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

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.

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 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