Digital and intelligent transformation is an inevitable requirement for the energy revolution and high-quality energy development. Traditional energy coal mines also need to be intelligent, such as coal mine production automation, coal mine safety monitoring and control, coal mine information management, coal mine environmental protection, etc.

The intelligent construction of coal mines is conducive to achieving high yield, efficiency and safe production. Its intelligent development is reflected in the power supply, which is one of the tiny hardware, and has corresponding upgrade requirements, such as improving reliability and safety, energy conservation and environmental protection, simplifying manual operations, reducing the difficulty of maintenance, etc. wait.

(1) Coal mine power supply solution framework

The front-end power supply of coal mine systems usually has voltages of 127VAC, 380VAC, 660VAC, 1140VAC, with a deviation of +10%/-25%. Some old equipment is 36VAC or 220VAC. 127VAC is commonly used in mining lighting systems. These voltages need to be pulled into the dangerous area, so an explosion-proof and intrinsically safe power box is required for explosion-proof design, and then the intrinsically safe power is output, and the intrinsically safe power is output to the positioning substation, various sensors and other equipment, and finally Achieve power supply to underground equipment.

(2) Grid side: ultra-wide voltage and ultra-small volume PVA

The front-end power supply voltage range is very wide, ranging from 127VAC to 1140VAC. The grid-side power supply needs to meet the ultra-wide and ultra-high input voltage. At the same time, it needs to take into account the characteristics, reliability, efficiency, intrinsically safe current limiting, voltage limiting and energy limiting. Volume and other factors.

WEHO coal mine special power supply PVA series has two input ranges, 85-900VAC and 460-1500VAC. Taking the PVA-R2 series as an example, it has an ultra-wide input voltage range of 85-900VAC, which eliminates the need to replace taps like a power frequency transformer and avoid misconnections. Wire.

At the same time, within the full voltage range, the PVA series products have excellent performance, high efficiency, and no obvious low-efficiency voltage range. Among them, the efficiency of the PVA-R2 series can reach up to 92%, exceeding the industry level.

Under the independent control chip + independent control topology technology, the performance of the PVA-R2 series has been greatly improved. For example, the EMS has been raised to level A, with its own peripheral circuits to effectively protect the optocoupler. At the same time, there are fewer components such as transformers and heat sinks, and losses are reduced. The reduction of electrolytic capacitors in low voltage has been improved.

In addition, while ensuring performance, the PVA-R2 series has also achieved dual optimization of volume and weight. For example, the volume of 120W is 140*90*37.5mm, which is 49% lower than other brands; the weight is 325g, which is 39% lower. This will help the whole machine to be light in weight, small in size, and easier to install and maintain.

(3) Secondary side: wide temperature, high efficiency and energy saving URB

Through AC/DC power supply multi-channel buck output, DC/DC power supply and protection circuit are provided. WEHO's wide voltage DC/DC power supply URB series can meet this application.

The wide-voltage DC/DC power supply URB series has multiple advantages such as wide input voltage, wide operating temperature, frequency conversion, energy saving, and low noise. Taking the 50W URB24_LD-50WR3G as an example, this product has an input voltage of 9-36VDC, an operating temperature of -40℃ to +105℃, a standby power consumption as low as 15mA, supports large capacitive loads, EMI meets CLASS B, and has complete protection functions.

The URB-R3G series is an independent IC design. The product adopts a variable frequency design and has high efficiency at full load. The full load efficiency can reach up to 92%. At the same time, the products have achieved 100% localization of components, making delivery more guaranteed.

(4) Intrinsically safe side: slow start K78+ low power consumption 485

There are roughly two types of output loads on the intrinsically safe side. One is a substation, and the back end is connected to 485 communication; the other is through the slow start circuit and K78 series, supplying power to 485 communication and sensors at the same time.

WEHO's intrinsically safe side dedicated point load power supply, 500-1500mA non-isolated K78 series, came into being. This series meets low starting current and comes with a slow start circuit. It is specially developed for coal mine sensors and has multiple technical advantages.

After the slow start circuit is 485 communication. WEHO's low-power 485 communication module also adopts independent IC design and is specially designed for intrinsically safe applications. The hidden power consumption of this product series can be as low as 5mA, the bus electrostatic protection capability in HBM mode is as high as ±8KV, and the bus isolation withstand voltage is ±58V.

(5) Summary

With the intelligent upgrading and transformation of coal mines, power supply supporting solutions and products also need to be updated accordingly. WEHO will accelerate the pace of joint exploration with the coal mining industry, and is committed to providing worry-free power supply to the majority of users, and using worry-free domestic intrinsically safe power supply to help the coal mining industry achieve less-manned, unmanned, safe, efficient, and green mining.