April 22, 2020 by Meenatachi Nagasubramanian
Even though using renewable energy resources like wind and solar power will greatly reduce the effect of pollution and global warming, it cannot be used as a standalone power source due to energy fluctuation.
Therefore, energy storage devices are used to achieve a smooth and continuous power flow. Furthermore, a DC-DC converter is used to transmit energy between the storage device and the rest of the power system.
In traditional power systems, generally, two DC-DC converters will be used, one for step-up conversion and other for step-down conversion.
Since the new TDK EZA series DC-DC converters are bi-directional, it eliminates the need for two DC-DC converters. Therefore, the step-up and step-down conversion is achieved by using a single unit.
The EZA series DC-DC converters are specifically designed for energy storage systems with rechargeable batteries. It can step down a grid voltage (320 VDC) obtained from renewable energy to a battery voltage (48 VDC), and step up when reversing the battery voltage to the grid voltage.
They are compact, efficient, and high-performance bidirectional DC-DC converters that enable intelligent power conversion in the era of smart grids.
While using renewable energy sources like solar/wind power, the stability of HVDC (High Voltage Direct Current) bus voltage of DC power supply systems is always a critical issue. Since power generated by these systems fluctuates according to the degree of solar radiation and wind speed.
However, the converters offer high efficiency and seamless power conversions without interruptions even during frequent switching while showing excellent performance in stabilizing HVDC bus voltages.
A product image of the EZA2500 power supply. Image Credit: TDK
The primary feature of the EZA series converters is that they achieve high-efficiency conversion while being isolated type converters using a transformer.
The EZA series' voltage ratio of the DC bus to the battery side is approximately 6 to 1. Generally, the higher the voltage ratio is, the lower the conversion efficiency.
However, the EZA series converters have realized bidirectional conversion with an efficiency of 94% or higher in both charging and discharging, by adopting advanced digital control technology.
Below is a comparison of the specifications between TDK's EZA2500 and Texas Instruments TIDA-00951, a comparable product to the EZA series converters.
The EZA series converters can be used for various types of industrial equipment that require energy regeneration such as cranes, robots, elevators, AGVs (autonomous ground vehicles), and forklifts.
With the increased usage of EVs (electric vehicles) and HEVs (hybrid electric vehicles), the demand for energy storage devices has also increased to a great extent.
Therefore, bidirectional DC-DC converters like TDK EZA series will play an important role in the coming years to provide a seamless transition between charge and discharge of power from renewable sources like sunlight and wind.
