WO2000074205A2

WO2000074205A2 - Method and circuits for controlling the power of an electronically switched, two-phase reluctance machine

Info

Publication number: WO2000074205A2
Application number: PCT/RO2000/000011
Authority: WO
Inventors: Jancu Lungu
Original assignee: Jancu Lungu
Priority date: 1999-05-26
Filing date: 2000-04-21
Publication date: 2000-12-07
Also published as: BR0006162A; EP1101268A1

Abstract

The invention explains principles and circuits for the power control of two-phase SR-Machines featuring a direct recovery of the phase switch-off energy and a 180° phase angle at full load. The power control relies physically on a shorter current flow (duty cycle) at the phase beginning. This can be done either through mechanical phase shift of a second Hall sensor or by using time delay circuits.

Description

Methods and circuits for power regulation of an electronically commutated, two-phase reluctance machine.

The invention relates to electronically commutated, two-phase reluctance machines (motors or generators, also called SR (Switched Reluctance) machines) which have a special one

Have a magnetic circuit, e.g. from international patent applications WO 96/09683 and WO

98/23024 known.

Such a motor, which functions in spite of simplicity, is shown in FIG. 1 for easier purposes

Understanding in compressed form (magnetic circuit and circuit).

Each one of the eight main (112) like secondary windings (1 13) is outlined as one on the

Magnetic yoke 11 attached inductance shown.

The main current paths (see "Definitions") are shown in bold.

The simplest circuit (see Fig.l) of an uncontrolled SR motor works in the sense of

Invention, as known from the prior art, with a Hall sensor 31 with two complementary "flip-flop" open-collector outputs 312, 313 as phase control, which was realistically outlined in the vicinity of the rotor. The gate electrodes of the circuit breakers 2 IX,

21 Y, e.g. Via a polarization "pull-up" resistor 35, voltage is alternately short-circuited to the negative potential (ground) via the Hall sensor outputs 312, 313, so that the main current stops.

In the case of an uncontrolled motor, the electrical angle 0 ° see Fig. 3 e.g. phase X is energized and its main current ceases at 180 °; At the same time, the Y phase is energized, namely up to 360 ° (= 0 °), which closes the electrical cycle. Adherence to the electrical switching points (phase change), which correspond to the tooth-to-tooth movement of the rotor, is important so that the stator 11 1 coming close and the rotor poles 121 can effectively attract each other, see Fig. 1, phase X DEFINITIONS

For the sake of simplicity, in the course of the description the semiconductor components such as Mosfets, IGBTs, which conduct the main current from the current source to the windings, are called "circuit breakers".

Main current in the sense of the invention is understood to mean the current which flows from the source via a circuit breaker in the windings. The flow duration of the main current is equal to the phase duration T at full load (flip-flop operation of the circuit breakers) and is as electrical angle seen 180 °. The phase change is carried out with the aid of a rotor position sensor 32, which rotates in front of one or more of the rotor position (Hall) sensors 31. Fig. 2 shows an overview of the arrangement of some components relevant to the invention with the signal forms for the engine control that occur in the course of the invention. As "phase control" see Fig. 2 the circuit parts are understood which control the phase change in flip-flop mode. This must take place in the rotor positions in which the efficiency of the conversion of electrical / mechanical energy is optimal with the given operating parameters.

Although a slight power control can also be achieved by adjusting the phase control, this is understood in the sense of this invention to mean a reduction in the main current running times via shorter "gate" pulses. This means that the power control includes the circuit parts which form gate control signals from rotor position signals, which are rectangular and last less than the phase length, as shown in FIG. 2, right. “By-pass diodes” are the diodes which supply the self-induction voltage Ua, which occurs at the connection between the circuit breakers and the windings when the main current is interrupted (the demagnetizing energy, or by-pass current) Ib, to the subsequent phase. "Phase angle w" (electrical = 180 °, mechanical = 180: number of rotor teeth) is the rotor angle which is passed between two phase changes, ie between two switching operations of the phase control (Hall sensor). "Tooth-tooth" or "alligned position" is the relative rotor-stator position in which the rotor 2 rotates if direct current flows continuously through a phase (minimal reluctance). The object of the present invention is to show possibilities of the power control of the above-mentioned SR machines without additional, costly power semiconductors. It should be taken into account that the efficiency of the machine should remain as high as possible. This means that both the recovery of the demagnetizing energy should be done efficiently and that the losses of the power electronics are minimized. The task is solved according to the teaching of the main claim. Simple circuit instructions and examples are available to the person skilled in the art so that he can combine them in the design of a suitable circuit variant, such as modules, in order to achieve a specific objective in the sense of the invention. "Power control" of an SR machine, in particular a motor, is understood in the sense of the invention to mean the reduction of the main current through targeted short-term blocking of the circuit breakers within the Phase duration, (of the phase angle). This causes the main current to be reduced to less than 180 ° or the relative operating time of the circuit breaker to be shortened.

This means that for the purpose of regulation, the two circuit breakers are no longer in the

Working push-pull ("flip-flop") mode. Fig. 3 shows the relevant control signals of the

Motors as rectangular (voltage) pulses.

The corresponding courses of the main current Ip (bold line) or the by-pass current Ib

(Dotted line) are shown superimposed. The shape of the pulses in regulated mode is shown on the right side (from 360 °), that in unregulated (flip-flop) mode on the left

Side (0-180 °).

Due to the magnetic circuits known from the prior art, which allows a very simple, highly efficient recovery of the demagnetizing energy of a phase that has just been switched off, a delay-free energization of the second motor phase has until now

The first switch-off takes place (flip-flop mode, "chaining" of the phases via the by-pass current).

In order to achieve a power control, it was proposed there, the main flow before the

Interrupt phase end. The current flow in this phase to be switched off should be maintained until the end of the phase duration by the feedback of the self-induction voltage Ua with the aid of two additional power transistors 21 1, see FIG. WO 96/09683, pp. 8-9, Fig. 6e.

These power transistors 21 1 were also in the case of regulation by the known ^6th

Pulse width modulation necessary.

If the self-induction voltage were not fed back via the transistors 211, this would have led to a useless forwarding of the by-pass current to the other phase at the wrong time, with serious consequences for the efficiency. So far, it has not been possible without additional expenditure on power electronics to achieve a power control based on the reduction in the on-time of the power switch 21.

A simpler solution is possible according to the teaching of this invention, even if the "fly-back" power transistors 21 1 are not present (see WO 96/09683-Fig. 6e) which, at the end of the phase duration, releases the demagnetizing energy when a circuit breaker is blocked 2 IX led to phase (X) from which they originate as follows:

After the motor has started, which always occurs in the "flip-flop" operating mode (FIG. 3, left side) of the circuit breaker, the main current can be delayed by holding the circuit breaker 21X, 21 Y locked after the phase change by a fixed or variable time period t be, (s. Fig. 3. right), a period of time that corresponds to an electrical angle v depending on the speed of the motor.

The main current of phase X therefore no longer sets at 360 °, but decelerates at 360 + v °, that of the Y phase at 540 + v °.

The circuit breakers are still locked at nxl 80 °.

This means that the occurrence of the self-induction voltage Ua (of the by-pass current Ib, at the end of the phase) always occurs at nx 180 °, ie with a relative position of the stator rotor teeth 11 1- 121, in which they can effectively attract each other. s. Phase X in Fig.l

The demagnetization energy (the by-pass current Ib, curve see Fig. 3, dotted line) can thus the subsequent phase via the by-pass diode 22 with a useful effect (as

Magnetizing current, accompanied by a torque), even if the

Main stream has not yet started.

If the main current Ip begins to flow after a delay t (electrical rotor angle v), its rise becomes steeper since the corresponding magnetic yoke 11 is already premagnetized via the by-pass current.

This means that a targeted blocking of the circuit breaker 21 of the X phase e.g. can be used in such a way that, due to the "concatenation" of the phases via the by-pass current, an appropriate premagnetization of the Y phase can be achieved via the diode 22X. By controlling these phase switching processes, e.g. in addition to the power control to achieve a certain current profile in the phases, which for optimal efficiency and / or for a

Noise reduction is cheap.

In view of the findings of this invention, mainly that the shortening of the main current duration at the beginning of the phase does not have to take place at the end of the phase as in the prior art, not only can the electronics outlay be reduced but also regulation within broader limits can be achieved.

The variable switch-on delay t of the circuit breaker 21 can take place electronically or via the mechanical displacement of a second Hall sensor 31 a. This can be achieved electronically with a delayed switch-on timer which is used for

Phase change is started, and the gate electrodes of the power switch 21 to the

Time t holds to the minus potential after the phase change. (see Fig. 3). This delay can be parametric, that is, for example, set using a circuit that compares a target value with the actual value and corrects it accordingly, in order to keep a certain control variable such as speed or torque constant, for example. So you would have to increase the delay t when increasing the speed, thereby reducing the main current until the speed drops to the set value. If the deceleration t is constant, a certain but inaccurate speed limitation is also achieved. If the speed of the motor increases, the relative duty cycle (power consumption) of the motor will decrease until there is a speed limitation. This happens because the phase duration T decreases at higher speed, while the delay t remains constant, so that the relative duty cycle = Tt decreases. The relationship

The main current angle / phase angle is reduced.

A simple power control, at which this ratio remains constant, can be achieved with the

Use two phase-shifted rotor position (Hall) sensors 31 with digital "open collector" outputs 312, 313, (see Fig. 4).

The gate electrode of the circuit breaker 21 is above the first Hall sensor (31)

Saturation potential brought "high" and short-circuited from the second Hall sensor 31a (whose outputs are connected in parallel) to the minus potential "los".

In the lower half of FIG. 4, the signals of an output 312 of the active are on level a

Hall sensor 31 (= control signals of gate Gx when switch 314 is open, 315 closed) or at level b that of the output of hall sensor 31 a (switch 315 open, 314 closed).

At level c, the resulting "X Gate" signal (down regulated power) is both

Switches are closed. The "high" pulse width of the "Y" phase is identical, but electrically out of phase by 180 °. If the signals of the two Hall sensors are phase-shifted by the angle v, the angle is always high while the gate electrode is "high" (= main current angle) (phase angle -

Phase shift of the Hall sensors.

Under certain circumstances, this power regulation can be more favorable for the motor of a power tool. With commercially available hand tools, the speed is increased by pressing the integrated switch near the motor, which in this case contains a potentiometer.

Such a switch can also cause the movement of a Hall sensor via a lever, for example, so that the power control function of the tool (see Fig. 5) can be represented as follows: ό -Depending on the desired direction of rotation, using the bistable left-right selector lever 36, the position for a start-up sensor 31 a relative to the transmitter magnet 32 is predetermined, with switching points that lie approximately in the first quarter of the phase angle, left or right of the neutral tooth. Tooth position, -At the beginning of the stroke of the lever 37, the start-up (Hall) sensor 31a is activated, for example, as shown in FIG. 3, and the motor starts in the preselected direction, -After reaching the lower speed limit, the second Hall sensor 31 activated, which, however, has the maximum angular displacement v, so that the main flow angle is small, and the motor operates with minimum power (or speed), - by pushing the lever 37 further, one of the Hall sensors 31 is moved as in FIG. 5 in such a way that the displacement v is reduced so that the main current angle increases and thus the performance of the motor.

If the phase shift of the two Hall sensors 31 is the same, the motor operates at full load (main current and phase angles are the same, flip-flop operation). For some applications (vacuum cleaner, for example), the movable Hall sensor 31 can be of the output size of a driven device (vacuum, Flow, temperature, current, vibration) can be adjusted depending on the B. for pressure with the help of a cylinder-piston-spring device 38, which allows particularly inexpensive overall solutions for the control (see Fig. 6).

In an internal combustion engine of a car, for example, which is equipped with a starter according to WO

98/23024 is provided, the vibrations of the gasoline engine can be dampened with the help of a Hall sensor, which is mounted free of torsional vibrations.

If the gasoline engine including the reluctance starter shows torsional vibrations, these lead to the vibration-free Hall sensor moving relative to the vibrating stator in such a way that the reluctance machine operates between the motor generator (brake) in the sense of a

Reduction of the vibrations of the gasoline engine oscillates.

These functions can of course also be implemented electronically, so that electrical phase shifts are used instead of a mechanical shift.

In the case of electronic solutions with time switches, it is essential to control longer or shorter main current running times synchronously with the current rotor / stator positions, which are favorable for converting the electrical into mechanical energy, and if necessary depending on a setpoint parameter (e.g. speed) to regulate. A rotor position signal must therefore be obtained for the machine control, which unambiguously reflects the angle of rotation and possibly the direction. This signal can be processed using known electronic means in such a way that control pulses for the circuit breakers 21 in flip-flop (full load) or power control mode can be obtained therefrom.

It is irrelevant what type of position sensors are used, these being referred to as Hall sensors 31 (analog, digital, differential, programmable) for the sake of simplicity in the course of the description.

With the help of a differential or programmable Hall sensor, the

Scan the rotor teeth so that a phase change signal can also be obtained without the aid of an encoder magnet 32. In the sense of the invention, the rotor position can also take place without the aid of a sensor, by electronically determining the reluctance of the motor phases, as is known from the prior art.

As FIG. 3 shows, where, as a comparison, the flip-flop phase change signal of an uncontrolled one

Motors and the sawtooth or sine signal of a rotor position encoder are shown, these variables can be used to obtain not only phase change but also other control signals.

Simple electronic means such as the Schmidt trigger are used. On

Sawtooth signals of this type can e.g. with the help of an analog Hall sensor 31c, which is polarized by a permanent magnet 33 and radially in front of one with the

The rotor is in solidarity rotating, soft magnetic "sawtooth disk" 32a (Fig. 6).

The magnetic field that drives the Hall sensor changes (the reluctance of the system)

"sawtooth-like," so that the output signal of the Hall sensor 31c (= input signal of the

Phase control trigger) has this shape.

From the sawtooth signal, a level switch 34 (Schmidt Trigger, see Fig. 2 and 3) can be used

Phase change signal (flip-flop) can be obtained when the trigger is in the middle of the

Rise phase (level Uk) tilts (phase change X to Y) or falls back to the starting position (Y to X) when the signal drops after the tooth tip Us (see Fig. Fig. 3 cf. Level a-c. The phase symmetry can easily be influenced by adjusting the breakover voltage Uk without the phase position (when falling back after the tooth tip) changing.

Phase symmetry means that the duration of the "high" phases at both X and Y outputs, ie at the gate electrodes Gx, Gy of the circuit breakers 2 IX, 21 Y, is always the same, be it in flip-flop or in power control mode. This is necessary in order to keep the currents of the two phases the same for the smooth running of the machine.

Should it e.g. B. because of the properties of the components, however, that the "high" phases at the gate of the circuit breakers 21X.21 Y have different lengths, it is z. B. with the basic circuit of FIG. 7 possible to obtain a voltage signal Ud (symmetry deviation), which is used to adjust the phase symmetry.

With the aid of this voltage Ud, the breakover voltage Uk of the trigger 34 is adjusted such that a phase symmetry is established.

The voltage Ud is the potential difference across two capacitors Cx, Cy which are connected via resistors Rx, Ry, to the gate electrodes Gx, Gy, the circuit breaker, are charged or discharged alternately and assume a voltage level which corresponds to the ratio of the on / off Duration of the respective switch 2 IX. 21 Y corresponds. This phase duration signal can also be used as an analog speed signal in flip-flop mode (e.g. when the machine starts up).

These options for influencing the phase change can be supplemented with a dynamic, main current-dependent variant (FIG. 8), which can mainly improve the starting behavior.

For this z. B. in the magnetic circuit of the encoder magnet (32) - Hall sensor 31, one (or more) current loop 322 (see Fig. 8) is introduced, which e.g. is traversed by the main current of a phase or by a suitable control current.

Depending on the current direction of current flow and strength, the magnetic field, which controls the Hall sensor 31 and thus the phase change, is influenced, so that feedback occurs between the main current Ip and the phase change. This enables a load-dependent adjustment of the phase change points as feedback. Such adjustment of the phase change can also be carried out with electronic means of phase shift (known from the prior art) in other areas if it is useful for optimizing the efficiency or for regulating the motor. For that it is e.g. B. cheap to gain a sine signal from an analog Hall sensor (Fig. 3, level d), because this can be processed more easily for the purpose of phase shift. The means described in connection with FIG. 3 and the means of phase adjustment known from the prior art can be used, for example. A phase change in the vicinity of the tooth-gap position (see Fig. 1, corners of the rotor and stator teeth of phase X) is favorable for starting the motor; however, the shift in the phase change with respect to this position should increase with increasing speed. For example, it is advantageous to use a speed (voltage) signal that increases easily with the switching frequency to cause a larger phase shift in the phase change.

The size of this shift will depend on the operating parameters (speed, torque) for optimum efficiency.

One way to determine this is to bring the phase shift at a constant (regulated) speed or load until the main current Ip or the by-pass current Ib reach the lowest value. The latter (Ib) can be measured with lower losses, possibly even without losses, via the self-induction voltage Ua. With an appropriate control circuit, this efficiency optimization can take place automatically.

If you use a programmable Hall sensor instead of a simple sensor, which has trigger modules that can be set on the same chip, it is possible to use the

Reduce circuit complexity significantly and control the phase shift of the output signals by programming the sensor.

The rotating magnetic field (the motor effect) of the machine arises from the superposition of the main current Ip and the by-pass current Ib, which always after the interruption of the

Main current of the other phase arises and the windings of the two phases pass through simultaneously.

In machines which, as described in WO 98/23024, are composed of two machine halves (with the same axis, mechanically offset by w / 2 for the purpose of torque smoothing), there is a possibility of reducing the peaks of the self-induction voltage Ua by the by-pass current Ib is not only fed to the complementary phase, that is from X to Y, but also to the phases of the second half of the machine; s. Fig.la.

The second half of the machine has the same minus connection as the first and is identical to this. In Fig. 1, the dashed, diagonally drawn diodes "22" show the possible

Current paths to the secondary windings "113" / circuit breakers "21" of the second machine sketched in Fig.la.

This means that the by-pass current Ib of phase X converges to phases Y and Y '(the second

Machine belonging) branches, or it will be directed to the Y ^' phase alone if this is for the Efficiency is cheap. A similar procedure is followed with the by-pass current Ib ^'of the second half of the machine. Both the main and the much weaker by-pass current (see FIG. 3) can, depending on one another, be controlled within certain limits for optimizing the motor function, and in this way, losses can be minimized. The main losses are: a) Ohmic losses in windings and circuit breakers, which are significant from the

Current peaks are dependent, which should therefore be avoided if possible, b) switching losses, which require avoiding too many switching operations, c) losses due to peaks in the self-induction voltage, (depending on the current peaks) which in

Avalanche mode are absorbed by the circuit breakers 21 and endanger them, d) - iron losses, which are roughly related to the losses under a) and b).

To achieve the best possible efficiency, it is necessary with as few as possible

Switching operations to achieve an appropriate course of the main current Ip, i.e. to avoid particularly high values at the time of switching off. For some

Operating conditions, it may be advisable to interrupt the

Take the main current Ip into account (see level e, right side) if high current peaks are avoided, which results in an increase in efficiency.

As a result, the current drawn by the motor has a lower ripple, and possibly to

The electrolytic capacitor required for smoothing becomes smaller. Fig. 3 -level a, b, show typical courses of the

Main current in an uncontrolled motor or only regulated via the delay t.

The current peaks Is at the end of the phase can be e.g. by reducing that to the phase position t2, (see plane a and e), where the main current Ip has a lower value, the gate of

Circuit breaker 21 is short-circuited for the time t3 at the minus potential (ground), which reduces the main current, in particular in the rear area, see FIG. Level e.

The power control ensures that the speed does not drop and reduces t to tl, whereby the main current remains at the nominal value, but without the pronounced peak Is, which can contribute to an increase in efficiency. In order to limit the starting current of the motor, the main current can be interrupted one or more times within the phase duration T upon reaching a predetermined peak value Iv (see level E, left) by a constant or parametrically variable duration t3, as in FIG. 3, Level e shown. There is no delay to the beginning of the phase (t = 0). The restart of the main current can, for. B. take place when the by-pass current has dropped to a predetermined value. This starting current limitation can also function as a protective function and is carried out, for example, with the aid of a transistor 42, see. Fig. 9.

Because the start and end of the phase are predetermined and the windings of the affected yokes, whether through the main or by-pass current, are constantly flowing through, this basically means no departure from the flip-flop start-up mode.

Without this protective function, especially when starting the motor, it cannot be avoided that the main current to be commutated reaches high values. As a result, the peaks of the self-induction voltage Ua also reach very high values which, despite the by-pass current Ib, exceed the dielectric strength of the circuit breakers 21 (Mosfets, IGBT's). However, the energy of the voltage peaks (= avalanche clamping) "capped" in avalanche mode endanger the circuit breakers. It is therefore cheaper to convert these peaks into heat by controlling the gate, i.e. by means of the chip's conductivity (active clamping). This is achieved with the aid of the circuit shown in FIG. 9, wherever through the Zener diode 40 and through

Blocking the transistor 41 the gate will get a positive potential (21 becomes conductive) as soon as the voltage applied to the power switch 21 approaches the avalanche value and thereby exceeds the zener voltage.

As FIG. 9 shows, the gate is via the open-colector output of the Hall sensor 31 (

Phase control) and additionally controllable via a series (41) or a parallel transistor 42.

As a result, the gate control can be decoupled from the phase control, if necessary, in order, for. B. to realize the most important operational and protective functions of the motor, such as: a) - on / off switching, b) - power and speed control c) - over- and undervoltage protection, d) - thermal shutdown, current limitation, and short-circuit protection, e ) Protection against inductive voltage spikes, as already mentioned. f) braking

The transistor 42 takes over protective functions and should short-circuit the gate at the minus potential if one of the states listed under c) or d) occurs.

A reluctance machine is known from WO 96/09683, which does not have a stator but two independent rotors 1, 2, the former, the field rotor 1, as shown in FIG. 10 (a rotating one

Stator similar), over two brushes 34 or. Slip rings are supplied with the main current Ip. The field rotor carries on the frame 5 the circuit breakers 21 and part of the phase and speed control, which are therefore movable and inaccessible for adjustment from the outside. For this type of settings, contactless transmission is necessary. B. to carry out the externally predetermined speed setpoint, which is carried out with the aid of an axially installed, rotating Hall sensor 39, which is controlled via a fixed control winding 49.

With the help of these components 39, 49, z. B. possible to regulate the time base, which controls the switch-on delay t of the power switch 21 (the power control), which is located on the rotating board 45 of the field rotor 1. The phase control rotates with the field rotor. The control winding 49 is energized during the set delay t. This controls the Hall sensor 39, which controls the power control described. Since the time base is controlled by phase changes, that is to say by the steep decrease in the main current Ip, this process, which can be easily recognized electronically, could even start an external time base. The advantages of the invention are based on the simplicity of the

15

(Power) circuits that allow inexpensive implementation.

In the following three circuit examples (Fig. 1 1, 12, 13) for the speed control are described, which can be used for the motor according to Fig.l. The circuit of the motor was shown in a simplified manner and supplemented differently depending on the example.

The two by-pass diodes (in series with the by-pass windings 1 13) were replaced with the same function by a single diode 221, the cathode of which is connected directly to the positive connection.

For the purpose of regulation, the control of the gate electrodes of the power switches 21 must be decoupled from the phase changeover at the beginning of the phase.

To cause a delay, is it easiest to start one from the phase control _? Combine set RC element with a level discriminator (trigger), so that a low signal appears at the output of the trigger during the delay t, which is the gate of the

Circuit breaker of the active phase of the motor switches "low".

The shutdown of a phase (change high-low) must the switch-on delay t des

Trip circuit breaker 21 of the next phase. 30 Fig. 11 shows between the circuit of an engine (left of the dashed line) and the

Level switch (here Schmitt trigger, right of the dotted line) is an example of the implementation

Invention. The two phase X and Y motor has main windings 112 in series with that

Circuit breakers 21 (both provided with an inverse diode) through which the main current Ip flows. The secondary windings 1 13 are traversed by the by-pass current Ib, which flows through the by-pass diode 221 to the positive line. The gate electrodes Gx, Gy of the circuit breaker 21 are "pulled up" by the resistors Rg if the on-off switch ID is closed. However, these are no longer directly "pulled" by the digital Hall sensor 31 with complementary (flip-flop) outputs Hx, Hy (= phase control), but via the diodes D1 to the negative potential.

Up to here, the function is the same as that of an uncontrolled motor.

The complementary outputs Hx, Hy of the Hall sensor 31, in front of which the sensor magnet 32 rotates, are connected to the “pull-up” resistors Rt in order to receive signals for the regulation. These charge the capacitors Ct during the "high" time of the outputs Hx, Hy of the Hall sensor 31.

If necessary, charging can be accelerated via diodes Di (dotted line) to improve the control behavior.

If one of the open-collector outputs Hx, Hy, of the Hall sensor 31 becomes "low", the respective capacitor Ct discharges above this or above the series resistor Rt, the latter RC-

Form elements (Rt, Ct) that determine the delay t for each phase for the purpose of speed control

At the connection point Rt-Ct, an asymptotically decreasing appears during the phase change

Minus potential Ut.

This negative voltage, which comes from either the X or Y phase, causes across the

Diodes De and the resistor Re a current It which tilts the Schmitt trigger ST.

As a result, the output transistor Ta becomes conductive. As a result, even after the phase change, the respective gate electrode of the active power switch 21 remains connected to the -potential for the time t via the diodes Dt or the transistor Ta and the low-resistance resistor R1, that is to say “low”.

The delay t of the main current Ip is set by the potentiometer Pt, which conducts an adjustable current Is towards the base of the input transistor Te

(Desired value setting). The subtraction of the setpoint current Is and the time-variable current It results in a resulting base current Ie.

When this reaches the threshold, the transistor Te becomes conductive, the

Output transistor Ta blocks, so that the respective gate of the power switch 21 on the

Resistor Rg can be "pulled up". The circuit breaker 21 thereby becomes conductive, the main current Ip therefore begins in the sense of the invention after the delay t.

The speed control circuit (on the right of the dashed line) can be attached to a separate circuit board that can be connected to an uncontrolled motor (e.g. via a plug connection). The same also applies to the circuit according to FIG. 12. At the input of the Schmitt trigger, influence on the base current Ie can be exerted in a variety of ways in order to refine the functions of the control or to protect the motor. At this point (see arrows) a control current can be fed in or withdrawn, either to influence the delay t (feedback functions e.g.) or the motor in the case

10 to stop a hazard by permanently blocking the input transistor Te. The deceleration t (the speed of the motor) can, for example, be influenced in the following situations:

- As feedback for speed control; If the speed drops below the setpoint, the delay t is reduced in order to increase the main current.

15

- As a starting current limitation; If the starting current or the self-induction voltage Ua reach too high values, the delay t is increased in order to lower the main current Ip. - For temperature stabilization; If the temperature of the engine or of individual parts rises, the delay t is increased.

- The speed of the motor can be adjusted via the switching frequency at the output of the phase control

20 determine, which can be converted into an analog signal if necessary. For this purpose, at least one of the signals of predetermined voltage at the output of the phase control (see FIG. 11, below the bold dashed line) is fed via a capacitor Ca (approximately 0.1 μF) to a circuit which charges the charge-discharge currents of the capacitor Ca via two Separates diodes D +, D- and integrates them to charge two capacitors C +, C- (5-1000μF) with parallel connections

25 discharge resistors Rd supplies.

The positive or negative charging of the capacitors C + or C- is proportional to the speed and each of these voltages can be used for control purposes if required. If, instead of the resistors Rd +, Rd-, a potentiometer Pi is connected to the connection points between the diodes D +, -, _n D- and the capacitors C +, C-, the cursor can be used to set a (feedback) signal that can be adjusted from negative to positive win, which is proportional to the speed and can be supplied, for example, as a feedback current to the input of the Schmitt trigger ST. In order, for example, to cause the motor to start smoothly, the values of the discharge resistors Rd or the capacitors C +, C- are selected such that one of the capacitors C +, C- reaches the voltage which corresponds to the speed of the motor more slowly. The signal tapped at the potentiometer Pi has a slower change after the motor is switched on and can therefore be used to gradually reduce the delay t, ie to bring about a smooth start.

FIG. 12 shows a circuit which enables speed control and limitation by means of the switch-on delay described above, in which this delay is controlled by means of a voltage which increases with the speed. As can be seen, this circuit has components (Rg, Dt, Rc, Ct, ST) which correspond to those of FIG. 11 and have been described in connection with this.

However, the capacitors Ct are charged or discharged via two pairs of diodes D +, D-. The positive portion of the currents flowing through the capacitors Ct charges the integration capacitor Cv via the diodes D + or the resistor Rv, so that its average charging voltage is proportional to the speed. The resistor R1 serves to discharge the capacitors Ct via the diodes D- when the respective outputs Hx, Hy, of the Hall sensor 31 are at the negative potential. The capacitance of this capacitor Cv and the resistance Rv are selected so that a voltage Uv, the middle one, arises at the cathode of the diodes D +

Value corresponds to the state of charge of the integration capacitor Cv (the speed), but which has sufficient ripple (which is mainly due to the voltage drop across the

Resistor Rv arises) to switch transistor Tv within the phase duration.

The resistor Rf and the capacitor Cf serve to remove any potential from this voltage Uv

Filter interference components.

The state of charge of the capacitor Cv, i.e. the rate of increase of this voltage with the speed, can be adjusted with the help of the potentiometer Pv, so that a

Speed control takes place.

How it works: When the speed of the motor is set via the potentiometer Pv

The value at the capacitor Cv is low enough so that the transistor Tv does not become conductive even at the beginning of the phase (when the capacitors Ct are in the charging phase).

If the speed of the motor increases, the voltage on the capacitor Cv increases and so does the

Voltage Uv at the cathode of diode D +. (The resistors Rc, Rv and the capacitor Ct form a voltage divider). Because the capacitor Ct corresponding to the phase to be switched on is discharged at the beginning of the phase, the voltage Uv has the highest value at this time.

The transistor Tv becomes conductive at the beginning of the phase and blocks the conductive polarized transistor Te of the Schmitt trigger, so that the output transistor Ta thereby becomes conductive. The gate electrodes of the circuit breakers 21 thus remain connected to the ground and the latter (21) is blocked. If after a delay t the voltage across the capacitor Ct rises, the voltage Uv drops sufficiently for the transistor Tv to block. This also blocks the output transistor Ta and the corresponding power switch 21 becomes conductive after the delay t. This process is repeated for each phase and the delay t takes on a value based on the described processes, which corresponds to the set speed. Because the charging voltage of the capacitor Cv influences the main current, the load state of the motor can be reduced or controlled by increasing this voltage, regardless of the speed.

Here, other control influences can intervene to increase or decrease the voltage. As explained above, the status of the machine can be checked depending on various parameters on the gate electrodes Gx, Gy of the machine. Given the circuits according to Fig.l 1-13, however, it is easier to achieve the functions described under a) to f) by not influencing the control parameters directly, but at the input of the level switch ST or at the input of the driver modules of the individual phases .

Fig. 13 shows a further circuit, where in principle the function of the Schmitt trigger including the inverting transistor according to Fig. 12 is implemented via two special control modules / phase (with threshold switch function, here Mosfet driver, eg the Micrel type (Mic 445 IB)) has been.

This variant allows better control due to shorter switching times, in particular larger mosfets or mosfet groups connected in parallel. The circuit according to FIG. 12 was changed as follows:

- A Mosfet driver Dr / Phase each with the inverting output O connected to the gate replaces Schmitt trigger ST and inverting transistor Tv. - The diodes Dl and the pull-up resistors Rg for the gate electrodes are dispensed with, because the outputs O of the two Mosfet drivers DrX, DrY, the gate electrodes Gx, Gy are opened and closed directly via bidirectional currents unload. - The outputs of the Hall sensor 31 control the inputs I of the Mofsfet drivers in such a way that their outputs are .low '^" (switch 21 blocked) when the respective output of the Hall sensor 31 (phase switch) is" high ".

- The voltage Uv (analog speed signal with superimposed AC voltage component) was fed directly to the inputs I of the Mosfet driver Dr via the decoupling diodes De. The function is similar to that of the circuit according to FIG. 12:

- If the output Hx of the Hall sensor 31 is "low", the output of the driver DrX is "high" and the motor starts in flip-flop mode (without control).

- If the speed exceeds a predetermined limit, the voltage Uv increases and the inputs of the drivers (DrX) briefly get values of the voltage Uv that are above the input threshold of the drivers (approx.1.5V), so that their outputs (the Gate electrodes) only after this voltage has decayed, ie after a delay t. ..high "so that the engine works in power control mode.

It is known from the prior art that a change between the motor-generator function (brake) is effected by phase shifting or switching between two Hall sensors 31, 31 ^' .

The energy recovery is with a vehicle drive or with a battery operated one

Power tool useful. The SR motors of the invention can be used without further measures

Generate a higher voltage than the voltage of the battery required to reach the generator

Speed led. This makes it particularly easy to implement the above function.

This usually happens when the power control function is switched off. the in

Generator mode is little needed.

It may be sufficient to swap the output signals of the phase control (low instead of high) in order to achieve a braking function with partial recharging of the battery.

Claims

Claims:

1.) Power control experience for two-phase, electronically commutated reluctance machines with direct transmission of the demagnetizing energy of a switched-off phase on the subsequent phase, characterized in that the activation of the main current (Ip) is delayed by a duration (t) after the phase change.

2.) Power control method according to claim 1, characterized in that between the

Blocking the line switch (21 X) of one phase (X) and the current conducting phase of the switch (21 Y) of the subsequent phase (Y) the self-induction voltage Ua, which when switching off the

Phase (X) on the connection between the main winding (112X) and the circuit breaker

(21X) arises via a by-pass diode (22) a phase (Y, X, Y ') is supplied, which is from the

Power source is still disconnected.

3.) power control method according to claims 1-2, characterized in that the

Speed control and limitation takes place in that the deceleration (t) is independent of the speed.

4.) power control method according to claims 1-2, characterized in that the

Switch-on delay (t) of the main current is speed-dependent and results from the superimposition of the complementary phase change signals with shape-like signals which are phase-shifted by an angle (v) independent of the speed.

5.) Power control method according to claims 1, 2 and 4, characterized in that the duty cycle of the power switch (21) of the phases (X, Y) via the phase difference of

Output signals of two Hall sensors (31, 31a) is regulated.

6.) Power control method according to claims 1 - 2 and 4, characterized in that the phase-shifted signals from two digital Hall sensors 31, 31a arise in that they are mechanically displaceable.

7.) Power control method according to claims 1-2 and 4, characterized in that the mechanical displacement of a Hall sensor (31) or the electrical phase shift of its output signal from an output variable such as pressure, flow, temperature, current,

Vibration amplitude, etc. ... dependent, which comes from a coupled work device.

8.) Power control method according to claim 7, characterized in that the displacement of the Hall sensor (31) or the electrical phase shift of its output signal changes the operation of the machine from a motor to a generator function.

9.) Power control method according to the preceding claims, characterized in that the desired direction of rotation takes place via the presetting of a start-up sensor (31) and the speed control takes place via the phase difference between the start-up sensor (31) and a second sensor (31 a), the phase difference is changed by adjusting these sensors (31, 31a) by hand, or by the electrical phase shift of the output signals.

10.) Power control method according to claims 1-4, characterized in that the switch-on delay (t) of the main current (Ip) takes place via an electronic timer which is set in motion by the high-low transition of the phase control.

1 1.) Power control method according to the preceding claims, characterized in that the interruption of the main current within a phase is used specifically to influence the current profile in this and the subsequent phase. •

12.) Power control method according to the preceding claims, characterized in that a sawtooth-shaped rotor position signal used for motor control is obtained with the aid of a profile disk (32) which rotates in front of an analog Hall sensor (31c) polarized by permanent magnets (33), which rotates together with the latter forms a system of variable reluctance such that the output signal of the Hall sensor (31c) is sawtooth-shaped.

13.) Power control method according to claim 12, characterized in that from the sawtooth signal of the Hall sensor (31 c) variable, rectangular control signals are obtained by comparing the level of the sawtooth signals with the adjustable tilt level (Uk) of a trigger (34).

14.) Power control method according to the preceding claims, characterized in that it uses an automatic phase symmetry method, for which a signal (Ud), which is proportional to the difference in the phase duration of the two phases, for changing the tilt level (Uk) of a trigger (34) serves, which corrects the phase width.

15.) Power control method according to the preceding claims, characterized in that the control of the digital phase change is derived from the detection of the phase position of a phase-shiftable analog signal as required.

16.) Power control method according to the preceding claims, characterized in that the optimization of the phase change (efficiency) by the automatic correction of the main (Ip) and 'or the by-pass current (Ib) and the course of the self-induction voltage (Ua) towards the minimum values or the power consumption of the motor.

17.) Power control method according to the preceding claims, characterized in that the control functions of the machine take place with the aid of a programmable Hall sensor (38d).

18.) Power control method according to the preceding claims, characterized in that the control functions of the machine take place with the aid of a differential Hall sensor, this being controlled directly by the teeth (121) of the rotor (2).

19.) Power control method according to the preceding claims, characterized in that the phase change is adjusted depending on a current which passes through the windings (1 12, 113) through a current path which passes through the magnetic control circuit of the Hall sensor (31).

20.) Power control method according to the preceding claims for two-phase reluctance machines, which consist of two angularly offset, independently functioning machine halves, characterized in that the by-pass current (Ib) is transferred from the phases of one machine half to the phases of the other machine half.

21.) Power control method according to the preceding claims, characterized in that the main current (Ip) is interrupted in any position (t2) within the phase duration for a short duration (t3).

22.) Power control method according to the preceding claims, characterized in that the starting current is limited by the interruption of the main current (Ip) when an upper limit is reached, its reclosing after a short, predetermined time or when a lower limit is reached.

23.) Power control method according to the preceding claims, characterized in that the unavoidable peaks of the self-induction voltage (Ua) are absorbed by voltage-controlled leading phases of the circuit breaker (21) which are dependent on Ua.

24.) Power control method according to the preceding claims, characterized in that the most important control and protection functions of the machine are carried out by the control of the power switches (21), for which their gate electrodes (Gx, Gy) as required via phase change, power control, input Off, over and under voltage protection, thermal shutdown, over current and short circuit as well as protection against inductive voltage peaks (Ua) can be controlled.

25.) Power control method according to the preceding claims for statorless reluctance machines with two independent rotors (1, 2), characterized in that their field rotor (1) carries the power electronics (21, 22) and part of the power control, the control signals from the outside without contact Get an axially installed Hall sensor (39), which is controlled by a fixed winding (49).

26.) Power control method according to claim 24, characterized in that the synchronization of the signals of the winding (49) takes place by recognizing the shape of the current and voltage profiles in the connecting lines.

27) Power control method according to claim 10, characterized in that the flip-flop signals of the phase control obtained at the outputs (Hx, Hy) of the phase control (31) alternately charge capacitors (Ct) assigned to each phase during the high phase, by discharging them during the subsequent low phase, in series with resistors (Rt) phase-synchronized voltage levels (Ut) arise, which are related to the beginning of the phase and are passed to the input of a level detector (ST, Dr).

28) Power control method according to the preceding claims, characterized in that positive or negative components are separated from the phase change signals, from which slowly variable analog voltage signals which can be set as setpoint are obtained by integration with the aid of capacitors (Cv) or resistors (Pv) that are proportional to the engine speed.

29) Power control method according to claims 27 and / or 28, characterized in that the phase-synchronous voltage level (Ut) with the analog voltage (Uv) over a resistor (Rv), which causes a ripple, superimposed for the purpose of speed setting and the level switch ( n) (ST, Dr) are fed in such a way that from the time of the phase change until a breakover voltage (Uv) is reached which determines the switch-on delay (t) of the circuit breakers (21), that is to say regulates the speed of the motor. 30) Power control method according to the preceding claims, characterized in that the electrical potentials of the gate electrodes (Gx, Gy) of the power switch (2 IX, 21 Y) independently of one another by the phase control (31) and / or by a level discriminator (ST) " low "can be switched.

31) Power control method according to the preceding claims, characterized in that one driver module (Dr) is used per phase, the inputs (I) of which each have a level detector and the outputs (O) of the gate electrodes (Gx, Gy) of the power switch (21 Switch alternately to "low" or "high" potential.

32) Power control method according to the preceding claims, characterized in that speed-dependent analog signals are used as negative feedback for influencing the starting behavior and the speed control of the engine.