JPH03218300A - Control method and device for engine generator - Google Patents

Abstract

PURPOSE:To stabilize terminal voltage of a load by setting a first voltage V1 and a second voltage V2 higher than the first voltage and controlling the number of revolution of an internal-combustion engine so that the generated voltage V0=V1 or V0=V2 only if V0<V1 or V0>V2. CONSTITUTION:An actuator 4 is driven by a battery 5 to feed fuel to an internal-combustion engine 2 thus rotating a generator 1 and feeding power to a load 3. Number of revolution of the internal-combustion engine 2 is detected and subjected to frequency/voltage conversion through a speed detecting circuit 8 thus producing a voltage Vn. On the other hand, output voltage ET from the generator 1 is inputted to a speed setting circuit 9 thus producing a speed setting signal Vno. A difference detecting circuit 10 determines the difference Vd between an actual speed signal Vn and the set speed signal Vno, then an operation is carried to produce a signal Vb for bringing the difference Vd to zero and the actuator 4 is controlled through an actuator drive circuit 6. The speed setting circuit 9 controls the rotational speed so that the output voltage Et will be between set voltages V1 and V2. By such method, terminal voltage of the load 3 is kept at an appropriate level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for controlling a motor generator and a control device used to carry out the method.

[Prior Art] In a motor generator that generates electricity by driving a generator with an internal combustion engine, the generator is a self-excited field magnet equipped with a self-excited field magnet on the rotor side, as shown in Fig. 6. Rotating alternating current generators are often used.

In Fig. 6, W{ is a field winding wound around the rotor core K, D is a diode connected to both ends of the field winding, and Wc
is a capacitor excitation winding with capacitor C connected to both ends, WL is an output winding with load L connected, and capacitor excitation winding Wc and output winding WL are connected to the stator core at an electrical angle of 90 degrees. It is wound with a phase difference.

In the above generator, a voltage is first induced in the capacitor excitation winding Wc by the residual magnetism of the rotor core K, and as a result, a phase-advanced current Ic flows through the capacitor excitation winding Wc.

A self-excitation phenomenon occurs due to the magnetizing action of this advanced phase current Ic, and at the same time, a field reverse phase electromotive force generated in the field winding W1 due to the armature reaction of the capacitor excitation winding Wc causes the field winding W1 to be connected to the diode D. Field current ■1 flows through.

Therefore, the rotor core K is further excited and the voltages of the output winding Wf and the capacitor excitation winding WC are established.

4 In addition, in a motor generator, the output frequency is constant (usually 5 Q
A control device is provided to maintain the rotational speed of the internal combustion engine at a set speed by controlling the amount of fuel supplied to the internal combustion engine.

[Problems to be Solved by the Invention] In the above-mentioned generator, when a load L is connected to the output winding WL, the field reverse phase electromotive force increases due to the synthetic armature reaction of the load current IL and the advanced phase current Ic, As a result, the field current If increases, so the voltage drop in the output winding due to the load is suppressed, and the voltage fluctuation rate is kept low.

However, if the load L is a capacitive load such as a mercury lamp,
Since the phase-advanced current Ic' flows through the output winding WL and increases the field reverse phase electromotive force due to the combined armature reaction, there is a risk that the terminal voltage El of the load will abnormally increase, causing an accident such as damage to the load. there were.

As a countermeasure against this problem, an overcurrent protection device such as a play force or a protector is connected to the output winding WL. However, this overcurrent protection device
Since the field current flowing through the rectifier D is not considered at all, the large field current I
If f continues to flow and this field current exceeds the maximum forward current of the diode D, there is a problem that the diode D will be damaged.

An object of the present invention is to provide a method for controlling a motor generator that can prevent an abnormal increase in output voltage when a capacitive load is connected to an output winding, and a method for controlling a motor generator to be used for carrying out the method. The purpose is to provide a control device.

[Means for Solving the Problems] The first invention of the present application is directed to the amount of fuel supplied to the internal combustion engine of a motor generator consisting of an internal combustion engine and a self-excited field rotation type generator driven by the internal combustion engine. The present invention relates to a method for controlling a motor generator, which controls the rotational speed of the internal combustion engine by controlling the output of the generator.

In the present invention, a first set voltage and a second set voltage higher than the first set voltage are set, and when the output voltage of the generator is equal to or lower than the first set voltage, the output of the generator is set. The rotational speed of the internal combustion engine is controlled to keep the voltage at the first set voltage, and when the output voltage of the generator is higher than the first set voltage and lower than the second set voltage, the output frequency of the generator is set to the set value. The rotational speed of the internal combustion engine is controlled to maintain the rotational speed of the internal combustion engine.

Further, when the output voltage of the generator is equal to or higher than the second set voltage, the rotational speed of the internal combustion engine is controlled so as to maintain the output voltage of the generator at the second set voltage.

A second invention of the present application includes an actuator that adjusts the amount of fuel supplied to an internal combustion engine that drives a self-excited field rotary generator, and a speed detection circuit that detects the rotational speed of the internal combustion engine and outputs a speed detection signal. a speed setting circuit that outputs a speed setting signal indicating the set speed of the internal combustion engine, and a speed deviation signal that receives the speed detection signal and the speed setting signal as input and outputs a speed deviation signal that indicates the deviation between the rotational speed of the internal combustion engine and the set speed. It includes a speed deviation detection circuit, an arithmetic circuit that calculates the actuator operation amount necessary to make the deviation zero, and an actuator drive circuit that provides a drive signal to the actuator based on the operation amount calculated by the arithmetic circuit. This invention relates to an apparatus for carrying out the method of the first invention.

In the present invention, the speed setting circuit includes an output voltage detection circuit that detects the output voltage of the generator and outputs a voltage detection signal, and a first voltage setting signal corresponding to the first setting voltage of the generator. A first voltage setting circuit outputs a first voltage setting circuit, a second voltage setting circuit outputs a second voltage setting signal corresponding to a second setting voltage larger than the first setting voltage, and sets an output frequency of the generator. a specified speed signal output circuit that outputs a specified speed signal that gives a specified rotational speed of the internal combustion engine necessary to equalize the specified speed; a first deviation calculation circuit that outputs a first deviation signal corresponding to the difference between the voltage setting signal and the voltage detection signal plus the specified speed signal; and a voltage detection signal, a second voltage setting signal, and the specified speed signal. a second deviation calculation circuit which receives the speed signal as an input and outputs a second deviation signal corresponding to the difference between the second voltage setting signal and the voltage detection signal plus the prescribed speed signal; When the voltage is less than or equal to the first voltage setting signal, a signal with a size corresponding to the first deviation number is output as the speed setting signal, and the voltage detection signal is thicker than the first voltage setting signal (than the second voltage setting signal). When the voltage detection signal is smaller than the second voltage setting signal, the specified speed signal is output as the speed setting signal, and when the voltage detection signal is equal to or higher than the second voltage setting signal, a signal smaller than the specified speed signal or a signal of a size corresponding to the second deviation signal is output as the speed setting signal. The present invention is characterized in that it includes a speed setting signal output circuit that outputs a setting signal.

1 action" As described above, the first set voltage and the second set voltage are set, and only when the output voltage of the generator is higher than the first set voltage and lower than the second set voltage, The rotational speed of the internal combustion engine is controlled to maintain the output frequency of the generator at a set value, and the output voltage is adjusted when the output voltage of the generator is below a first set voltage and when it is above a second set voltage. If the rotational speed of the internal combustion engine is controlled to maintain the first set voltage and the second set voltage, the amount of fuel supplied to the internal combustion engine will change when the terminal voltage of the load attempts to abnormally increase due to the connection of a capacitive load. is reduced to suppress the rotational speed of the generator and limit the output voltage of the generator to the second set voltage. Therefore, it is possible to prevent an abnormal increase in the output voltage of the generator and an increase in the field current, and it is possible to protect the load and the diodes provided in the rotor.

[Example] Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an apparatus for carrying out the method of the present invention. In the figure, 1 is a self-excited field rotating alternating current generator as shown in FIG. An internal combustion engine drives the generator, and 3 is a load connected to the output winding of the generator 1. Reference numeral 4 denotes an actuator for operating a fuel supply amount adjusting means for adjusting the amount of fuel supplied to the internal combustion engine, and this actuator is normally driven by an electromagnet or an electric motor. In this example, a battery 5 is used as a power source for the actuator, and the drive current supplied from the battery 5 to the actuator 4 is controlled on/off by an actuator drive circuit 6 comprising a transistor switch or the like.

A rotation sensor 7 detects the rotation of the internal combustion engine 2 and generates a speed detection signal having a frequency proportional to the rotation speed of the internal combustion engine. The output signal of the rotation sensor is input to the speed detection circuit 8. The speed detection circuit 8 is composed of a frequency/voltage conversion circuit, and outputs a voltage proportional to the frequency of the output signal of the rotation sensor (proportional to the rotational speed of the internal combustion engine). As the rotation sensor, a signal generator attached to the internal combustion engine may be used. Also, if the internal combustion engine is a gasoline engine and is equipped with an ignition device, one of the ignition coils in the ignition device may be used. The secondary coil may be used as a rotation sensor, and a pulsed voltage induced on the primary side of the ignition coil at each ignition timing may be used as a speed detection signal.

The speed detection signal Vn11 obtained from the speed detection circuit 8 is input to the deviation detection circuit 10 together with the speed setting signal Vno obtained from the speed setting circuit 9. The deviation detection circuit 10 determines the deviation between the speed detection signal Vn and the speed setting signal Vno, and outputs a speed deviation signal Vd (-Vn - Vno) indicating the deviation between the actual rotational speed of the internal combustion engine and the set speed. This speed deviation signal is input to the arithmetic circuit 11-. The calculation circuit 11 calculates the operation amount of the actuator 4 necessary to make the speed deviation zero, and generates an operation signal v corresponding to the operation amount.
b and gives the operation signal vb to the actuator drive circuit 6. The actuator drive circuit 6 provides a drive signal to the actuator 4 to operate the actuator 4 by the calculated operation amount.

In the conventional motor generator control device, the speed setting circuit 9 outputs a constant speed setting signal, but in the control device implementing the method of the present invention, the speed setting circuit 9 outputs a constant speed setting signal. A voltage detection signal corresponding to the output voltage El is input, and a speed setting signal that differs depending on the output voltage of the generator is output.

That is, the speed setting circuit 9 generates a speed setting signal Vno of a magnitude necessary to maintain the output voltage of the generator at the first setting voltage when the output voltage 2 of the generator becomes lower than the first setting voltage. and when the output voltage of the generator is in a range higher than the first set voltage and lower than the second set voltage, a speed setting signal Vno of a magnitude necessary to maintain the output frequency of the generator at the set value is output. Output. Further, when the output voltage of the generator becomes equal to or higher than the second set voltage, a speed setting signal Vno of a magnitude necessary to maintain the output voltage of the generator at the second set voltage is output.

Referring to FIG. 2, an example of the configuration of the speed setting circuit 9 is shown. This speed setting circuit 9 includes a generator output voltage detection circuit 1.2, a first voltage setting circuit 13, a second voltage setting circuit 14, a specified speed signal output circuit]-5, and a first voltage setting circuit 1.2.
It consists of a deviation calculation circuit 16 and a second deviation calculation circuit 17, a first integration circuit 18 and a second integration circuit 19, and a first setting signal switching circuit 20 and a second setting signal switching circuit 21. ing.

The generator output voltage detection circuit 12 includes a voltage dividing circuit connected to both ends of the output winding, and detects the voltage Et at both ends of the output winding of the generator and outputs a voltage detection signal et.

The first voltage setting circuit 13 is constituted by a voltage dividing circuit including resistors R1 and R2, and divides the output voltage Ed of a DC constant voltage power supply (not shown) to set the first set voltage El of the generator.
A first voltage setting signal all corresponding to f is output.

The second voltage setting circuit 14 is constituted by a voltage dividing circuit consisting of resistors R3 and R4, and divides the voltage Ed of the DC power supply to generate a second set voltage El2 corresponding to a second set voltage El2 which is larger than the first set voltage. A voltage setting signal et2 is output.

The specified speed signal output circuit 15 is constituted by a voltage dividing circuit consisting of resistors R5 and R6, and divides the DC voltage Ed to provide the specified rotational speed of the internal combustion engine necessary to equalize the output frequency of the generator to the set value. Outputs the specified speed signal eno. The output terminal of this specified speed signal output circuit is directly connected to the output terminal to of the speed setting circuit.

The first deviation calculation circuit 16 includes an operational amplifier OP1 and a resistor R.
7 to R12, and inputs the voltage detection signal et, the first voltage setting signal etl, and the specified speed signal eno, and outputs the first voltage setting signal et1 and the voltage detection signal et1.
A first deviation signal ep [=Kp(e+1+eno-e+)] corresponding to the difference between the two and the specified speed signal eno
(However, Kp is a proportionality constant).

The second deviation calculation circuit 17 includes an operational amplifier OP2 and a resistor R.
13 to R18, and a voltage detection signal et
A second deviation signal e corresponding to the difference between the second voltage setting signal and the voltage detection signal plus the specified speed signal is obtained by inputting the second voltage setting signal et2 and the specified speed signal eno.
Outputs q[-Kq(e j2+e noej)] (where Kq is a proportionality constant).

The first integrating circuit 18 includes a resistor R20 and a capacitor C1, and integrates the first deviation signal ep to produce a signal ei.
Output l.

The second integration circuit 19 includes a resistor R21 and a capacitor C2, and integrates the second deviation signal eq to output a signal ei2.

The first setting signal switching circuit 20 includes an operational amplifier OP3 and a diode D1 whose anode is connected to the output terminal of the amplifier.
The cathode of the diode D1 is connected to the output terminal to of the speed setting circuit. A signal ei obtained by integrating the first deviation signal into the positive phase input terminal of the operational amplifier OP3
l is input, and a specified speed signal eno is input to the negative phase input terminal.

In this first setting signal switching circuit 20, when the voltage detection signal et is less than or equal to the first voltage setting signal elf (the output voltage is less than or equal to the first setting voltage), the signal eil obtained by integrating the first deviation signal ep is When is equal to or higher than the specified speed signal eno, the diode D1 becomes conductive and outputs the signal eil to the output terminal to. That is, at this time, a signal eil corresponding to the first deviation signal ep is output as the speed setting signal Vno.

When the voltage detection signal e1 is larger than the first voltage setting signal eft and the signal eil is smaller than the specified speed signal eno, the diode DI becomes non-conductive and the output 16 of the signal eil is stopped.

The second setting signal switching circuit 20 includes an operational amplifier OP4,
It consists of a diode D2 whose anode is connected to the output terminal of the operational amplifier OP4, and the cathode of the diode D2 is directly connected to the output terminal to of the speed setting circuit. A signal ei2 obtained by integrating the second deviation signal eq is input to the positive phase input terminal of the operational amplifier OP4, and a specified speed signal eno is input to the negative phase input terminal.

In this second setting signal switching circuit, the voltage detection signal el is equal to or higher than the second voltage setting signal et2 (the output voltage is equal to or higher than the second set voltage), and the signal ei2 obtained by integrating the second deviation signal eq is When the speed signal eno is equal to or lower than the specified speed signal eno, the diode D2 becomes conductive to lower the potential of the output terminal to. As a result, the speed setting signal Vno decreases, working to decrease the rotational speed of the engine. Voltage detection signal et
is smaller than the second voltage setting signal et2 (the output voltage is lower than the second setting voltage), and the signal ei2 obtained by integrating the second deviation signal eq is larger than the specified speed signal eno, the diode D2 becomes non-conductive.

In this embodiment, the first and second setting signal switching circuits 20
and 21, when the voltage detection signal et is equal to or less than the first voltage setting signal etl, a signal having a magnitude corresponding to the first deviation signal ep is outputted as the speed setting signal Vno, and the voltage detection signal et becomes the first voltage setting signal etl. The voltage setting signal etl is larger than the second voltage setting signal etl.
When the voltage detection signal et is smaller than the second voltage setting signal el2, the specified speed signal eno is output as the speed setting signal Vno, and when the voltage detection signal et is equal to or higher than the second voltage setting signal et2, a signal smaller than the specified speed signal eno is output as the speed setting signal. A speed setting signal output circuit is configured to output the speed setting signal.

In this embodiment, the characteristics of the speed detection circuit 8 for detecting the rotational speed N of the internal combustion engine are as shown in FIG. 3, and the speed detection signal Vn changes linearly with the rotational speed N.

Further, the output characteristics of the generator are as shown in FIG. 4, and the output voltage El of the generator increases almost linearly as the rotational speed N increases.

The load characteristics of the generator are as shown in Figure 5, and the output voltage Et
decreases as the load current increases. In this embodiment, the range between the first set voltage Ell and the second set voltage El2 is set as the permissible voltage fluctuation range.

In the above embodiment, when the output voltage of the generator becomes equal to or less than the first set voltage and the voltage detection signal et becomes equal to or less than the first voltage set signal all, the signal eil obtained by integrating the first deviation signal ep becomes the specified value. When the speed signal exceeds eno, the potential at the output terminal of the operational amplifier OP3 rises to the level of the signal eil, so the diode D1 becomes conductive and the signal e is output to the output terminal to.
il is output.

At this time, a signal eil corresponding to the first deviation signal ep is output as the speed setting signal Vno. As a result, the rotational speed of the internal combustion engine is controlled so as to maintain the output voltage of the generator at the first set voltage Ell.

When the output voltage El of the generator is higher than the first set voltage Et1 and lower than the second set voltage El2, the potential of the output terminal of the operational amplifier OP3 decreases to approximately the ground potential, and the operational amplifier OP319 Since the potential at the output terminal of diodes D1 and D2 rise to the level of signal ei2, both diodes D1 and D2 are in a non-conducting state. At this time, the specified speed signal eno is output as the speed setting signal Vno. As a result, the rotational speed of the internal combustion engine is controlled to be maintained at a specified speed, and the output frequency of the generator is maintained constant. The output voltage of the generator varies depending on the load.
The set voltage Elf varies between the set voltage Elf and the second set voltage El2.

When the output voltage Et of the generator becomes equal to or higher than the second set voltage El2 and the voltage detection signal ej becomes equal to or higher than the second voltage set signal el2, the potential of the output terminal of the operational amplifier OP4 decreases to approximately the ground potential. Diode D2 becomes conductive and lowers the potential at output terminal to. As a result, the speed setting signal Vno decreases, so the rotational speed of the internal combustion engine decreases. As a result, when the output voltage of the generator becomes lower than the second set voltage, the speed setting signal changes to the specified speed signal en.
o, the rotational speed of the internal combustion engine is kept at a specified speed, and the output frequency of the generator is kept constant.

In the above embodiment, when the output voltage of the generator exceeds the second 20 set voltage, the speed setting signal Vno is set to be a signal lower than the specified speed signal eno. When the voltage exceeds the set voltage, a signal ei2 having a magnitude corresponding to the second deviation signal eq may be outputted as the speed setting signal.

[Effects of the Invention] As described above, according to the present invention, the first set voltage and the second set voltage
and a set voltage of the internal combustion engine to maintain the output frequency of the generator at the set value only when the output voltage of the generator is higher than the first set voltage and lower than the second set voltage. of the internal combustion engine so as to maintain the output voltage at the first set voltage and the second set voltage when the output voltage of the generator is below the first set voltage and when it is above the second set voltage, respectively. Since the rotational speed is controlled, when the terminal voltage of the load is about to rise abnormally due to the connection of the capacitive load, the rotational speed of the internal combustion engine can be reduced to suppress the increase in the output voltage. Therefore, it is possible to prevent an abnormal increase in the output voltage of the generator and an excessive increase in the field current.
It is possible to protect the load and the diodes provided in the rotor.

Furthermore, when the output voltage becomes lower than the first set voltage due to an increase in the load, the rotation speed of the internal combustion engine can be increased and the output voltage of the generator can be increased. can be prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a configuration example of a control device that implements the method of the present invention, FIG. 2 is a circuit diagram showing a configuration example of a speed setting circuit used in the control device of the present invention, and FIGS. 5
The figures are diagrams showing the characteristics of the speed detection circuit, the output voltage versus speed characteristics of the generator, and the load characteristics of the generator, respectively, used in the embodiment of the present invention. Figure 6 is an example of the configuration of the generator controlled by the present invention. FIG. 1-... Generator, 2... Internal combustion engine, 3... Load,
4...Actuator, 5...Battery, 6...
Actuator drive circuit, 7... rotation sensor, 8...
- Speed detection circuit, 9... Speed setting circuit, 10... Deviation detection circuit, 11... Arithmetic circuit, 12... Output voltage detection circuit, 13... First voltage setting circuit, 14.・・・
2nd voltage setting circuit, 1-5... Specified speed signal output circuit, 16... First deviation calculation circuit, 17... Second deviation calculation circuit, 18... First integration circuit , 19...
Second integration circuit, 20...first setting signal switching circuit,
21... Second setting signal switching circuit, K... Rotor core, W1... Field winding, D... Diode, Wc...
...Capacitor excitation winding, C...Capacitor, WL.
...Output winding.

Claims (2)

[Claims] (1) The rotational speed of the internal combustion engine is controlled by controlling the amount of fuel supplied to the internal combustion engine of a motor generator consisting of an internal combustion engine and a self-excited field rotation type generator driven by the internal combustion engine. In a method of controlling a motor generator, the output of the generator is controlled by setting a first set voltage and a second set voltage higher than the first set voltage, and controlling the output of the generator. The rotational speed of the internal combustion engine is controlled to keep the output voltage of the generator at the first setting voltage when the voltage is below the first setting voltage, and the output voltage of the generator is set to the first setting voltage. When the output voltage of the generator is higher than the second set voltage and lower than the second set voltage, the rotational speed of the internal combustion engine is controlled to keep the output frequency of the generator at the set value, and when the output voltage of the generator is equal to or higher than the second set voltage. A method for controlling a motor generator, comprising controlling the rotational speed of the internal combustion engine so as to maintain the output voltage of the generator at the second set voltage. (2) an actuator for adjusting the amount of fuel supplied to the internal combustion engine of a motor generator consisting of an internal combustion engine and a self-excited field rotation type generator driven by the internal combustion engine; and a rotational speed of the internal combustion engine. a speed detection circuit that detects and outputs a speed detection signal, a speed setting circuit that outputs a speed setting signal indicating a set speed of the internal combustion engine, and a speed setting circuit that receives the speed detection signal and the speed setting signal as input and controls the rotation of the internal combustion engine. a speed deviation detection circuit that outputs a speed deviation signal indicating the deviation between the speed and the set speed; a calculation circuit that calculates the operating amount of the actuator necessary to make the deviation zero; In a motor generator control device comprising: an actuator drive circuit that provides a drive signal to the actuator based on a manipulated variable, the speed setting circuit has an output that detects the output voltage of the generator and outputs a voltage detection signal. a voltage detection circuit; a first voltage setting circuit that outputs a first voltage setting signal corresponding to a first setting voltage of the generator; and a second voltage setting circuit that outputs a second setting voltage that is larger than the first setting voltage. a second voltage setting circuit that outputs a second voltage setting signal that provides a specified rotational speed of the internal combustion engine necessary to make the output frequency of the generator equal to the set value; a speed signal output circuit, which receives the voltage detection signal, the first voltage setting signal, and the specified speed signal as input, and corresponds to the difference between the first voltage setting signal and the voltage detection signal plus the specified speed signal. a first deviation calculation circuit that outputs a first deviation signal; and a first deviation calculation circuit that receives the voltage detection signal, the second voltage setting signal, and the specified speed signal as input and specifies the difference between the second voltage setting signal and the voltage detection signal. a second deviation calculation circuit that outputs a second deviation signal corresponding to the sum of the speed signal; and a second deviation calculation circuit that outputs a second deviation signal corresponding to the sum of the speed signal; outputting a signal having a magnitude as a speed setting signal, and outputting the prescribed speed signal as the speed setting signal when the voltage detection signal is greater than the first voltage setting signal and smaller than the second voltage setting signal; a speed setting signal output circuit that outputs, as the speed setting signal, a signal smaller than the specified speed signal or a signal having a size corresponding to the second deviation number when the voltage detection signal is equal to or higher than the second voltage setting signal; A control device for a motor generator, comprising: