Background technology
The industries such as known coal petrochemical industry, its production occasion belongs to explosive atmosphere, and if any damp, steam or dust, the RHVC worked in such circumstances, requires to possess explosion-proof performance, current underground coal mine main flow electric pressure is 660 V or 1140V, and the frequency converter of down-hole application does not possess the ability taking into account two kinds of electric pressures, and frequency converter can only export a kind of electric pressure, i.e. 660V or 1140V, the load of underground coal mine has diversity, as rubber conveyer, water pump, emulsion pump etc., requires heavy load starting, frequent speed governing, therefore, requires that frequency control equipment has higher compatibility, as shown in Figure 1, main circuit of frequency converter comprises circuit breaker, three-phase rectifier, filter capacitor, IGBT inverter etc. to the main circuit topology of present main flow, " a kind of high-power three-level explosion-proof frequency converter " patent of invention of Xuzhou China Mining Drives & Automation Co., Ltd.'s application proposes a kind of high-power three-level explosion-proof frequency converter, comprise 3 identical unit blocks, load-carrying guide rail and bonnet, each unit block comprises power cell, bus, main capacitance, building-out capacitor and radiator, power cell is equally spaced to be distributed on the substrate of radiator, and be fixedly connected with the substrate of radiator, bus comprises AC and DC side, AC is connected with power cell, DC side is bolted on the binding post of main capacitance, connected by bronze medal bolt between the AC of bus and DC side, building-out capacitor is connected with power cell, and be arranged on the AC of bus, connected by the bronze medal of the DC side of bus between each unit block.Beneficial effect is once break down or damaging, and only need changing corresponding unit, reducing plant maintenance to greatest extent to normally producing the impact brought." explosion-proof frequency converter movement and explosion-proof frequency converter " utility model patent of Ying Weiteng electric limited company application discloses explosion-proof frequency converter movement and explosion-proof frequency converter, comprising: a backboard; Be arranged on described backboard, for the three-phase alternating current of input is converted into a galvanic rectification unit; Be arranged on described backboard, for by the DC conversion of input being an inversion unit of three-phase alternating current; Be arranged on described backboard, be mainly used in a capacitance component of filtering energy storage; Wherein, described capacitance component is between described rectification unit and inversion unit, the same face that described rectification unit, inversion unit and capacitance component are arranged in described backboard is closely connected, and the technical scheme that this invention provides can effectively reduce the volume of explosion-proof frequency converter movement.The output voltage of above-mentioned explosion-proof frequency converter is single electric pressure, for the down-hole occasion using 660V, 1140V simultaneously, needs the explosion-proof frequency converter of outfit two kinds of electric pressures, and therefore, the versatility of explosion-proof frequency converter is not strong.Existing explosion-proof frequency converter generally uses air-cooled, and cooling effectiveness is lower, and therefore, frequency inverter capacity is less.Existing explosion-proof frequency converter structure is more complicated, brings certain constant to maintenance work.
Summary of the invention
The object of the invention is for above-mentioned deficiency, and the one proposed exports two kinds of electric pressures, and capacity is constant, adapt to the multiple load in down-hole, can improve the compatibility of production equipment, cooling effectiveness is high, and explosion-proof frequency converter capacity is large, adopt modularized design scheme, the high-capacity non-explosive frequency converter of ease of assembly and maintenance.
Technical solution of the present invention is: the input of the four-quadrant rectification unit of frequency converter is connected with input reactance device, output is connected with the input of three inversion units, the output of three inversion units is connected with out put reactor respectively, the output of three inversion units is connected with the Star transformation contactor of three inversion unit Y-connections, and by the triangularity changing-over tentaculum of three inversion unit triangles connections.
Described in technical solution of the present invention three inversion unit is all single-phase inversion unit.
Four-quadrant rectification unit described in technical solution of the present invention and an inversion unit form a power model, and another two inversion units form another power model; Two described power models are located in the B chamber in two inner chambers in frequency converter.
Star transformation contactor described in technical solution of the present invention and triangularity changing-over tentaculum are arranged on the base plate below two power models, adopt cable to be connected with between two power models.
Out put reactor described in technical solution of the present invention and input reactance device are located in the A chamber in two inner chambers in frequency converter.
Water inlet pipe and outlet pipe is provided with in the A chamber of the fixing out put reactor described in technical solution of the present invention and input reactance device.
The working method of the four-quadrant rectification unit of described in technical solution of the present invention and three inversion unit employing common DC bus.
Described in technical solution of the present invention two power model all adopts low inductance busbar to connect.
Tool of the present invention has the following advantages:
1, three inversion unit outputs of explosion-proof frequency converter can carry out the conversion of star connection, delta connection, can take into account two kinds of electric pressures, and namely 1140V voltage or 660V voltage, can be applicable to the load of different electric pressure;
2, when explosion-proof frequency converter exports 1140V voltage or 660V voltage, capacity remains unchanged;
3, the major loop of each power model is relatively independent, and a rectification unit and three inversion units adopt common DC bus working method; Modularized design carried out by whole frequency converter, is easy to safeguard;
4, adopt the type of cooling of water-cooled, radiating efficiency is high, and explosion-proof frequency converter output capacity is large;
5, for star connection, delta-connection two kinds of connections of explosion-proof frequency converter three inversion unit outputs, share an out put reactor, circuit structure is simple and reliable.
Embodiment
As shown in Figure 2, the present invention includes inversion unit 1, inversion unit 2, inversion unit 3, four-quadrant rectification unit 5, out put reactor 7, Star transformation contactor 8, triangularity changing-over tentaculum 9, input reactance device 10; The input input of four-quadrant rectification unit 5 being connected with input reactance device 10, three inversion units 1,2,3 is connected with the output of four-quadrant rectification unit 5, and the output of three inversion units 1,2,3 is connected with out put reactor 7 respectively; The output of three inversion units 1,2,3 is connected with the Star transformation contactor 8 of three inversion units 1,2,3 Y-connection, and by the triangularity changing-over tentaculum 9 of three inversion units 1,2,3 triangle connection, three inversion units 1,2,3 are all single-phase inversion unit, mutual alternate angle 120 ° between the single-phase voltage of three inversion unit 1,2,3 outputs; In the present invention, the effect of out put reactor 7 is: when the Y-connection of three inversion units 1,2,3 or triangle connect, can suppress the du/dt that frequency converter exports; When three inversion units 1,2,3 triangle connects, the circulation between three inversion units 1,2,3 can also be suppressed, out put reactor 7 needs one, and not need to arrange a reactor respectively when triangle connection or Y-connection.Four-quadrant rectification unit 5, inversion unit 1 form power model 6, and inversion unit 2 and inversion unit 3 form power model 4; Power model 4 and power model 6 are configured with a control box respectively, place controller in control box; The connected mode of three inversion units 1,2,3 can be changed by Star transformation contactor 8, triangularity changing-over tentaculum 9, obtain two kinds of output voltages, namely Star transformation contactor 8 close a floodgate, triangularity changing-over tentaculum 9 separating brake, three inversion unit 1,2,3 outputs are Y-connection, and frequency converter exports 1140V voltage; Star transformation contactor 8 separating brake, triangularity changing-over tentaculum 9 close a floodgate, and three inversion unit 1,2,3 outputs are that triangle connects, and frequency converter exports 660V voltage.When three inversion unit 1,2,3 Y-connections export 1140V voltage or triangle connection output 660V voltage, the output capacity of explosion-proof frequency converter remains unchanged.
As shown in Figure 3, the internal structure of frequency converter of the present invention is, explosion-proof cabinet inside is provided with one piece of division board 15, cabinet internal cavities is divided into two inner chambers, i.e. A chamber and B chamber, and dividing plate 15 has certain heat insulating function, and the heating between two inner chambers does not interfere with each other.Meanwhile, dividing plate 15 has certain electromagnetic isolation effect, and dividing plate 15 and explosion-proof casing together constitute electromagnetic shielding space, without electromagnetic interference between two inner chambers; Out put reactor 7 of the present invention and input reactance device 10 are positioned over A chamber, can avoid the normal work of temperatures involved to other device of generation during two reactor work; Two reactors 7,10 are all heavier devices, and maintenance workload is few, therefore places separately, decreases maintenance workload.Power model 4 of the present invention and power model 6 adopt and are bolted to above backboard 16, and backboard 16 is provided with internal thread, and in the direction towards power model 4,6, namely positive apparent direction can install easily, dismantle power model and 4 power models 6, easy to maintenance.In order to strengthen the intensity of backboard 16, be provided with reinforcement steel bar at the back side of backboard 16.Star transformation contactor 8 and triangularity changing-over tentaculum 9 are arranged on the below of power model 4 and power model 6, are fixed on base plate, adopt cable to be connected with between power model 4, power model 6.The arrangement in water route of the present invention be water inlet pipe 12 for water inlet, outlet pipe 11 is for water outlet, and water inlet pipe 12, outlet pipe 11 adopt steel pipe.Power model 4 and power model 6 are connected with adopting flexible pipe 13 between water pipe, and have employed fast insert-pull water swivel, water-tight during plug, easy to maintenance.Water inlet pipe 12, outlet pipe 11 pass from the A chamber of placing out put reactor 7 and input reactance device 10, have certain cooling effect to A chamber.The cooling effectiveness of this water-cooling pattern is high, and therefore the capacity utilization of power device IGBT is high, and the output capacity of explosion-proof frequency converter is large.The arrangement of DC side busbar of the present invention is: adopt copper bar 14 DC side to be linked together between power model 4 and power model 6; DC side between four-quadrant rectification unit 5 and inversion unit 1, is linked together by the low-inductance bus of power model 6 inside; DC side between inversion unit 2 and inversion unit 3, is linked together by the low-inductance bus of power model 4 inside.A rectification unit and four-quadrant rectification unit 5, and three inversion units and inversion unit 1, inversion unit 2, inversion unit 3, adopt common DC bus working method.
As shown in Fig. 4,6, power model 6 of the present invention is made up of four-quadrant rectification unit 5, inversion unit 1.Four-quadrant rectification unit 5 is three-phase four-quadrant rectifiers, and inversion unit 1 is single-phase inverter, and whole power model 6 is made up of with corresponding annex IGBT, DC capacitor, resistance.Explosion-proof frequency converter of the present invention, rectification side adopts four-quadrant rectifier system, and input power factor is high, and harmonic content meets Standard; Power model 6 comprises 10 IGBT power devices 21, control box 22, safe metal film type electric capacity 23, low-inductance bus 27, substrate 29; Substrate 29 both as coldplate, also as the fixed head of power model 6; Substrate 29 is drilled with through hole above, is convenient to rigid power module 6; Substrate 29 have inlet opening 24 and apopore 26; Substrate 29 inside is provided with cooling water channel; Inlet opening 24 and apopore 26 adopt fast insert-pull water swivel, water-tight during plug; Power model 6 is configured with handle 25 above, is convenient to assembling; Export the wiring of copper bar terminal 28 for outlet side, the wiring of input side is in the lower end of power model 6; Low-inductance bus 27 is as the DC side of power model 6, and DC side and power model 4 DC side can link together by the binding post above it.
As shown in Fig. 5,7, power model 4 of the present invention comprises inversion unit 2 and inversion unit 3, and inversion unit 2 and inversion unit 3 are all single-phase inverters, and whole power model 4 is made up of DC capacitor, resistance, IGBT and corresponding accessory.Power model 4 comprises 8 IGBT power devices 31, control box 32, safe metal film type electric capacity 33, low-inductance bus 37, substrate 39; Substrate 39 both as coldplate, also as the fixed head of power model 4; Spudded in above substrate 39 through hole, is convenient to rigid power module; Substrate 39 have inlet opening 34 and apopore 36; Substrate 39 inside is provided with cooling water channel.Inlet opening 34 and apopore 36 adopt fast insert-pull water swivel, water-tight during plug.Power model 4 is configured with handle 35 above, is convenient to assembling.Export the wiring of copper bar terminal 38 for inversion unit 2 outlet side, the outlet side wiring of inversion unit 3 is in the lower end of power model 4.Low-inductance bus 37 is as the DC side of power model 4, and DC side and power model 6 DC side can link together by the binding post above it.Power model 4 comprises inversion unit and inversion unit 3, the two common DC bus.
The control system of explosion-proof frequency converter of the present invention is all integrated in control box 22 and control box 32, and control box adopts metallic shielding structure.Control box realizes the functions such as systems axiol-ogy, switching, protection, control, possesses essential safety function.Explosion-proof frequency converter of the present invention adopts speed-sensorless control mode, and starting torque is large, and overload capacity is strong, and control precision is high, fast response time.Between the single-phase voltage of three inversion unit 1,2,3 outputs, mutual alternate angle 120 °, is controlled by control box 22, control box 33.
As shown in Figure 8, explosion-proof frequency converter of the present invention exports 1140V voltage.The inversion unit of each inversion unit exports as 660V voltage, and Star transformation contactor 8 closes a floodgate, triangularity changing-over tentaculum 9 separating brake, thus defines the topological structure of 1140V voltage output; V1, V2, V3 of three inversion units are shorted together, and form neutral point; U1, U2, U3 of three inversion units export as three-phase, and now explosion-proof frequency converter exports 1140V voltage.
As shown in Figure 9, explosion-proof frequency converter of the present invention exports 660V voltage.The inversion unit of each inversion unit exports as 660V voltage, Star transformation contactor 8 separating brake, and triangularity changing-over tentaculum 9 closes a floodgate, thus defines the topological structure of 660V voltage output; U1/V1, U2/V2, U3/V3 head and the tail of three inversion units are connected successively, and form delta connection, explosion-proof frequency converter exports 660V voltage.