Mining intrinsically safe power supply

Abstract

The utility model discloses a mining intrinsically safe power supply, which relates to the technical field of mining power supplies and comprises a 220V alternating-current input interface, an over-current protector, a first anti-surge protector, an EMC (Electro Magnetic Compatibility) anti-interference circuit, a bridge rectifier filter circuit, a high-frequency switching power supply, a common-mode filter, an intrinsically safe circuit, a second anti-surge protector and an intrinsically safe output interface. The 220V alternating current input interface is connected with the over-current protector, the over-current protector is connected with the first anti-surge protector, and the first anti-surge protector is connected with the EMC anti-interference circuit. According to the utility model, the design structure is reasonable, the high-frequency flyback switching power supply scheme design is adopted according to product power and output current parameters, the multi-mode PWM switching power supply integrated protection chip is adopted, and the output adopts the synchronous rectification chip design, so that the conduction loss of the original Schottky diode is greatly reduced; therefore, the working efficiency of the intrinsically safe power supply product is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mine power supplies, in particular to an intrinsically safe mine power supply. Background Art

[0002] In order to strengthen coal mine production safety, prevent and reduce coal mine production safety accidents, and protect the lives and property of the people, the rapid development of coal mine automation has made the use of intrinsically safe power supplies in mines more and more frequent, and at the same time, the requirements for its use are becoming more and more stringent. Due to the special working environment underground in coal mines, there are certain flammable and explosive gases. To avoid sparks generated by short circuits in intrinsically safe power supplies igniting flammable and explosive gases underground and causing safety accidents such as gas explosions, the output short-circuit ignition requirements for intrinsically safe power supply products for mining are particularly high, and they are also indispensable safety power supply products in mines.

[0003] Early mining power supply designs often focused on mechanical strength and basic circuit protection, but were limited in their ability to cope with transient voltage fluctuations, surge current shocks, and electromagnetic interference (EMI / EMC) under complex working conditions. This not only affected the stability and reliability of the power supply, but also made it difficult to meet the needs of modern mining equipment for efficient and intelligent power supplies. To this end, we provide a mining intrinsically safe power supply to solve the above problems. Utility Model Content

[0004] 1) Technical issues solved

[0005] The purpose of the utility model is to make up for the deficiencies of the prior art and provide an intrinsically safe power supply for mining.

[0006] 2) Technical solution

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a kind of intrinsically safe power supply for mining, comprising a 220V AC input interface, an overcurrent protector, a surge protector 1, an EMC anti-interference circuit, a bridge rectifier filter circuit, a high-frequency switching power supply, a common mode filter, an intrinsically safe circuit, a surge protector 2, and an intrinsically safe output interface, wherein the 220V AC input interface is connected to the overcurrent protector, the overcurrent protector is connected to the surge protector 1, the surge protector 1 is connected to the EMC anti-interference circuit, the EMC anti-interference circuit is connected to the bridge rectifier filter circuit, the bridge rectifier filter circuit is connected to the high-frequency switching power supply, the high-frequency switching power supply is connected to the common mode filter, the common mode filter is connected to the intrinsically safe circuit, the intrinsically safe circuit is connected to the surge protector 2, and the surge protector 2 is connected to the intrinsically safe output interface.

[0008] Furthermore, the high-frequency switching power supply includes a switching power supply chip, a high-frequency transformer, a synchronous rectification chip, a π-type filter, and an optically coupled voltage reference chip. The switching power supply chip and the high-frequency transformer are both connected to a bridge rectifier filter circuit, the switching power supply chip is connected to a high-frequency transformer and an optical coupler, the high-frequency transformer is connected to a synchronous rectification chip, the synchronous rectification chip is connected to a π-type filter, and the π-type filter is connected to an optically coupled voltage reference chip.

[0009] Furthermore, the intrinsically safe circuit includes two switch circuits connected in series, and the two switch circuits are respectively connected to the common mode filter and the second surge protector.

[0010] 3) Beneficial effects:

[0011] Compared with the existing technology, the intrinsically safe power supply for mining has the following beneficial effects:

[0012] 1. The utility model adopts a high-frequency flyback switching power supply solution design based on the product power and output current parameters, and adopts a multi-mode PWM switching power supply integrated protection chip. The output adopts a synchronous rectification chip design, which greatly reduces the original Schottky diode conduction loss, thereby greatly improving the working efficiency of the intrinsically safe power supply product.

[0013] 2. The utility model adopts a multi-mode PWM switching power supply chip, which has perfect protection mechanisms such as accurate over-current protection, over-voltage protection, output short-circuit protection, over-temperature protection, and has a built-in soft start function, thereby improving the stability of the switching power supply during operation.

[0014] 3. The utility model adopts a closed-loop control of the output voltage feedback circuit through a switching power supply solution. It is composed of an optocoupler, a voltage reference chip and a potentiometer. It has the functions of high and low voltage isolation, stable output voltage, precise adjustment, and strong load capacity.

[0015] 4. The intrinsically safe circuit part of the utility model adopts IC chip control, and has a double undervoltage and overvoltage protection with an accuracy of 2%, adjustable surge current control, adjustable, 5% accuracy (15mV) current limit, short-circuit protection, DC power supply good monitoring function and other complete protection mechanisms, fast response speed, and stable; it can achieve precise undervoltage, overvoltage and overcurrent protection control, so as to achieve extremely small short-circuit sparks or no sparks at the output, and has high safety and stability in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a block diagram of the power supply product of the utility model;

[0017] Figure 2 This is a block diagram of the composition of the medium and high frequency switching power supply of the utility model;

[0018] Figure 3 This is a partial circuit schematic diagram of the high-frequency switching power supply of the utility model;

[0019] Figure 4 This is a partial circuit schematic diagram of the intrinsically safe circuit of the utility model. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] like Figure 1-4 As shown, the utility model provides a technical solution: a mining intrinsically safe power supply, including a 220V AC input interface, an overcurrent protector, a surge protector, an EMC anti-interference circuit, a bridge rectifier filter circuit, a high-frequency switching power supply, a common mode filter, an intrinsically safe circuit, a surge protector, and an intrinsically safe output interface, wherein the 220V AC input interface is connected to the overcurrent protector, the overcurrent protector is connected to the surge protector, the surge protector is connected to the EMC anti-interference circuit, the EMC anti-interference circuit is connected to the bridge rectifier filter circuit, the bridge rectifier filter circuit is connected to the high-frequency switching power supply, the high-frequency switching power supply is connected to the common mode filter, the common mode filter is connected to the intrinsically safe circuit, the intrinsically safe circuit is connected to the surge protector, and the surge protector is connected to the intrinsically safe output interface.

[0022] The high-frequency switching power supply includes a switching power supply chip, a high-frequency transformer, a synchronous rectification chip, a π-type filter, and an optically coupled voltage reference chip. The switching power supply chip and the high-frequency transformer are both connected to a bridge rectifier filter circuit, the switching power supply chip is connected to the high-frequency transformer and the optical coupler, the high-frequency transformer is connected to the synchronous rectification chip, the synchronous rectification chip is connected to the π-type filter, and the π-type filter is connected to the optically coupled voltage reference chip.

[0023] The multi-mode PWM switching power supply chip U1, the Vcc pin is connected to the rectifier bridge filter capacitor 310V voltage through R3 as the input power supply when the AC power is turned on. After the output voltage is established, the high-frequency transformer feedback winding will continuously power the switching power supply chip through the diode D2. The D pin (the drain of the internal high-voltage MOSFET) is the PWM output, and the drain voltage peak absorption network composed of R2, C3, and D1; R1 is used to set the output current overcurrent protection value; the COMP pin is the voltage feedback pin, and the secondary side output voltage feedback circuit is connected to the optocoupler to adjust the PWM duty cycle to control the output voltage to be stable. T1 is a high-frequency transformer; the synchronous rectifier chip U2 has a relatively low on-resistance, small conduction loss and high efficiency; C5 and R4 are the RC peak absorption circuit of the synchronous rectifier chip U2; C6, L1 and C7 are the π-type filter circuit output by the switching power supply; the output voltage feedback circuit composed of U3, U4, R5, R6, R7, R8, C8 and RW1 is used for voltage closed-loop control of the switching power supply chip to make the output voltage stable; by adjusting the resistance values ​​of R8 and RW1, the output voltage can reach the required precise value.

[0024] The intrinsically safe circuit includes two switch circuits connected in series, and the two switch circuits are respectively connected to the common mode filter and the surge protector. Each level of the intrinsically safe circuit composed of R11, R12, R13 (R18, R19, R20) measures the power supply undervoltage and overvoltage sampling circuit at the input; R14 (R21) is a current detection resistor, which is used to set the output current parameter value; each level of output measurement voltage feedback signal composed of resistors R16 and R17 (R23, R24) is used to generate a current limit threshold setting; capacitor C1 is an IC chip to control the MOSFET switch timing setting input; according to the IC chip specification, FLT is connected to the UV pin, and the chip automatically retries to release the fault mode when the current is lower than the current limit threshold after overcurrent protection; the above circuits are all used for the IC chip to control the on and off of Q1 (Q2) in the MOSFET, as well as the on and off delay time.

[0025] It should be noted that, in this article, the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model; the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "fixed", "installed", "connected", and "connected" should be understood in a broad sense. For example, "installed" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a mechanical connection or an electrical connection; "connected" can be a direct connection, an indirect connection through an intermediate medium, or a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An intrinsically safe power supply for mining, characterized in that: It includes a 220V AC input interface, an overcurrent protector, a surge protector 1, an EMC anti-interference circuit, a bridge rectifier filter circuit, a high-frequency switching power supply, a common mode filter, an intrinsically safe circuit, a surge protector 2, and an intrinsically safe output interface. The 220V AC input interface is connected to the overcurrent protector, the overcurrent protector is connected to the surge protector 1, the surge protector 1 is connected to the EMC anti-interference circuit, the EMC anti-interference circuit is connected to the bridge rectifier filter circuit, the bridge rectifier filter circuit is connected to the high-frequency switching power supply, the high-frequency switching power supply is connected to the common mode filter, the common mode filter is connected to the intrinsically safe circuit, the intrinsically safe circuit is connected to the surge protector 2, and the surge protector 2 is connected to the intrinsically safe output interface.

2. The intrinsically safe power supply for mining according to claim 1, characterized in that: The high-frequency switching power supply includes a switching power supply chip, a high-frequency transformer, a synchronous rectification chip, a π-type filter, and an optically coupled voltage reference chip. The switching power supply chip and the high-frequency transformer are both connected to a bridge rectifier filter circuit, the switching power supply chip is connected to the high-frequency transformer and the optical coupler, the high-frequency transformer is connected to the synchronous rectification chip, the synchronous rectification chip is connected to the π-type filter, and the π-type filter is connected to the optically coupled voltage reference chip.

3. The intrinsically safe power supply for mining according to claim 1, characterized in that: The intrinsically safe circuit includes two switch circuits connected in series, and the two switch circuits are respectively connected to a common mode filter and a second surge protector.

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