CN1033776C - Energy economizer controlled-current start and protection for induction motors - Google Patents
Energy economizer controlled-current start and protection for induction motors Download PDFInfo
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- CN1033776C CN1033776C CN 85105328 CN85105328A CN1033776C CN 1033776 C CN1033776 C CN 1033776C CN 85105328 CN85105328 CN 85105328 CN 85105328 A CN85105328 A CN 85105328A CN 1033776 C CN1033776 C CN 1033776C
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Abstract
The present invention relates to an induction motor started under the conditions of reduced input current, low energy consumption and small mechanical stress. A stator of the induction motor is started by the excitation of a sine wave source and is protected when running after being started so as to avoid the situations of phase loss, over-low or over-high voltage, rotor locking, etc. of an AC power supply. The stator can achieve almost optimum operation efficiency of the motor during running in a small load when and after started. When the motor is to be started or after the motor is started, a connected motor protector can prohibit a wave corrector from providing power for a stator winding in the situations of rotor locking, starting stall caused by the abnormal AC power supply, over-large running current or rated load of the motor or the reverse rotation of the motor.
Description
Put it briefly; the present invention relates to input power control field to induction motor; relate to a kind of electric current Demodulation Type energy-saving controller of motor or rather; also provide the starting of controlled current flow and the protection of stator winding, make it avoid and/or because rotor stall state or abnormity of power supply cause also operation for a long time under input current is significantly greater than specified full load amplitude situation in dephasing by reducing input voltage.
The power supply that is produced when at present, deciding the voltage starting for reduction induction motor quota springs up develops many kinds of one type of prior art syringe.Usually, the stator voltage that one of supply has earlier reduced, then a Best Times in the cycle with a series of manual step or automatically increase to quota by this starting voltage that reduces gradually and decide voltage, (that is " the voltage increase is the slope to the time " formula).United States Patent (USP) the 4th, 404, No. 511 (the motor power (output) controlling factors devices with reduced voltage starter) are an example of " voltage ramp formula " motor starter, energy saver when this design also includes a load and reduces, can after any manual starting time interval, begin to work, and in this time interval, the quota of power line is decided voltage and is put on the stator winding (no matter actual start request how) the most at last.Common in the prior art as the starting device of motor that reduces voltage in employing; protection when this patent can't provide for power supply generation abnormality also can't (or starting back) provide overcurrent protection for stator winding when rotor stall phenomenon takes place when motor starting.
United States Patent (USP) the 4th; 086; No. 406 is the example of appointing fixed " ramp type " step-down motor starter another time; this starter includes stator over-current protective device and AC (interchange) abnormity of power supply protective device, does not adjust input voltage to improve the device of motor operational efficiency but do not include the starting back according to the load needs.The defencive function of described motor is very complicated, and its basic principle and circuit are with of the present invention different fully.
Say that synthetically prior art listed above has been represented the electronic type starting of present motor and basic conception and the technology that the stator over-current protective device is adopted.With regard to motor starting control, the characteristic of these prior aries is lentamente the stator input voltage to be increased to quota gradually by a voltage that has reduced in time to decide voltage, wherein time factor can be selected arbitrarily, or comprises a predefined optimal time interval.But under any circumstance, described time factor is not subjected to control corresponding to the characteristic of motor performance that really is controlled and actual torque load thereof.With regard to stator over-current protection, prior art can be described as, and to the alternating current peak value or the mean value of the rms current that flows into stator winding, and/or the sensitivity that its temperature is risen is controlled in the predetermined or manually selected time interval.Prior art generally all is to utilize a plurality of electronic comparator and complicated circuit arrangement to realize to the protection of power failure.
Time factor arbitrarily " stator voltage ramp type " start-control device of control often causes insecure starting, the unsteadiness of electric motor system, unnecessary power wastage and in the electric motor overheating phenomenon of spending the slow accelerating period and or remarkable vibration during motor starting a certain section in the time.And, these prior-art devices allow that often thereby excessive stator current amount wasted electric power greatly, because motor starting load (normally less) seldom needs the quota of AC power supplies to decide voltage, this quota is decided voltage finally will receive motor later in the motor starting time).Because the relation of the transient state stator starting current that the partly sinusoidal wave relevant phase place of peak values of ac factor and power supply and the switching that is produced is relevant, make that effective and glitch-free operation of the stator rms current overcurrent protective device that responds the peak values of ac that is higher than a certain threshold level is very difficult to realize by the electronic type reduced voltage starter.
The 4th of present inventor, 297, in No. 628 United States Patent (USP)s " induction motor energy-saving appliance ", a kind of AC energy saving device is disclosed, the utilization of this device relates to some stator starting current characteristic that rotor mechanical load size and electric energy are converted to the motor performance of mechanical energy efficient, so that induction motor is moving with minimum power input to the scope of maximum rated load by zero.This aforesaid U.S. Patent (4,297,628) has been described and has been applicable to that monocyclic-start induction motor adopts the stator current demodulating equipment of the energy-conservation stator power control system of Wave shape changing device.This aforementioned patent is also with reference to the 4th of present inventor, 242, No. 625 United States Patent (USP)s " polyphase induction motor energy-saving appliance ", it discloses the device of roughly the same pattern, adopt two can be in response to the wave converter of electric current paramodulant motor load sniffer with the relevant control of load/efficient that produces, input to a threephase motor AC power supplies.
The purpose of aforementioned present inventor's previous invention is that the AC power supplies control device that can respond the having the characteristic relevant with load/efficient an of induction motor and move will be provided, thereby the stator input power that described characteristic is changed by being proportional to operating load is keeping being close to best motor efficiency by zero with low, specified or high supply voltage to the scope of maximum rated mechanical load.Yet these have invention not have the energy-conservation of motor starting earlier, the attenuating of starting overcurrent, the protection of abnormity of power supply or when motor starting or starting back the characteristics such as overcurrent protection of stator winding under the rotor stall situation take place.People know when deciding the voltage starting motor with the power line quota; the stator overcurrent be running current five to octuple; thereby make motor bear serious electromechanical stress; even when motor can normally freely start also is a kind of waste of electric power; if in addition (motor) driving mechanism was stopped by resistance or when carve the starting successor to stop operating in when starting, all can make stator winding be subjected to nonvolatil damage soon.In addition, the circuit interruption device of thermal type usually can averting a calamity property, be the motor fault of property temporarily, but when stall incident or abnormity of power supply take place, can not avoid permanent winding damage to a certain degree, so just shortened the useful life of motor.
Purpose of the present invention promptly is significant improvement to be provided and to be provided for the protective device of threephase motor the induction motor starting technique, makes that motor exempts from that supply voltage is too high or too low, dephasing and comprising betides during starts or the harm of the serious overload of incidents such as rotor stall after this.
The present invention has got rid of all harmful problems such as all difficulties, limitation, energy waste of starting of prior art induction motor and protective device.This be since practice the applicant in the U.S. 4,297, the result of a basic new design that discloses first in No. 628 patents is promptly about the control of the stator input power new design with the new circuit device aspect that is used to monitor the initial starting current characteristic of the stator relevant with performance.Just as will be described later, processing and the control of using the short time (number microsecond) potential pulse to carry out is depended in the control of stator power, the characteristic of described short time voltage pulse be by the motor person's character with spinner velocity (slip), motor load, the stator current peak amplitude during each half period of power conversion efficiency and power supply is relevant.
The stator of the AC induction motor of standard is to utilize by a wave converter, or encourage by a sine power supply by two wave converters during for threephase motor, the operation of these wave converters can change each part of being supplied with each cycle sine wave of stator winding by power supply.Wave converter can be the 4th of Hai Dejie (Hedge), 242, the pattern of being discussed in No. 625 United States Patent (USP)s, or for here with the pattern of the power-saving technology integrated circuit that the embodiment of the invention adopted (EnergyEconomizer Technology Integrated Circuit-EET-IC) discussed.According to the present invention, wave converter is to add circuit device, manual adjustment, reaches the signal of telecommunication sensitivity of representing the stator starting current characteristic of electric motor state (i.e. excitation or dead electricity) to be produced by monitoring.A described add circuit device and an energy-saving type stator current supervising device, and described EET-IC is together to form a kind of have energy-conservation two kinds " mode of operation " and the induction motor power control system of two kinds " guard modes ".
These two kinds of modes of operation are: motor starting and motor operation.Each state has a relevant guard mode, in order to avoid stator winding suffers motor starting to reach the infringement that after this potential infringement condition is caused between on-stream period.Or rather, during motor starting, the operation that partly is under an embargo of the energy-saving appliance control circuit of the stator current modem device in the EET-IC, and the delay of the phase angle of localized source voltage alternating is coupling under the preferable maximum square starting current condition of manual selection and can produces a stator voltage root-mean-square value.If armature spindle can freely begin rotation, motor promptly begins acceleration under the voltage of this preferable (attenuatings) and in check electric current.According to the circuit arrangement that causes the stator current characteristic relevant by the common motor characteristic control system of the present invention is remained under the described starting state and show that up to described characteristic motor has been accelerated near synchronous speed with spinner velocity.At this moment, circuit arrangement is according to the indication of this speed and control system is converted to operating condition, and under this operating condition, the size of stator voltage is controlled by the demand of rotor loading torque.Like this, according to instruction of the present invention, time that motor starting system is required and the voltage swing that is connected to stator are promptly controlled by actual conditions, rather than control with the arbitrarily selected time interval by artificial mode, this control mode is decided voltage no matter the motor actual loading needs how all little by little to be provided with quota at last.Or rather, when rotor can rotate freely, mainly listed factor determined the present invention's start mode duration length and the stator voltage of being supplied size by following:
1. the selected optimum start size of current of operator.
2. the main mechanical property of motor operated driving mechanism.
3. be the peculiar electromechanical characteristic of controlled motor and
4. arrive the real work loading demand of motor when being bordering on synchronizing speed when motor.
But; be stuck at armature spindle (rotor stall state) and under starting state, can't begin to rotate when maybe can't be rotated further; after postponing a manual seclected time, " starting state protection " of the present invention installs promptly by forbidding that described wave converter finishes just ongoing " motor starting state ".Before master's (power supply) switch was switched off, control system can maintain in one " the logical state of AC power supplies resistance ".When supplying AC power supplies once again, can begin one new " starting state " again.Like this, even motor is to start to be defined near the controlled input current of quota fixed load, if and motor be can not normally quicken the time, " starting state " also can at the end automatically transfer to " the logical state of AC power supplies resistance " in the aforementioned selected time cycle.In other words, according to the present invention, motor accelerates to approaching synchronous speed with full load or high current and promptly is considered to a potential damaged condition in a specific time cycle, even stator winding is not as yet because of the overheated termination that also is enough to cause ac-input power supply of too high electric current.
Finish at motor starting; and after described control system is transferred to " operating condition "; " operating condition protection " device just is unlocked, and still is failure to actuate when the required load of mode device is complementary but separate at the stator current that stator input power supply and aforementioned Hai Dejie (Hedge) invent.Therefore, at nominal load scope run duration, can keep being close to best motor operational efficiency.But, under rotor stall situation, should " operating condition protection " device can be almost immediately by forbidding that described wave converter ends previous " operating condition " and carry out " mode is led in the AC power supplies resistance " till this master (power supply) switch is turned off.When main switch was switched on again, this controller can be taked one current controlled " start mode ".If rotor stall state takes place, then " originate mode " promptly ended as described above; If rotor is free to rotate, then described controller can automatically be transferred to its energy-saving type " drive manner " when rotor has accelerated near synchronizing speed.
Inputing to three phase mains input voltage of the present invention comes under observation to watch out for potential infringement amplitude variation or to lose mutually with electric current.If an input power cord becomes " open circuit " (that is " losing mutually "), stator power can be interrupted within a power cycle.If rise on the supply voltage or fall has surpassed, for example, the nominal rating value positive 20 percent or negative 65 percent, then the stator input power also can be logical by resistance.
As described below, present invention resides on the basic conception practice and enforcement means aspect and diverse induction motor starter controller of known technology and stator winding protector.
In the accompanying drawing:
Fig. 1 is a system block diagram of the present invention;
Fig. 2 is the simplified block diagram that is applied to an integrated circuit of the present invention;
Fig. 3 is the schematic diagram of signal processing circuit;
The exemplary operation waveform of Fig. 4 for being produced by sampling transformer assembly 6,7 and 8;
Fig. 5 is the schematic diagram of solid- state switch assembly 9 or 10;
Fig. 6 is the simple equivalent circuit of an induction motor;
Fig. 7 A and 7B have described the load/efficient correlation properties of stator starting current; With
Fig. 8 is the schematic diagram of three-phase DC power supply 16.
Most preferred embodiment of the present invention now is described
In order to help to understand the present invention, at first discuss by the basis of the generation of the natural electric current characteristic between a sinusoidal AC power supply and an induction electric machine stator with the proportional power control signal of load.
Specific load/efficiency correlation curve is shown among Fig. 7 A and the 7B.For the purpose of illustrating, the electric current (Fig. 7 A encloses next part with dotted line) that is risen by null value is called as " stator starting current " (note work " I
Sic"), and I
SicTime cycle be decided to be 400 microseconds (Fig. 7 B) approximately.
Fig. 6 is the simple equivalent circuit of an induction motor, and this figure shows that the size of stator current all is respectively by the vector sum of motor inductance and caused inductance of rotor mechanical load and resistive component at any time.These current components are presented at I among Fig. 7 A
SicParticular characteristics in time cycle.These characteristics are that the rule by command current and induction motor natural property is determined.
Fig. 7 A is presented at the stator current half period under the different rotor load, and show that each cycle internal stator size of current and rotor loading need be directly proportional, promptly when load increases when the stator input voltage is adjusted to very high motor efficiency, stator current also increases, and vice versa.Analysis betides the situation of broken circle part among Fig. 7 A can find I
SicRise time and size be a function of the stator current peak value after a while the time; I
SicSituation in Fig. 7 B, show more clearly, this figure is a broken circle enlarged drawing partly among Fig. 7 A.
At I
SicIn time, the stator current component increases with a kind of ad hoc fashion.More particularly, the inductive component amplitude rises (no matter its peak value after a while has much) with exponential curve when the stator current half period begins, and the resistive component amplitude then can freely change with the loading moment of rotor with being directly proportional.Like this, when input voltage begins to be connected to the motor stator period of the day from 11 p.m. to 1 a.m, perhaps motor just with the high-efficient operation that approaches synchronizing speed under and rotor loading when changing, the resistive component of stator current is decision I
SicThe main changing factor of characteristic.When turning round with high efficiency, motor produces specific I under any nominal load situation
SicCharacteristic.This characteristic just changes when motor power (output) is too high or not enough.
For these reasons, can be from I
SicCharacteristic derives an efficient reference signal and is used for controlling a stator input voltage closed-loop control device with the change of work rotor loading demand.
Energy saver in the 4th, 297, No. 628 United States Patent (USP)s of Hai Dejie (Hedge) just depends on above-mentioned I
SicLoad/efficient correlation properties.More particularly, utilize the primary coil that makes stator current pass through a transformer, I
SicCharacteristic can be converted into corresponding short pulse duration (microsecond) characteristic, and wherein, the iron core of transformer is promptly saturated under than the also little electric current of zero (empty axle) load current.Utilize this device, the secondary coil of transformer promptly produces a potential pulse output, its lasting rise time and amplitude and I
SicCharacteristic is corresponding.
Know I as the front
SicWhen operating with peak efficiency, motor can show the characteristic that it is specific.This characteristic is that torque load(ing) and the length velocity relation between the inductance of the stator current that produced by induction electric machine rotor slip characteristic and the resistive component obtained.Corresponding to these characteristics, when the motor rotor mechanical load increases or stator winding when being short of power, this resistive component can increase, and vice versa.
In the 4th, 297, No. 268 United States Patent (USP)s of Hai Dejie (Hedge), I
SicCharacteristic includes " positive load " feedback, and is used as the controlling element of a stator power closed-loop control system, and this characteristic can be used as benchmark by manual adjustment to very high efficiency state of motor.Like this, when to the aitiogenic I of slip
SicDuring characteristic changing, stator input power supply changes too, and described (benchmark) state of motor efficiency then remains unchanged.
Or rather, if described closed-loop control device relates to the I corresponding to the motor peak efficiency at first
SicCharacteristic, just can automatically change the stator voltage size with the change of resistance (rotor loading) component of showing the stator current that continues, and this component (illustrating as preceding) is I
SicMain changing factor.The proportional variation of this stator voltage and load can make stator winding avoid excessively being driven or drive deficiency; Therefore, motor turns round with minimum power input when zero load, then moves with peak efficiency when nominal load.
Discussion by the front can be understood, and stator starting current is caused by motor slip characteristic and be relevant with spinner velocity.Therefore, I
SicCharacteristic includes the whether stall of indication rotor simultaneously, rotates lentamente, perhaps near the intrinsic signal device that turns round under the synchronizing speed.The present invention utilizes the described I relevant with speed
SicCharacteristic is come:
1. keep relevant stator power control device in " start mode " till rotor accelerates near synchronizing speed.
2. if rotor can not accelerate to approaching synchronous speed then open the AC power supplies inhibiting apparatus in the time cycle of reasonable (the best) in this " start mode ".
3. if rotor stall incident takes place then opens the AC power supplies inhibiting apparatus in the time at the best number of times of power supply alternation in relay motivation " starting " motor " drive manner " afterwards.
Referring to figs. 1 to 3, wherein identical number is represented components identical, and a standard three-phase AC induction motor 11 is provided with the rotor that stator winding 13,14 and 15 and has the rotating shaft 12 that can link load.Three-phase AC power supplies 300 is normally respectively via solid line 19 and 19A and dotted line 301 and 301A; Solid line 18,18A and 18B and dotted line 302 and 302A; Solid line 17 and 17A and dotted line 303 represented lines are directly received stator winding 13,14 and 15.According to the present invention is not this common power connection, be that power supply 300 is not directly to be connected to stator winding 13,14 and 15, but be connected to the former end of a current sampling transformer device 6 with line 19, the former end of another of assembly 6 borrows line 19A to be connected to a side of a solid-state power switch assembly 10, and its other end is connected to stator winding 13 with line 19B again; Line 18 is connected to the former end of power sampling transformer assembly 7; The other end process line 18A of assembly 7 is connected to an end of a solid-state power switch assembly 9, and this assembly other end then is connected to stator winding 14 via line 18B; Line 17 is connected to the main end of current sampling transformer device 8, and the other end warp 17A of this assembly is connected to stator winding 15. Switch module 9 and 10 can include, and for example three polar crystal assemblies or silicon control rectification sub-member are with each relevant door trigger amplifier shown in Fig. 5 and trigger the coupling transformer circuit.These thyristor power source switch module responses are included in the output pulse sequence of each the wave converter assembly in the integrated circuit 1 (EET-IC) and move.These wave converters can be the forms in Bai Ke the 4th, 190, No. 793 United States Patent (USP)s of people such as (Parker), or include the integrated circuit among the EET-IC of the present invention.In both cases, the operating member of these wave converters is by at first occurring then appearing at 500 and 501 on the online 46A, be that a DC (direct current) control voltage on the output of emitter follower 50 and 52 is controlled, in one case, its common input from line 46A can be the function of the operational efficiency of load on the motor 11 or motor 11, and in another case, can decide by the manual adjustment of starting current ADJ potentiometer 211.As will be described; in some cases; the operation of wave converter also can respond a dc voltage on the pin 6 that is connected to EET-IC1 and move; perhaps for being under an embargo before a dc voltage is removed AC power supplies earlier and then replys being provided with for the purpose of the protection motor by the temporary transient pin of giving EET-IC1.
More particularly, mention as top, current sampling transformer device 6,7 and 8 former end and stator input power cord such as the 19A among Fig. 4, one of 18A and 17A are connected in series.The current sampling transformer device that is presented among Fig. 4 includes a saturated core transformer, and it has the secondary coil of a primary winding and a center tap, is connected to two diodes 861 and 862 with common way of full-wave rectification.A duration that is begun to obtain on the starting current by the stator winding by this primary winding is quite lacked the potential pulse of (microsecond) on the secondary coil of this saturated core transformer, (in other words, when stator current is at first risen by formerly null value) generates when this starting current is reverse.The direction of stator starting current how no matter therefore the output of these rectifier diodes just comprised positive pulse.The various individual characteristics of this potential pulse, the absolute time of its rise time, amplitude, time span and generation for example, all along with the waveform and the size of the voltage that is applied, the special electromechanical character of the temporary load of motor and motor itself, for example torque load(ing) speed characteristics and changing.
When motor zero and maximum rated load between during running energy-efficient performance of the present invention and above the 4th, 297, No. 628 United States Patent (USP)s of the rough Hai Dejie that discussed (Hedge) suitable.
The load pulse processor 2 of motor among Fig. 1 and 3, originate mode processor 3 and DC control voltage processor 5 waits circuit that each square frame comprises and internal circuit and the starting current adjuster ADJ211 of EET-IC1 to work in coordination so that when the output of AC power supplies 300 at first is switched to power input of the present invention, command one current controlled, the operation of " originate mode " that voltage reduces, and reach the operation of commanding " operation mode " after being bordering on synchronous speed at motor 11.The signal input that the response of protection processor 4 is sent here by motor load pulse processor 2, and and the internal circuit cooperation of EET-IC1 and provide different " originate modes " reach " operation mode " AC power supplies termination (motor protection) to act on." originate mode "; the typical operation oscillogram that the operation of " operation mode " and relevant protected mode thereof will be below repeatedly produced by sampling transformer assembly 6,7 and 8 with reference to the demonstration of the circuit diagram of the signal processing circuit outside the EET-IC1 (integrated circuit) of figure 1 system block diagram of the present invention, Fig. 3 and Fig. 4 and being illustrated.
In order to help to understand total system operation of the present invention, at first the built-in function of EET-IC1 introduced in summary.With reference to 2, one simplified block diagrams that show power-saving technology (tradition) integrated circuit (EET-IC1) of its six function element of figure.
Operational scenario below with reference to system in Fig. 1,2, the 3 and 4 explanation originate modes.
When three phase mains 300 at first is connected to line 17,18 and at 19 o'clock, along with DC power supply 16 ends " A " rise to its about 27 volts normal value, capacitor 203 is obtained charging current by the pin 5 of EET-IC1.This action makes the 601 (see figure 2) conductings of originate mode switch, and thereby make EET-IC1 inner wire 606 and 607 and outer pin 7 be pulled to electronegative potential, just approach earthing potential, the charging effect of this capacitor 203 is made of an originate mode instruction delivering to EET-IC1 pin 5.Therefore, EET-IC1 and relevant circuit are promptly taked one of following seven kinds of originate modes:
1. electric current demodulator 600 is forbidden by line 606, and this action is connected to positive 14VDC with the pin 11 of EET-IC1 through an internal resistance.
2. appearing at the wave converter 604 of pin 6 of EET-IC1 and 605 assisted instruction is forbidden by line 607.
When the base stage of originate mode maintained switch 204 via resistance 208 isolating diodes 209, when the pin 7 of line 401 and EET-IC1 is pulled to electronegative potential, on online 802 to the just conducting of signal of the pin 5 of EET-IC1.
When the contact of resistance 102 and isolating diode 103 via isolating diode 106, the pin 7 of line 902 and EET-IC1 and when being reduced to electronegative potential, the protection of operation mode rotor stall then is under an embargo.
When the 211A of starting current regulator potentiometer ADJ211 end via isolating diode 212, the pin 7 of line 504 and EET-IC1 and when being reduced to electronegative potential, the ADJ potentiometer just begins control.
When the end 49A of starting current balanced potentiometer 49 via resistance 214, isolating diode 213, the pin 7 of line 504 and EET-IC1 and be provided a ground connection with reference to the time, potentiometer 49 is activated.
7. the negative terminal of capacitor 43 is via isolating diode 213, the pin 7 of line 504 and EET-IC1 and be reduced to electronegative potential, therefore, can make the rise time delay of the DC control voltage that adds to emitter-follower transistor 52 base stages via starting current balanced potentiometer end 49B.
In order to help to understand the operation of system in originate mode, the solid-state switch door that below description is made EET-IC1 (pin 3 and 13) send triggers the circuit arrangement that output is controlled, EET-IC1 (Fig. 2) includes two identical wave converters 604 and 605, and they respectively have five kinds of possible inputs:
1. the DC through outer pin #16 (15) controls voltage.
2. pass through (power supply) zero crossing bias voltage of outer pin 14 (19).
3. by the assisted instruction of pin # 6 through common wire 609.
4. an inhibit command of process common wire 608.With
5. pass through the triggering timing signal of pin #1 (12).
Fig. 3 shows that the triggered time signal of pin #1 and #12 is provided by electric capacity 1E and 1H respectively, and the component in these capacitors and the wave converter 604 and 605 cooperates and the width and the repetition rate of establishment door trigger impulse.When DC control voltage generator gate triggering signal then when pin # 16 and #15 surpass a specific threshold value, but the phase zero suitable with by DC power supply 16 intersect that bias voltage adds to pin #14 and #19 and time of making zero crossing on three-phase AC power supplies voltage online 18 and 19 slightly before, promptly be under an embargo during the intersection and after a while.Resistance 53,57 and electric capacity 56 and 58 reach the described zero crossing bias voltage cooperation on pin 14 and 19 and make the line 500 and 501 of DC control voltage in Fig. 1 and 3 that is supplied on line 50A and the 52A with the element among the EET-IC1 at DC control voltage processor 5, present sawtooth (ramp type) waveform on pin # 16 and the #15.
Referring to the waveform of Fig. 1 upper left side, notice in DC control voltage ramp to reach threshold value (shown in dotted line 505) that before the door triggering signal produced, time delay (after AC power supplies 300 zero crossings) reduced with the increase of DC control voltage, and vice versa.Therefore as can be seen, when the door triggering signal comes across pin # 3 and #13, when promptly voltage zero is intersected, the delay at its phase angle be with line 50A and 52A (Fig. 3) on the size of DC control voltage, and the threshold value 505 that described door trigger produces is relevant.
Operation mode run duration when motor steady running or load increase lentamente, the size of described DC control voltage is the correlation function of a load/efficient of rotor slip, and the threshold value of described door triggering for generating be internal circuit by EET-IC1 be provided with fix.But, under the situation that some load increases, a corresponding aanalogvoltage can appear in #6 at the acceleration pin, and will there be explanation its reason back.Here only it is also noted that under a particular value, the positive dc voltage that puts on pin # 6 can be lower than the threshold value (Fig. 1 center line 505) of described door triggering for generating pro rata, thereby reduces the delay at phase angle when producing this triggering signal.When this particular value was above, pin # 6 presented a priority status, and these triggering signals are produced (even also being the same) continuously when voltage zero is intersected.
Wave converter input pin # 14 is the positive internal voltage output that AC power supplies is ended breech lock 603 (within the EET-IC1) through the common wire 608 (Fig. 2) of two converters, and the inhibit command that its response puts on the pin # 18 of EET-IC1 produces.No matter how this positive voltage on the line 608 to the voltage input of the pin #6 (acceleration) of EET-IC1 and #15, #16 (DC controls voltage) all makes converter 604 and 605 stop the generator gate triggering signal.When this wave converter was under an embargo as described, solid- state switch 9 and 10 did not receive a triggering signal, therefore just AC power supplies was not coupled to the stator winding 13 and 14 of motor 11.
Now refer again to Fig. 1 and 3, the system operation of the present invention during originate mode is described, as previously mentioned, the charging effect of electric capacity 203 has made EET-IC1 be in a kind of " originate mode " established by seven kinds of particular electrical circuit states.The controlled current flow characteristic of the originate mode operation that elder generation's explanation state 1,5,6 and 7 is established.
With reference to figure 3, originate mode state 1 makes the electric capacity 42 and 46 of DC control voltage processor 5 begin to charge to a maximum positive voltage by the pin #11 of EET-IC1, this voltage is subjected to the dividing potential drop effect of fixed resistance 210 and starting current adjuster ADJ (variable resistor) 211, and the end 211A of ADJ211 is decided to be earthed voltage by starting state 5.In other words, the described maximum positive voltage that is coupled to the moveable arm 49B of starting current balanced potentiometer 49 via line 46A has become " DC controls voltage " of the selectable optimum range of any operator.Because potentiometer 49 (being started with the ground connection reference voltage by state 6 provides dividing potential drop) is coupled to the pin 15 (wave converter #1) of EET-IC1 by line 46A process emitter follower 50 and 52 (through the related elements of its emitter-base bandgap grading) and the described DC control voltage of #16 (wave converter #2) can be adjusted so that the starting current that equates flows into stator winding 13 and 14.Electric capacity 48 (for good and all the base stage by emitter follower 50 is connected to earth point) and 43 (the originate mode operating period when state 7 is connected to earth point by the base stage of emitter follower 52) causes rising at DC control voltage a time delay of the selected definite value of described operator.Summation is got up, and electric capacity 42,46,43 and 48 charging postpone to produce one to be increased gradually, that is the DC of " ramp type " control voltage, and the speed of its rising and last amplitude are to be set by starting current adjuster ADJ211.Because previous reasons, originally solid-state switch 9 and 10 is coupled an electric current that reduces to stator winding 13 and 14, and increases to the maximum an of the best gradually along with time lapse, and the moment of motor 11 also thereby with the same manner correspondingly increases.If the selected current controlled maximum moment of operator is enough to overcome the start request of inertia load, motor 11 just begins to rotate and accelerate to one and approaches synchronous rotating speed, and originate mode processor 3 automatically changes EET-IC1 over to operation mode under this speed.Under described operation mode, the size of described DC control voltage has become continuous (subsequent) function of rotor loading demand.
In the selected starting current deficiency of operator so that motor 11 accelerates to intimate synchronizing speed; or take place during motor starting under the situation of rotor stall; protection processor 4 can be after a manually selected time of delay, starts " AC power supplies is forbidden latch circuit " 603 (Fig. 2) through the pin # 18 of EET-IC1.Then, solid- state switch 9 and 10 stops electric current being imported stator winding 13 and 14 immediately." double mode " operation of protection processor 4 will be discussed after a while.Here only it is also noted that; motor 11 is bordering on synchronous rotating speed if can't accelerate in the rational time; because the operator selectes starting current irrelevantly or because the cause of rotor stall incident then can cause one " originate mode protection " action, previous " originate mode " ended.
Here can sum up " controlled current flow " main points of " originate mode " of the invention described above.With reference to figure 3, when AC power supplies 300 at first was coupled (connection), the charging effect of the electric capacity 203 of " originate mode processor " 3 made EET-IC1 and relevant external circuit enter one group of particular state.Four kinds of states wherein are that following compounding practice is made in the last generation of online 46A one " DC controls voltage ":
1. obtain the amplitude peak that the operator can utilize " starting current adjuster ADJ " 211 to select.
With a kind of " ramp type " but not step function " characteristic and rise to this amplitude peak.
3. can be in manufactory by adjusting " starting current balance " potentiometer 49 in originate mode, to provide through solid- state switch 9 and 10 and the identical currents of stator winding 13 and 14.
Because the stator power that is applied is corresponding to line 49A described " DC controls voltage ", motor 11 is at first controlled by the selected stator voltage electric current that has reduced of described operator and is started, till motor 11 one of arrival are bordering on synchronous speed, after this, this stator current size (and institute's making alive) is subjected to utilizing the energy-conservation load/control from view of profit that practical experience obtained of aforesaid energy-saving appliance technology (EET).
In order to help to understand " the originate mode processor " 3 that will narrate the back and protection processor " 4 effect, explanation earlier is by the common input signal of line 802 couplings by " motor load pulse processor " 2 (it orders their operation) output.With reference to the waveform of being described among the figure 4, solid line waveform 803 be when motor 11 during in zero (empty axle) load running by the stator current of the primary coil that flows through sampling transformer 6,7 and 8 through in addition generation after the full-wave rectification of diode 861 and 862.In the potential pulse exponential type discharge between AC power supplies 300 commutation is to be arranged at the result that element within the motor load pulse processor 2 as shown in Figure 3 is connected to line 17B, 18C and 19C.The voltage waveform that is shown among Fig. 4 is representative, and can reflect that the selected and design of element is convenient, and just, they are not qualification in essence.They are that a prototype of the present invention is measured when operation.
Motor 11 is run duration in typical loading range, the resistive component of the stator current that the peak value of waveform 803 is responded to according to the load of rotor torque and changing between online 805 and 806.But when the slip when the slip of rotor is turned round effectively than motor 11 is much bigger, for example in the 11 starting accelerating periods of motor, the peak value increase of waveform 803 will surpass line 800, and be proportional to the increase of this slip.When the rotor stall, shown in dotted line waveform 804, this peak amplitude is significantly greater than amplitude during the normal running.In other words, sampling transformer 6,7 and 8 waveform output amplitude can be considered an aspect, it be by the slip characteristic of induction motor correctly generate, can show whether motor 11 is in by constitutionally:
1. can reach the running under the high efficiency intimate synchronizing speed.
2. being lower than the running of this high efficiency speed, or
3. halted state just, not in running, but is just being born stator current (for example " rotor stall " state).
When the input power supply was applied on the induction motor at first with the moment of starting motor, its rotor is static.Therefore, before rotation really begins, all have rotor stall situation.After start the accelerating period, the slip of rotor reduces constantly till the intimate synchronous speed that reaches nominal load.
With reference now to Fig. 3,, for above-mentioned reason, the crest amplitude that is connected to circuit in " motor load pulse processor " 2 by line 17B is showing the dynamic situation of motor 11 always.For example, when local sine voltage-beginning is added to stator winding 14 and 15 via solid-state switch 9, electric current just begins to flow through " ST#3ASSY " 8, and " ST#2ASSY " 7 and described stator winding show a rotor stall state when crest amplitude on online 17B of result and the 18C begins.Suppose that rotor begins to quicken, this peak value is stably along with motor 11 reduces near synchronous speed.
Still with reference to figure 3, notice that the negative electrode of 47 volts of Zener diodes 20 and 21 is received line 17B and 18C respectively, and its anode is connected to the base stage of emitter-base bandgap grading limit with device 25.With reference to figure 4,47 volts of Zener conduction thresholds that are labeled as line 800 will be higher than the peak change of the waveform 803 that (line 805 and 806) run duration obtains in the typical loading range of motor 11.Like this, at general loading range run duration, Zener diode 20 and 21 is not coupled to emitter follower 25 with any part of waveform 803.But, as previously mentioned, when rotor stall state (for example a moment of motor starting), in fact the peak value of waveform 803 rises to the conduction threshold (line 800) that is higher than Zener diode 20 and 21.Therefore, during motor starting, up to motor 11 accelerate to be bordering on synchronous speed before, the online part more than 800 of the peak value of waveform 803 is coupled to the base stage of emitter follower 25, is connected to line 802 again.This part of waveform 803 is increased to hundreds of microseconds and is become the control signal that inputs to " motor load pulse processor " 2 by tens of microseconds by the effect of electric capacity 24.
Go on to say the operation of the present invention system in originate mode below with reference to Fig. 3.When playing proper AC power supplies and just being switched on, the charging effect of electric capacity 203 is coupled to pin # 5 with positive voltage, makes EET-IC1 enter one " originate mode " and makes pin # 7 reduce to earth potential, and establish aforementioned seven kinds of particular conditions.Continuing " originate mode processing " that discussion state 3 set up below, will to put it be to decide according to state 1,5,6 and 7 situations that produced (instruction of controlled current flow aspect).
With reference to figure 3, the front has been stated state 3 and can have been made on " originate mode maintained switch " transistor 204 online 802 and to utilize the pin #5 that its base earth is connected to signal EET-IC1 via resistance 208 isolating diodes 209 and the inner lead that is connected to the EET-IC1 element of pin #7.The circuit element of originate mode processor 3 will be described below.The base stage and the reverse biased resistance 201 between the emitter that are connected " originate mode maintained switch " transistor 204 can be guaranteed ending of transistor 204 when EET-IC1 is not in originate mode.Resistance 205 provides the discharge path of electric capacity 203, electric capacity 203 is connected between the contact between the pin #5 of the collector electrode of DC power end " A " and transistor 204 and EET-IC1, and electric capacity 207 is connected between the contact between the pin #5 of the collector electrode of earth point and transistor 204 and EET-IC1.Notice that as preceding when AC power supplies was switched at first, electric capacity 203 was coupled to the pin #5 of EET-IC1 with the rising positive voltage of DC power end " A ", this kind action is to be made of a system " originate mode " instruction.Electric capacity 207 has following multiple function:
1. it provides a low resistance AC filtering path for DC power supply 16 fluctuation or irrelevant (extraneous) noise of coming from AC power supplies 300 couplings by electric capacity 203.
2. the signal pulse that produced of its rotor slip of being come by line 802 couplings via transistor 204 for originate mode operating period provides integration, and therefore the dc voltage (keeping EET-IC1 in " originate mode ") of a quite stable is provided at the pin 5 of EET-IC1.
3. because the conducting of transistor 204; only during originate mode; therefore the described integral action of electric capacity 207 just similarly occurs on online 802, protects the electric capacity 101 of processor 4 to be forbidden postponing the dc voltage level of (variable resistor) 100 couplings through AC power supplies but not the pulse of short time is charged.When will be described later the operation of protection processor 4 operational modes, its importance discussed.
With reference to figure 3, consider now to be switched a series of situations that to line 17,18 and 19, taken place in AC power supplies 300 1:
1.EET-IC1 and interlock circuit utilizes the charging effect of electric capacity 203 to be entered the specific start-up mode state by order; A wherein said state can be connected originate mode maintained switch 204, and this action can be connected to the output line 802 of motor load pulse processor 2 common joint of the pin # 5 of electric capacity 207 and EET-IC1.
2.DC control voltage processor 5 orders EET-IC1 to produce solid-state switch door triggering signal as described above, this effect can be with the sine voltage and the electric current of part, that is the starting power that lowers is coupled to motor 11.
3. flow through ST#3ASSY8, ST#2ASSY7, with the electric current of the AC power supplies 300 of stator winding 14 and 15 at the beginning by producing a control signal output on the motor load pulse processor 2 online 802, its characteristic is equivalent to rotor stall state (that is till motor 11 begins to quicken) characteristic at the beginning.
4. the transistor 240 that is unlocked of the described pulse on the line 802 passes to the pin # 5 of integrating capacitor 207 and EET-IC1 and a lasting positive dc voltage originate mode instruction is provided.Therefore, system also can maintain the originate mode state even when electric capacity 203 no longer extracts charging current by the end " A " of DC power supply 16.
Up to motor 11 accelerate to be bordering on synchronous speed before, (its reason is as described above) on online 802 appears in signal pulse constantly, and therefore, system held is at " controlled current flow originate mode ".
6. along with electrical motors arrives near synchronous speed, originate mode command signal pulse (being produced by significant rotor slip) no longer is coupled to line 802 by motor load pulse processor 2, just, waveform 803 no longer includes any part and surpasses line 800, i.e. Zener diode 20 and 21 conduction threshold.
7. owing to no longer accept pulse, electric capacity 203 and 207 discharges via the pin # 5 of resistance 205 and EET-IC1 apace.
8. therefore, the voltage of the pin # 5 of EET-IC1 is reduced to below the starting order critical value, and EET-IC1 switches in the operation mode, wherein simultaneously:
B. electric current demodulator amplifier 600 is no longer by internalized prohibition (Fig. 2).
C. inner assisted instruction line 609 stops to end (Fig. 2) by outside pin # 6.
9. because the starting power that the decision of the control of the DC on the online 46A (Fig. 3) voltage amplitude has been reduced by the selected starting current adjuster ADJ211 of operator is set the load/efficiency ratio output (the pin #11 of EET-IC1) that is transformed into electric current demodulator amplifier 600, therefore motor 11 stators inputs has become the function of rotor mechanical loading demand, does not have full sine-wave power to be coupled over (unless real loading demand is arranged) from AC power supplies 300.
Can sum up " originate mode processing " of the present invention main points below.
With reference to figure 3, when AC power supplies 300 is converted to line 17,18 and at 19 o'clock, originate mode processor 3 begins operation.Or rather, electric capacity 203 is coupled to the rising positive voltage of AC power supplies 16 they " A " end the contact of the pin #5 of collector electrode, resistance 205 and the electric capacity 207 (its other lead is grounded) of originate mode hold switch transistor 204 and EET-IC1.The positive voltage that EET-IC1 is coupled electric capacity 203 recognizes that to do be originate mode " unlatching " instruction, thereby sets up one group of specific originate mode state inner and outside.One of described starting state is opened the originate mode maintained switch 204 of connection.The control impuls that the rotor slip produced (" controlled current flow " starting by motor 11 is produced) that occurs on online 802 is coupled to originate mode maintained switch 204, be integrated into a continuous positive dc voltage through electric capacity 207, this voltage adds to the pin #5 of EET-IC1 by parallel connection.When described rotor slip pulse no longer occurred on online 802, this situation ordinary representation motor 11 had accelerated near synchronous rotating speed, and the originate mode that electric capacity 207 is discharged to the pin #5 of EET-IC1 instructs below the critical value.At this moment, EET-IC1 then presents " operation mode " state, the base stage of originate mode hold switch transistor 204 is the ground connection via the pin #7 of EET-IC1 no longer, and transistor 204 ends, and effectively the remainder of line 802 by the circuit of originate mode processor 3 is disconnected.Like this, may just not be 207 integrations of electric capacity occurring continuous rotor slip on online 802 pulse of inducting under some operational situation momently, also not be coupled to the pin #5 of EET-IC1, therefore, can not order EET-IC1 to enter originate mode again.
If because blocking rotor then make the motor fail to start, then repair converter because the effect of protection processor 4 when ending when the ripple of EET-IC1, the originate mode retentive control signal pulse on the line 802 promptly disappears, and relevantly protects processing then will give explanation after a while.
Below discussion state 4 and state 3 (originate mode processing enabled instruction), and main points of " the originate mode protection " of establishment together such as state 1,5,6 and 7 (controlled current flow instruction).
Remember that when the signal pulse that the rotor slip is inducted begins to occur on online 802 command signal just is access in line 17,18 and 19 in AC power supplies and inputs to protection processor 4 and originate mode processor 3 in (by the AC power supplies 300) short time afterwards.The electric capacity 207 of also remembering originate mode processor 3 is to be connected on the line 802 by the conducting of (having only originate mode) originate mode hold switch transistor 204.Like this, in " originate mode " operating period, these control signal pulses are by electric capacity 207 integrations, and the command signal of line 802 has become a corresponding D C voltage level.When the circuit of research protection processor 4, postpone two charging paths of electric capacity 101 existence noticing from command signal line 802 to AC power supplies.Constituted " operation mode " AC power supplies inhibit command path from line 802 through resistance 102 and diode 103 to the path of electric capacity 101, the path of ending to postpone (variable resistor) 100 by AC power supplies then is " originate mode " inhibit command path.At last, remember that " originate mode " state 4 utilizes by diode 106, line 902 and be connected to pin #7 EET-IC1 inner member the inside conducting and the contact of the anode tap of resistance 102 and diode 103 reduced to earth potential and end AC power supplies is ended to postpone " operation mode " charging path of electric capacity 101.Illustrated from the front, electric capacity 101 charges to the pin #18 that makes EET-ID1 and starts the delay that AC power supplies is ended the critical value of latch circuit 603 (inside of EET-IC1 as shown in Figure 2) as can be seen, is the dual function that the dc voltage level of the line 802 upper rotor part slips signal instruction of being inducted and AC power supplies end to postpone the manually selectable resistance of resistance 100.Therefore this suspended market order time delay can be adjusted to and make motor 11 have grace time its typical starting duty can be accelerated to speed near synchronous speed in high efficiency mode smoothly, if but motor 11 is not or can not start rightly, just stop originate mode.For example, if selected " controlled current flow " of operator provides unsuitable starting torque, rotor stall situation maybe but takes place when the attempt starting, or the mechanism loading that is driven at starting accelerating period motor has blocked, charging charge on the electric capacity 101 can rise to the suspended market order critical value, and by forbidding stopping to the door triggering command of solid-state switch 9 and 10 operation of originate mode.
In other words, it " originate mode protection " device of the present invention can be summarized as, and can avoid the excessive input current of delivering to motor 11 that is caused by following factors:
1. in the time of " rationally " (selected), can't accelerate near synchronous rotating speed by the operator.
Before starting is quickened or in rotor stall situation takes place.
Before explanation " operation mode protection " operation, the characteristic and the processing of the potential pulse that the rotor slip that occurs on online 802 is correlated with to be discussed earlier and analyze under some situation.Stator current sampling transformer output waveform with reference to figure 4.Occur the amplitude of the control signal pulse on online 802 and width at last and be proportional to waveform 804 that part of of the conduction threshold (line 800) that surpasses Zener diode 20 that rise basically, and be proportional to rotor slip at that time.In other words, the rotor stall situation that is taken place when motor 11 runnings makes online 802 pulse, ratio as, if heavy (or mistake) loads on motor with the energy-conservation running under the zero load that is depressurized to, when under " load of Clutch Coupling " purposes, turning round, suddenly the pulse that is added on the motor to be produced has more high-amplitude and bigger width.
Under rotor stall situation, for the purpose of protecting, preferably the input power on the motor 11 to be removed immediately.But, if add a nominal load suddenly, or overload to a certain degree, cause motor 11 (before with the voltage that reduces in idle commentaries on classics with energy savings) to bear excessive rotor slip, the stator voltage that applied of then preferably will raising soon also makes motor 11 accelerate to the optimum efficiency speed relevant with a load again.In the present invention, the rotor slip signal output of being inducted side by side makes EET-IC1 carry out appropriate required action via " motor 11 load pulse processors " 2 and " protection processor " 4 by line 802 in " operation mode " operating period.With reference to figure 3 and notice that line 802 is connected to " accelerations " pin # 6 of EET-IC1 with the control output of emitter follower 25 (input of its signal is from the rotor slip of ST#2ASSY7 and the ST#3ASSY8 pulse of inducting) via resistance 30, and be connected to " AC power supplies termination " pin # 18 via the circuit of protecting processor 4.
It is different that " starting " of character under the inner member co-operating of originate mode processor 3 circuit and EET-IC1 that the control signal on online 802 occurs reaches in " running " pattern.Or rather, in " originate mode " operating period, the integration (being integrated into a corresponding D C voltage level) that the pulse that the rotor slip is inducted on online 802 occurs is given setting earlier when being connected to line 802 in the emitter-base bandgap grading collector electrode conducting of originate mode hold switch transistor 204 and with electric capacity 207 unearthed.But, state as preceding, the resistance 201 that transistor 204 is reversed bias voltage in " operation mode " operating period remains on cut-off state, like this, during " operation mode ", the control signal on the line 802 is included in its amplitude and the width pulse relevant with respect to the characteristic of rotor slip with induction motor at that time during each source current alternation when occurring.
Occur the description of the control signal on online 802 in view of the front is relevant in " operation mode " operating period, go on to say the reaction of motor load pulse processor 2 and 4 pairs of described signals of protection processor.Suppose such a case, be that motor 11 is at energy-saving appliance, electric current demodulation of the present invention partly, lower under the stator voltage control action to approach synchronous rotating speed and minimum power input idle running (i.e. " non-loaded "), suppose now that a medium overload is added in suddenly on the pony axle 12 and generation limiting performance requirement situation.Since the stator voltage of motor 11 than transmit in addition 5 percent required voltages of full load moment much lower, rotor slip meeting begins increase along with each time alternation of power supply 300.Adding the initial moment after the load, the increase that inputs to the load/efficient associated control signal amplitude of motor load pulse processor 2 on the online 18c (output of ST#2ASSY7) can make the electric current demodulator amplifier 600 in the EET-IC1 begin to increase to appear at the DC control voltage on the line 46A of DC control voltage processor 5.Therefore, the phase angle of door triggering for generating postpones to be reduced, and motor 11 stator voltages begin to rise.But the long integration time constant (the best stability of a system is necessary) of circuit element has been avoided the rising that is exceedingly fast of DC control voltage between the pin #11 of EET-IC1 and line 46A.Like this, under " steplike function ", with regard to regard to the heavy duty demand that it " step function " formula of purpose is discussed, the climbing of DC control voltage is also insufficient, so the rotor slip continues to increase.Like this; during several identical mains half-cycle; the control impuls that the rotor slip is inducted appears at the output of emitter follower 25, and is coupled to a resistance 30 (response of the element in protection processor 4 and the originate mode processor 3 will be explained below) in the load pulse processor 2 via line 802.
Each mains half-cycle is increased and the described control impuls that increases its amplitude and width is coupled to an end of resistance 30 charging capacitor 31 between the other end that is connected in earth point and resistance 30 and the contact of EET-IC1 acceleration pin #6 along with the rotor slip.Remember, noticed during in front to the explanation of the wave converter of EET-IC1, below a particular value, the positive voltage on the pin #6 reduces the critical value (505 lines among Fig. 1) of the door triggering for generating of described wave converter, and reduces the phase delay of this triggering for generating.The increment rate that described effect can be coupled to solid-state switch 9 and 10 stator voltage of motor 11 accelerate to surpass that electric current demodulator amplifier 600 in the EET-IC1 commanded by the climbing on the online 46A of DC control voltage.In other words, under the loading demand of this supposition, when the online 46A of DC control voltage rises, increase the critical value decline that positive voltage on the pin #6 (31 charging times of electric capacity being produced by line 802 upper rotor part slip control impuls) can make a triggering for generating simultaneously, and this has just quickened to add to the increment rate of the stator voltage of motor 11.Along with stator voltage increases, i.e. the also proportional increase of control impuls amplitude and width on the line 802 has more been quickened door and has been triggered the slip that the phase angle postpones, and just, has played the positive feedback effect of rotor slip in the increase of the positive voltage of pin #6.In several mains half-cycle thereafter, motor 11 stator voltages rise to is enough to produce the desired big moment of product loading demand.Along with the acceleration of motor 11, the rotor slip reduces rapidly, and the control impuls that this too high slip produced promptly no longer occurs on online 802.Therefore electric capacity 31 discharges at once, the electric current demodulator amplifier 600 of EET-IC1 then get again its to motor stator voltage with the proportional control of load.
The present invention can be summarized as follows for the response that a supposition extreme load that is coupled to motor 11 requires when the stator voltage running that reduces with energy-saving appliance.
At first, notice when protection processor 4 circuit also receive the signal that the rotor slip inducted on common wire 802, just do not produce suspended market order EET-IC1.Though the situation of the sudden change load of being supposed is quite extreme, being not sufficient to need be to the protection action of motor 11.When being responded the protection that the rotor stall is discussed in the back, the circuit of at this moment protecting processor 4 described in detail.Above 2 pairs of the motor load pulse processors suppose that the response of situation has following two aspects:
1.EET-IC1 pin #10 (to the input of the summation bias voltage of electric current demodulator amplifier 600) instruct and increases dc voltage being proportional under the new load request and export (pin #11).
2. Zener diode 20 and 21, electric capacity 24, resistance 22 and emitter follower 25 handled rotor slip control impuls are connected to (acceleration) pin # 6 of EET-IC1 by RC time constant element via line 802.
EET-IC1 makes motor 11 stator voltages rise to the required sinusoidal all-wave power of medium overload by the rising load of being supposed that applies in the steplike function mode to the response of the above-mentioned control input of sending from motor load pulse processor 2 apace.
The following describes the operation mode protection.With reference to figure 3, protection processor 4 responds sensed motor rotor slip character constantly to be caused and control signal pulse on online 802 occurs.Notice that the suspended market order critical value that described control impuls can charge to AC power supplies termination delay electric capacity 101 the pin # 18 of EET-IC1 has two paralleled paths.The operation mode path by resistance 102 and diode 103, is ended when motor 11 startings are quickened.But when motor 11 arrived near synchronous rotating speed, EET-IC1 was converted to the operation of operation mode, and two paths are unlocked, so electric capacity 101 can directly charge through variable resistor 100 and resistance 102 and diode 103.Because the charging interval at operation mode operating period electric capacity 101 be reduced, resistance 102 selected resistances should be lower than the maximum value of variable resistor 100.
In operation mode operating period, (originate mode processor 3) electric capacity 207 is not connected on the line 802 by originate mode maintained switch 204, and therefore during operation mode, the control impuls of line 802 becomes the dc voltage of first-class amount without integration.For this reason, to come across in the alternating cycles that continues on the line 802 in the control impuls that the rotor slip is inducted be to charge in the duty cycle mode to electric capacity 101.Just, electric capacity 101 charges according to variable control impuls amplitude and width according to line 802 when a source current half period begins, and to next current half begin time discharge.Be also noted that resistance 22 (in the collector electrode of emitter follower 25) makes the control impuls of the relative short time on the line 802 avoid fast rise with the charge constant of integrating capacitor 207 (being started by originate mode maintained switch 204), or rise to the amplitude of its maximum possible at the integration dc voltage of originate mode operating period chien shih line 802.But in operation mode, described control impuls is really not so restricted, and it rises to apace compared with peak amplitude also high in the dynamic model formula.Also be appreciated that; with the minor variations of the pulse duration of proportional this control impuls of slip be that described integral action by electric capacity 207 causes; although this importance when the originate mode protection charging of electric capacity 101 is very little; but in operation mode; the width of described control impuls shows to land influences its charge/discharge duty cycle; thereby influence greatly rises to the climbing speed of termination critical value of the pin #18 of EET-IC1.Or rather, the amplitude of the successional control impuls that rotor stall state is produced and width can be between several half periods charge to electric capacity 101 AC power supplies suspended market order level (mainly passing through resistance 102 and diode 103), but the situation of moderate excessive rotor slip then can not.
The response of protection processor 4 in the situation of considering now to be supposed in front that adds heavy duty suddenly, when rotor slip when initial instantaneous increases after this load adds, electric capacity 101 begins charging according to the amplitude of the described control impuls on the line 802 and width.Though excessive rotor slip meeting temporarily takes place, the real stall of rotor, therefore, these pulses even in a half period, can not reach the amplitude and the width of rotor stall.Like this, under the worst load condition, protection processor 5 can not send an AC power supplies suspended market order.
Suppose a kind of situation now, wherein motor 11 is to turn round with the rotating shaft 12 of zero load, and is connected on the stuck mechanism loading with clutch.In other words, suppose that the motor 11 that is turning round almost is that a rotor stall incident takes place instantaneously.In the initial instantaneous moment after this incident takes place, circuit of the present invention produces response with aforementioned manner, and just, it begins to increase stator voltage to a new loading demand value of motor 11.But, in the back in this case, increasing fast along with stator voltage response aforesaid " assisted instruction " effect, the rotor slip also continues to increase.Like this, in several half periods of electric current, the control impuls on the line 802 is promptly taked a size and a form during corresponding to rotor stall situation.Within several mains half-cycle after motor 11 rotor stalls, electric capacity 101 is charged to is enough to make the pin # 18 of EET-IC1 to enter an AC power supplies door triggering suspending mode.Dc voltage input up to the pin # 20 that receives EET-IC1 is removed, and before adding, EET-IC1 can maintain under the described suspending mode, and solid- state switch 9 and 10 promptly can not be connected to stator voltage on the motor 11.
Aforementioned the present invention is that supposition three-phase AC power supplies 300 is to supply with motor 11 with the specified input voltage of nominal at the line 17,18 and 19 of Fig. 1 in the operation that " starting " reaches in " running " pattern.Yet, during the long-life of an industrial threephase motor, three kinds of general A c-power supply abnormal case may cause induction motor serious or even destructive damage, they are:
1.AC input " losing mutually ", that is line 17,18 and 19 has become open circuit between AC power supplies 300 and motor 11.
2.AC the voltage ratio motor nominal rating value of power supply 300 exceeds a lot.
3.AC the voltage of power supply 300 is showing when being lower than motor starting or the nominal rating value during with the running of 75% (or higher) of maximum rated load after starting.When these anomalies were the incident of short time, stator winding can be not impaired.But, if this situation takes place often or continue the oversize time, then excessive stator current not only wastes energy and causes nonvolatil motor to damage often.Illustrate as the back; the configuration of three-phase DC power supply 16 of the present invention can be monitored the characteristic of ac power cable input voltage and indicate EET-IC1 to enter the abort state of AC power supplies under some rough sledding; thereby protection motor 11 is avoided the specific unusual infringement of ac input voltage.
As shown in Figure 8, three-phase DC power supply 16 utilizes transformer coupled device to produce low-power (for example 50mw) bias voltage of various systems by AC power supplies 300 warps 17,18 and 19 inputs.Or rather, all-wave, all half cycles of unfiltered negative supply voltage are to utilize general transformer/diode rectifier assembly 715 and by generating on line 17,18 and 19, and are used as:
A. via line 750,751 and 752 signal inputs to power processor 6.
B. via output 8 and 10 and arrive electric current demodulator amplifier 600 (Fig. 2) and via output " D " and " F " to wave converter #1,604 and #2,605 (Fig. 2) are to " reverse biased " input of the suitable phase place of tool of EET-IC1.
This power supply 16 also sends the dc voltage of full-wave rectification by capacitive coupling device by AC power supplies incoming line 17,18 and 19, and provides simultaneously with other circuit element cooperations:
1. the dc voltage through regulating is for the usefulness of discrete and integrated circuit component operation.
2. supply the radio frequency interference filtering (RFI noise suppressed) of described input power cord.
3. to a certain degree capacitive power factor correction on described input power cord.
4. use for the solid-state element switch, just, to the low dc voltage and the low current control device of the contactless AC power supplies switching usefulness of the motor 11 (within the treatable power capacity scope of solid-state switch technology institute) of any horsepower of tool (size) or input voltage rated value.
Or rather, electric capacity 700,701 and 702 is coupled to three-phase full-wave diode bridge 703 with three-phase AC voltage from described incoming line.The positive dc voltage output of bridge 703 then connects by line 717:
1. reach " Y " to solid- state switch assembly 9 and 10 interior door trigger amplifiers by end " Z " respectively via RC decoupling network A+.
2. via holding " A " to originate mode processor 3.
3. to the negative electrode of one first adjuster Zener diode 704, its anode is by resistance 705 ground connection.
4. pass through the negative electrode of resistance 707 to 1 second adjuster Zener diodes 708, its plus earth.
5. to the anode of a filter capacitor 709, its negativing ending grounding.
6. through end " R " and line 714 to one motor AC power supplies switches 713.Aforesaid capacitive couplings device satisfies the dc voltage demand of discrete of the present invention and integrated circuit and carries out other practicable function.
For example, described device provide simultaneously one by line 17,18 and 19 through electric capacity 700,701,702, diode bridge 703 and electric capacity 709 and the Low ESR AC signalling channel of ground connection.Like this, switch the high-frequency noise (RFI) that is produced by the phase angle delay AC power supplies of solid- state switch 9 and 10 and be switched on ground connection, this kind effect has significantly reduced by line 17, produce on 18 and 19, perhaps be coupled to AC power supplies 300, just, along the RFI that enters ac power cable.Be also noted that electric capacity 700,701 and 702 is the parallel ground that is connected to basically, and via ac-input power supply line 17,18 and 19 and be connected to motor 11, this motor is owing to due to its essence, comprise that one will reduce an inductive load of described incoming line power factor.Described so parallel capacitor connecting device also provides power factor correction to a certain degree, and this correction can be offset the inductive of motor 11 partly, and this is particularly important to fractional horse power motor.
At last, a parallel end with " A " " R " is connected to the anode of bridge 703 through line 717.State as preceding, all positive DC system operation voltages are produced by bridge 703.Therefore, if line 717 (the positive DC output of bridge 703) is converted to ground connection, for example at the end (its other end be ground connection) of " R " end via line 714 to SPST (single-pole single-throw(SPST) switch 713, in fact then described system DC operating voltage promptly turn-offs.Under this " shutoff " state, solid- state switch 9 and 10 startup triggering signal can't produce, and therefore, the voltage on the AC power supplies 300 online 18 and 19 just can't be coupled to the stator winding 13 and 14 of motor 11.
Like this, single is that line 717 ground connection (" R " end) just be can be used to cut off, and just turn-offs the AC power supplies that is connected to motor 11, and vice versa.
Moreover, hold ground connection promptly to interrupt the power consumption of other circuit elements of 703 feeds of three-phase diode bridge with " R ".But the power factor correction function of electric capacity 700,701 and 702 then still continues, because they are directly to pass through switch 713 through 703 utilizations of passing a bridge now, rather than by the AC grounded circuit via electric capacity 709, ground connection.
In other words, the present invention adopts the arrangement of capacitive coupling bridge rectifier component 703 to carry out the function of several useful and/or necessary (suppressing as control of electric electromechanics source switch and RFI) synergistically with remainder of the present invention, and does not just supply the DC operating voltage.
The dc voltage adjusting of DC power supply 16 and the compensation arrangement of AC power supplies 300 high voltage incidents are discussed below.Still with reference to figure 8, the output of noting the line 717 of bridge 703 is via the Zener diode 704 of a 25V and resistance 705 and ground connection.Owing to making the harmless lost territory of the voltage that is significantly higher than required AC power supplies, the conducting of several different circuit elements and Zener diode 704 drops in the AC impedance of electric capacity 700,701 and 702.By the design alternative to component value, a low-voltage (for example 2 volts) can the conducting owing to Zener diode 704 obtains at resistance 705 two ends when AC power supplies 300 supply nominal rating voltages.When described AC change in voltage, described low-voltage also changes pro rata.Therefore, described low-voltage can be used as ac power cable voltage amplitude response bias voltage and holds the waveform transformation part that is coupled to EET-IC1 by E via line 716.Like this, when AC power supplies voltage rises, and when the unadjusted reverse biased output of transformer device 715 is also risen, the positive bias output of end E is risen similarly, this effect has compensated the back bias voltage increase to EET-IC1, vice versa, and described slide-back can make the present invention be significantly higher than " starting " under the rated voltage situation of motor 11 at ac input voltage and reach in " running " pattern and improve energy-saving effect.
With reference now to Fig. 8, the supervision effect and the motor protection effect of AC power supplies 300 of a power processor 6 of three-phase DC power supply 16 is described.The reverse biased output of transformer device 715 is via line 750,751 and 752 and signal is inputed to power processor 6 same resistance 710 1 ends, these resistance 710 other ends are common junction and draw current resistor 711 to be connected to Zener voltage via one and regulate the negative electrode of diode 708 and and then be connected to the AC power supplies termination pin #18 of EET-IC1 by diode 712 and " P " end.Utilize the selected of component value, all supply 65% or the as many as line 17,18 and 19 time more of specified (nominal) input voltage, can make this common junction present a specific negative value when the three-phase of AC power supplies 300.If described AC power supplies voltage is reduced to this below 65% value, then the common junction of resistance 710,711 and diode 712 will be owing to drawing current resistor 711 to rise a positive voltage level.Be the diode 712 of positive bias in this case, with the pin #18 of described contact positive voltage conducting to EET-IC1, this effect includes an AC power supplies suspended market order to EET-IC1.Like this, reduce to 65% when following of rated value at the voltage of AC power supplies 300, (motor 11 is in serious low-power in this case, and suffer starting difficulty or because of medium or higher nominal load overheated) power processor 6 promptly sends an AC power supplies suspended market order (positive voltage) to EET-IC1.Solid-state switch 9 and 10 is owing to no longer receive the unlatching triggering signal of being sent here by EET-IC1, and stops described low input to be coupled to from AC power supplies 300 stator winding 13 and 14 of motor 11 again.
Now consider a kind of dephasing situation on arbitrary line of input power cord 17,18 and 19 again, when all each phases all existed, the common joint of resistance 710 bore continuous negative dc voltage.But,, then between remaining two power line, cause " single-phase " situation if lose any one input mutually.Under this single-phase AC power supplies input condition, the common junction of resistance 710 promptly obtains the rectified waveform of single-phase full wave.Be some negative half period sine waves that rise to null value, but not aforesaid by the three-phase input continuously negative dc voltage that power supply produced.Like this, along with this first single-phase negative half period rises to zero, draw current resistor 711 can make the common junction of resistance 710,711 and diode 712 rise to a positive voltage.As in the situation of aforementioned low ac input voltage, described contact positive voltage has constituted an AC power supplies suspended market order to EET-IC1 pin # 18, just AC power supplies no longer is coupled to the stator winding 13 and 14 of motor 11 by solid- state switch 9 and 10.
Sum up below when motor 11 is in following situation, the present invention reaches unique energy-conservation and motor protection operation in " running " pattern in " starting ":
1. do not require the starting of protective effect and the running that continues.
2. lose phase AC power supplies input, that is, dephasing when starting or when continuing running.
3. when motor attempt starting, exist or generation mechanicalness rotor stall situation.
4. in operation mode, that is rotor stall incident takes place after the normal starting.
5. cross the voltage of the AC power supplies 300 of low (65% or lower).
6. the voltage of the AC power supplies 300 of too high (125% or higher).
The following describes and be applicable to above-mentioned situation #1, #2, #3, #5 and #6.When initial a flash that AC power supplies 300 just has been energized, Fig. 1 shows:
At described initial a flash, and several later AC power supplies because solid- state switch 9 and 10 is in off state, do not have electric current to flow through the stator winding of motor 11 so EET-IC1 produces the triggering signal of opening door as yet within the half period.
In the moment behind electric power starting, suppose top situation #1 and with reference to figure 3.The system reverse bias voltage at once by DC power supply 16 via 8; 10; " F " and " D " end and be coupled to EET-IC1; and positive dc voltage is risen via " A ", " C " and " E " end; up voltage has constituted a system activation signal on " A " of DC power supply 16 end, and therefore, EET-IC1 commands internal circuit; originate mode processor 3, the external circuit of protection processor 4 and DC control voltage processor 5 enter one group and work in coordination and set up the particular state that the back is called the originate mode operation.Briefly, described state:
Thereby a. having triggered originate mode processor 3 makes EET-IC1 remain on described originate mode operation down till motor 11 accelerates near synchronous speed.
B. making the AC power supplies of protecting processor 4 abort the start delay can work.With
C. by solid- state switch 9 and 10 Current Control of stator winding is transferred to via the originate mode of starting current adjuster ADJ (variable resistor) from load/efficiency response (electric current demodulator) part of EET-IC1 and manually controls.
Top C item makes the operator can (manually) select the originate mode maximum moment that motor 11 is produced by the controlled current flow that limits stator current.It is required to suppose that this selected originate mode moment is enough to satisfy motor 11 starting duties, rotor promptly quickens not having to begin under the situation of high surge current so, these cross high surge current be included in the power line quota when decide the voltage starting generation or adopt the resulting surge current of various prior art reduced voltage starting devices greater than required electric current.If the selected starting torque of operator is not enough to practical requirement; promptly; can't end to accelerate in time of delay near synchronous rotating speed in the selected AC power supplies of operator; protection processor 4 promptly commands EET-IC1 to go to forbid the unlatching of solid- state switch 9 and 10; thereby make the unlikely inflow motor 11 of stator current before AC power supplies 300 is turned off and opens once more.Therefore the operator need not measuring instrument just can make the starting demand of unknown load simply selected, as long as the controlled quentity controlled variable that increases starting current adjuster ADJ211 gradually until AC power supplies 300 open and motor in the accelerating time that the operator selectes successfully till the starting.
When adjusting like this, the rotation meeting of motor 11 increases gradually along with rotor torque and begins at leisure, then accelerates to reposefully near synchronous rotating speed to be close to minimum power consumption in the time that natural characteristic determined of rotor loading demand and motor 11.Under this speed, originate mode processor 3 is transferred to system's control by EET-IC1 the operation of operation mode.In this operation mode, the size of stator voltage of reduction that is coupled to the foot winding of motor 11 by solid- state switch 9 and 10 then responds the load pulse of electric current demodulator part of EET-IC1 and proportional with loading demand basically.Like this, controlled current flow during starts the quota of power line decide voltage and just will never be received on the motor 11, even also like this in finishing in the originate mode operation, unless rotor loading has actual needs.
Supposition now is before motor 11 startings, and ac-input power supply line 17,18 or one of 19 is by open circuit (top situation #2), or in operation mode operation after a while this situation takes place.This situation is called as " dephasing ".In this case, the power processor 6 (Fig. 8) of three-phase DC power supply 16 makes EET-IC1 forbid the open-minded of solid- state switch 9 and 10 within the one-period of AC power supplies 300.Like this, if attempt starting motor 11 in this case, then EET-IC1 has promptly changed the AC power supplies abort state over to before the originate mode operation can begin, thereby avoids rotor stall starting current to flow into any stator winding.If dephasing takes place when operation mode motor of the present invention, then the stator current that flows in Sheng Xia two power windings promptly is interrupted during AC power supplies 300 electric current alternations once.In other words, in the one-period of AC power supplies 300 or shorter time, provide the protection of input dephasing in the present invention under any mode of operation to motor 11.
The rotor stall state (above-mentioned state #3) of hypothesis generation when motor 11 to be ready starting now.The originate mode operation response of protection processor 4 is with respect to the stator current sampling control impuls characteristic also bigger than full load; and make EET-IC1 when a selected starting time delay period of operator finishes, enter the AC power supplies abort state, because motor 11 can't accelerate near synchronous rotating speed.But if the selected controlled current flow of operator is less than the full load rated value, though then motor 11 does not turn round, also can be not impaired, so EET-IC1 just can not entered the AC power supplies abort state by instruction yet.In other words, protected motor 11 make its not the normal reduced voltage starting electric current of the long-time high value of reason or rotor stall state super-high-current and suffer damage.
Rotor stall incident (above-mentioned state #4) takes place in hypothesis during motor 11 runs well now.Protection processor 4 operation mode operational orders (operator can not adjust) response is a stator current sampling control impuls characteristic corresponding to rotor stall situation when the AC voltage that increases fast is coupled to motor 11 stator winding.Several power supply alternation after the rotor stall makes EET-IC1 enter the AC power supplies abort state in the time.
The voltage of now supposing AC power supplies 300 significantly is lower than specified (defined on the famous brand) input voltage (above-mentioned state #5) of motor 11.About below 65% in supply voltage nominal rating value, power processor 6 (three phase mains 16 of Fig. 8) can make EET-IC1 enter the AC power supplies abort state, to avoid motor 11 startings or to continue the operation of its operation mode.But; if motor 11 is just to turn round near under the maximum rated load; and power supply 300 voltages reduce (making motor 11 stall enter rotor stall state) significantly; then protect 65% (or following) that processor 4 or power processor 6 can reduce to the nominal rating value at AC power supplies 300 voltages before, make EET-IC1 enter the AC power supplies abort state.
Now the voltage of hypothesis AC power supplies 300 is significantly higher than specified (defined on the famous brand) input voltage (above-mentioned state #6) of motor 11.The breakdown voltage ratings of also supposing solid- state switch 9 and 10 is not to be a limiting factor of performance, just, described assembly under the nominal voltage that is higher than the AC power supplies 300 that (for the purpose of discussing) suppose with normal running.
The present invention can be under the situation of the overvoltage amplitude of AC power supplies 300 about 20% (that is 120% nominal value), provides above-mentioned energy-conservation in starting and operation mode, and motor protection function.But; rising with the work overvoltage surpasses about 20%; the effect of promptly becoming of the high bias compensation circuit of three-phase DC power supply 16 is little; and also begin to increase with the increase of the voltage of work AC power supplies 300 by the rotor slip control signal pulse amplitude of being inducted that motor load pulse processor 2 is coupled to protection processor 4; promptly; this control impuls characteristic become to the supply voltage sensitivity (and just in " starting " pattern to the sensitivity of " manually selecting " or in " running " pattern to " load control " sensitivity); or rather; in the starting and the two kinds of pattern operations of turning round, shortened the AC power supplies of protection processor 4 according to the described supply voltage response of described control impuls amplitude and ended to postpone.Like this; when the amplitude of AC power supplies voltage 300 increases to some percentage (more than 120% of nominal value), protection processor 4 can make EET-IC1 enter abort state during attempt starting motor 11, just; in 11 accelerating periods of motor, finish the originate mode operation.In other words, solid-state switch 9 and 10 is its action if the voltage ratio nominal rating voltage of AC power supplies 300 supplies just was under an embargo when much bigger (promptly surpassing 125%) in originate mode, the potential hazard of stator current amplitude when therefore protecting motor 11 to avoid starting.
The AC power supplies abort actions of protection processor 4 in some cases, (as AC power supplies 300 voltages after motor starting, that is when the present invention has entered the operation mode operation, if voltage rises above 20% when above of normal rating) equally also can produce.Remember the existing explanation in front, the control impuls amplitude that the rotor slip is inducted can increase with the remarkable increase of supply voltage.Therefore, under Shuo Ming the originate mode operational circumstances, the AC power supplies abort actions of protection processor 4 becomes to too high supply voltage amplitude, and the unexpected increase of loading demand, particularly loading demand has controlled response in the above.More particularly; under nominal supply voltage certain occasion more than 120%; described control impuls amplitude can rise to is enough to make protection processor 4 to make EET-IC1 enter illegal state, and to stop the conducting of solid- state switch 9 and 10, This move has been ended the stator winding of electric current inflow motor 11.The loading demand that becomes heavily the unexpected increase that (or mistake) carry by utmost point underloading can make protection processor 4 suspended market order take place under than the also low down overpressure value of (for example) steady load operation mode operation and move.
The summary system is in the performance that is higher than under specified AC power supplies 300 voltages, and controlled current flow (falling voltage) starting and energy-saving operation pattern operation subsequently can continue till described supply voltage is higher than nominal value about 120%.Greater than a certain specific voltage of this value the time, be coupled to the instruction that the AC power supplies of the stator winding of motor 11 can protected processor 4 by solid- state switch 9 and 10 and end.
Though the specific embodiment of an operation model of setting up according to the present invention below has been described, has implemented to those skilled in the art and may make many conspicuous variations.For example, almost completely rely on analog circuit and signal pulse processing unit at this illustrated embodiment, but the equivalent electric circuit of nearly all analogue means can also utilize the technology of microprocessor, by foundation notion of the present invention, corresponding hardware and software are finished.Its example for example; in the originate mode operation; that protects processor 4 ends delay period by the selected AC power supplies of operator; it utilizes signal pulse to obtain; an electric capacity is charged to a specific charge threshold level) via a manual variable resistor 100; can utilize digital counting and manual programming are carried out in this pulse, the certain pulses when promptly selecting the AC power supplies abort actions is taken place is counted and is realized.
Therefore, must understand, above stated specification only is to be used for explaining orally the present invention, but not is used for limiting the present invention, and all change and modification of doing according to the present invention's principle all should be included in the claim of request of the present invention.
Claims (16)
1. power control system, it comprises an induction motor with rotor and stator winding, sine-wave power is used to and makes described rotor rotation and encourage described stator winding, a motor current demodulator that is coupled to stator winding, monitor to all parameters of the starting current of stator winding when zero increases in order to the electric current in stator winding, described motor current demodulator is worked for the output control signal that produces its amplitude and depend on the starting current parameter that efficient is relevant, with the control circuit of a response from the output control signal of motor current demodulator, this circuit is by changing that part of energising of controlling described power supply to stator winding of being coupled to each sine wave of stator winding from power supply, and described control system is characterised in that:
-at the start mode run duration, be used to select the peaked device that can manually set of motor starting moment (211);
-at described start mode run duration, with so that the device (3,601) that described motor current demodulator (600) lost efficacy,
The described manual tunable arrangement of-response (211) is to add to the device (5 of the maximum current of described stator winding from described power supply in described start mode run duration restriction, 9,10), thus guarantee that described start mode run duration motor moment can not exceed the maximum of the described motor starting moment of having selected; And
-response is just reaching the device (3) of the motor speed that is close to synchronizing speed, so that described control circuit (1) is operated for changing described power control system over to operational mode from described start mode.
2. power control system as claimed in claim 1 is characterized in that: described induction motor (11) is a threephase motor with three stator winding (13,14,15); This power supply (300) be the three phase mains that its three-phase is linked described threephase stator winding respectively, one of described at least power supply mutually and the connection between its stator winding comprise the part (6,7 or 8) of described electric current demodulator.
3. power control system as claimed in claim 2 is characterized in that comprising:
-each mutually described power supply (17,18,19) can be coupled to capacitive the device (700,701,702) of a three-phase full-wave diode bridge (703), described diode bridge for produce the DC operating voltage of using for described control circuit and operate and
-with the output capacitive of described bridge be coupled to the device (709) on ground.
4. power control system as claimed in claim 2 is characterized in that comprising:
-have three transformers (715) of level winding at the beginning of the three-phase (17,18,19) that is connected to described power supply (300) respectively,
-link three rectifier (see figure 8)s of described three phase convertor secondary winding respectively;
-concurrently with the device (6A, 710) of the rectification of described three secondary winding output feed to a common point;
Thereby-the current potential that is used to monitor described common point place is surveyed at least one mutually described power supply and is occurred the monitoring device (711,712) of opening a way mutually; And
-be used to respond described open-circuit condition and stop electric current to be conducted to the inhibiting apparatus (16A, 1) of described stator winding from described power supply (300).
5. power control system as claimed in claim 1 is characterized in that comprising:
-be used to monitor described power supply (300) output voltage amplitude device (6,7,8,4) and
-be used to respond rise and reach the above described output voltage of predetermined limit value and forbid the device (1) of described power supply described stator winding electrifying.
6. power control system as claimed in claim 1 is characterized in that comprising:
-be used to monitor described power supply (300) output voltage amplitude device (6A) and
-be used to respond and drop to the following described output voltage of certain predetermined limit value and end of the excitation of described power supply described stator winding.
7. power control system, it comprises an induction motor with rotor and stator winding, a sine-wave power is used to described rotor rotation and encourages described stator winding, a motor current demodulator that is coupled to stator winding, in order to the electric current in stator winding when zero increases, monitor to the operational efficiency relevant parameter of the starting current of stator winding, this demodulator is worked for the output control signal that produces its amplitude and depend on the starting current parameter that this efficient is relevant, with the control circuit of a response from the output control signal of motor current demodulator, in order to control of the excitation of described power supply, it is characterized in that stator winding:
-the device (3) that lost efficacy at the described motor current demodulator of motor starting system runtime chien shih (600) and
-after described start mode, reach intimate synchronizing speed and trigger described motor current demodulator (600) is transformed into described power control system the motor operational mode from described start mode device (3) in order to respond described motor speed.
8. as the control system of power claim 7, it is characterized in that comprising: be used for during described start mode the appearance of response rotor stall state and forbid the device (1,4) of described power supply (300) with the described stator winding of electric current supply.
9. as the control system of claim 7 or 8, it is characterized in that comprising the appearance that is used for response rotor stall state during described operational mode and forbid the device (1,4) of described power supply (300) the described stator winding of electric current supply.
10. control system as claimed in claim 7 is characterized in that comprising that being used for response described motor of response (11) in a predetermined interval fails to reach intimate synchronous rotating speed and forbid the device (1,4) of described power supply (300) to described stator winding excitation.
11. control system as claimed in claim 10 is characterized in that comprising the manual tunable arrangement (100) that is used for optionally changing the described time interval.
12. control system as claimed in claim 7 is characterized in that:
-described motor (11) is a three phase induction motor,
-described power supply (300) is a three phase mains, and Qi Gexiang is connected respectively to the stator winding (13,14,15) of described motor (11).
13., it is characterized in that comprising being used for responding all mutually at least one open-circuit conditions that occurs mutually of described power supply and forbidding that electric current flows through the device of described motor stator winding (6A, 1) as the control system of claim 12.
14. control system as claimed in claim 7 is characterized in that comprising being used to limit the manual tunable arrangement (211) that described start mode run duration can add to the maximum current of described stator winding from described power supply (300).
15. control system as claimed in claim 7, it is characterized in that comprising be used to respond described supply voltage surpass the variation of a predetermined limit value and forbid described power supply (300) to the inhibiting apparatus of the excitation of described stator winding (1,4,6A).
16. power control system with AC induction motor of a rotor and a stator winding, it comprises motor power and described power supply is coupled to described stator winding with the control circuit of control to described stator winding excitation, it is characterized in that: described control circuit comprises that one has manual tunable arrangement (211) so that set one at the start mode run duration, the peaked start mode control circuit of starting torque (1-10) that described motor (11) is to be applied, described start mode control circuit (1-10) can not consider to be described stator winding (13 during being set in described start mode during the described start mode under the situation of practical function in described epitrochanterian load, 14,15) Nei the electric current maximum that can rise to and operating; One is coupled to described stator winding (13 with described power supply (300), 14,15) operational mode control circuit (1,2,4-10), to control the current amplitude that is added to described stator winding from described power supply, and irrelevant with the setting of described manual tunable arrangement (211), the part of described operational mode control circuit (600) is inoperative at described start mode run duration as a function that acts on described rotor (12) for this amplitude; Be used for rotating speed when described rotor (12) and reach the circuit arrangement (3) that triggers the described part (600) of described operational mode control circuit when being close to synchronizing speed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 85105328 CN1033776C (en) | 1985-07-12 | 1985-07-12 | Energy economizer controlled-current start and protection for induction motors |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 85105328 CN1033776C (en) | 1985-07-12 | 1985-07-12 | Energy economizer controlled-current start and protection for induction motors |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN85105328A CN85105328A (en) | 1987-01-07 |
| CN1033776C true CN1033776C (en) | 1997-01-08 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 85105328 Expired - Lifetime CN1033776C (en) | 1985-07-12 | 1985-07-12 | Energy economizer controlled-current start and protection for induction motors |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1033776C (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102006045000A1 (en) * | 2005-09-29 | 2007-04-19 | Danfoss Compressors Gmbh | Method and control system for starting a motor for driving a compressor |
| CN103546088B (en) * | 2012-07-13 | 2016-08-10 | 安川电机（中国）有限公司 | The revolution speed control device of motor and method for controlling number of revolution |
| CN104601074B (en) * | 2015-02-25 | 2017-04-26 | 珠海派诺科技股份有限公司 | Motor rotation speed measurement method based on root mean square demodulation |
| CN111431446B (en) * | 2019-01-08 | 2022-02-01 | 台达电子工业股份有限公司 | Motor control method and device |
| EP3790177A1 (en) * | 2019-09-09 | 2021-03-10 | Andreas Stihl AG & Co. KG | Electric processing device and method for operating same |
| CN112993941B (en) * | 2021-04-27 | 2022-10-18 | 山东富智大兴电机有限公司 | Motor overload protection circuit |
-
1985
- 1985-07-12 CN CN 85105328 patent/CN1033776C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CN85105328A (en) | 1987-01-07 |
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