CN2159082Y

CN2159082Y - Switch-type DC power transformer

Info

Publication number: CN2159082Y
Application number: CN 93206129
Authority: CN
Inventors: 邵学飞; 李威强
Original assignee: HAERBIN CITY SANJIAN TRANSFORMER INST
Current assignee: HAERBIN CITY SANJIAN TRANSFORMER INST
Priority date: 1993-03-05
Filing date: 1993-03-05
Publication date: 1994-03-16
Anticipated expiration: 2003-03-05

Abstract

The utility model discloses a switch type DC power changing device, which relates to the technical field of electric energy conversion and transmission technology, and is mainly used as the power supplies of lighting and auxiliary signal devices in the tramway vehicles of mines and in the tramway vehicles (the trolley buses) of cities. The utility model comprises an input protective circuit, a switch type DC-AC electric energy conversion circuit, an internal operation power supply, a protective circuit, a regulation control and pulse-generation distributing circuit, and an output circuit. The utility model has the advantages of high automation degree, reliability, safety, and energy saving, being an ideal auxiliary power-supply device in the vehicles.

Description

Switch-type DC power transformer

The utility model discloses a kind of switching mode DC power supply converting means, relate to electric energy conversion and transmission technique field.

There is (nothing) rail electric car in mine rail electric locomotive or city, need a kind of illumination, supply unit of signal and other servicing unit of being used for.The electric circumstance of such device operation is poor, and outstanding behaviours exists: 1) the voltage ripple of power network scope is big, and fluctuating range surpasses ± 20%; 2) the frequent at random break-make of input power supply.This reliability, fail safe and life-span for device is undoubtedly acid test.Especially the latter---the frequent break-make of power supply is very big to the safety hazards of device.At first, because the existence of inductance and electric capacity in the device, frequent break-make power supply will cause frequent overvoltage, and its maximum overvoltage peak value may reach the twice of line voltage, and the element of switching circuit is had serious harm.Secondly frequent on/off certainly will cause the frequent variations of built-in function power supply, when internal power source voltage was low, device was devoted oneself to work, and the electronic switch trigger impulse of generation is strong inadequately, it is insufficient that electronic switch is opened (conducting), enters amplification region work and will burn switch element.The break-make power supply will cause the transformer in the switching circuit to produce frequent surge current continually in addition.Frequent break-make power supply has also proposed very high specification requirement to the automation of device.Significantly voltage ripple of power network then claimed apparatus enough voltage regulations or the like are arranged.A series of specific question like this has constituted the development difficulty of this series products.This is a like product poor reliability up to now, and the life-span is short, is difficult to practical main cause.

The utility model provides a kind of high-quality DC power convertor that the relatively poor occasion of electric circumstance is used that adapts to just at above-mentioned specific condition.

Formation of the present utility model comprises: input protection circuit; Switching mode direct current---ac conversion circuit (calling switching circuit in the following text); The built-in function power supply; Protective circuit; Regulating and controlling and pulse generation distributor circuit; Output circuit.Structural principle such as Fig. 1.It is characterized in that described input protection circuit is to be made of an inductance and a diode inverse parallel, as shown in Figure 2.Switching circuit as major component, adopts half bridge inverter circuit or plural serial stage half bridge inverter circuit according to the withstand voltage of switch element and line voltage grade with electronic switch, and as Fig. 3, the latter's switch transformer secondary sides at different levels are taked additive polarity series connection output; The built-in function power supply is set up by the capacitance partial pressure starting, and the out-put supply feedback is kept, principle such as Fig. 4; Protective circuit has three kinds of functions: A) under voltage is blocked (shutdown) protection, when the built-in function supply voltage is lower than set point, blocks the electronic switch trigger impulse and makes device be in wait or shutdown; B) threshold currents protection when switching circuit electric current during greater than set point, is chopped the trigger impulse current limliting of electronic switch off; C) overcurrent protection when the switching circuit electric current surpasses set point, is blocked the electronic switch trigger impulse and is shut down; The characteristics of output circuit are to be used to throw light on be with the output branch road of light signal exchange directly output.

Below in conjunction with description of drawings operation principle of the present utility model.Owing in the device a lot of electric capacity are arranged, insert power supply moment will produce the huge impact electric current, to such an extent as to will damaging capacitive effect, the result burns device device lifetime.Therefore, it is necessary adding input protection restriction impulse current.Input protection in the past mainly contains two kinds, and a kind of is to seal in the inductance chokes.Though inductance can play chokes, it forms vibration with electric capacity again simultaneously, produces overvoltage, and the overvoltage amplitude has produced new harm near 2 times, loses more than gain.Second kind is to seal in resistance, and resistance has overcome the negative interaction of inductance, and its choking effect and energy consumption increase almost are synchronous.Also be that pros and cons are with depositing.The utility model is taked inductance and the antiparallel method of diode as shown in Figure 2, overcome the crosstalk sense effectively and produced the negative interaction of overvoltage, brought into play the advantage of its idle chokes, made among Fig. 1 (1) right side E ' become that an amplitude approaches E and ripple is better than the direct voltage relatively stably of E.Provide a power environment preferably for installing inside.Built-in function power supply (3) as shown in Figure 4.The capacitance partial pressure circuit draws energy from E ' when device inserts electrical network, is stored in C ₄₂And to pressurizer W power supply generation+V.When+the V rising is above the under voltage protection threshold value that is provided with in the protective circuit (5), and pulse blocking is removed, and switching circuit work produces out-put supply, the out-put supply of feedback at this moment and C ₄₂Common so that replace C fully ₄₂To W power supply, holdout device operate as normal.When power interruptions, be stored in C ₄₃On electric energy will keep switching circuit and work on a little while so that pass through V ₄₂With C ₄₁On electric energy put, for power supply connect once more start ready.Regulating and controlling and pulse generation distributor circuit (4) detect output voltage (or electric current) in real time in the course of work, and the on off operating mode of by-pass cock circuit (2) is realized the adjusting control to output.Protective circuit (5) is sense switch electric current I and built-in function power supply+V in real time, starts current limliting in time, and overcurrent and under voltage protection are sent control signal to (4) and carried out the corresponding protection operation.Fig. 5 shows a kind of embodiment of protective circuit.

The utility model can be stood the abominable electric circumstance test in mine because of having adopted abovementioned technology, and reliability and life-span improve greatly.The safe operation cycle is long.Energy-conservation, electric energy transmitting efficient surpasses more than 85 percent.Especially its output circuit is changed the main output that each producer all will install---the mode that illumination and light signal power branch are also exported after the rectification.Save the high-power high-frequency rectifier cell, reduced the switch transformer cost, and dwindled the volume of device greatly.Like product the utlity model has higher technical-economic index as compared with the past, and is significant to the equipment that improves mine locomotive.

Fig. 1 is a structure principle chart of the present utility model.Wherein, E is the input voltage of direct current network, and E ' approximates E, V ₀Be one of alternating voltage branch road of switching circuit output, P is that electronic switch triggers control impuls, and I is the switching circuit inverter current, and C is the protection operation signal, and AC is for exchanging output branch road, DC ₁～DC _nIt is direct current output branch road.(1) is input protection circuit; (2) be switching circuit; (3) be the built-in function power supply; (4) be to regulate control and pulse generation, distributor circuit, (5) are protective circuits.

Fig. 2 is that input protection circuit schematic diagram L is an inductance, and V is a diode.

Fig. 3 is the switching circuit principle schematic, and wherein (a) is the half bridge inverter circuit structure chart, (b) is plural serial stage half bridge inverter circuit structure chart.Wherein T and T _nBe the switching circuit transformer, TA is a current transformer, the balancing capacitance for sealing in case of necessity in the frame of dotted line garden.

Fig. 4 is built-in function power principle figure, and wherein W is an integrated regulator.Other symbol all is that the electronic component standard symbol will not be given unnecessary details.

Fig. 5 is a kind of embodiment schematic diagram of protective circuit.

Fig. 6 is the principle assumption diagram of switching circuit (2) among the embodiment of the present utility model.

One of embodiment of the present utility model, its structure chart such as Fig. 1, wherein (1) as shown in Figure 2, (2) as shown in Figure 6, (3) are regulated control and pulse generation distributor circuit (4) and are constituted with operational amplifier, time-base circuit and gate circuit as shown in Figure 4.Its working system is the Fixed width frequency modulation system.(5) as shown in Figure 5.Operation principle as previously mentioned.

Claims

1, a kind of switching mode DC power convertor, its formation comprises: input protection circuit, switching mode dc-ac conversion circuit, built-in function power supply, protective circuit, regulating and controlling and pulse generation distributor circuit, output circuit; It is characterized in that described input protection circuit is to be made of an inductance and diode inverse parallel; The switching mode dc-ac conversion circuit is to be major component with the electronic switch, the device that is used for the low-voltage electrical network adopts half bridge inverter circuit, the device that is used for high voltage power network adopts the plural serial stage half bridge inverter circuit, and the switch transformer secondary sides at different levels in the plural serial stage inverter circuit are taked additive polarity series connection output; The built-in function power supply is set up by the capacitance partial pressure starting, and the out-put supply feedback is kept; Output circuit is used to throw light on and the output branch road of light signal, directly draws from the switch transformer secondary.