CN210431227U - High-voltage power supply circuit applied to explosion-proof frequency converter - Google Patents

Abstract

The utility model discloses a be applied to high voltage power supply circuit of explosion-proof converter, including main loop, control circuit and power supply circuit, power supply circuit keeps apart the transform and produces +15V electricity supply control circuit part with the +15V voltage of outer confession, and the control circuit part is got the electricity after, produces the drive PWM signal, the MOS pipe of main loop passes through PWM signal control, the main loop is through the switching on of inside MOS pipe turn-off and drive. The utility model discloses a high voltage power supply circuit has both guaranteed the reliability of explosion-proof converter, has guaranteed field maintenance personnel's safety again, and the cost is less than UPS again far away.

Description

High-voltage power supply circuit applied to explosion-proof frequency converter

Technical Field

The utility model relates to an explosion-proof converter equipment field of low pressure, concretely relates to be applied to high-voltage power supply circuit of explosion-proof converter.

Background

In the 1140V explosion-proof frequency converter, because the voltage variation range of a direct current bus is 1500V-1900V, no matter a single-ended flyback switching power supply or a double-ended flyback switching power supply can not directly get electricity from the direct current bus of the frequency converter, when the explosion-proof frequency converter is in operation and suddenly cuts off power, the main circuit of the explosion-proof frequency converter has about 1800V direct current voltage, and the main circuit discharges about 10 minutes, but the control power does not have electricity because of sudden power cut, thus causing two problems, 1 threatens the safety of field maintenance personnel, 2 is that the IGBT can be triggered by mistake at the moment of power cut of the control circuit, and the explosion-proof frequency converter can be damaged because the main circuit has high voltage electricity. In order to solve the problem, conventionally, an energy storage device is added at an input end of a switching power supply, as shown in fig. 1, an alternating current 220V power supply is input at a J1 terminal, and is rectified by diodes D1, D2, D3 and D4 to obtain a direct current voltage of 310V, energy storage capacitors C1 to C5 are charged through a pre-charging resistor R1, a J2 terminal is connected to the input end of the switching power supply, after the switching power supply works, a voltage is fed back to a J3 terminal, a relay K1 is controlled to pull in, and the pre-charging resistor R1 is short-circuited. When the explosion-proof frequency converter is suddenly powered off, the energy storage capacitors C1-C5 can continue to supply power to the switching power supply. In addition to the energy storage device shown in fig. 1, a UPS may be used as the energy storage device.

1.2.2 analyzing the defects of the existing similar energy storage devices (which must be provided)

1. The storage capacity of the energy storage device shown in fig. 1 depends on the voltage levels of the energy storage capacitors C1-C5 and 1140V of the explosion-proof frequency converter, the power of the switching power supply is generally larger than 50W, the electric energy provided by the energy storage capacitors often cannot support how long the switching power supply is used, and then no electric energy is available, and at this time, although the voltage of the main loop is reduced, the safe voltage value is not yet obtained, which still is a problem affecting the safety of maintenance personnel.

2. The UPS is used as energy storage equipment, the two problems can be completely solved, new problems can occur, the cost is overhigh, the scheme is almost not used by a manufacturer, the explosion-proof frequency converter is frequently powered off in a coal mine, the UPS is frequently used for providing a power supply, the electric energy of the UPS can be exhausted every time, the service life of the UPS can be greatly shortened, and the field application of the scheme is restricted. 3 the 220V power supply in the frequency converter is taken from the input main loop, and is changed into the 220V power supply through the transformer, and the quality of the power supply electric energy input into the main loop by the frequency converter is poor, so that the service life of the UPS is also influenced. Therefore, improvements in the prior art are needed.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects in the prior art, the high-voltage power supply circuit applied to the explosion-proof frequency converter is provided, so that the purposes of voltage reduction and voltage stabilization are achieved, and the reliability of the explosion-proof frequency converter is ensured.

In order to realize the above object, the utility model provides a be applied to high voltage power supply circuit of explosion-proof converter, including main loop, control circuit and power supply circuit, power supply circuit keeps apart the transform and produces +15V electricity supply control circuit part with the +15V voltage of outer confession, and the control circuit part is got electric back, produces the drive PWM signal, the MOS pipe of main loop passes through PWM signal control, the main loop switches on through inside MOS pipe and cuts off the drive.

The high-voltage power supply circuit applied to the explosion-proof frequency converter comprises an input end, a thermistor, a plurality of filter capacitors, a voltage-sharing resistor, a transistor, an output filter capacitor and an output inductor.

The control circuit comprises a first chip U1, a first triode Q3, a second triode Q4, a driving transformer T1, two suppression diodes, a capacitor and a resistor.

The above-mentioned high voltage power supply circuit who is applied to explosion-proof frequency converter, power supply circuit includes second chip U2, third chip U3, fourth chip U4, third triode Q1, fourth triode Q2, switching transformer T2, rectifier diode, resistance and electric capacity.

In the high-voltage power supply circuit applied to the explosion-proof frequency converter, the input end of the main loop comprises a first input end DC +, a second input end DC-, and a main loop terminal J1 is connected with the first input end and the second input end.

The utility model discloses owing to use above technical scheme, make its beneficial effect who has be:

1. the linear three-level regulator and the Buck switch-type regulator are combined together, the advantages that the linear three-level regulator realizes high-voltage operation by using a low-voltage component and the Buck switch-type regulator realizes DC/DC voltage reduction are utilized, and the linear three-level regulator and the Buck switch-type regulator are combined together skillfully;

2. one working state of a linear three-level is utilized, and a transistor is not required to be controlled;

3. the reliability of the explosion-proof frequency converter is guaranteed, the safety of field maintenance personnel is guaranteed, and the cost is far lower than that of a UPS.

Drawings

FIG. 1 is a circuit diagram of a prior art rectified stored energy power supply;

fig. 2 is a schematic diagram of a main loop part of a high-voltage power circuit applied to an explosion-proof frequency converter;

fig. 3 is a schematic diagram of a control circuit part of a high-voltage power circuit applied to an explosion-proof frequency converter;

fig. 4 is a schematic diagram of a part of a power supply circuit of a high-voltage power supply circuit applied to an explosion-proof frequency converter;

fig. 5 is the overall schematic diagram of the high-voltage power supply circuit applied to the explosion-proof frequency converter of the utility model.

Detailed Description

In order to make the technical means, the inventive features, the objectives and the functions of the present invention easy to understand, the present invention will be further described with reference to the following specific drawings.

The first embodiment of the utility model discloses a high voltage power supply circuit for explosion-proof converter, including main loop, control circuit and power supply circuit, power supply circuit keeps apart the transform and produces +15V electricity supply control circuit part with the +15V voltage of outer confession, and the control circuit part is electrified back, produces the drive PWM signal, and the MOS pipe of main loop passes through PWM signal control, and the main loop is through switching on of inside MOS pipe V1, V2 and turn off and drive.

In a specific use, as shown in fig. 2, in the circuit diagram of the main loop portion, DC + and DC-are input ends, NTC1 and NTC2 are thermistors, C1, C2 and EC1 to EC6 are input filter capacitors, R1 to R12 are voltage-sharing resistors, V1 to V6 form a linear three-level topology, L1 is an output inductor, EC7 and EC8 are output filter capacitors, R18 to R21 are voltage-sharing resistors of the output filter capacitors, and the main loop portion functions to step down the input DC voltage DC + and DC-to 600V DC voltage; fig. 3 shows a control circuit, which mainly includes a first chip U1, a chip UC3844B used in the U1, a first transistor Q3 and a second transistor Q4 of a MOS transistor, a driving transformer T1, transient suppression diodes D1 and D2, and associated resistors and capacitors. The function of the circuit is to generate PWM driving waveforms with variable duty ratios, and to control the on and off of MOS transistors V1 and V2 in the main loop part, thereby realizing the purpose of voltage reduction of the main loop; fig. 4 shows a power supply circuit, which mainly includes a second chip U2, a third chip U3, and a fourth chip U4, where U2 uses a chip UC2525AN, U3 uses a chip P181, U4 uses a TL431, a third transistor Q1 and a fourth transistor Q2 of MOS transistors, a switching transformer T2, a rectifying diode D5, and related resistors and capacitors. The function of this part is to isolate the external +15V voltage supplied by the control power supply terminal J3 to generate +15V voltage, and supply power to the control part, so that the control part can work by power.

In addition, as shown in fig. 5, a main loop terminal J1 is connected to a DC bus DC +, DC-of the explosion-proof frequency converter, a thermistor NTC1 and NTC2 can suppress a charging current at the moment of power-up, electrolytic capacitors EC 1-EC 6 form an input filter, a neutral point N is manufactured, V1-V6 form a one-line three-level topology, when V1 and V2 are simultaneously turned on, an input voltage DC + is directly applied to an input end of an inductor L1, capacitors EC7 and EC8 are charged through the inductor L1, when V1 and V2 are simultaneously turned off, a reverse induced electromotive force generated by L1 causes V3 and V4 to be simultaneously turned on to realize continuous current, and capacitors EC7 and EC8 are used for supplying electric energy to an output voltage terminal J2. In the circuit, a linear three-level regulator and a Buck switching regulator are skillfully combined together, and the advantages that the linear three-level regulator uses low-voltage components to realize high-voltage operation and the Buck switching regulator realizes DC/DC voltage reduction are utilized and are skillfully combined together. Simultaneously in traditional style of calligraphy three levels, components and parts V3, V4 should be MOS pipe or IGBT, but in the utility model discloses in, only utilized a operating condition in the style of calligraphy three levels, need not control V3, V4, so choose for use the lower diode of cost to replace, improved a style of calligraphy three level topological structure.

The first chip U1 adopts a conventional power control chip UC3844, which can output a PWM control signal with a maximum duty ratio of 50%, and R31 and C9 are oscillation circuits, and provide a switching frequency of 40KHz for the UC 3844; the resistors R22-R27 are output voltage detection circuits, output voltage closed-loop control is achieved, the output voltage of the output voltage J2 terminal can be stabilized at 600V, the resistors R13-R17 are current detection resistors, and when the voltage at two ends of each resistor exceeds 1V, overcurrent protection is achieved.

The control power supply terminal J3 is externally supplied with +15V power, is isolated by the second chip U2 and the transformer T2, and provides an operating voltage of +15V for the first chip U1.

In summary, the design has two input terminals, i.e., the terminal J1 is the main loop terminal, the terminal J3 is the control power terminal, requiring the external supply of 15V power, the terminal J2 is the output voltage terminal, connected to the subsequent switch power, if the explosion-proof frequency converter is suddenly powered off, the external power supply for controlling the power supply terminal J3 is not available, the high-voltage power supply circuit is also inoperable, in order to solve the problem, a double-power supply mode can be adopted to supply power to a J3 terminal, firstly, an external power supply is adopted to start the high-voltage power supply circuit to work, the high-voltage power supply circuit outputs 600V to a switch power supply, the switch power supply supplies control power to an explosion-proof frequency converter, and simultaneously, a +15V power supply is fed back to the high-voltage power supply circuit, so that the high-voltage power supply circuit and the connected switching power supply can work normally even if the power is cut off suddenly until the voltage of the direct-current bus of the explosion-proof frequency converter is reduced to be below a safety value. The utility model discloses a high voltage power supply circuit has both guaranteed the reliability of explosion-proof converter, has guaranteed field maintenance personnel's safety again, and the cost is less than UPS again far away.

The above description has been made of specific embodiments of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that devices and structures not described in detail are understood to be implemented in a manner common in the art; various changes or modifications may be made by those skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims (5)

1. The utility model provides a be applied to high voltage power supply circuit of explosion-proof converter which characterized in that: the power supply circuit is used for isolating and converting +15V voltage supplied externally and generating +15V power to supply to the control circuit part, the control circuit part generates a driving PWM signal after being electrified, an MOS (metal oxide semiconductor) tube of the main circuit is controlled by the PWM signal, and the main circuit is driven by the conduction and the disconnection of the MOS tube inside.

2. The high-voltage power supply circuit applied to the explosion-proof frequency converter according to claim 1, wherein: the main loop comprises an input end, a thermistor, a plurality of input filter capacitors, a voltage-sharing resistor, a transistor, an output filter capacitor and an output inductor, wherein one end of the thermistor is connected to the input end, the input filter capacitors are connected to the other end of the thermistor, the voltage-sharing resistor, the transistor and the output filter capacitor are respectively connected with the input filter capacitor in parallel, the output inductor is arranged between the transistor and the output filter capacitor, and the output filter capacitor is grounded.

3. The high-voltage power supply circuit applied to the explosion-proof frequency converter according to claim 1, wherein: the control circuit comprises a first chip U1, a first triode Q3, a second triode Q4, a driving transformer T1, two suppression diodes, a capacitor and a resistor, wherein one end of the first chip U1 is connected with a first triode Q3 and a second triode Q4, the other end of the first chip U1 is connected with an input end, the first triode Q3 is connected with a power supply, the second triode Q4 is connected with the driving transformer T1 in parallel, and the two suppression diodes, the capacitor and the resistor are respectively connected in a loop of the control circuit.

4. The high-voltage power supply circuit applied to the explosion-proof frequency converter according to claim 1, wherein: the power supply circuit comprises a second chip U2, a third chip U3, a fourth chip U4, a third triode Q1, a fourth triode Q2, a switch transformer T2, rectifier diodes, resistors and capacitors, the second chip U2, the third chip U3 and the fourth chip U4 are sequentially connected, the first end of a second chip U2 is connected with the input end, the second end of the second chip U2 is respectively connected with the third triode Q1 and the fourth triode Q2, the third triode Q1 and the fourth triode Q2 are respectively connected with a power supply, the switch transformer T2 is connected with the rectifier diodes in parallel and respectively connected with the input ends, and a plurality of resistors and capacitors are arranged in the whole loop.

5. The high-voltage power supply circuit applied to the explosion-proof frequency converter according to claim 1, wherein: the input end in the main loop comprises a first input end DC +, a second input end DC-, and a main loop terminal J1 is connected with the first input end and the second input end.

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