The topology structure of adjustable DC power supply continues to iterate with power demand and application scenarios, with the core goal of improving efficiency, power density, and dynamic response capability. The following analysis is conducted from the dimensions of technological evolution and selection:
1、 Topological structure evolution path
Low power scenario (<100W)
In the early days, single ended flyback was mainly used, with simple structure and low cost, but there were defects such as low magnetic core utilization and large output ripple. Subsequently, by introducing a forward topology and optimizing the magnetic reset circuit, the power scalability was improved. The current mainstream solution is the flyback/forward variant of integrated synchronous rectification technology, which improves efficiency to over 85% by reducing conduction losses and is suitable for scenarios such as consumer electronics and small laboratories.
Medium power scenario (100W-1kW)
Push pull topology became the early mainstream due to its bidirectional excitation characteristics, but the voltage stress on the switching transistor was high (up to twice the input voltage). The half bridge topology balances transformer voltage through capacitor voltage division, reduces switch tube stress, and extends output power to kilowatts, widely used in industrial automation equipment. The full bridge topology further optimizes the stress distribution of the switch tube, supporting high input voltage scenarios such as communication power supply and medical equipment testing.
High power scenario (>1kW)
The combination of full bridge topology and soft switching technology (such as LLC resonance) has become mainstream, reducing the volume of passive devices through high-frequency (>100kHz) and achieving an efficiency breakthrough of 93%. Modular stacking design supports N+1 redundancy, meeting high reliability requirements such as data centers and semiconductor manufacturing. For example, photovoltaic inverter testing requires simulating a wide range of voltages (0-1000V), and the full bridge topology combined with multi-level technology can accurately reproduce complex operating conditions.
2、 Core considerations for technology selection
Balance of power and efficiency
Prioritize choosing flyback/forward topology for low-power scenarios, balancing cost and efficiency.
The switching losses of half bridge/full bridge topologies need to be evaluated in medium to high power scenarios, and soft switching technology can significantly improve high-frequency efficiency.
Dynamic response and stability
In dynamic load scenarios such as motor drive and wireless communication, it is necessary to choose a topology with fast transient response speed (such as a full bridge) to ensure voltage fluctuations of ≤± 0.5% during sudden load changes.
Precision testing scenarios (such as semiconductor manufacturing) require low ripple (≤ 5mVp-p), and linear power supply or synchronous rectification technology can meet the requirements.
Functional scalability
New energy vehicle battery testing requires bidirectional energy feedback function and supports four quadrant operation.
Photovoltaic research and development requires simulating I-V curves under different lighting conditions, and the power supply is required to have a list programming (LIST mode) function.
environmental adaptability
Industrial scenarios require temperature resistance (-40 ℃~+85 ℃), anti vibration design, and support for forced air cooling or water cooling for heat dissipation.
The aerospace industry requires electromagnetic compatibility (EMC) certification to ensure stable operation in complex electromagnetic environments.
3、 Typical application scenarios
Aerospace: Full bridge topology simulation of 28V/270V aviation bus, supporting anti surge and anti pulse interference, ensuring the reliability of radar system ground testing.
Semiconductor manufacturing: Half bridge topology driven ion implantation equipment, ripple ≤ 5mVp-p, to avoid wafer damage.
New energy vehicles: Modular full bridge power supply supports 100kW level motor controller testing, multi-channel parallel connection achieves energy feedback, and efficiency is improved by 25%.
4、 Selection suggestions
Clear requirement priority: Sort by power range, efficiency, dynamic response, and functional scalability to avoid excessive design.
Verify key indicators: Require suppliers to provide measured data (such as ripple and transient response time), rather than just parameter specifications.
Pay attention to standardization compatibility: Choose power supplies that support general protocols such as SCPI and LabVIEW for easy integration into automated testing systems.
The topology selection of adjustable DC power supply should be based on the application scenario, balancing performance, cost, and scalability. With the popularity of wide bandgap devices such as SiC and GaN, future topologies will evolve towards higher frequencies and higher power densities, continuously driving the expansion of industrial testing boundaries.