AC power provides alternating current output, where the voltage polarity and current direction continuously change with time, typically used for testing products designed to operate from utility power grids such as household appliances, motors, and industrial equipment. Meanwhile for DC power, it provides direct current output with constant polarity and stable voltage/current, commonly used for testing electronic devices, batteries, EV components, solar inverters, and DC-powered systems.
Technical Support & FAQ
Looking for technical details or application guidance for our products? Find quick answers to common questions about our power solutions below.
General
The choice between an AC or DC power supply depends on the type of equipment and input power requirement of the device under test (DUT). Typically, a label will be written on the surface of the device and the easy way to notice it is by looking into the Inputs section.
- Choose an AC power source when testing products that operate from utility/grid power, such as household appliances, motors, industrial equipment, or AC-input power supplies. AC sources are commonly used when voltage and frequency variation simulation is required.
- Choose a DC power supply when testing electronic devices, batteries, EV components, solar inverters, telecom equipment, or any product that requires stable DC voltage/current input. DC sources are ideal for battery simulation, renewable energy testing, and electronic component validation.
- AC power stands for Alternating Current power supply, meaning it delivers electrical power where the voltage and current periodically change direction, similar to standard utility/grid electricity.
- DC power stands for Direct Current power supply, meaning it delivers electrical power with a constant polarity, where voltage and current flow in one steady direction.
- AC power supply (Alternating Current): Outputs voltage and current that periodically reverse direction. It is used to simulate utility grid power and is typically applied in testing appliances, motors, and AC-input equipment.
- DC power supply (Direct Current): Outputs a steady voltage with fixed polarity and current flowing in one direction. It is used for electronics, batteries, EV systems, and renewable energy applications like PV and energy storage testing.
AC power has traditionally been preferred for long-distance transmission because its voltage can be easily transformed, reducing transmission losses. Preen’s AFV+ series of AC power source exhibit certain qualities that fulfill requirements, leveraging advanced PWM technology to furnish power with a Total Harmonic Distortion (THD) of less than 0.5% and a capacity of up to 2000kVA. Power plants can effortlessly generate substantial amounts of AC power and channel it through power lines, subsequently stepping down the voltage to an acceptable level upon reaching residential and commercial establishments.
1. Renewable Energy, Photovoltaic (PV) & Smart Grid Simulation
• Grid Connection & PCS Compliance: Utilizing our PAS Series Regenerative Grid Simulator to simulate grid voltage and frequency anomalies (under/over voltage, under/over frequency) compliant with international regulations such as IEEE 1547.1, EN 50530, and UL 1741.
• Turnkey Automated Verification: Deploying our Smart Inverter ATS designed specifically for comprehensive performance and maximum power point tracking (MPPT) testing of PV inverters and Power Conditioning Systems (PCS).
• Solar Array Simulation: Replicating dynamic solar panels with our ADG+ Series High Power DC Power Supply, featuring built-in EN50530 formulas for static and dynamic efficiency evaluation.
2. Electric Vehicles (EV) & Charging Infrastructure (EVSE)
• EVSE Interoperability Validation: Providing specialized EVSE ATS and EVSE Burn-in ATS for automated AC/DC charger testing, fully compliant with international standards (IEC 61851 and SAE J1772).
• Powertrain Component Testing: Delivering high-voltage DC solutions (up to 2000V) via the ADG+ and ADG-L Series for rigorous R&D and aging tests of EV motors, compressors, and DC/DC converters.
3. Industrial Protection, Components & High-Current Testing
• High-Current Auto-Range Verification: Ideal for testing heavy-duty industrial components such as fuses, contactors, IGBT modules, and air circuit breakers (ACB).
• High Start Inrush Current Simulation: Deploying the AFV-P Series to deliver up to 9 times the rated current, effortlessly activating inductive loads without requiring oversized power capacity.
4. Aerospace & Advanced R&D Laboratories
• Avionics & High-Frequency Simulation: Supplying wide frequency configurations (up to 2000Hz via AFV-P series or 840Hz via AFV+ series) to support commercial aircraft power system testing.
• Pre-Compliance EMC Verification: Simulating power line disturbances (PLD) such as sags, surges, dropouts, and spikes for IEC 61000-4-11 / -14 / -28 compliance testing.
AC Power Source
A Programmable AC Power Source is a test and simulation device that provides controllable AC power instead of fixed utility power from the grid. Unlike a standard wall outlet with fixed voltage and frequency, it allows users to adjust parameters such as output voltage (e.g. 0–350 Vac), frequency (e.g. 5–2000 Hz), and waveform characteristics (pure sine wave or distorted conditions)
This enables engineers to simulate real-world and abnormal power conditions in a controlled environment, including different country standards, voltage fluctuations, frequency variations, power interruptions, and harmonic distortion.
It is widely used in applications such as product development, compliance testing, R&D validation, and quality assurance for electrical and electronic equipment. Typical applications include testing power supplies, home appliances, industrial equipment, HVAC systems, and components used in aerospace, automotive, and renewable energy systems.
Programmable AC power sources are widely used to verify product safety, reliability, and compliance with international standards before products are released to the market.
Preen AC Power Sources technology built-in advanced PWM high frequency switching technology with high power capacity, programmable simulation functions, precision output, and industrial-grade reliability. Product lineup ranges from small power compact benchtop/rack-mount models 0.6kVA to high-power up to 2000kVA, making our units suitable for every testing requirements.
Here are the key advantages and features:
- Single and three phase output selection
- Wide range of output power 0.6kVA-2000kVA in a single unit.
- Wide range of output voltage 0-350V (400V or 600V opt.)
- Wide range of output frequency 5-2000Hz.
- Low THD (Total Harmonic Distortion) as low as ≤0.3%.
- Low load regulation as low as ≤0.07%
- Built-in programmable RAMP, STEP, and Transient features with memories and sequences to simulate power line disturbance such as dip and spike
- Simulate power line disturbance that defined in IEC61000-4-11, IEC61000-4-28, IEC61000-4-14 standard.
- Soft start feature to effectively reduce the starting current of motor or inductive load.
- Overload capability 125% /600sec, 150%/30sec, 200%/10sec.
- Three Phase Independent Angle Adjustment to simulate unbalanced phase shifting and simulate single-phase three-wire or single-phase two-wire system for more versatile testing capabilities.
- Independent Three-Phase Voltage Adjustment to simulate power disturbances such as voltage unbalance and phase loss, compliant with IEC61000-4-34 (GB/T 17626-34).
- Remote Sensing feature to compensate the voltage drop caused by the cable length, to avoid the inconvenience of adjusting the voltage
- Built-in Intuitive HMI and touch screen for easy set-up and quickly access output settings and measurements.
- Complementary remote control software Preen Program for easy setting and reporting and LabVIEW driver.
- Support Modbus and SCPI command.
- Complete interface connection for Ethernet, RS-232&RS-485, USB, GPIB, Analog & PLC Remote.
- CE & RoHs compliant.
* The further characteristics for each series feature should base on description on catalog.
| Product Name | Image | Features | Output Power | Output Voltage | Output Frequency | THD | Load Regulation | Efficiency | Operational Temperature | IP Level | Overload Capacity | Crest Factor | Inrush Current | Response Time | DC Output Voltage | Input Power Factor | Input Voltage | Input Frequency | Remote Interface | Weight | Certification | Application | View |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AFV-P Series High Performance Programmable AC Power Source |  | Programmable AC power source with DC output and precision measurement. | 600VA~6kVA | 0~310V; 0~350V | A: 5~2000Hz B: 15~1000Hz | ≤ 0.3-2% | ≦ 0.07% F.S. | ≧ 77%-85% at max. power | 0-40℃ | - | - | ≧ 3 | ≧ 4.5 times of max.output current (rms) | ≦ 300 μs | 0-210V / 0-420V | ≧ 0.9 at Max. Power; ≧ 0.98 at Max. Power | 98-132VAC/196-264VAC; 90-264VAC/180-264VAC | 47~63Hz | Standard: RS232,RS485, Ethernet, USB, PLC Remote In&Out Option: GPIB, Analog | 16～61.5kg (35.3～135.6lbs) | CE & RoHS | Home Appliance, Laboratory, components, Motor & Compressor testing | More |
| AFV+ Series High Power Programmable AC Power Source |  | An upgraded high power programmable AC power source of AFV series, with improving THD and Load Regulation. | 10kVA~2000kVA | 0~310V | A: 45~500Hz B: 45~120Hz C: 300~840Hz | ≦ 0.5% | ≦ 0.5% | ≧85%-90% at max. power | 0℃-45℃ | - | - | ≧ 3 | - | ≦ 1ms | - | ≧ 0.9 at Max. Power | 380VAC±15%; 200VAC, 208VAC, 240VAC, 400VAC, 480Vac Optional | 47~63Hz | Standard: RS232, RS485, Ethernet Option: Interface Card(RS232&RS485, Ethernet,USB) GPIB, Analog | - | CE & RoHS | Home Appliance, Laboratory, Motor & Compressor testing, Industrial Power Supply | More |
| AFV Series High Power Programmable AC Power Source |  | High power programmable AC power source utilizing advanced PWM technology to deliver power. | 10kVA~2000kVA | 0~310V | ≦ 1% | ≦ 1% | ≧85%-90% at max. power | 0℃-45℃ | - | - | - | - | ≦ 2ms | - | ≧0.9 at max. power ≧0.85% at max. power | 380VAC±15%; 200VAC, 208VAC, 240VAC, 400VAC, 480Vac Optional | 47~63Hz | Standard: RS232, RS485, Ethernet Option: Interface Card(RS232&RS485, Ethernet,USB),GPIB, Analog | - | CE & RoHS | Home Appliance, Laboratory, Motor & Compressor testing, Industrial Power Supply | More | |
| PAS/PFV Series Regenerative Grid Simulator |  | Regenerative high power AC power source, built in with Low Voltage Ride Through Test (LVRT) test function. | 30kVA~2000kVA | 0～300V 0-350V(opt) | 45~65Hz 40~70Hz (Opt.) | ≦ 2% | ≦ 1% | ≧ 92% at Max. Power | 0℃-45℃ | - | - | - | - | ≦ 2ms | - | ≧ 0.99 at Max. Power | 380VAC±15% | 47~63Hz | Standard: RS232, RS485, Option: Ethernet, GPIB | - | CE & RoHS | PV Inverter, EVSE, Laboratory, Renewable Energy | More |
| AFC Series AC Power Source / Frequency Converter |  | AC power source which can simulate standard or abnormal voltage and frequency status. | 10kVA~2000kVA | 0~310V | 45~65Hz, 100Hz/120Hz/200Hz/240Hz/400Hz (Opt.) | ≦ 2% | ≦ 1% | ≧85%-90% at max. power | 0℃-45℃ | - | - | - | - | ≦ 2ms | - | ≧0.85 ≧0.9 at max. power | 380VAC±15%; 200VAC, 208VAC, 240VAC, 400VAC, 480Vac Optional | - | Standard: RS232, RS485 | - | CE & RoHS | Home Appliance, Laboratory, IT/SMT Production Line, Motor & Compressor testing | More |
| AMV/AMF Series 400Hz Power Supply / Ground Power Unit |  | Ground power unit which is compliant with MIL-STD-704F. | AMV: 30kVA~180kVA AMF: 500VA~400kVA | 115/200V ±10% | AMV: 300~500Hz(Stand Alone) 400Hz(Fixed) AMF: 350~450Hz 400Hz (Fixed) | AMV: ≦ 2% AMF: ≦ 0.5-3% | AMV: ≦ 1% AMF: ≦ 0.5-1.5% | AMV: ≧ 92% at Max. Power AMF: ≧ 87% at Max. Power | AMV: -40℃-55℃ AMF: -20℃-45℃ | AMV: IP54 | AMV: 125%/600s, 150%/30s, 200%/10s, (Optional) 150%/60s, 200%/30s, 250%/10s, 300%/1s AMF: 120%/1 hr, 150%/60s, 200%/15s | - | - | - | - | AMV: ≧94%at max. power AMF: ≧85% at max. power | - | - | AMV: RS-485 AMF: RS-485 (opt.) | - | - | Avionics & Aerospace | More |
DC Power Supply
A Programmable DC Power Supply is a test and simulation equipment that provides controllable and adjustable DC electrical power for testing, validation, and product development applications. Unlike a conventional fixed DC power supply, a programmable DC power supply allows users to precisely set and control key output parameters such as voltage, current, power limit, ramping speed, sequencing, and protection settings including OVP, OCP, and OTP. It can also be remotely controlled through communication interfaces such as Ethernet, USB, RS232, RS485, or GPIB, allowing seamless integration into automated test systems and production environments.
Programmable DC power supplies are widely used in applications including EV and automotive electronics testing, battery simulation, renewable energy systems, aerospace and defense equipment, industrial electronics validation, research laboratories, power tools and production burn-in testing. Modern programmable DC power supplies are available in a wide power range, from compact benchtop units to ultra-high-power systems designed for demanding applications such as EV, marine, renewable energy, and AI server power testing.
Programmable DC power supplies offer precise, stable, and adjustable DC output for a wide range of testing and simulation applications. Compared to conventional fixed power supplies, programmable models provide greater flexibility, higher accuracy, and advanced control functions that help improve testing efficiency, product reliability, and automation capability.
Preen’s DC power supplies feature a high power density and efficient system design, ranging from 5 kW to 15 kW in compact 3U low-power models up to 30 kW to 1800 kW high-power systems. Both low and high-power units support series and parallel connection for flexible system expansion, and can be configured in master-slave operation to ensure synchronized control, stable performance, and easy scalability for higher voltage or current requirements.
Here are the key advantages and features:
- Wide Output range 5kW to 1800kW
- Max. Output Voltage up to 2000V and Max. Output Current up to 2500A
- Auto-range function to generate both high output current at low output voltage or high output voltage at lower output current in single unit, avoiding the for multiple supplies saving cost and space.
- Mode : Constant Voltage (CV)/ Constant Current (CC)/ Constant Power (CP)
- Fast transient response, high load regulation rate & low ripple
- Built-in programming function uses GROUPs and STEPs to set voltage, current, and time, enabling step or continuous output changes with adjustable rise and fall times.
- Solar array simulation and control software features to simulate IV curve and MPPT efficiency testing (Support SAS Testing Mode & EN50530 Testing Mode)
- Remote Sensing feature to compensate the voltage drop caused by the cable length, to avoid the inconvenience of adjusting the voltage
- Built-in Intuitive HMI and touch screen for easy set-up and quickly access output settings and measurements.
- Complementary remote control software Preen Program for easy setting and reporting and LabVIEW driver.
- Support Modbus and SCPI command.
- Complete interface connection for Ethernet, RS-232&RS-485, USB, GPIB, Analog & PLC Remote.
- CE & RoHs compliant.
* The further characteristics for each series feature should base on description on catalog.
| Product Name | Image | Features | Output Power | DC Output Voltage | DC Output Current | Output Ripple | Load Regulation | Line Regulation | Response Time | Efficiency | Line Drop Compensation | Transient Response Time | Input Power Factor | Remote Interface | Certification | Application | View |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ADG-L Series Programmable DC Power Supply |  | Programmable DC power supply with three different output power, 5kW, 10kW and 15kW. Utilizing PWM technology. | 5kW～75kW | 0~2000V | 0~2550A | down to < 0.05% | ≦ 0.3% | ≦ 0.08% | ≦ 5ms | ≧ 84-90% at Max. Power | - | - | 0.99 at Max. Power | Standard: RS-232, RS-485, Ethernet, USB, Analog Option: GPIB | CE & RoHS | General R&D, ATS, PV Inverter, Renewable Energy, AI Industry, IGBT, Air Circuit Breaker, Switchgear | More |
| ADG+ Series High Power Programmable DC Power Supply |  | An upgraded high power DC power supply of ADG series, ADG+ series can simulate solar array with the optional I-V curve function. | 30kW～1800kW | 0~2000V | 0~2500A | down to < 0.05% | ≦ 0.3% | ≦ 0.05% | Down to ≤ 6ms | ≧ 84-90% at Max. Power | - | - | ≥ 90% at Max. Power | Standard: RS232, RS485, Analog, Ethernet, USB Option: GPIB | CE & RoHS | General R&D, ATS, PV Inverter, Renewable Energy, AI Industry, IGBT, Air Circuit Breaker, Switchgear | More |
| ADC Series Rack Mount DC Power Supply |  | DC power supply which has high power density, high accuracy and wellaround protection.Widely adopted in production lines, burn-in tests, laboratories and integrated systems. | 2kW～8kW | 0~600V | 0~68A | < 0.15% | < 0.05% | < 0.5% | - | ≧ 85-89% at Max. Power | 0～3V | < 1ms | - | - | CE | Industrial Power Supply | More |
Selecting the right DC power supply depends on several key factors, including output voltage, output current, power capacity, accuracy, response time, and communication interfaces.
Preen programmable DC power supplies support remote control through multiple communication interfaces, including RS-232/485, LAN, USB, Analog Control, and GPIB, allowing easy integration into various testing and automation environments. Our power sources are LabVIEW-based, and we can provide dedicated drivers to help customers quickly integrate the system into their existing automated test platforms. Preen also have self-developed remote-control software called Preen Program, which enables users to perform remote operation, parameter setting, monitoring, and data management conveniently through a user-friendly interface.
DC power supply, so called bench power supply, is a type of device that exclusively and constantly creates and supplies a Direct Current (DC).
DC power supplies are widely used by R&D engineers, production lines, laboratories, universities, automotive industries, battery manufacturers, semiconductor companies, and renewable energy sectors. They are essential for providing stable and controllable DC voltage/current during product development, component testing, aging tests, battery simulation, and quality verification.
A DC power supply is typically connected between the AC input source and the device under test (DUT). Users configure the desired voltage and current limits before powering the DUT.
Depending on the application, the power supply may operate in constant voltage (CV) mode or constant current (CC) mode to ensure safe and stable operation during testing.
A DC power supply converts AC power from the utility grid into stable DC output through several stages including rectification, filtering, voltage regulation, and feedback control.
Advanced programmable models also include digital control systems to precisely regulate voltage and current while protecting against overload, overvoltage, and short-circuit conditions.
When selecting a DC power supply, users should evaluate:
- Required voltage, current range and total power capacity
- Communication interfaces
- Future expansion requirements
- Choosing a supply with sufficient performance margin helps ensure long-term reliability and flexibility for future applications.
The operating voltage for DC applications depending on the industry and device type. Common examples include:
- 5V / 12V / 24V for electronics and industrial control systems
- 48V for telecom equipment and servers
- 200V–800V for EV battery systems
- Up to 1500V for renewable energy and high-power industrial applications
In terms of power supply, three primary components are typically involved: a transformer, rectifier, and filter. First, the incoming AC voltage is adjusted through a transformer to meet the voltage required by the load. Second, the rectifier converts the sinusoidal AC waveform into DC power. Finally, the filter helps smooth the output to provide a more stable DC voltage for electrical and electronic applications.
Sometimes devices require DC-DC power conversion when operating with DC input power. Unlike AC power, DC power cannot directly use a traditional transformer to change voltage levels (whether stepping up or stepping down). Therefore, DC-DC power supplies are designed to solve this challenge.
A DC-DC power supply typically includes an inverter and rectifier to convert DC into AC, allowing the voltage to be adjusted through a transformer. After reaching the desired voltage, the power is converted back to DC and regulated to provide stable output for electrical and electronic applications.
For cleaner output performance, regulated DC-DC power supplies are strongly recommended, especially for precision equipment.
Programmable DC power supplies allow precise control, automation, and remote operation, unlike traditional fixed-output or manually adjusted power supplies.
Preen programmable DC power supplies support remote control through SCPI commands and communication interfaces including USB, Ethernet, RS-232/RS-485, and optional GPIB.
It is an important function in renewable energy testing, especially for photovoltaic (PV) inverter, solar charger, and MPPT (Maximum Power Point Tracking) evaluation. By simulating the current-voltage characteristics of a solar panel or array, engineers can reproduce realistic operating conditions in a controlled laboratory environment without depending on actual sunlight.
Advanced DC power supply models such as ADG-L and ADG+ offer solar array simulation and control software features to simulate IV curve and MPPT efficiency testing (Support SAS Testing Mode & EN50530 Testing Mode).
Preen’s solution on How to Simulate Solar Array IV Curve demonstration video: https://www.youtube.com/watch?v=s-WSZjL5228
Units can be connected in a master-slave parallel configuration to increase total output power through simple system setup. This configuration enables stable operation and higher power capacity for demanding applications.
All Preen programmable DC power supplies include built-in protection:
• Over-voltage (OVP)
• Over-current (OCP)
• Short circuit (SCP)
• Over-temperature (OTP)
These features ensure reliable and safe operation under demanding test conditions.