JPS61251435A - Control system for engine-driven generator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for an engine-driven generator that controls switching of the generated voltage of a 9i electric machine driven by an engine.

In general, when it comes to cars, etc., as shown in Figure 2,
A generator 3 driven by a battery 1 and an engine 2 is connected in parallel to an electric load 4, and the generated voltage of the generator 3 can be sufficiently supplied for charging the battery 1 and the capacity of the electric load 4. Usually, a predetermined voltage (for example, 14.5V) of the battery 1 is specified so that the voltage is 14.5V. Therefore, the power generated by one generator 3 changes depending on the usage status of one electric load, and the load on the engine 2 that drives the generator 3 changes proportionally, but if the capacity of the electric load 4 is small and When the engine 2 is in an operating state other than deceleration, the generated voltage of the generator 3 can be lowered to the charging voltage of the battery 1 (for example, 12.5V) to reduce the load on the engine 2 from the generator 3. By doing so, the load on the generator 3 is eliminated, the driving loss of the engine 2 is reduced accordingly, and fuel efficiency can be improved.

Figure 3 shows the characteristics of the generator output current with respect to the engine speed when the generated voltage is taken as a parameter.9
As the power generation voltage increases, the amount of power generation increases and the battery charging speed increases. By taking advantage of this temporality and generating power at a lower voltage during normal load conditions, the charging current will be reduced and the engine load will be reduced. become. Also.

When the electrical load becomes heavy, switching the power generation voltage to a higher value to increase the amount of power generation makes it possible to sufficiently meet the load request and to suppress battery discharge.

Therefore, in the past, a circuit configuration was used in which a battery and a generator driven by an engine were connected in parallel to the electrical load, and the circuit was configured to respond to the charging state of the battery, the application state of the electrical load, and the operating state of the engine. In order to keep the battery voltage constant at all times, the voltage regulator detects the battery voltage and compares it with a preset reference voltage, and controls the generator's field current on and off according to the comparison result. Switching control is performed to increase or decrease the generated voltage.

However, with conventional engine-driven generator control like this, when one generator is switched to the small power generation side, which produces a lower amount of power, electricity with a large inrush current when turning on the headlamp or near conditioner, etc. When a load is applied, when the 1st generator is switched to the large power generation side that generates a higher amount of power, at the beginning of the switching, the ion concentration in the battery electrolyte is adjusted to a higher J1 voltage based on the difference in the reference power generation voltage. This is because the on-time of the line current becomes longer, and the amount of power generated by the generator increases rapidly until the equilibrium state is restored, resulting in a sudden drop in engine speed.

The drivability of the car is impaired.

The present invention has been made in consideration of the above points, and controls the switching of the generated voltage of the generator so that even if an electrical load with a large inrush current is applied, the load will not be suddenly applied to the engine. The present invention provides a control method for an engine-driven generator that allows

1. In order to achieve the object of the present invention, a battery is connected in parallel to the battery so that the battery voltage becomes a reference voltage under the control of a controller in response to an output signal of a comparator that compares the battery voltage with a preset reference voltage. For controlling the on/off switching of the field winding current of a generator,
Means for measuring and holding the on-state duration time of the field winding current of one generator in the controller, means for detecting that the current on-state duration time is longer than the previous duration time by a predetermined time, and the detection. A means for temporarily forcibly switching off the field winding current of the generator, a means for detecting an operating state in which the output torque of the engine is high, and a means for detecting an operating state in which the output torque of the engine is high; The invention also provides means for canceling the forced switching to the field winding current of the machine.

In this case, in particular, the present invention focuses on the fact that torque fluctuations due to generator load become less of a problem when the engine's output torque is high and the operating conditions are bad. A control method is used to cancel the switching.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a circuit configuration for concretely implementing the control method for an engine-driven generator according to the present invention, in which the terminal voltage VB of the battery 1 and the preset reference generation voltage V
s and a switching element SW that reads the output signal of the comparator CMP and switches the field coil FC in the generator 3 to the stronger side.
On.

It consists of a controller CNT that turns off the power. Note that the reference power generation voltage Vs is set to be 14.5 V when the voltage is divided by the resistor R1 and the resistor R2, and 12.5 V when the voltage is divided by the combined resistance of R1, R2 and the resistor R3. ing. Further, the switching transistor Tr that turns on and off the resistor R3 is connected to the near conditioner operating signal S1. Headlamp lighting signal S2.
It is turned on or off in response to a determination output signal from a logic circuit LOG that reads the deceleration signal S3 and determines the electrical load state and engine operating state.

In a device configured in this way, conventionally, when the reference voltage Vs changes as shown in FIG. 4 when the electric load (near conditioner) is switched from off to on, the comparator CMP at that time is In response to the output signal of , the switching element SW is turned on and off as appropriate so that the battery voltage v8 is maintained at the reference power generation voltage Vs, as shown in the figure. In that case, when VB < Vs, the output signal of the comparator CMP becomes a high level 14 Hly and the switching element SW is turned on, and when ≧Vs, the output signal of the comparator CMP becomes a low level II L 11. The switching element SW is turned off.

However, if the switching element SW is simply turned on and off in accordance with the output signal of the comparator CMP, as shown in FIG. Even if the switching element SW is turned on by switching the reference power generation voltage Vs, a long time Ton is required until the switching element SW recovers to the reference voltage Vs at time t2. Furthermore, as shown in FIG. 5, the amount of power generated by the single generator 3 increases rapidly in response to the inrush current when the electric load 4 is turned on, and the engine speed Ne also decreases rapidly, causing the engine idle-up control to be controlled. Even if this is done, it is difficult to prevent the engine speed from decreasing because the engine load increases before the response time until the engine speed Ne rises to a predetermined value.

Therefore, in the present invention, in the controller CNT, means for measuring and holding the on-time of the switching element SW by an internal counter, and means for detecting whether the current on-time is longer than the previous on-time by a predetermined time;
When this is detected, a means is taken to temporarily forcibly turn off the switching element SW.

In this case, 1, for example, as shown in FIG. 6, the previous on time t
If the entertainment off time tc is provided after the on time tn, which is (n-1) plus the excess time tα, has elapsed, the battery voltage ■, which has dropped below the reference voltage Vs at time t1, will rise to the reference voltage Vs again. When forced off several times during the period Ton' until recovery, tc,
After setting the initial value for each time of tc, variable control of the on time can be performed, such as increasing the on time each time the forced off is repeated (in this case, the forced off time tc is constant) or forced off. Variable control of the off time is executed such that the forced off time is lengthened each time the power is turned off. In that case, various methods can be considered as follows.

First, when performing variable control of the on-time, the first method is to set the current 16 hours as a function of the previous ta(n-1), that is, ta:f (ta(n-1)), and set the current 16 hours as a function of the previous ta(n-1). is set as the previous ta(n-1) time plus 1 for a constant time, and 16 hours is increased additively by the constant time Kl.

Also, as the second method, tα=f(ta(n
-1)), the current 16 hours are the previous ta.
It is set as (n-1) time multiplied by a constant coefficient kl, and 16 hours are increased proportionally at a constant rate.

In addition, as a third method, a function of the number of forced offs n that has been performed for the past 16 hours, that is, tα=f(n
), and the current 16 hours is set as the value obtained by multiplying the number of forced offs by 2 by a certain coefficient and adding it to the previous ta(n -1) time. It is made to increase at a constant rate according to the number n of forced offs.

Furthermore, as a fourth method, the current 16 hours are
(n-1) as a function of time and number of forced offs, ie, ta = i (ta (n-1) * n), and the previous t
The current 16 hours are set to be the sum of a(n-1) time multiplied by a constant coefficient kl and the number of forced off times n multiplied by a constant coefficient by 2. is increased at a constant rate according to the previous value tα(n-1) and the number n of forced offs.

Next, when performing variable control of the off time, the first method is to set the current tc waiting time as a function of the previous te (n - 1), that is, tc = f (tc (n - 1)), and set the current tc waiting time as a function of the previous te (n - 1), The waiting time is set as the previous tc(n-1) time plus 2 for a fixed time, and the waiting time te is increased by 2 for each fixed time. In that case, the above-mentioned method of increasing the 16 hours additively by a certain period of time Kl is also adopted.

As a second method, the current tc waiting time is a function of the number n of forced offs performed up to that point, that is, tc = f (
n), and the current tc waiting time is set to the value obtained by multiplying the number of forced offs by 3 by a certain coefficient,
The tc waiting time is increased at a constant rate according to the number of times n of forced off. In that case, the above-mentioned 16
A method is also adopted in which the time is increased additively by a constant time Kl.

Furthermore, as a third method, the current tc waiting time is
(n-1) as a function of time and number of forced offs, ie, t c = f (t c (n-1) v n),
The current 16 hours is set as the sum of the previous tc(n-1) time multiplied by a constant coefficient by 4 and the number of forced off times n multiplied by the constant coefficient by 2. , 16 hours are increased at a constant rate according to the previous value tα(n-1) and the number n of forced offs.

In that case as well, the above-described method of increasing the 16 hours incrementally by a constant time Kl is also adopted.

When performing on/off control of switching to the high power generation side in the generator 3 as described above, especially in the present invention, when the output torque of the engine 2 is in a high operating state, a relatively large electrical load 4 is applied and a large electric load 4 is applied. Since the generator load when switched to the power generation side has little effect on the engine 2 by reducing the engine speed, the controller CNT determines the operating state in which the output torque of the engine 2 is high from the operating state signal DS. A means for detecting this and a means for releasing the forced off state of the switching element SW upon detection are provided.

As a specific method for detecting the operating state in which the output torque of the engine 2 is high from the operating state signal DS, the rotation speed Ne of the engine 2 or the generator 3 is adopted as the operating state signal DS, and the detected The actual rotation speed Ne of the engine 2 and the preset reference rotation speed Ns (for example, 10
1000 rpm, and if No≧Ns+, it may be determined that the output torque of the engine 2 is higher than a predetermined value.

In addition, the throttle opening (or accelerator opening) θt of the engine 2 is used as the operating state signal DS, and the detected throttle opening θt and the preset reference opening number O
3 (for example, 10 degrees), and when θt≧θS, it may be determined that the output torque of the engine 2 is higher than a predetermined value.

Further, the negative pressure on the intake manifold side of the engine 2 is adopted as the operating state signal O8, and the detected engine negative pressure P is set as a preset reference negative pressure Ps (for example, 4
00vHg).

When P, ≧Ps, it may be determined that the output torque of the engine 2 is higher than a predetermined value.

FIG. 7 shows a controller C when implementing the present invention.
It shows the flow of NT processing.

First, the output signal of the comparator CMP is at high level II.
If it is a high level ItH#l, check the operating state of the engine 2 and check whether the output torque T is a constant torque Ts.
It is determined whether the above is true or not.

At that time, if T≧Ts, the switching element SW is kept in the on state. At that time, if T<Ts, the count value A of the tα counter (provided inside the controller CNT) that measures the tα time is compared with the tα set value B.

At that time, if A≦B, the count value of A is incremented, and then it is checked whether the flag Fa for setting tc and te is set.

If it is set, an on signal is given to the switching element SW to switch the field coil FC of the generator 3 to the stronger side. Also, if flag Fa is not set, flag Fa
After setting t, the calculation subroutine is entered, where t
After resetting c and tc, an on signal is given to the switching element SW.

At that time, if A>B, the content of the te counter (provided inside the controller CNT) that measures the tc waiting time is incremented, and the count value C and t
Compare the C setting value, and when C>E, increment the contents of the n counter (provided inside the controller CNT) that counts the number of forced off times, and then check whether the flag Fa is set or not. After that, perform the same processing as above. Moreover, when C:mE, after resetting the flag Fa, the switching element SW
An off signal is given to the generator 3 to keep the field of the generator 3 in a cut-off state.

Also, the output signal of the comparator CMP is at low level rr.
If L u, set the contents of the n counter to zero, reset the flag Fa, and then switch the switching element SW.
give an off signal to.

Note that the tα counter and the tc counter function as a so-called soft timer for causing the generator 3 to perform soft power generation. A again.

B and Fa are each initially set to zero.

FIGS. 8 to 11 show the contents of each calculation subroutine when the first to fourth methods are used to perform the variable on-time control described above.

FIGS. 12 to 14 show the contents of each calculation subroutine when the first to third methods are used to perform variable control of the off-time described above.

In this way, in the present invention, when the battery voltage decreases and the period during which the power generation amount of the generator 3 is switched from the small power generation side to the large power generation side becomes longer, the time period for switching to the high power generation side is temporarily increased. Since the generator performs soft power generation while forcibly switching the power generation amount of the generator to the small power generation side, as shown in Fig. 15, even if a large electrical load 4 is applied, the power generation of the generator 3 is maintained. The amount of power generated will no longer increase rapidly as in the past. Therefore, the load on the engine 2 is lightened and the engine speed Ne does not drop sharply and greatly, and when controlling the idle up of the engine 2, it takes a response time T until the engine speed Ne rises to a predetermined level.
up' is shortened, the engine 2 can be idled up with good responsiveness, and the drivability of the automobile is not impaired. In addition, especially in an operating state where the output torque of the engine 2 is high, the field winding current of the first generator 3 is forced to temporarily switch to the off side while the field winding current of the first generator 3 continues to be in the on state, causing the generator to perform soft power generation. Because I'm trying to get it removed.

Battery 1 without compromising the drivability of the car
charging can be carried out efficiently.

In the control system for the engine-driven generator according to the present invention, when controlling the field winding current of the charging generator to switch on and off so that the battery voltage always becomes the reference voltage, This has the excellent advantage of effectively preventing a sudden load on the engine when a large electrical load is applied and the generator is switched to the large power generation side.

[Brief explanation of the drawing]

Fig. 1 is an electrical wiring diagram showing an example of a circuit configuration for concretely implementing the control method for an engine-driven generator according to the present invention, and Fig. 2 is a circuit diagram showing a connection state of a battery, a generator, and an electric load. , Fig. 3 is a diagram showing the output current characteristics of the generator with respect to the engine speed, Fig. 4 is a characteristic diagram showing the on/off state of the switching element in the conventional control method with respect to changes in battery voltage, and Fig. 5 is the characteristic diagram of the conventional control method. Figure 6 shows the control method of the present invention in response to changes in battery voltage. FIG. 7 is a characteristic diagram showing the on/off state of the switching element in the method; FIG. 7 is a diagram showing the processing flow of the controller when implementing the present invention; FIG.
14 to 14 are diagrams each showing an example of the calculation subroutine in the flow, and FIG. 15 shows the on/off states of the switching elements according to the control method of the present invention. 2 is a time chart showing the characteristics of the power generation amount of the generator and the engine rotation speed in the electrical load application state 1. FIG. 1... Battery 2... Engine 3... Generator 4... Electrical load CMP... Comparator CN
T...Controller FC...Field coil Fig. 1 Vcc Fig. 2 Fig. 3rI! J Figure 4 Akiyami □ Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. A generator connected in parallel to the battery so that the battery voltage becomes a reference voltage under the control of a controller according to an output signal of a comparator that compares the battery voltage with a preset reference voltage. In a device that performs on/off switching control of the field winding current, the controller includes a means for measuring and holding the on-state duration time of the field winding current of the generator, and a means for measuring and holding the on-state duration time of the current on-state current. means for detecting that a predetermined period of time has become longer than the duration of the engine, means for temporarily forcibly switching off the field winding current of the generator at the time of detection, and detecting an operating state in which the output torque of the engine is high. A control method for an engine-driven generator, comprising means for canceling forced switching to field winding current of the generator upon detection thereof. 2. The first device is characterized in that the means for detecting an operating state in which the output torque of the engine is high is to detect that the rotational speed of the engine is higher than a certain level.
A control method for an engine-driven generator as described in Section 1. 3. The engine drive according to item 1 above, characterized in that the means for detecting the operating state in which the output torque of the engine is high is to detect that the rotational speed of the generator is higher than a certain level. Generator control method. 4. The engine drive according to item 1 above, characterized in that the means for detecting an operating state in which the output torque of the engine is high is to detect that the throttle opening of the engine is greater than a certain level. Generator control method. 5. The description of item 1 above, wherein the means for detecting the operating state in which the engine output torque is high is configured to detect that the negative pressure on the intake manifold side of the engine is higher than a certain level. A control method for engine-driven generators.