JP2002529041A - Adjustment of alternator - Google Patents

Abstract

(57) Abstract A method for adjusting an alternator to which a converter bridge is assigned, for example a claw-pole alternator driven by an internal combustion engine, is described. The converter bridge has a controllable switching element, which is controlled by the control logic and is supplied with current at a predetermined time at the alternator terminals, whereby the induction of the alternator is induced. Enhanced. In this case, the current is delivered from the charge accumulator, which is connected to the alternator winding via a switching element at a predetermined time for this purpose.

Description

DETAILED DESCRIPTION OF THE INVENTION

The invention is based on a method for adjusting an alternator, for example a claw-pole type alternator driven by an internal combustion engine, according to the preamble of the independent claim.

2. Description of the Related Art In a vehicle, a claw-pole type alternator is used to prepare electric energy for a vehicle-mounted power supply device. Such a three-phase alternator is connected to the vehicle's DC voltage network via a diode rectifier bridge. Alternator power delivery begins as soon as its induced voltage exceeds the power supply voltage. Alternator power delivery is regulated via field current strength. The adjustment amount for this is usually:
The power supply voltage or the output voltage of the alternator is used.

[0003] In order to reduce fuel consumption, the idle speed of the engine in modern vehicles is kept as low as possible. A small engine speed also affects the alternator speed. This is because the alternator is driven by the engine. The alternator supplies energy even when the alternator rotation speed is low, so that the alternator can still deliver sufficient electrical energy to the on-board power grid even when the engine is running at no load and the battery can be recharged. A request to send should be imposed. In addition, the alternator should deliver as much energy as possible at normal speeds. Therefore, optimal alternator regulation should allow, on the one hand, a normal increase in power and, on the other hand, a reduction in the starting speed (Angehdrehzahl), that is to say the speed at which the alternator can deliver power.

A three-phase alternating current alternator for motor vehicles, which delivers improved output power compared to conventional alternators, is known from EP-A-0 762 596. This three-phase AC alternator has a full-wave controlled rectifier bridge having six controlled switches instead of a conventional rectifier bridge. By appropriately controlling the switches of the bridge, for example, having switchable semiconductor elements, a phase adjustment can be implemented in which the phase voltage of the alternator is shifted relative to the phase current. This results in an additional current flowing through the stator winding, which increases the output power of the three-phase AC alternator compared to a three-phase AC alternator with a simple diode bridge. Become.

Advantages of the invention The method for regulating an alternator according to the invention having the features of claim 1 has the following advantages: the alternator delivers higher output power and Particularly at lower rotational speeds, a higher output power is delivered. It is particularly advantageous that the so-called starting speed of the alternator, ie from which power can be delivered at all, is reduced compared to conventional alternators.

[0006] These advantages are realized with the method according to claim 1. This method can be used because the alternator is assigned a converter bridge with switching elements instead of a conventional diode. With the correct control of these switching elements, the alternator terminal can be connected to the positive or negative pole of the battery, irrespective of the natural firing time of the diode bridge. By appropriate control of the switching elements, additional current can be supplied to the alternator terminals and the power delivered by the alternator can be increased. Such additional current is firstly drawn from a battery or possibly an intermediate circuit capacitor and supplied to the alternator via a switching element. The point in time of supply to the alternator strand is preferably chosen such that this point is in the section where the strand current during the diode operation is low or missing (missing). The alternator power rise due to DC pulsation is associated with enhanced pulsation of the delivered current. This wave nature is combined with alternator delivery current and current pulse extraction. However, with the use of additional capacitors, a smoothing is also advantageously achieved.

Drawings Embodiments of the present invention are shown in FIGS. 1-4 and will be described in detail in the following description.

DESCRIPTION FIG. 1 shows the components of the invention of an alternator, for example a claw-pole alternator 10, together with a converter bridge 11 and a load 12. Symbolically, three stator windings 13, a field winding 14, and a field current Ierr of the claw-pole type alternator 10 are shown. The converter bridge 11 has switching elements 15 to 20 which are connected to the stator winding 13 of the claw-pole alternator 10 in the usual way, as in a diode bridge. The switching elements 15 to 20 are connected to a capacitor 21. The power supply voltage UNez is extracted from the capacitor. Power supply voltage is load 1
2 can be supplied. A battery 21a, such as an on-board power supply battery, can be used instead of a capacitor. For the load 12, only the variable resistor 22 and the switch 23 are shown symbolically.

The method according to the invention for adjusting an alternator is implemented by means of the circuit arrangement shown in FIG. By appropriate control of the switching elements 15 to 20,
Additional current is supplied to the alternator terminal. The switching elements 15 to 20 act as current valves and are also referred to hereinafter as valves. In particular, additional current pulses are applied during an otherwise currentless time interval. These current pulses cause the alternator inductance to be charged by magnetic energy. The supply of the direct current pulse additionally supplies the alternator with inductive reactive power. This reactive power corresponds to the additional magnetizing current.

By providing an additional magnetizing current to the stator winding, the power delivery of the alternator can be increased compared to pure diode operation. In that case, the phases in which the switching elements 15 to 20 of the converter bridge 11 are conducting are shifted as a whole. At this time, a phase shift occurs between the alternator voltage and the alternator current. At that time, the device consumes reactive power. That is, as soon as the phase current in one of the stator windings has a zero crossing (commutation should occur in the case of diode operation), by a corresponding control of one or more switching elements Commutation is delayed. The subsequent connection to the battery is maintained by the switching element which is closed. The switch-on time and the longest switch-on duration of the switching element or switch are determined by the logistics of the valve opening. This time corresponds to the otherwise current-free time region of the strand.

[0011] Adjustment of the switch-off time, that is, the commutation time, is important for alternator power delivery. This deviation between current and voltage can be adjusted according to various methods. Some of such methods which offer special simplicity possibilities for adjustment will be described with reference to the embodiment shown in FIGS. The adjustment described below is configured such that the switching element is controlled only in the so-called missing phase of the current and is switched off as soon as the measured current exceeds a permissible value.

Adjustment of the height of the output voltage of the alternator is typically a voltage which is a component of a claw-pole alternator, for example shown at 10 in FIG. 1, and whose field current can be predetermined. Is performed by using a voltage regulator (regulator) that adjusts the height of the motor.

[0013] 1. FIG. 2 shows an adjustment circuit for a switch or a switching element (valve). With this, the adjustment of the switch current can be described. For this adjustment, the current flowing through the switching element is detected and used for preparation. For example, the current I flowing through the switching element 15 is
And is supplied to the comparator 25 as the actual current value Iist. This comparator 25 is additionally supplied with a maximum value Imax for the current. 2 further comprises an AND gate 26 and a logistic 27 for valve opening, wherein the AND gate 26 interconnects the output of the comparator 25 and the logic 27 for valve opening. Is bound to. A control for a valve with a locking function against re-switching on, for example, controls the valve 15 depending on the output of an AND gate 26.

The upper voltage regulation or power regulation of the alternator is carried out by means of the regulation circuit shown in FIG. 2, whereby the maximum value for the switch current is released (enabled). If the actual current of the switch exceeds this specified value, the valve is shut off. The current is then diverted to the complementary diode of the bridge arm.

For a perfect function, a locked valve lock is required. I mean,
This is because as soon as the current becomes zero after the valve is shut off, the valve is newly connected through (through connection) by a pure current comparison. This function is shown in FIG.
Is realized by the logic circuit shown in FIG.

[0016] 2. Adjustment of the phase current Since the maximum value of the DC current is the same as the maximum value of the phase current, another possibility for adjusting the alternator lies in switching the switches depending on this phase current. For this purpose, instead of the switch current, the currents flowing through the phase windings U, V and W of the alternator are measured and supplied to a regulating unit. An example for such an adjustment circuit is shown in FIG.

In this adjustment, since two switches, for example 15 and 18 of the converter arm, always control one phase, the control is also advantageously integrated in the adjustment unit. Control of the valve is indicated in FIG. 3 by 28a and 28b. As soon as the associated phase current exceeds the maximum value that can be determined in advance, a shut-off point of the valve connected through occurs.

[0018] 3. FIG. 4 shows a further regulation circuit for the switching element or the valve in which the regulation of the direct current IG can be performed. Since the direct current, ie the output current of the alternator, is used for the adjustment, it is only necessary to measure the value supplied to the comparator and compared with the target value. The regulation circuit shown in FIG. 4 corresponds to the circuit of FIG. 2, but instead of the valve current I, the direct current IG of the alternator is the basis for the regulation.

[0019] A combined regulation via DC current and switch current is also realized. In order to reduce the number of current measurements, the valve current can also be derived from the measured direct current.

[Brief description of the drawings]

FIG. 1 is a circuit diagram schematically illustrating a circuit device including an alternator, a converter bridge, and a load.

FIG. 2 is a schematic circuit diagram showing an embodiment of an adjustment circuit for a switching element (a current flowing through the switching element is used).

FIG. 3 is a schematic circuit diagram showing another embodiment (in which phase current is used) of an adjustment circuit for a switching element.

FIG. 4 is a schematic circuit diagram showing still another embodiment (in which a direct current is used) of an adjustment circuit for a switching element.

Claims (9)

[Claims] 1. A method for adjusting an alternator, for example a claw-pole type alternator driven by an internal combustion engine, wherein the alternator is assigned a converter bridge having a controllable switching element, and the switching element is arranged in an adjusting device. Controlling the switching element such that an additional current is supplied to an alternator terminal and the alternator inductance is up-charged by magnetic energy, wherein the energy is taken from a capacitor or a battery. And how. 2. The current supplied is composed of a plurality of current pulses, wherein the time of supply of the current to the alternator winding is the minimum amount that the strand current can be predetermined. The method of claim 1, wherein the method is selected to have. 3. The method according to claim 1, wherein the switching on time and the longest switching on time of at least one switching element of the converter bridge are fixed using a logistic for valve opening. 4. The control of the switching element using a comparison result determined in a comparator, wherein the comparator compares the actual value of the current with a predetermined maximum value. The method for adjusting an alternator according to any one of claims 1 to 3. 5. The method according to claim 4, wherein the actual value is a current flowing through the switching element and measured using the measuring device. 6. The method according to claim 1, wherein the actual value is at least one phase winding of the alternator.
The method for adjusting an alternator according to claim 4, wherein the current is a current flowing through W and measured using a measuring device. 7. The alternator adjustment method according to claim 4, wherein the actual value is a sending current of the alternator measured using a measuring device. 8. A method for adjusting an alternator, characterized in that a combination of the current delivered by the alternator and the current flowing through at least one switch is used as an actual value. 9. A method for adjusting an alternator, characterized in that the field current is additionally adjusted by means of a voltage regulator such that the output voltage of the alternator is set to a value which can be determined in advance.