How does a bidirectional programmable DC power supply simultaneously simulate battery charging and discharging?

Publish Time: 2025-11-11

In the research and testing of cutting-edge technologies such as new energy, electric vehicles, energy storage systems, and smart grids, accurate simulation of battery behavior has become an indispensable part. Traditional testing solutions often require separate configuration of charging power supplies and electronic loads, which is not only costly and complex in wiring, but also difficult to achieve seamless switching between charging and discharging states. The emergence of a bidirectional programmable DC power supply has completely changed this situation—it acts like a "smart energy hub," automatically switching between power supply mode and load mode on the same device and the same port according to instructions, thereby simulating the entire charging and discharging process of a real battery with high precision and high efficiency.

1. Bidirectional Topology: Free Switching of Energy Flow

The core of a bidirectional programmable DC power supply lies in its four-quadrant operating power electronic topology. Unlike unidirectional power supplies, which can only convert grid power into DC output, bidirectional power supplies integrate reversible power devices, allowing current to flow in both directions. When operating in "source" mode, the device provides a stable voltage or current to the device under test (DUT) like a regular DC power supply. Upon receiving a discharge command, it immediately switches to "sink" mode, actively absorbing feedback energy from the battery under test and efficiently converting it into AC power to feed back to the grid, rather than dissipating it as heat. This millisecond-level seamless switching capability perfectly replicates the dynamic characteristics of frequent charging and discharging of batteries in real-world use.

2. High-Precision Modeling: Reproducing Real Battery Behavior

Modern bidirectional power supplies not only possess bidirectional energy flow capabilities but also have a built-in powerful programmable simulation engine. Users can set key parameters of the battery model via host computer software or a control panel, such as nominal voltage, capacity, internal resistance, SOC-OCV curve, charge/discharge rate limits, and temperature influence coefficient. The power supply then calculates and dynamically adjusts its output/input characteristics in real time, making the DUT "think" it is interacting with a real battery. For example, when testing electric vehicle charging stations, the power supply can simulate the charging process of a lithium battery from 20% to 100% SOC; and when testing the BMS balancing function, it can simulate the inconsistency in discharge caused by differences in internal resistance among multiple batteries. This high-fidelity simulation greatly improves the realism and coverage of the test.

3. Application Scenarios: Covering the Entire R&D Chain

In battery management system development, bidirectional power supplies can replace expensive and limited-lifespan real battery packs, safely verifying extreme conditions such as overcharge, over-discharge, and short circuits; in electric vehicle motor controller testing, it can both power the inverter and absorb energy generated by regenerative braking of the motor, completely simulating the vehicle's driving cycle; in energy storage converter verification, it can simulate the coordinated operation of photovoltaic + battery systems, testing its switching logic and energy dispatch strategies in off-grid/grid-connected modes. Furthermore, because energy can be fed back to the grid, the electricity cost of long-term testing is significantly reduced, and the burden of laboratory thermal management is also greatly alleviated.

4. Intelligent Collaboration and Automated Integration

The high-end bidirectional programmable DC power supply supports communication protocols such as SCPI, Modbus, and CAN, allowing for easy integration into automated testing platforms. With script programming, it can automatically execute hundreds of charge-discharge condition combinations, generating complete test reports and significantly improving R&D efficiency and data traceability.

Through its innovative "dual-function" architecture, the bidirectional programmable DC power supply liberates battery charge-discharge simulation from cumbersome and inefficient traditional methods. It is not only a testing tool but also a bridge connecting virtual models and the physical world. In today's rapidly evolving energy technology landscape, this device, combining high precision, high efficiency, and high flexibility, is becoming a key driving force for the development of green technologies.