A kind of electric motor protective device
Technical field
The utility model relates to AC voltage-stabilizing converter technique field, specifically, relates to a kind of electric motor protective device.
Background technology
Current, using prevailing equipment in the Electric Machine Control is exactly variable frequency drives, frequency converter almost is applied in all industrial occasions, and the typical application occasion comprises: various pumps, air-conditioning system, elevator, lift, conveyer, lathe and various new forms of energy equipment.The operation principle of frequency converter is the voltage by the output pulse width modulation waveform, produces the sinusoidal current of different frequency, the control rotating speed of motor.
The particular theory of operation of frequency converter has caused following three kinds of problems: electric harmonic problem, shortening electrical machinery life problem, electromagnetic interference problem.The harm of three kinds of problems:
The electric harmonic problem is to have the rectifier of frequency converter front end to produce, and the ac/ac power converter of any band direct current smoothing capacity all can produce harmonic current problem in various degree when work.The harm of harmonic wave earth-current is, when it flows into public electric wire net, under the effect of electric network impedance, produce harmonic voltage (Ohm's law), cause the grid voltage waveform distortion, thereby other equipment on the interference electrical network, in addition, when the high-frequency harmonic electric current transmits on cable and transformer, can cause electric energy loss to increase.Because the variety of problems that harmonic wave brings, power supply department has proposed requirement for restriction to the harmonic current that the user produces, and international standard is IEEE519, GB14549 during domestic standard.
Shortening the electrical machinery life problem is to have very high frequency by problem, PWM waveform that the PWM waveform voltage that frequency conversion is exported causes, these high frequency voltage compositions are to causing the loss of electric machine to increase the overshoot voltage problems such as (puncturing the insulating barrier of motor windings) of (causing motor overheating), bearing leakage current excessive (burning bearing), motor side, and these problems have seriously shortened the life-span of motor.Particularly driver is when motor (for example more than the 100M) far away, and overshoot voltage can reach normal voltage more than 2 times, and the winding insulation of motor is formed serious threat.
Electromagnetic interference problem comprises the content of two aspects, and one is that frequency converter injects electromagnetic interference to electrical network, and this interference is different from harmonic current, and its frequency is higher, is commonly referred to as radio frequency interference.This interference can be disturbed other equipment on the electrical network, can produce radiation simultaneously, disturbs the electronic equipment that closes on.The another kind of interference is to have the PWM waveform voltage of frequency converter output to produce, and when PWM voltage transmits on the interconnected driving cable of frequency converter and motor, can produce extremely strong electromagnetic interference (EMI) emissions, and this electromagnetic interference (EMI) emissions forms interference to other electronic equipments that close on.
The utility model content
The purpose of this utility model is to provide a kind of electric motor protective device, uses the electric harmonic that brought, shortens defectives such as electrical machinery life, electromagnetic interference to solve traditional frequency conversion device in the prior art.
The technical problem that the utility model solved can realize by the following technical solutions:
A kind of electric motor protective device comprises input terminal group, lead-out terminal group, prime reactor composition, back level reactor composition and a three-phase electrochemical capacitance, it is characterized in that:
Back level reactor composition is connected to the prime reactor and forms, the three-phase electrochemical capacitance is connected to back level reactor and forms, the input terminal group is connected to the prime reactor and forms, the lead-out terminal group is connected to back level reactor and forms, and a described three-phase electrochemical capacitance has the axial of horizontal direction, prime reactor composition also has the axial of horizontal direction respectively with back level reactor composition, and the prime reactor is formed the vertical lower position that is arranged on a three-phase electrochemical capacitance with back grade reactor composition.
Electric motor protective device of the present utility model; comprise input terminal group, lead-out terminal group, prime reactor composition, back level reactor composition and a three-phase electrochemical capacitance; has the elimination electric harmonic; reduce noise of motor, vibration and caloric value; can suppress electromagnetic interference; accurately sine wave output voltage is eliminated the moment shake, prolongs characteristics such as electrical machinery life.
Description of drawings
The reader will become apparent various aspects of the present utility model after the reference accompanying drawing has been read embodiment of the present utility model.Wherein:
Fig. 1 is the schematic perspective view of the utility model electric motor protective device primary structure;
Fig. 2 is the schematic perspective view that the utility model prime reactor is formed and back level reactor is formed.
Primary clustering symbol description in the accompanying drawing
Input terminal group 11 input terminals 111,112,113
Lead-out terminal group 12 lead-out terminals 121,122,123
The prime reactor is formed 13 first reactors 131
Second reactor 132 the 3rd reactor 133
Back level reactor is formed 14 the 4th reactors 141
The 5th reactor 142 the 6th reactor 143
Three-phase electrochemical capacitance 15 iron cores 161,162,163,164,165,166
Silicon steel sheet 167
Resin plate 17 lock members 18
First wire rod, 21 second wire rods 22
First wire rod twines core length H
Second wire rod twines core length h
Embodiment
With reference to the accompanying drawings, the specific embodiment of the present invention is described in further detail.
As shown in Figure 1, the utility model comprises input terminal group 11, lead-out terminal group 12, prime reactor composition 13,14 and three-phase electrochemical capacitances 15 of back level reactor composition.Back level reactor is formed 14 and is connected to prime reactor composition 13, a three-phase electrochemical capacitance 15 is connected to back level reactor and forms 14, input terminal group 11 is connected to the prime reactor and forms 13, lead-out terminal group 12 is connected to back level reactor and forms 14, a described three-phase electrochemical capacitance 15 has the axial of horizontal direction, the prime reactor form 13 with back level reactor form 14 also have respectively horizontal direction axially, and the prime reactor is formed 13 and is formed the 14 vertical lower positions that are arranged on a three-phase electrochemical capacitance 15 with back level reactor.See through above-mentioned configuration, can reach preferable space and save effect.
In order to adapt to three-phase alternating current, as shown in Figure 1, prime reactor described in the utility model is formed 13 and is comprised first reactor 131, second reactor 132 and the 3rd reactor 133; Back level reactor is formed 14 and is comprised the 4th reactor 141, the 5th reactor 142 and the 6th reactor 143; Wherein, first reactor 131, second reactor 132, the 3rd reactor 133, the 4th reactor 141, the 5th reactor 142 and the 6th reactor 143 have an iron core separately.First reactor 131, second reactor 132 all use identical material, the long-pending wire rod winding iron core of same cross-sectional with the 3rd reactor 133, to reach same size; The 4th reactor 141, the 5th reactor 142 use identical material, the long-pending wire rod winding iron core of same cross-sectional with the 6th reactor 143, to reach same size; Wherein, the wire rod that wire rod that first reactor 131, second reactor 132 and the 3rd reactor 133 use and the 4th reactor 141, the 5th reactor 142 and the 6th reactor 143 use, its material is identical, but its sectional area is different.Further, in order to reach preferable effect, the iron core 161 of first reactor 131, the iron core 162 of second reactor 132 have identical length with the iron core 163 of the 3rd reactor 133; The iron core 164 of the 4th reactor 141, the iron core 165 of the 5th reactor 142 have identical length with the iron core 166 of the 6th reactor 143; The length of iron core 161,162,163 is greater than the length of iron core 164,165,166; Described each iron core 161,162,163,164,165,166 has identical material, same cross-sectional is long-pending.In the present embodiment, input terminal group 11 further includes three input terminals 111,112,113, is connected to the prime reactor respectively and forms 13 first reactor 131, second reactor 132 and the 3rd reactor 133.Lead-out terminal group 12 includes three lead-out terminals 121,122,123, is connected to back level reactor respectively and forms 14 the 4th reactor 141, the 5th reactor 142 and the 6th reactor 143.
As shown in Figure 2, each iron core 161 (162,163,164,165 or 166) is repeatedly to put be combined into by a plurality of silicon steel sheets 167.Electric motor protective device described in the utility model further includes resin plate 17; each reactor is provided with a pair of resin plate 17 in the present embodiment; therefore have six pairs of resin plates 17; each is folded in an iron core 161 (162,163,164,165 or 166) wherein resin plate 17; perhaps; also can utilize other non-magnetic materials; for example replace aforesaid resin plate 17 with stainless sheet steel, each can be closely linked by lock member 18 to resin plate 17 (or stainless sheet steel) and iron core 161 (162,163,164,165 or 166).
As shown in Figure 2, described prime reactor composition 13 uses first wire rod 21 and second wire rod, 22 winding iron cores 161 (162,163,164,165 or 166) respectively with back level reactor composition 14.In order to form the reactance that varies in size, can design the sectional area that the sectional area of first wire rod 21 is different from second wire rod 22, for example, first wire rod 21 uses circular enamelled wire, and second wire rod 22 uses flat enamelled wire, but not as limit.Moreover, in order to form the reactance that varies in size, also can design and the prime reactor is formed in 13 the length H that twines iron cores with first wire rod 21 form the length h that twines iron cores in 14 with second wire rod 22 greater than back level reactor.In addition, each reactor surface coverage has insulation to coat, and is not worn, makes moist and the effect of oxidation with the wire rod that plays each reactor composition of protection.
The above is a better embodiment of the present invention only, is not in order to limit interest field of the present invention; Simultaneously above description should be understood and be implemented for those skilled in the art, so other does not break away from the equivalence of being finished under the disclosed spirit and change or modification, all should be included in the claim scope of application.