Category: Articles

The Ideal Regenerative Grid Simulator for Microgrid Testing

Microgrid Solar Wind Power Testing - NH Research (NHR)

NHR’s Regenerative Grid Simulator Accurately Emulates the Utility Grid

Regenerative Grid Simulator Model 9410 - NH Research (NHR)If you’re looking for a regenerative grid simulator or grid emulator, NHR’s 9410 has key competitive advantages over the market. NHR’s Regenerative Grid simulator is ideal for simulating complex power disturbances ideal for testing micro-grid and smartgrid applications.

NHR’s Regenerative Grid Simulator (9410) is a unique four-quadrant bi-directional AC/DC source that simulates the utility voltage and regenerates power sourced by grid-tied inverters. Greater than 90% of power is returned to the facility thereby providing significant energy savings. The 9410 is used as a grid simulator, or emulator for testing PV inverters and other grid-tied products for compliance to IEEE 1547, UL 1741, and global industry standards. A wide-range of AC conditions can be emulated including phase imbalance (in voltage and/or phase angle relationship), voltage sag, frequency changes and harmonic injection.

Modular and Scalable Power

The Regenerative Grid Simulator (9410) is flexible in both output form and power level. Output can be AC or DC and the AC can be single, split or 3-phase. Frequency is programmable between 30 and 100 Hz. Power is scalable from 4 kW to 96kW. With this broad selection of power, phase configuration and frequency, this grid simulator provides the flexibility to test the widest range of grid-tied products. The included measurement system also eliminates the need for additional power meters, DMMs, oscilloscopes, or spectrum analyzers.

3 Channel Multiple Configuration - NH Research (NHR)

Figure 1 – 3 channels with multiple configuration possibilities

Accurate Emulation of Complex Power Disturbances

The Regenerative Grid Simulator (9410) is able to replicate power line disturbances through a combination of user-definable waveforms and Macros. User-defined waveforms permit generation of non-sinusoidal voltages including asymmetrical inflections, transient anomalies, voltage harmonics, or any other irregularity which can be drawn as a single-cycle. The grid simulator can emulate sub-cycle transients, phase jumps and multi-cycle line conditions as required.

Simulating Voltage Harmonics - NH Research (NHR)

Simulating Area EPS Voltage Harmonics

Simulating Sub-cycle Transients - NH Research (NHR)

Simulating Sub-cycle Transients

Simulating Phase Jump - NH Research (NHR)

Simulating Phase Jump

Simulating Abnormal Voltages - NH Research (NHR)

Simulating abnormal voltages (sags, swells & drop outs)

This modular Grid-Simulator is used to verify product AC performance while a 9200/9300 Bi-directional DC Source may be used to emulate any energy storage system.

For more information, please visit our product webpage or contact us for a quote.

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Applications Include:

  • Grid Simulation: Microgrid, Smartgrid systems
  • V2G, ESS
  • On-board Chargers, Grid-aware Chargers
  • Grid Utility Test
  • PV/Grid Tied Inverter Test
  • Compliant with UL1741, IEEE1547 and similar grid-tied standards world-wide
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Regenerative AC Load with 4 Quadrant Functionality

EVs Charging - NH Research (NHR)

Bi-directional AC Load Accurately Emulates Complex Load Profiles

If you’re looking for a regenerative AC load with advanced capability, NHR’s 9430 has key advantages over the market. NHR’s Regenerative AC Load is ideal for simulating almost any complex linear or non-linear load.

The 9430 is a current-regulated, 4-quadrant AC load with selectable phase inputs/outputs and a built-in waveform digitizing measurement system. Greater than 90% of power is returned to the facility thereby providing significant energy savings. Applications include testing of Vehicle to Grid (V2G), solar and grid-tied inverters, UPSs, AC sources, rectifiers, circuit breakers and fuses.

AC Load 4-Quadrant Operation Offers Bi-directional Capability

Regenerative AC Load Model 9430 - NH Research (NHR)The most unique feature of NHR’s Regenerative AC Load (9430) is the ability to operate in all 4-quadrants. The 4-quadrant AC load allows for emulation of current draws historically requiring use of discrete components such as capacitors and inductors. Multiple bi-directional power conversion stages take place internally to generate the AC or DC current output depending on the hardware operating mode.

This bi-directional capability significantly expands load simulation relative to 2-quadrant AC loads. The Regenerative AC Load (9430) allows creating the reverse current caused by inductive or capacitive loads (low power factors). Power is sent back to the UUT (source) during part of the AC cycle (Fig. 1). In this manner, the 9430 accurately duplicates real-world reactive electrical power flows.

Inductive Load Bi-directional Waveform - NH Research (NHR)

Figure 1 – 0.5 PF Inductive Load waveform showing bi-directional power flows.

HIVAR design provides reactive loading without derating True Power

This advanced design feature allows for testing high reactive load input power without the customary reduction of true power (Watts) normally required with conventional loads. The HiVAR design provides testing sources with reactive power (VARs) as large as 2.6 x true power (Watts). All 9430 Loads are rated both for true power and apparent power. For instance, a 12kW AC load is also rated for 31.5kVA.

This Regenerative AC Load (9430) supports full-time current loading including at full Line-Neutral voltage up to true power rating of the system, providing a wider operating envelope. By comparison, traditional AC loads are resistive, and are unable to provide a true power factor shift, and are able to only draw current up to the thermal power rating of the system.

Constant Power Envelope - NH Research (NHR)

Constant Power Envelope for 9430-12 operating as 1-Φ-load

Regenerative AC Load with Several Emulation Modes

To provide testing under the broadest range of loading conditions, the Regenerative AC Load (9430) will operate in several emulation modes. Constant Current (CC) Mode provides current to be drawn constantly, making it suitable for linear, non-linear and regulation loading. Constant Resistance (CR) Mode allows the load to emulate a power resistor with a unity power factor. Constant Power (CP) Mode emulates a load such as a switching power supply. Constant Apparent Power (CS) Mode expressed as VA, is a vector quantity where there is both real power and reactive power. Constant RL (CRL) Mode emulates a resistive load with an inductive component such as a motor.

User-defined Waveforms

The Regenerative AC Load (9430) has an easy to use graphics editor to create waveforms based on current, power and crest factor. Easily duplicate waveform distortions or transient events such as spikes, dropouts or any other anomaly that can be drawn as a single cycle. A second powerful user-defined waveform tool is the Macros. These are pre-programmed sequence of settings where each new setting is effective for a sub-cycle, any number of cycles or for a fixed amount of time.

For more information, please visit our product webpage or contact us for a quote.

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Applications Include:

  • Full Line Disturbances at Any Power Factor
  • Grid Utility Test, Inverter Test, UPS Test
  • EV Load Testing
  • Switch, Fuse Test
  • Linear and Non-linear Loading, Inductive and Capacitive Loading Requirements
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DC Electronic Loads with Accuracy, Reliability & Speed

Modular, Benchtop DC Electronic Loads 120V, 600V

4700 DC Electronic Load (front)If you’re looking for a DC electronic load with high current and low voltages, or low current and high voltages, NH Research (NHR) has a range of options. NHR’s DC Electronic Loads are ideal for testing medium-to-high-power applications in all markets.

All of NHR’s DC electronic loads provide ultra-fast transient simulations and comprehensive measurements to accurately test real-world conditions. The 4700 DC Load (120V) is well-suited for low voltage and high current applications whereas the 4670 DC Load (600V) is ideal for high power applications. The 4300 Series DC Loads are ideal for lower power, multi-channel testing and 9300/9200 NHR’s Regenerative DC Loads offer increased energy savings and additional bi-directional capability.

4700/4760 Benchtop DC Loads

In this article, we’ll share details specifically on the benefits of the 4700/4760 benchtop DC loads. This series can be used as part of an automatic test station or as a stand-alone, bench-top set-up. Our modular, flexible test equipment has the accuracy, reliability, and speed required for applications such as DC converters, avionics, fuel cells and batteries, EV components, radar testing, power supplies and much more.

With a large user-friendly interface, test engineers can easily use this equipment for engineering characterization and test program development. It can be operated manually through the touch-panel, or automated. Automated testing may be PC-controlled either through NH Research’s emPower™ test executive or user-written test programs in LabVIEW, LabWindows/CVI or in any programming language which supports IVI Drivers.

Create Complex, Fast-Transient Load Profiles

NHR’s DC Electronic Loads (4700/4760) are capable of creating a wide variety of complex dynamic load profiles. Types of profiles include micro-second pulses, multiple pulses of varying width, stepped responses, variable slew rates and even simulating an AC component on the DC waveform.

The key to this capability is called a Macro, each of which contains up to 100 steps and is executed directly by the load to achieve the fastest possible transition speed. Once created, Macros can be stored in the system controller for downloading to the load when execution is required.

Fast Transient Load Profile - NH Research (NHR)

Figure 1 – Various Fast Transient Load Profiles

Scalable Power, Wide Operating Envelope

Easily add power modules scale power and meet new testing demands over time. For added flexibility, NHR’s dc electronic loads also have a wide operating envelope to provide rated power anywhere between 5V and 120V. Below 5V the load maintains full current capability down to 1V and then linearly reduced current down to 0.15V.

Constant Power Operating Envelope - NH Research (NHR)

Figure 2 – Constant Power Operating Envelopes

For more information, please visit our product webpage or contact us for a quote.

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Applications Include:

  • ATE Testing: Radar Power Testing, Aviation, Power Supply, Solar Panel
  • Power Devices: Chargers, Adapters, DC Supplies, LED drivers, Telecom Rectifiers
  • Fuel Cells/Super Capacitor Test
  • Power Conversion
  • EV Subsystem Test: OBC, V2G, APM, DC/DC Converter
  • Ideal for Fast Transients, Ultra-low Voltage Loading (down to .01 VDC)
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