JPS61251434A - 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 system for an engine-driven generator that controls switching of the generated voltage of the generator driven by the engine.

In general, when it comes to automobiles, as shown in Figure 2,
A battery 1 and a generator 3 driven by an engine 2 are connected in parallel to an electric load 4, and the generated voltage of the 1 generator 3 can be sufficiently supplied for charging the battery 1 and the capacity of the electric load 4. Usually, a predetermined voltage of the battery 1 (for example, 14.5V) is specified so that the voltage is 14.5V. Therefore, the power generated by the generator 3 changes depending on the usage status of the electric load, and the load on the engine 2 that drives the generator 3 changes in proportion to it, but if the capacity of the electric load 4 is small and the engine When the engine 2 of the generator 3 is in an operating state other than deceleration, the generated voltage of the generator 3 is lowered to the charging voltage of the battery l (for example, 12.5V), and the engine 2 of the generator 3 is activated.
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.
As the power generation voltage increases, the amount of power generation increases and the battery charging speed increases. Utilizing this characteristic, if power is generated at a lower voltage during light and heavy loads, which is the normal state, the charging current will be reduced, which will lighten the engine load and reduce the engine load. Become. Also.

When the electrical load becomes heavy, by switching the power generation voltage to a higher value to increase the amount of generated ffi, it becomes 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 a generator is switched to the high power generation side that generates a higher amount of power, at the beginning of the switch, the ion concentration in the battery electrolyte is adjusted to the higher power generation voltage based on the difference in the reference power generation voltage. The on-time period of the current becomes longer, and the amount of power generated by the generator rapidly increases during the time it takes to recover to an equilibrium state, resulting in a sudden drop in engine speed, impairing the drivability of the vehicle.

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 is not 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, the present invention has a comparator which is connected in parallel to the battery so that the battery voltage becomes a reference voltage under the control of a controller according to the 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 setting a reference voltage in a comparator by increasing it or switching it to a lower value depending on the electrical load or the operating state of the engine; means for detecting, means for forcibly switching the field winding current of the generator to the OFF side during a preset second period at the time of the detection, and said first period in accordance with the setting state of the reference voltage. The purpose is to take measures to change the situation.

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.
(e.g. 12.5V) Comparator CMP
I, a comparator CMP2.I, which also compares the battery voltage v6 with a reference voltage Vs2 (for example, 14.5V) set higher. AND gate Gl which takes an AND between the negation signal of control signal C8 for switching the generator 3 between the large power generation side and the small power generation side and the output signal of comparator CMPI; control signal C8 and comparator CMP2;
AND gate G2. performs AND with the output signal of G2. Each of them and Kate G1. A comparison section A consisting of an OR gate G3 that takes the OR of the output signal of G2, and a switching element SW that reads the output signal of the comparison section A and controls the current flowing through the field coil FC in the generator 3 are turned on and off. It is composed of a controller section B and a controller section B. Note that the control signal CS is sent to the controller section B.
This is an on/off signal for the switching element SW output from the switching element SW.

In a device configured in this way, conventionally, when the battery voltage V, for example, changes as shown in FIG. The switching element SW is configured such that the battery voltage Vδ is maintained at a predetermined reference voltage Vs at
The switch is turned on and off as appropriate, as shown in the figure.

In comparison section A, when the control signal C5 is at low level 11L11, which is the switching signal for the small power generation side, the lower reference voltage Vsl on the comparator CMPI side is set, and the control signal C8 is the switching signal for the large power generation side. When the signal is at a high level ``H'', the comparator CM
The higher base voltage Vs2 on the P2 side is set. Further, when VB < Vs 1 or VB2, the output signal of the comparator A becomes a high level ''Hn, giving a field winding conduction command to the controller B, and vP, ≧Vsl or Vs 2. When , the output signal of comparator A is low level.
L'', ? is designed to give a field winding cutoff command to the controller section B.

However, if the switching element SW is simply turned on and off according to the output signal of the comparator A, the switching element SW will turn off and the generator 3 will switch to the small power generation side as shown in FIG. For example, if a large electrical load 4 such as a near conditioner is turned on at the time tl, the electrical load increases and the generator 3 is switched to the large charging side until the voltage reaches the reference voltage Vs2 at the time t2. It takes a long time.

At that time, as shown in FIG. 5, the amount of power generated by the generator 3 also increases rapidly in response to the inrush current when the electric load 40 is turned on, and accordingly, the engine speed Ne also decreases rapidly, causing the engine 2
When the idle up control is performed, the response time Tup until the engine speed Ne rises to a predetermined value becomes long. that time.

In particular, since the comparison section A is switched to the higher reference voltage Vs2, the load fluctuation applied to the engine 2 becomes large.

Therefore, in the present invention, particularly in the controller 1-roller section B, there is provided a means for detecting that the on state of the switching element SW has continued for a preset predetermined period of time, and a means for temporarily forcibly turning off the switching element SW upon detection. and,
Means is provided for changing the predetermined time or the forced off time in accordance with the setting state of the reference voltage which is switched to a higher or lower value in the comparison section A.

FIG. 6 shows an example of the configuration of the controller section B in such a case, and includes an on-delay type timer (delay time tα) 5 triggered by the on/off signal S2 of the switching element SW output from the output terminal 9UT. , a one-shot timer (set time tc) 6 triggered by the timer output S3, an AND circuit that takes the logical product of the negative signal of the timer output S4 and the comparator output signal S1 input from the input terminal IN. It consists of

FIG. 7 shows a time chart of various signals.

Therefore, in the device configured in this way, as shown in FIG. 8, for example, a large electrical load is applied at time point 11, and the battery voltage vB recovers from the lower reference voltage Vsl to the higher reference voltage Vs2. If it takes a relatively long time Ton to reach time t2, then the ON time of the switching element SW becomes longer than the set time tα of the timer 5.

When 11 hours have elapsed from point 11, timers 5 and 6 are activated to force off the tc period.

FIG. 9 shows a specific example of the circuit configuration of the comparator section B.

Now, with the relationship shown in FIG. 8, the reference voltage Vs at time 11
The period T during which the battery voltage Vβ, which has decreased below l, turns on the switching element SW and reaches the reference voltage Vs2.
Depending on the waiting time tα and tc during the on period, various methods can be considered as follows when forced off.

First, the first method is to set the tc waiting time constant and then
When the ON command for the switching element SW is issued from the comparison section A, as long as a higher reference voltage Vs2 is set in the comparison section A, the generator is shortened by 11 hours and increases the ratio of the forced off period as a whole. 3 JI! Suppress the amount of electricity.

In this case, as shown in FIG.
becomes a discharge state and reaches a high level ``H'', Rp
It enters a gradually charging state with the time constant of r Cp, but the control signal C sent to the SG terminal of controller section B
When the negative signal 1 of 8 is at the low level "Ln", the charging start voltage starts from almost the ground potential, but when the negative signal 1 is at the high level ttHrr, it starts from the initial voltage due to the Zener voltage of the Zener diode ZD. The potential of the capacitor cp, at which charging begins, is taken out via the operational amplifier, and the comparator CMP in the circuit configuration shown in FIG.
It may be added as the reference voltage value of No. 3. In this case, as the reference voltage value of the comparator CMP4 in the circuit configuration of FIG. 9, a potential at a resistance division point as shown in FIG. 11 may be added.

Also, as a second method, after keeping the 11 hours constant,
When a command to turn on the switching element SW is issued from comparison section A, as long as a higher reference voltage Vs2 is set in comparison section A, the tc waiting time will be longer and the ratio of the forced off period will be increased as a whole to generate power. The amount of power generated by machine 3 is suppressed.

In this case, as shown in FIG. 12, when the output signal S1 of the comparator section A sent to the input terminal IN of the controller section B becomes a low level "L", the capacitor C
p' supplies an initial voltage determined by the presence or absence of a voltage drop due to the Zener voltage of the Zener diode ZD to the capacitor CP', and at the same time the capacitor CP' reaches a high level 'H', the capacitor CP' discharges gradually with the time constant of the resistor RP'. state.

The voltage drop due to Zener diode ZD is in controller part B.
Negation signal of control signal C8 sent to SG terminal of ? The Zener voltage drop becomes zero when r becomes a low level "L"', and becomes present when it becomes a high level II HIF.In this case, the reference voltage value of the comparator CMP3 in the circuit configuration of FIG. In this case, a potential at a resistance dividing point as shown in FIG. 11 may be applied.

As a third method, after keeping the tc waiting time constant,
Even if a command to turn on the switching element SW is issued from the comparison section A, when the comparison section A switches from the lower reference voltage Vsl to the higher reference voltage Vs2, the time is shortened by 10 hours. I'll do what I want.

In this case, as shown in FIG. 13, when the output signal Sl of the comparator section A sent to the input terminal IN of the controller section B is at a low level "L", the negative signal of the control signal C8 is ?3. Except when switching from high level II HII to low level ``L'''', the initial value due to the zener voltage of the zener diode ZD is applied to the capacitor Cp, and the output signal S1 is at the high level 118 #
When it reaches l, it enters a charging state with a time constant determined by RP z CP. On the other hand, when the signal 1 switches from a high level "HIT" to a low level It L II, the initial value of Cp is lowered to almost the ground potential.The potential of the capacitor Cp in this RC timer circuit is taken out via an operational amplifier. The comparator CMP3 in the circuit configuration shown in FIG.
It may be added as a reference voltage value.

Also, as a fourth method, after fixing 10 hours,
Even if a command to turn on the switching element SW is issued from the comparator A, the tc waiting time is lengthened when the comparator A switches from the lower reference voltage Vsl to the higher reference voltage Vs2. 1 Rub.

In this case, as shown in FIG. 14, when the output signal S1 of the comparator section A sent to the input terminal IN of the controller section B is at a low level "L", the negation signal CI of the control signal C8 is Except when switching, the capacitor Cp' supplies the initial voltage due to the Zener voltage of the Zener diode ZD to the capacitor Cp', and when Sl reaches the high level ゛H'°, the capacitor Cp' is gradually discharged with a time constant determined by CP' t RP'. On the other hand, when the signal switches from high level It HII to low level 11 L 71, the initial value of Cp' is lowered to approximately +V c' c. Calculate the potential of capacitor Cp' in this PC timer circuit. It may be taken out via an amplifier and added as the reference voltage value of the comparator CMP4 in the circuit configuration of FIG.

In this way, in the present invention, when the battery voltage decreases and the field winding current of the generator 3 remains on for a long time, the power generation amount of the generator 3 is temporarily forcibly suppressed, and the load on the engine is suddenly increased. As shown in Fig. 15, even if a large electrical load 4 is applied, the power output 11ffi of the generator 3 increases rapidly as in the conventional case. Things will go away. As a result, the load on the engine is lightened, the engine speed Ne does not drop sharply and greatly, and the response time Tuρ' until the engine speed Ne rises to a predetermined level when controlling the engine idle up is shortened. This allows the engine to idle up with good responsiveness, and the drivability of the vehicle is not impaired.

In the control system for the engine-driven generator according to the present invention, the battery voltage is increased and lowered according to the switching control of the power generation amount in the generator, so that the battery voltage reaches the set reference voltage. When performing on/off switching control of the field winding energization, it is possible to effectively prevent a sudden load on the engine when a large electrical load is applied and the generator is switched to the large power generation side. It has the great advantage of being able to

[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. Fig. 6 is a block diagram showing an example of the configuration of the controller. , Fig. 7 is a time chart of various signals in the controller, Fig. 8 is a characteristic diagram showing the on/off state of the switching element in the control method of the present invention with respect to changes in battery voltage, and Fig. 9 is a specific diagram of the controller. 10 to 14 are electrical wiring diagrams showing an example of the reference voltage setting circuit of each comparator in the circuit configuration of FIG. 9, and FIG. 15 is an electrical wiring diagram showing an example of the circuit configuration of the present invention. Time chart 1 showing the characteristics of the on/off state of the switching element, the application state of the electrical load, the amount of power generated by the generator, and the engine speed depending on the control method.
− is.

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. The field winding current is controlled to be switched on and off, and the reference voltage in the comparator is increased depending on the electrical load or engine operating condition, and the reference voltage is switched to a lower value. means for detecting that the on state of the winding current continues for a preset first period; and upon detection, forcibly turning off the field winding current of the generator for a preset second period. 1. A control method for an engine-driven generator, comprising: means for switching to the side, and means for changing the first period according to a setting state of a reference voltage. 2. The engine generator control system according to item 1 above, characterized in that the first period is shortened when the reference voltage is set high. 3. When the reference voltage is switched from low to high,
2. The engine generator control system according to item 1 above, characterized in that the first period is shortened. 4. Compare the battery voltage with a preset reference voltage. According to the output signal of the comparator, adjust the field winding current of the generator connected in parallel to the battery so that the battery voltage becomes the reference voltage under the control of the controller. A means for performing on/off switching control, including a means for setting the field winding current of the reference voltage in a comparator by switching it to a higher or lower value according to the on/off switching, and switching on the large power generation side in the generator. means for detecting that the condition has continued for a preset first period; means for forcibly switching the power generation amount of the generator to the small power generation side for a preset second period upon detection; and a reference. A control method for an engine-driven generator, comprising means for lengthening the second period depending on a voltage setting state. 5. The engine generator control system according to item 4 above, characterized in that the second period is lengthened when the reference voltage is set high. 6. When the reference voltage is switched from low to high,
4. The engine generator control system according to item 4, characterized in that the second period is lengthened.