BLDC Motor Drive (Inverter)

Air Conditioners or some types of cooling systems have become an integral part of most households globally. With the climate fluctuating every few days, there has been a drastic increase in the popularity of heating and cooling systems. This trend is popular domestically, as well as commercially. When people buy such cooling appliances to increase their comfort, they expect it to start working from the get-go without any hindrance. An electronic appliance that doesn’t deliver on its promised performance is useless.

Overview

Our client is a manufacturer of one of India’s widest ranges of air conditioning and commercial refrigeration products and had a product that delivered sub-optimal performance. They also had a comprehensive range of air purifiers, water purifiers, air coolers, cold storage, and other specialty products. The product was an inverter in need of major upgrades to function efficiently and reduce its overall power consumption. While starting the inverter, it passed a high current that damaged other surrounding devices and also caused an unceasing flickering of lights. Cooling appliances generally deliver a mild chilly temperature within a few seconds of starting. However, this particular inverter took a substantially long time to reach the desired cooling temperature after getting started. Here’s how we helped our client resolve the issue.

Approach

Our team of experts at Alpha ICT is experienced at dealing with a wide range of power electronics. Firstly, we prioritized a thorough examination of the device and highlighted the areas that needed modifications and upgrades. After conducting a detailed inspection, we decided to incorporate a better compressor technology to make the device fully functional and efficient. We also slowed the ramp up and ramp down of the compressor. The inverter was damaging devices with its power surges, and we needed to eliminate that and ensure the increased safety of the appliance. Therefore, we accommodated a larger input voltage range to counter the effect of inconsistent power input. As we specialize in delivering end-to-end results, we employed an exhaustive list of solutions to deliver to our clients their desired result.

Results

For the upgrading process of the inverter, our team incorporated a variable speed BLDC motor compressor. We also converted its drive to a constant voltage and variable frequency and allowed the compressor to run near peak rated speed.

We incorporated an active PFC (Power Factor Correction) circuit at the mains input stage to resolve the start surge problem. With the help of our firmware services, we were able to correctly employ a design for the BLDC motor drive and its air conditioning application. We also included EMS vendor identification for the manufacturing of PCB assemblies. Additionally, we included the BLDC motor driver with power and a control card.

For the controller, we prioritized a single board solution with double-sided PTH. We also employed a microcontroller, PFC Driver, IPM, Bridge rectifier for the hardware of the device. We coded and programmed the entire product using C language. 

Our focus was to enhance the functionality of the product. So, after strategically employing our resources, we were able to achieve the following results:

  • Reduced power consumption by 30%
  • Substantial reduction of the starting surge
  • Supported wide mains input voltage range
  • Successfully achieved the desired cooling effect within a lesser time

The finished generic inverter can now be tailored for multiple applications with its new and enhanced features.

Conclusion

The project was complex in terms of the hardware required to resolve the existing issues within the product. However, with the help of our capable team and our emphasis on delivering satisfactory results, we were able to enhance the features of the inverter and upgrade it using a BLDC Motor Drive.
  • BLDC Motor Control
  • Active PFC 
  • Power Electronics 
  • Single board solution – double side PTH
  • Schematics, BOM, Layout & Gerber: PADS from Mentor Graphics 
  • Microcontroller: Renesas R5F524T8ADFM
  • PFC Driver: Infineon IRS44273L
  • IPM: Mitsubishi PSS20S92F6-AG-N
  • Bridge Rectifier: Vishay GBPC35
  • MOSET: ST Microelectronics STGW30V60DF
  • Code in C