How to Deploy Sustainable, High Density & Flexible Rack Power Systems

MEAN WELL Product Manager, Kai Li and Sager Electronics Technical Support Manager, Don Baldwin



(Image: MEAN WELL)

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Figure 1: This rack mount system uses 40 power supplies in parallel (bottom) and a dedicated controller (top) to deliver 128 kW of 48 Vdc power for an RF amplifier

­More and more of the industry's applications are requiring, sustainable, high density and flexible rack mount power supplies as we move towards power systems with high-efficiency power conversion and intelligent power management. To avoid the hassle of designing power converters and power management systems from the ground up, system designers need look no further than an off-the-shelf option which can deliver up to 128 kW in a single intelligent chassis. MEAN WELL's NCP-3200 series 3200 W rack-mounted switching power supply and battery charger family is the ideal solution. Authored by MEAN WELL Product Manager, Kai Li, and Sager Electronics Technical Support Manager for Power, Don Baldwin, this article discusses how to deploy sustainable, high density and flexible rack power systems in your applications and the solutions offered from MEAN WELL and Sager Electronics.

System designers need sustainable, high-density, and flexible rack mount power systems for various applications like power management in data centers and communications installations, electric vehicle (EV) charging, horticultural and agricultural operations, burn-in systems, and more. To support sustainability, these power systems require high-efficiency power conversion and intelligent power management. While it’s possible to design power converters and power management systems from scratch, it’s a time-consuming and challenging activity involving getting numerous certifications. The power converters may need to deliver a variety of voltages including 24, 48, or 380 Vdc, increasing the design effort. Plus, system integration issues, including software and firmware development, can be daunting and delay time to deployment. Instead, designers can turn to off-the-shelf power converters and power management systems that can deliver up to 128 kilowatts (kW) in a single intelligent chassis, with the option to stack multiple chassis for higher power applications. The power converters have nominal output voltages of 24, 48, and 380 Vdc that are also programmable. The 24 and 48 Vdc units can operate in power supply or battery charger mode selected using PMBus or CANBus commands or a dedicated power management system. They have universal AC inputs, efficiencies up to 94.5%, and active current sharing. They are designed to meet numerous industry standards, including the SEMI F47 voltage sag immunity standard with an input of 200 Vac. This article begins with a review of key industry trends, including the need for more and more power in the same physical space, green energy and sustainable systems, and advanced power management capabilities to support evolving application requirements. It then presents the features and capabilities of the NCP-3200, 3200 W rack-mounted switching power supply and battery charger family from MEAN WELL. It closes with a brief summary of the capabilities of the CMU2 intelligent controller.

More power and features, less space

 Rackmount power systems are often designed around 1U (1.75 inches or 44.45 millimeters (mm)) high racks that are either 19 or 23 inches wide. Getting higher power into a fixed rack space requires high efficiency power supplies. These power supplies must be able to operate in parallel to deliver combined high-output power, and they need connectivity to support system monitoring and control. For example, a single compact rack power system for applications like computing and communications can be required to deliver over 100 kW of 48 Vdc power and include a dedicated system controller (Figure 1). For applications that can benefit from high voltage DC (HVDC) power, units are available that deliver 380 Vdc.

380 Vdc power

Microgrids using 380 Vdc can improve efficiency and reduce costs in various applications and are being developed and deployed for commercial and industrial installations, data centers and telecommunications facilities, EV charging infrastructure, and indoor horticultural and agricultural operations. The use of 380 Vdc requires less current to deliver an equivalent power level, enabling the use of smaller conductors. Copper is expensive, and smaller conductors contribute to lower distribution system costs. Lower currents result in lower power transmission losses (IR drops) in cabling, improving power distribution efficiency. Using 380 Vdc in a data center or telecommunications installation can result in 7% to 15% lower capital expenditures (CAPEX) and operating expenditures (OPEX) than traditional 48 Vdc power distribution1. Actual savings need to be calculated based on specific power levels and operating conditions. 380 Vdc power distribution brings similar benefits in semiconductor manufacturing, grid-connected energy storage systems, commercial-scale greenhouse lighting, and other applications. In the case of commercial greenhouses, 380 Vdc power is being used to power vast numbers of LED luminaries. In addition to the efficiency and cost benefits outlined above, LED lighting in greenhouses reduces radiant heat production, simplifying the maintenance of the optimal temperature and humidity. The color temperature of LEDS can be precisely controlled for optimal plant growth, adjusting flowering periods and color, promoting fruit ripening at specific times, and improving quality.

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Figure 2: Using 380 Vdc power distribution for LED lighting can bring multiple benefits to industrial greenhouses, including lower costs and higher productivity. (Image: Dreamstime)


3.2 kW 1U rack mount power converters

 Power distribution system designers can use NCP-3200 series power supplies from MEAN WELL that are available in models that provide low-voltage safety extra low voltage (SELV) compliant 24 and 48 Vdc power as well as 380 Vdc power. The 24 and 48 Vdc models (called ‘2-in-1’ units) are available with firmware settings optimized for operation as dc power supplies or battery chargers. These power supplies can operate from inputs of 90 to 264 Vac or 127 to 400 Vdc. Examples of the numerous models available include (Figure 3): • NCP-3200-024, with a 24 Vdc, 133 Ampere (A) output • NCP-3200-24CAN, with a 24 Vdc, 133 A output, and CAN connectivity • NCP-3200-048, with a 48 Vdc, 67 A output • NCP-3200-48CAN, with a 48 Vdc, 67 A output, and CAN connectivity • NCP-3200-380, with a 380 Vdc, 8.4 A output • NCP-3200-380CAN, with a 380 Vdc, 8.4 A output, and CAN connectivity mode, these supplies have built-in charging modes and can be user programmed. Additional features include:

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Figure 3: NCP-3200 3200W rackmount power supply and battery charger. (Image: MEAN WELL)


The NCP-3200 series has programmable output voltage and output current that can be adjusted using an external analog signal or digital communication protocols (PMBus/CANBus). They can be configured to charger mode using PMBus, CANBus, or MEAN WELL’s proprietary SBP-001 interface. In battery charger mode, these supplies have built-in charging modes and can be user programmed. Additional features include:

• Built-in ORing FET or diode, depending on output voltage, to support hot swapping.

• Active current sharing up to 10 rack shelves with a maximum of 4 units per shelf.

• Automatic intelligent fan speed control.

• Operating temperature range -30 to +70 °C, with derating above 50 °C.

• Remote on/off control.

• Short circuit, overload, over-voltage with automatic reset, and over-temperature protections.

• Meet International Electrotechnical Commission (IEC) electromagnetic compatibility (EMC) standards for emissions and susceptibility.

General purpose smart controller

NCP-3200 power supplies are designed to integrate with MEAN WELL’s CMU2 Multi-Industry General Purpose Smart Controller. This controller can set the output current and voltage and monitor power supply operation, including internal temperature, fan speed, series number, and firmware version. It can remotely control a single unit, system, or paralleled power supplies. Application-specific firmware is available for power management, burn-in test systems, horticultural lighting, and EV charging. And users can develop additional firmware for custom applications. Key features of the CMU2 controllers include:

• 7” touch panel and buttons for on-site operation

• Ethernet port for on-site or remote monitor and control

• Selectable PMBus, CANbus, RS-485, and RS-232 communication protocols

• Four user-programmable relay outputs for remote monitoring or warning

• Web-based monitoring and control user interface (UI)

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Figure 4: CMU2 controllers are available in rack mount (left) and standalone (center) configurations. (Image: MEAN WELL)



 A range of applications, including industrial, green energy, data centers, communications, and greenhouse operations, can benefit from high power density rack mount power supplies and battery chargers. Power designers for those systems can use the NCP-3200 series 3.2 kW units from MEAN WELL that can operate as power supplies or battery chargers to deliver up to 128 kW in ten 19-inch wide 1U high racks, including a system controller. These power converters include a comprehensive suite of features and are available with outputs of 24, 48, and 380Vdc.

Sager Power Systems