehicle generator control device” that realizes a gradual excitation function with a simple digital circuit. In this control device, a gradual excitation circuit constituted by a digital circuit including a counter or the like is used, and when a control operation is started in response to a power generation instruction signal input from the outside, the counter or the like is in an initial state. Therefore, a power-on reset circuit is required. A predetermined gradual excitation control is started by resetting the gradual excitation circuit by the power-on reset circuit.
[0004]
[Problems to be solved by the invention]
By the way, in the control device disclosed in the above-mentioned JP-A-7-177678, the power-on reset circuit operates in response to the power generation instruction signal input at the start of power generation. If intermittent, the slow excitation control is erroneously started even during normal power generation operation that is not at the start of power generation, and there is a problem that the power generation capacity is temporarily suppressed and the power generation state becomes unstable. For this reason, if a large load current is flowing at this time, the battery voltage will be reduced by about 1 to 2 V, and the lamps that have been lit will temporarily become dark, causing discomfort to the driver of the vehicle. Will give.
[0005]
The present invention was created in view of the above points, and an object of the present invention is to provide a vehicle power generation control device capable of maintaining a stable power generation state with respect to the intermittent generation instruction signal. is there.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, a vehicle power generation control device according to the present invention is a voltage control that controls an output voltage of a vehicle generator by intermittently connecting a switching element connected in series to an excitation coil of the vehicle generator. A circuit, a gradual excitation control circuit that limits the rate of increase in the conductivity of the switching element, a reset circuit that generates a reset signal in response to a power generation instruction signal input from the outside, and when the reset signal is generated by the reset circuit And a continuity setting circuit for detecting a state quantity related to power generation of the vehicle generator and setting a continuity value of the switching element controlled by the gradual excitation control circuit based on the state quantity. Even when the power generation instruction signal input from the outside is temporarily interrupted while the vehicle generator is generating power, the continuity of the switching element is set according to the state quantity (power generation state) related to power generation. As with the start of power generation, a low continuity rate is not set by mistake, and a stable power generation state can be maintained.
[0007]
In addition, the state quantity described above is the amount of exciting current of the vehicular generator, and the continuity setting circuit desirably sets the value of the continuity of the switching element based on the amount of exciting current. Since the time constant of excitation current decay is about 100 msec, the value of the excitation current is substantially maintained even when the power generation instruction signal is momentarily interrupted for several msec. Therefore, by setting the continuity of the switching element according to the value of the excitation current after the power generation instruction signal is resumed, the state before the momentary interruption can be substantially reproduced, and a stable power generation state can be maintained. it can.
[0008]
Further, the above-described continuity setting circuit detects the rotational speed of the vehicular generator, and it is desirable to set the continuity based on the state quantity when the detected rotational speed is equal to or greater than a predetermined value. As a result, even if a reset signal is erroneously output when the rotational speed increases and the power generation state is generated, this power generation state can be reproduced, and a stable power generation state can be maintained.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a vehicle power generation control device (hereinafter referred to as a “regulator”) according to an embodiment to which the present invention is applied will be described with reference to the drawings.
[0010]
FIG. 1 is a diagram showing a configuration of a regulator according to an embodiment to which the present invention is applied, and also shows a connection state between the regulator and a vehicle generator and a battery.
[0011]
In FIG. 1, the regulator 1 is for controlling the voltage at the output terminal (B terminal) of the vehicle generator 2 to be a predetermined adjustment voltage setting value (for example, 14 V). In addition to the B terminal, the regulator 1 has a power terminal (IG terminal), an alarm terminal (L terminal), and a ground terminal (E terminal). The IG terminal is connected to the battery 3 via the key switch 4. The L terminal is connected to the battery 3 via the charge lamp 5 and the key switch 4. The charge lamp 5 is turned on when the key switch 4 is on and the vehicle generator 2 is not in the power generation state, and is turned off when power generation is started. The E terminal is connected to the frame of the vehicle generator 2.
[0012]
The vehicle generator 2 includes a three-phase stator coil 121 included in a stator as a stator, a rectifier circuit 123 provided for full-wave rectification of the three-phase output of the stator coil 121, and a rotor. An excitation coil 122 included in the rotor is included. Control of the output voltage of the vehicular generator 2 is performed by appropriately turning on and off the energization of the exciting coil 122 by the regulator 1. The output terminal (B terminal) of the vehicle generator 2 is connected to the battery 3, and a charging current is supplied from the B terminal to the battery 3.
[0013]
Next, the detailed configuration and operation of the regulator 1 will be described. As shown in FIG. 1, the regulator 1 includes a power supply circuit 10, a power-on reset circuit 11, a reference voltage circuit 15, a voltage comparator 16, an analog-digital (A / D) conversion circuit 17, a rotation detection circuit 18, and an oscillation circuit. 19, gradual excitation circuit 20, AND circuit 21, freewheeling diode 22, transistors 23, 24, 25, and resistors 30-34.
[0014]
The power supply circuit 10 generates a predetermined operating voltage when a battery voltage is applied to the IG terminal. The state in which the battery voltage is applied to the IG terminal corresponds to the input state of the power generation instruction signal. The power-on reset circuit 11 generates a reset signal when an operating voltage is applied from the power supply circuit 10. Specifically, the power-on reset circuit 11 includes a resistor 12, a capacitor 13, and an inverter circuit 14. One end of the resistor 12 is connected to the power supply circuit 10, and when the operating voltage generated by the power supply circuit 10 is applied to the resistor 12, the capacitor 13 is charged according to the time constant of the resistor 12 and the capacitor 13. Therefore, the output of the inverter circuit 14 becomes a high level corresponding to a short time until the terminal voltage of the capacitor 13 exceeds a predetermined value, and this is output as a reset signal. This reset signal is input to the gradual excitation circuit 20.
[0015]
The reference voltage circuit 15 generates a reference voltage necessary for controlling the output voltage of the vehicular generator 2 to a predetermined adjustment voltage set value. This reference voltage is applied to the plus terminal of the voltage comparator 16. A voltage obtained by dividing the B terminal voltage by the resistors 30 and 31 is applied to the negative terminal of the voltage comparator 16. The voltage comparator 16 compares the reference voltage applied to the plus terminal with the divided voltage applied to the minus terminal, and sets the output to a high level when the divided voltage becomes lower than the reference voltage. The output terminal of the voltage comparator 16 is connected to one input terminal of the AND circuit 21.
[0016]
The oscillation circuit 19 generates a predetermined clock signal CLK. This clock signal CLK is input to the gradual excitation circuit 20. The gradual excitation circuit 20 is for limiting the rate of increase of the excitation current when a reset signal is input corresponding to the power generation start state, and uses a clock signal CLK input from the oscillation circuit 19 to generate a predetermined signal. A gradual excitation output pulse having a gradual excitation limiting duty ratio is generated. The output terminal of the gradual excitation circuit 20 is connected to the other input terminal of the AND circuit 21. The output terminal of the AND circuit 21 is connected in common to the gates of the transistor 23 as a switching element connected in series to the exciting coil 122 and the transistor 24 provided for detecting the exciting current.
[0017]
The resistors 32 connected to these gates are for generating the bias voltages of the transistors 23 and 24, respectively. The resistor 33 connected between the source of the transistor 24 and the E terminal is for current detection, and a terminal voltage corresponding to the value of the flowing current is applied to the A / D conversion circuit 17.
[0018]
The A / D conversion circuit 17 converts the terminal voltage of the resistor 33 into 4-bit digital data. This 4-bit data is input to the gradual excitation circuit 20. The rotation detection circuit 18 detects the number of rotations of the vehicle generator 2 by monitoring a phase voltage appearing in any phase of the stator coil 121. The rotation detection circuit 18 has two output terminals a and b. One output terminal a is connected to the gradual excitation circuit 20 and the other peripheral force terminal b is connected to the transistor 25 via the resistor 34. Connected to the gate.
[0019]
The regulator 1 of the present embodiment has such a configuration, and the operation thereof will be described next. FIG. 2 is a diagram illustrating the operation timing of the regulator 1.
[0020]
When the key switch 4 is turned on by the driver of the vehicle, a battery voltage is applied to the power supply circuit 10 provided in the regulator 1, so that a predetermined operating voltage generated by the power supply circuit 10 is supplied to each circuit, The regulator 1 starts a control operation. At this timing, a high level reset signal is output from the power-on reset circuit 11 for a predetermined time.
[0021]
Immediately after the key switch 4 is turned on, since the vehicular generator 2 is in a rotation stopped state, the voltage at the B terminal is lower than the adjustment voltage set value, and the output of the voltage comparator 16 is at a high level. On the other hand, immediately after the key switch 4 is turned on, the gradual excitation circuit 20 outputs a gradual excitation output pulse that is a PWM signal having a duty ratio of about 25% (described later). Since the AND circuit 21 receives a high level signal of the voltage comparator 16 at one input terminal and a gradual excitation output pulse having a duty ratio of about 25% at the other input terminal, this gradual excitation output. An excitation current drive pulse corresponding to the duty ratio of the pulse is input to the transistors 23 and 24, and the intermittent state of these is controlled. Thereafter, the gradual excitation action by the gradual excitation circuit 20 gradually increases the duty ratio of the gradual excitation output pulse, and the excitation current flowing through the transistor 23 controlled by this duty ratio also gradually increases. When the B terminal voltage of the vehicular generator 2 becomes equal to or higher than the adjustment voltage set value, the output of the voltage comparator 16 changes from the high level to the low level, and the transistor 23 maintains the off state. For this reason, the B terminal voltage which became more than an adjustment voltage setting value falls again. In this way, feedback control is performed so that the B terminal voltage matches the adjusted voltage setting value.
[0022]
Further, a current (for example, about 1/1000) proportional to the current flowing between the source and drain of the transistor 23 for exciting current drive flows between the source and drain of the transistor 24. For this reason, a voltage proportional to the excitation current is generated at one end of the resistor 33, and the A / D conversion circuit 17 converts this voltage into 4-bit data. The rotation detection circuit 18 detects the rotation speed of the vehicle generator 2 by detecting the phase voltage of the stator coil 121.
[0023]
When the power generation is stopped and the phase voltage is lower than the set level, or lower than the starting rotation (for example, 1000 rpm or lower), the output terminal b of the rotation detection circuit 18 becomes high level and the transistor 25 becomes conductive, and charging is performed. Lamp 5 is lit. Further, when the rotational speed of the vehicular generator 2 increases and becomes, for example, an idling rotational speed (for example, 3000 rpm) or more, the output terminal a of the rotational detection circuit 18 becomes high level, and the rotational speed detection state is gradually excited. The circuit 20 is notified.
[0024]
Next, detailed configurations and operations of the rotation detection circuit 18 and the gradual excitation circuit 20 will be described.
[0025]
FIG. 3 is a diagram showing a detailed configuration of the rotation detection circuit 18. As shown in FIG. 3, the rotation detection circuit 18 includes three voltage comparators 60, 61, 62, a diode 63, two capacitors 64, 65, and four resistors 70, 71, 72, 73. Yes. The voltage dividing circuit B1 is configured by the resistors 70 and 71. When the phase voltage Vp of the stator coil 121 is applied to one end of the voltage dividing circuit B1, the voltage dividing determined by the resistance ratio of the two resistors 70 and 71 is made. A voltage is applied to the positive terminal of the voltage comparator 60. A predetermined reference voltage Vref1 is applied to the negative terminal of the voltage comparator 60. Since the phase voltage Vp rises and falls periodically when in the power generation state, the voltage comparator 60 outputs a rectangular wave synchronized with the voltage change cycle of the phase voltage Vp.
[0026]
This rectangular wave is input to a differentiation circuit composed of a capacitor 64 and a resistor 72. In this differentiating circuit, two types of differential outputs having different polarities are generated at the rising and falling timings of the input rectangular wave, but only the positive differential output is selectively passed through the diode 63 at the subsequent stage. The capacitor 65 is charged. The resistor 73 connected in parallel to the capacitor 65 is used for discharging the capacitor 65, and the voltage determined as a result of charging / discharging becomes the terminal voltage of the capacitor 65. In the two voltage comparators 61 and 62, reference voltages Vref2 and Vref3 corresponding to the number of rotations to be detected are set, respectively. For example, in the voltage comparator 61, the reference voltage Vref2 corresponding to a rotation speed of 3000 rpm or less is applied to the minus terminal, and the terminal voltage of the capacitor 65 is applied to the plus terminal. Therefore, when the rotation speed becomes 3000 rpm or more, the output of the voltage comparator 61 changes from the low level to the high level, and this output is input from the output terminal a of the rotation detection circuit 18 to the gradual excitation circuit 20. In the voltage comparator 62, a reference voltage Vref3 corresponding to a rotation speed of 1000 rpm is applied to the plus terminal, and a terminal voltage of the capacitor 65 is applied to the minus terminal. Therefore, when the rotation speed becomes 1000 rpm or more, the output of the voltage comparator 62 changes from a high level to a low level, and this output is input from the output terminal b of the rotation detection circuit 18 to one end of the resistor 34.
[0027]
FIG. 4 is a diagram showing a detailed configuration of the gradual excitation circuit 20. As shown in FIG. 4, the gradual excitation circuit 20 includes a timing pulse generation counter 40, an up / down counter 41, a PWM counter 42, a timing logic circuit 43, a stored value update signal generation circuit 44, an RS flip-flop 45, a magnitude comparator 46, A gradual excitation output latch 47 and an OR circuit 48 are included.
[0028]
The timing pulse generation counter 40 is for setting the rising timing of the gradual excitation output pulse. When the reset signal RST output from the power-on reset circuit 11 is output, the count value is reset, and then a counting operation synchronized with the clock signal CLK output from the oscillation circuit 19 is performed.
[0029]
The timing logic circuit 43 includes three inverter circuits and a NAND circuit, and generates an output pulse when the count value of the timing pulse generation counter 40 is “0010”.
[0030]
The up / down counter 41 is for storing the duty ratio of the gradual excitation output pulse, and performs a counting operation using a signal output from the output terminal Q10 of the timing pulse generation counter 40 as an operation clock. Specifically, the output terminal of the voltage comparator 16 is connected to the up / down (U / D) terminal, and when the output of the voltage comparator 16 is at a high level, a count-up operation synchronized with the clock is performed, and In addition, when the output of the voltage comparator 16 is at a low level, a countdown operation synchronized with the clock is performed.
[0031]
When the reset signal RST is output from the power-on reset circuit 11, the stored value update signal generation circuit 44 sets only the third bit of the up / down counter 41 and resets the other first, second, and fourth bits. To do. Further, the output value of the RS flip-flop 45 is input to the stored value update signal generation circuit 44. In the RS flip-flop 45, the output terminal of the timing logic circuit 43 is connected to the set terminal S, and the output terminal of the power-on reset circuit 11 is connected to the reset terminal R. Therefore, the RS flip-flop 45 is set when the pulse is first output from the timing logic circuit 43 after the reset signal RST signal is input. The output of the RS flip-flop 45 is input to a differentiating circuit composed of a capacitor 50 and a resistor 51. A pulse is sent from the differentiating circuit to one input terminal of the AND circuit 52 at the timing when the RS flip-flop 45 is set. Is entered. One output terminal a of the rotation detection circuit 18 is connected to the other input terminal of the AND circuit 52. When the output terminal a is at a high level (the rotational speed of the vehicle generator 2 is 3000 rpm or more). Only in the case), the AND circuit 52 outputs a pulse at the timing when the pulse is input from the differentiating circuit. At this time, each bit of the 4-bit data output from the A / D conversion circuit 17 is set in the up / down counter 41.
[0032]
The PWM counter 42 is for setting the falling timing of the gradual excitation output pulse. A pulse output from the timing logic circuit 43 and a reset signal RST are input to the OR circuit 48, and when either is input, the PWM counter 42 is reset, and then the clock output from the oscillation circuit 19 A counting operation synchronized with the signal CLK is performed.
[0033]
The magnitude comparator 46 compares the output value A of the up / down counter 41 with the output value B of the PWM counter 42, and sets the output to a high level when A <B. The gradual excitation output latch 47 is configured by an RS flip-flop, and is set when a pulse is output from the OR circuit 48, and is reset when the output of the magnitude comparator 46 changes from low level to high level. The output of the gradual excitation output latch 47 is inputted as a gradual excitation output pulse from the gradual excitation circuit 20 to the other input terminal of the AND circuit 21 shown in FIG.
[0034]
Next, the operation of the gradual excitation circuit 20 will be described. When the key switch 4 is turned on, the reset signal RST is output from the power-on reset circuit 11 and only the third bit of the up / down counter 41 is set. Therefore, the gradual excitation output latch 47 is set at a timing when a pulse is output from the OR circuit 48, and is reset when the count value of the PWM counter 42 exceeds "0010". The PWM counter 42 is a 4-bit counter and returns to “0000” again when the count value reaches “1111”. Therefore, the duty ratio of the gradual excitation output pulse output from the gradual excitation output latch 47 is approximately 25%. Become.
[0035]
Further, immediately after the key switch 4 is turned on, the vehicular generator 2 is not generating power, so the B terminal voltage is below the adjustment voltage set value, and the output of the voltage comparator 16 is maintained at a high level. The exciting current driving transistor 23 operates with a duty factor of 25%. Thereafter, the up / down counter 41 periodically performs a count-up operation according to the state in which the high level output of the voltage comparator 16 is input to the up / down terminal. As a result, the duty ratio of the gradual excitation output pulse gradually increases (for example, 15% per second), and the excitation current also gradually increases.
[0036]
Thus, when the output voltage (B terminal voltage) of the vehicle generator 2 rises and exceeds the adjustment voltage set value, the output of the voltage comparator 16 changes from high level to low level. The transistor 23 is cut off, and the B terminal voltage decreases. At this time, the up / down counter 41 is in a state where the low level output of the voltage comparator 16 is inputted to the up / down terminal, and periodically performs a countdown operation. Thereby, the duty ratio of the gradual excitation output pulse gradually decreases. In this way, the B terminal voltage is controlled so as to substantially match the adjustment voltage setting value, and at the same time, the setting value of the up / down counter 41 is also feedback controlled to a value substantially equal to the conductivity of the transistor 23 in a steady manner. The
[0037]
When this feedback control is stable in an idling state or the like, when the load switch 8 is turned on and the electric load 9 is connected, the battery voltage temporarily decreases and the B terminal voltage becomes lower than the adjustment voltage setting value. Although the output of the voltage comparator 16 maintains a high level state, since the duty ratio of the gradual excitation output pulse output from the gradual excitation circuit 20 increases only gradually, the excitation current also increases only gradually. Thereby, a rapid increase in the drive torque of the vehicular generator 2 can be suppressed, and a drop in engine rotation can be prevented.
[0038]
Next, when a relatively large electric load 9 is connected in the idling state, for example, the excitation current driving transistor 23 is assumed to be operating at a conduction ratio of about 50% duty ratio. Consider a case where the operation of the power supply circuit 10 is stopped for about 1 msec due to a momentary interruption of the input power generation instruction signal and the reset signal RST is output from the power-on reset circuit 11. The value of the up / down counter 41 in the gradual excitation circuit 20 is temporarily set to “0010” at the output timing of the reset signal RST. Thereafter, when a pulse is output from the timing logic circuit 43, since a high level signal is output from the output terminal a of the rotation detection circuit 18 at this time, the signal at that time point output from the A / D conversion circuit 17 is output. 4-bit data corresponding to the excitation current value is set in the up / down counter 41. Since the excitation coil 122 has a time constant of about 100 msec, the value of the excitation current hardly changes before and after the power-on reset circuit 11 malfunctions, and the transistor 23 has a continuity immediately before the power-on reset circuit 11 malfunctions. (50%) can be almost maintained. Therefore, the B terminal voltage does not fluctuate greatly, and a stable power generation state can be maintained.
[0039]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the excitation current is accurately detected so that the gradual excitation operation by the gradual excitation circuit 20 returns to normal after the power-on reset circuit 11 malfunctions. Is compared with a predetermined threshold value. When the excitation current is lower than this threshold value and the rotational speed of the vehicle generator 2 is low, the duty ratio of the gradual excitation output pulse is set to 25%. In that case, it may be set to 100%. Thus, the circuit may be simplified to prevent only a decrease in the B terminal voltage when the power-on reset circuit 11 malfunctions.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a regulator according to an embodiment.
FIG. 2 is a diagram illustrating operation timing of a regulator.
FIG. 3 is a diagram showing a detailed configuration of a rotation detection circuit.
FIG. 4 is a diagram showing a detailed configuration of a gradual excitation circuit.
[Explanation of symbols]
1 Regulator (Vehicle power generation control device)
2 Vehicle generator 3 Battery 4 Key switch 10 Power supply circuit 11 Power-on reset circuit 15 Reference voltage circuit 16 Voltage comparator 17 Analog-digital (A / D) conversion circuit 18 Rotation detection circuit 19 Oscillation circuit 20 Slow excitation circuit 22 Reflux Diode 23, 24, 25 Transistor 30-34 Resistance

Claims (3)

A voltage control circuit for controlling an output voltage of the vehicle generator by intermittently connecting a switching element connected in series to an excitation coil of the vehicle generator;
A gradual excitation control circuit for limiting a rate of increase in the conductivity of the switching element;
A reset circuit that generates a reset signal in response to a power generation instruction signal input from the outside;
When the reset signal is generated by the reset circuit, the excitation current amount of the vehicle generator is detected, and the continuity ratio of the switching element controlled by the gradual excitation control circuit based on the excitation current amount A continuity setting circuit for setting the value of
A vehicle power generation control device comprising: In claim 1,
The continuity ratio setting circuit detects the rotational speed of the vehicular generator, and sets the continuity ratio based on the exciting current amount when the detected rotational speed is a predetermined value or more. A vehicle power generation control device. In claim 1 or 2,
The gradual excitation control circuit is configured to increase the conductivity of the switching element from a low conductivity at the start of power generation,
Even when the power generation instruction signal is momentarily interrupted for several milliseconds , the continuity ratio setting circuit does not erroneously set the low continuity ratio as at the start of power generation. The conduction factor of the switching element is set based on the amount of excitation current having a decay time constant of about 100 msec so that the state can be substantially reproduced and a stable power generation state can be maintained. A power generation control device for a vehicle.

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